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My DIY Valve Spring Replacement; 2003 C5 Z06 42K Miles
From the very beginnings of my search, purchase, and ownership of my 28K Mile, 2003 C5 Z06 back in Feb 2017, I have always had the infamous valve spring failure in my mind (mine had the Yellow springs, fyi). I called a few shops and got quotes ranging from $650 to $900 here in the Bay Area of California, but that was the extent of my effort to address the situation. More recently, an acquaintance of mine who I run into, occasionally, told me that his 66' Cobra broke a spring and dropped the valve in the engine...not good. This got me thinking again. I began to read every thread regarding the procedure on this forum as well as the youtube videos that I could find. Ultimately, I felt comfortable that I could do it, so I started my plan. I am writing this to share my experience so that it may be helpful to others.
A quick bit about myself - I grew up in a household where my father, mechanical engineer who also loves cars, would never take our cars to shops as he felt he could always do a better job because nobody would spend the same amount of time that he would; I agree. My role in this way of life started by holding flashlights at a very young age, to being the tool runner, to doing oil changes, brakes, etc. The older I got, the more complex things I learned and before I knew it, I developed that same mentality. This also was a result of witnessing some very poor work done by shops where I started to say to myself "I know I can do it better." For what it's worth, I am an accountant that likes cars...and working on them.
Well, here we are; I decided to change the valve springs by myself. With that said, I am going to list the methods I used, the parts I used, and interesting things I noticed/tips.
1. Methods -Compressed Air or Nylon Rope. I went with the compressed air method at TDC. I suppose the Nylon rope method would have been quicker as one of the hardest things, for me, was fitting the Air Hose Adapter into the spark plug hole. This may or may not be an issue for you, but my hands measure 10.25inch and I found it extremely difficult to rotate the rubber hose perfectly to get it threaded into the spark plug hold without stripping anything. The hose adapter I used was purchased from JEGS.com and there isn't any tool that I could think of to use, so I literally would install the adapter by rotating the hose very slowly until it threaded into the spark plug hole. Luckily, I was able to twist the hose tight enough with my hand to keep the pressure in the cylinder with the air compressor
Finding TDC, compression stroke: In my search, I didn't find a whole lot of info on how to best find TDC for each cylinder, so I made a chart based on the following:
--It takes 720 Degrees for a full cycle (4-cycle engine)
--Given that every cylinder fires in the 720 degrees of rotation, a cylinder fires every 90 Degrees. Once you find TDC on cylinder #1, a clockwise rotation of the crank 90 degrees gets you to TDC of the next cylinder in the firing order. (If you want this visual chart that I created, I can provide it. It shows you what stage each cylinder is at any time in relation to another cylinder, see snapshot below in attachments). I found TDC by watching the Intake Valve and Exhaust Valve on Cylinder #1 as I rotated the crank by hand. Once the Intake valve closed +180-degrees of rotation, you're very close to TDC on the compression stroke. I then marked the crank and 90-degree intervals with blue tape to keep track while turning the crank.
Note: I utilized TDC on the compression stroke FOR EACH CYLINDER to remove the rocker arms, change valve springs, and obviously re-install the rocker arms. Some people said that you can remove the rocker arms without TDC, but I disagree in that if you remove a rocker arm that is compressing a spring, you're putting unnecessary stress on the bolt that you are taking it out. It may make no difference, but whatever; my car, my time. Utilizing TDC when compressing the cylinder with air is also personal preference, but I figured it was extra security in the event that I lose pressure from the air compressor.
Put the front of the car up on ramps and jacked up the rear on jack stands: You'll be bending over for several hours, make it easier on your back.
2. Parts
Valve Springs: I went with PAC-1218. After speaking with my uncle, the folks and PAC, and the dealer, the PAC springs seemed like a no-brainer. It's a higher quality spring and if I'm going through the hassle of changing them out because the OEM springs are prone to failure, the GM OEM springs don't get another shot for redemption whether they are revised springs or not.
Valve Intake and Exhaust Seals: If you're in there, might as well change them. I bought OEM from GM.
Valve Spring Retainer, Valve Spring Locks: I reused these; no point in changing them out as they were spotless.
Spark Plugs: GM Iridium Plugs; supposed to be pre-gapped and some of them were not, I adjusted those.
Spark Plug Wires GM Performance Wires (Red) - NOTE: Two of the original wires tore when I was removing them. Save yourself the hassle and just buy new wires.
Spark Plug Air Hose Adapter: 14MM adapter from JEGS.com
Valve Stem Seal Installation Tool: Also from JEGS.com. You could use a socket, but the tool fits exactly perfect on the seal; no risk of damage. Personal preference, do what you want.
Valve Spring Compression Tool: I bought the Crane Spring Compression tool for LS Engines. This made changing the springs as easy as tying my shoes. Two springs at a time, perfect fit, couldn't have been easier.
Telescoping Pen Magnet: You'll need this when removing the valve locks; they are small and if you drop one, you'll be spending time trying to find it.
15/16 Offset Wrench: You need this tool to rotate the crankshaft without removing any steering components.
Misc:You obviously need various sockets, screw drivers, torque wrench, paper towels, flashlights, air compressor, etc
3. Interesting things I noticed/Tips.
-Disconnect the battery. Minor, but important for safety.
-The hardest part for me, again, was installing the 14mm sparkplug hose adapter into the spark plug hole. Imagine trying to install a garden hose by rotating the hose while grasping it a few inches away from the neck without looking, using only one hand...you'll catch my drift.
-Make sure you have a good torque wrench. I own a Beam Style torque wrench but decided to borrow a clicker-type torque wrench. Turned out that the clicker-type torque wrench was broken and when I was reinstalling the rocker arm bolts, I most definitely exceeded 15% of the recommended 22ft pounds for the bolts. To be safe, I bought new rocker arm bolts.
-Give yourself adequate time. I made a few trips to the store during the process for an adapter for my compressor, new rocker arm bolts, batteries, etc.
-Buy the Crane Compression Tool. It's expensive, but its quality made and it was perfect. JEG's make their own version, but I heard about the bolts wearing down during use; sounds like an annoying deviation of the plan.
-Have the firing order and cylinder stage chart up on a computer or piece of paper. This is very helpful to keep track of which cylinder you have at TDC.
-Take the time and torque the rocker arms at TDC for each cylinder and valve covers to proper torque.
From the very first step of jacking up the car to finishing up and starting the car, this took me about 12 hours with breaks, some cussing, trips to the store, etc. I have not done this before, yet I consider myself decently capable with working on cars just to give you an idea. As I mentioned, I took my time to make sure I didn't mess anything up and double checked everything. In the end, it fired up successfully (some valve train clatter at first, but vanished in short time once the oil circulated) and the engine is MUCH quieter and smoother. I can totally feel a difference when driving the car which is also attributable to new plugs and wires. Good luck if you decide to attempt this on your own!
Last edited by 2003C5Z06DEC; 12-25-2017 at 06:25 PM.
Reason: Technical info edit
From the very beginnings of my search, purchase, and ownership of my 28K Mile, 2003 C5 Z06 back in Feb 2017, I have always had the infamous valve spring failure in my mind (mine had the Yellow springs, fyi). I called a few shops and got quotes ranging from $650 to $900 here in the Bay Area of California, but that was the extent of my effort to address the situation. More recently, an acquaintance of mine who I run into, occasionally, told me that his 66' Cobra broke a spring and dropped the valve in the engine...not good. This got me thinking again. I began to read every thread regarding the procedure on this forum as well as the youtube videos that I could find. Ultimately, I felt comfortable that I could do it, so I started my plan. I am writing this to share my experience so that it may be helpful to others.
A quick bit about myself - I grew up in a household where my father, mechanical engineer who also loves cars, would never take our cars to shops as he felt he could always do a better job because nobody would spend the same amount of time that he would; I agree. My role in this way of life started by holding flashlights at a very young age, to being the tool runner, to doing oil changes, brakes, etc. The older I got, the more complex things I learned and before I knew it, I developed that same mentality. This also was a result of witnessing some very poor work done by shops where I started to say to myself "I know I can do it better." For what it's worth, I am an accountant that likes cars...and working on them.
Well, here we are; I decided to change the valve springs by myself. With that said, I am going to list the methods I used, the parts I used, and interesting things I noticed/tips.
1. Methods -Compressed Air or Nylon Rope. I went with the compressed air method at TDC. I suppose the Nylon rope method would have been quicker as one of the hardest things, for me, was fitting the Air Hose Adapter into the spark plug hole. This may or may not be an issue for you, but my hands measure 10.25inch and I found it extremely difficult to rotate the rubber hose perfectly to get it threaded into the spark plug hold without stripping anything. The hose adapter I used was purchased from JEGS.com and there isn't any tool that I could think of to use, so I literally would install the adapter by rotating the hose very slowly until it threaded into the spark plug hole. Luckily, I was able to twist the hose tight enough with my hand to keep the pressure in the cylinder with the air compressor
Finding TDC, compression stroke: In my search, I didn't find a whole lot of info on how to best find TDC for each cylinder, so I made a chart based on the following:
--It takes 720 Degrees for a full cycle (4-cycle engine)
--Given that every cylinder fires in the 720 degrees of rotation, a cylinder fires every 90 Degrees. Once you find TDC on cylinder #1, a clockwise rotation of the crank 90 degrees gets you to TDC of the next cylinder in the firing order. (If you want this visual chart that I created, I can provide it. It shows you what stage each cylinder is at any time in relation to another cylinder, see snapshot below in attachments). I found TDC by watching the Intake Valve and Exhaust Valve on Cylinder #1 as I rotated the crank by hand. Once the Intake valve closed +180-degrees of rotation, you're very close to TDC on the compression stroke. I then marked the crank and 90-degree intervals with blue tape to keep track while turning the crank.
Note: I utilized TDC on the compression stroke FOR EACH CYLINDER to remove the rocker arms, change valve springs, and obviously re-install the rocker arms. Some people said that you can remove the rocker arms without TDC, but I disagree in that if you remove a rocker arm that is compressing a spring, you're putting unnecessary stress on the bolt that you are taking it out. It may make no difference, but whatever; my car, my time. Utilizing TDC when compressing the cylinder with air is also personal preference, but I figured it was extra security in the event that I lose pressure from the air compressor.
Put the front of the car up on ramps and jacked up the rear on jack stands: You'll be bending over for several hours, make it easier on your back.
2. Parts
Valve Springs: I went with PAC-1218. After speaking with my uncle, the folks and PAC, and the dealer, the PAC springs seemed like a no-brainer. It's a higher quality spring and if I'm going through the hassle of changing them out because the OEM springs are prone to failure, the GM OEM springs don't get another shot for redemption whether they are revised springs or not.
Valve Intake and Exhaust Seals: If you're in there, might as well change them. I bought OEM from GM.
Valve Spring Retainer, Valve Spring Locks: I reused these; no point in changing them out as they were spotless.
Spark Plugs: GM Iridium Plugs; supposed to be pre-gapped and some of them were not, I adjusted those.
Spark Plug Wires GM Performance Wires (Red) - NOTE: Two of the original wires tore when I was removing them. Save yourself the hassle and just buy new wires.
Spark Plug Air Hose Adapter: 14MM adapter from JEGS.com
Valve Stem Seal Installation Tool: Also from JEGS.com. You could use a socket, but the tool fits exactly perfect on the seal; no risk of damage. Personal preference, do what you want.
Valve Spring Compression Tool: I bought the Crane Spring Compression tool for LS Engines. This made changing the springs as easy as tying my shoes. Two springs at a time, perfect fit, couldn't have been easier.
Telescoping Pen Magnet: You'll need this when removing the valve locks; they are small and if you drop one, you'll be spending time trying to find it.
15/16 Offset Wrench: You need this tool to rotate the crankshaft without removing any steering components.
Misc:You obviously need various sockets, screw drivers, torque wrench, paper towels, flashlights, air compressor, etc
3. Interesting things I noticed/Tips.
-Disconnect the battery. Minor, but important for safety.
-The hardest part for me, again, was installing the 14mm sparkplug hose adapter into the spark plug hole. Imagine trying to install a garden hose by rotating the hose while grasping it a few inches away from the neck without looking, using only one hand...you'll catch my drift.
-Make sure you have a good torque wrench. I own a Beam Style torque wrench but decided to borrow a clicker-type torque wrench. Turned out that the clicker-type torque wrench was broken and when I was reinstalling the rocker arm bolts, I most definitely exceeded 15% of the recommended 22ft pounds for the bolts. To be safe, I bought new rocker arm bolts.
-Give yourself adequate time. I made a few trips to the store during the process for an adapter for my compressor, new rocker arm bolts, batteries, etc.
-Buy the Crane Compression Tool. It's expensive, but its quality made and it was perfect. JEG's make their own version, but I heard about the bolts wearing down during use; sounds like an annoying deviation of the plan.
-Have the firing order and cylinder stage chart up on a computer or piece of paper. This is very helpful to keep track of which cylinder you have at TDC.
-Take the time and torque the rocker arms at TDC for each cylinder and valve covers to proper torque.
From the very first step of jacking up the car to finishing up and starting the car, this took me about 12 hours with breaks, some cussing, trips to the store, etc. I have not done this before, yet I consider myself decently capable with working on cars just to give you an idea. As I mentioned, I took my time to make sure I didn't mess anything up and double checked everything. In the end, it fired up successfully (some valve train clatter at first, but vanished in short time once the oil circulated) and the engine is MUCH quieter and smoother. I can totally feel a difference when driving the car which is also attributable to new plugs and wires. Good luck if you decide to attempt this on your own!
Excellent write up. I also plan to do this soon. I have the PAC 1218 springs, Trick Flow valve spring compression tool, air hose to pressurize the cylinder, GM red wires, NGK TR6 plugs (what are in it now) and GM valve cover gaskets. Also a few spare retainer locks just in case a loose one or two.
I haven't done this before and had many questions on determining TDC and the process in general. Your write up is very helpful in getting me prepared to take on this project. If I could Get a copy of your spread sheet details I would appreciate it greatly. My email is switchplanner@yahoo.com
Thank you, Jim
Very nice write up. Just to mention I used the compression method when I did my springs a few years ago and I just compressed each cylinder and changed both springs, I didn’t worry about the position of each. Seemed to work fine that way and was very simple.
I just did this job this past weekend, using the PAC-1218 springs. I'd add that if you are using the air method, make sure that you put the car in gear with the parking brake on. I found this out the hard way when I forgot that particular step and the engine quicky rotated 180 degrees as soon as I pressurized the cylinder.
I would agree with the comment that threading the air connector into the spark plug hole was a challenge at times. I used the Lisle 19700 and it would've been much easier if the hose was about 4" long rather than the 12" long that it is.
I used the Trick Flow valve compressor and it worked flawlessly.
I had 2 rocker bolts that were slightly loose, so cleaned out all of the rocker bolt holes with brake cleaner and degreased the bolts before adding a small amount of blue thread locker. The rockers were torqued using the sequence in the factory service manual - others have remarked that they just pulled them down, but I figured that an extra rotation of the crankshaft was worth it. YMMV. My pulley is held on with an ARP bolt that needed a 27mm or 1 1/8" wrench.
Altogether, it's a fairly straightforward job, just take your time and make sure you follow the steps.
I just did this job this past weekend, using the PAC-1218 springs. I'd add that if you are using the air method, make sure that you put the car in gear with the parking brake on. I found this out the hard way when I forgot that particular step and the engine quicky rotated 180 degrees as soon as I pressurized the cylinder.
I would agree with the comment that threading the air connector into the spark plug hole was a challenge at times. I used the Lisle 19700 and it would've been much easier if the hose was about 4" long rather than the 12" long that it is.
I used the Trick Flow valve compressor and it worked flawlessly.
I had 2 rocker bolts that were slightly loose, so cleaned out all of the rocker bolt holes with brake cleaner and degreased the bolts before adding a small amount of blue thread locker. The rockers were torqued using the sequence in the factory service manual - others have remarked that they just pulled them down, but I figured that an extra rotation of the crankshaft was worth it. YMMV. My pulley is held on with an ARP bolt that needed a 27mm or 1 1/8" wrench.
Altogether, it's a fairly straightforward job, just take your time and make sure you follow the steps.
From the very beginnings of my search, purchase, and ownership of my 28K Mile, 2003 C5 Z06 back in Feb 2017, I have always had the infamous valve spring failure in my mind (mine had the Yellow springs, fyi). I called a few shops and got quotes ranging from $650 to $900 here in the Bay Area of California, but that was the extent of my effort to address the situation. More recently, an acquaintance of mine who I run into, occasionally, told me that his 66' Cobra broke a spring and dropped the valve in the engine...not good. This got me thinking again. I began to read every thread regarding the procedure on this forum as well as the youtube videos that I could find. Ultimately, I felt comfortable that I could do it, so I started my plan. I am writing this to share my experience so that it may be helpful to others.
A quick bit about myself - I grew up in a household where my father, mechanical engineer who also loves cars, would never take our cars to shops as he felt he could always do a better job because nobody would spend the same amount of time that he would; I agree. My role in this way of life started by holding flashlights at a very young age, to being the tool runner, to doing oil changes, brakes, etc. The older I got, the more complex things I learned and before I knew it, I developed that same mentality. This also was a result of witnessing some very poor work done by shops where I started to say to myself "I know I can do it better." For what it's worth, I am an accountant that likes cars...and working on them.
Well, here we are; I decided to change the valve springs by myself. With that said, I am going to list the methods I used, the parts I used, and interesting things I noticed/tips.
1. Methods -Compressed Air or Nylon Rope. I went with the compressed air method at TDC. I suppose the Nylon rope method would have been quicker as one of the hardest things, for me, was fitting the Air Hose Adapter into the spark plug hole. This may or may not be an issue for you, but my hands measure 10.25inch and I found it extremely difficult to rotate the rubber hose perfectly to get it threaded into the spark plug hold without stripping anything. The hose adapter I used was purchased from JEGS.com and there isn't any tool that I could think of to use, so I literally would install the adapter by rotating the hose very slowly until it threaded into the spark plug hole. Luckily, I was able to twist the hose tight enough with my hand to keep the pressure in the cylinder with the air compressor
Finding TDC, compression stroke: In my search, I didn't find a whole lot of info on how to best find TDC for each cylinder, so I made a chart based on the following:
--It takes 720 Degrees for a full cycle (4-cycle engine)
--Given that every cylinder fires in the 720 degrees of rotation, a cylinder fires every 90 Degrees. Once you find TDC on cylinder #1, a clockwise rotation of the crank 90 degrees gets you to TDC of the next cylinder in the firing order. (If you want this visual chart that I created, I can provide it. It shows you what stage each cylinder is at any time in relation to another cylinder, see snapshot below in attachments). I found TDC by watching the Intake Valve and Exhaust Valve on Cylinder #1 as I rotated the crank by hand. Once the Intake valve closed +180-degrees of rotation, you're very close to TDC on the compression stroke. I then marked the crank and 90-degree intervals with blue tape to keep track while turning the crank.
Note: I utilized TDC on the compression stroke FOR EACH CYLINDER to remove the rocker arms, change valve springs, and obviously re-install the rocker arms. Some people said that you can remove the rocker arms without TDC, but I disagree in that if you remove a rocker arm that is compressing a spring, you're putting unnecessary stress on the bolt that you are taking it out. It may make no difference, but whatever; my car, my time. Utilizing TDC when compressing the cylinder with air is also personal preference, but I figured it was extra security in the event that I lose pressure from the air compressor.
Put the front of the car up on ramps and jacked up the rear on jack stands: You'll be bending over for several hours, make it easier on your back.
2. Parts
Valve Springs: I went with PAC-1218. After speaking with my uncle, the folks and PAC, and the dealer, the PAC springs seemed like a no-brainer. It's a higher quality spring and if I'm going through the hassle of changing them out because the OEM springs are prone to failure, the GM OEM springs don't get another shot for redemption whether they are revised springs or not.
Valve Intake and Exhaust Seals: If you're in there, might as well change them. I bought OEM from GM.
Valve Spring Retainer, Valve Spring Locks: I reused these; no point in changing them out as they were spotless.
Spark Plugs: GM Iridium Plugs; supposed to be pre-gapped and some of them were not, I adjusted those.
Spark Plug Wires GM Performance Wires (Red) - NOTE: Two of the original wires tore when I was removing them. Save yourself the hassle and just buy new wires.
Spark Plug Air Hose Adapter: 14MM adapter from JEGS.com
Valve Stem Seal Installation Tool: Also from JEGS.com. You could use a socket, but the tool fits exactly perfect on the seal; no risk of damage. Personal preference, do what you want.
Valve Spring Compression Tool: I bought the Crane Spring Compression tool for LS Engines. This made changing the springs as easy as tying my shoes. Two springs at a time, perfect fit, couldn't have been easier.
Telescoping Pen Magnet: You'll need this when removing the valve locks; they are small and if you drop one, you'll be spending time trying to find it.
15/16 Offset Wrench: You need this tool to rotate the crankshaft without removing any steering components.
Misc:You obviously need various sockets, screw drivers, torque wrench, paper towels, flashlights, air compressor, etc
3. Interesting things I noticed/Tips.
-Disconnect the battery. Minor, but important for safety.
-The hardest part for me, again, was installing the 14mm sparkplug hose adapter into the spark plug hole. Imagine trying to install a garden hose by rotating the hose while grasping it a few inches away from the neck without looking, using only one hand...you'll catch my drift.
-Make sure you have a good torque wrench. I own a Beam Style torque wrench but decided to borrow a clicker-type torque wrench. Turned out that the clicker-type torque wrench was broken and when I was reinstalling the rocker arm bolts, I most definitely exceeded 15% of the recommended 22ft pounds for the bolts. To be safe, I bought new rocker arm bolts.
-Give yourself adequate time. I made a few trips to the store during the process for an adapter for my compressor, new rocker arm bolts, batteries, etc.
-Buy the Crane Compression Tool. It's expensive, but its quality made and it was perfect. JEG's make their own version, but I heard about the bolts wearing down during use; sounds like an annoying deviation of the plan.
-Have the firing order and cylinder stage chart up on a computer or piece of paper. This is very helpful to keep track of which cylinder you have at TDC.
-Take the time and torque the rocker arms at TDC for each cylinder and valve covers to proper torque.
From the very first step of jacking up the car to finishing up and starting the car, this took me about 12 hours with breaks, some cussing, trips to the store, etc. I have not done this before, yet I consider myself decently capable with working on cars just to give you an idea. As I mentioned, I took my time to make sure I didn't mess anything up and double checked everything. In the end, it fired up successfully (some valve train clatter at first, but vanished in short time once the oil circulated) and the engine is MUCH quieter and smoother. I can totally feel a difference when driving the car which is also attributable to new plugs and wires. Good luck if you decide to attempt this on your own!
iridium plugs have iridium in the tips. I was under the impression of you gap them, you end up damaging the iridium electrode and they end up not firing right. You said you adjusted your iridium plugs, can I ask how you did that?
the iridium plugs I bought clearly are not gapped right.
im about to do my Z06 springs. Thank you for this write up.
rlwagner1975 - I was not aware that iridium plugs are not supposed to be gapped. I gapped them as I’ve gapped other plugs and it’s been 50k+ miles since I did that. Curious to hear more from someone who has more technical knowledge but from what I read, the reason they don’t need adjustment is the materials used appropriately compensate for variations in the gap that a non-iridium plug isn’t able to achieve, coupled with the being a more fragile material.
rlwagner1975 - I was not aware that iridium plugs are not supposed to be gapped. I gapped them as I’ve gapped other plugs and it’s been 50k+ miles since I did that. Curious to hear more from someone who has more technical knowledge but from what I read, the reason they don’t need adjustment is the materials used appropriately compensate for variations in the gap that a non-iridium plug isn’t able to achieve, coupled with the being a more fragile material.
I found this video, you can gap them, but you don’t want to touch the electrode when your doing it.
I completed this job today. And while I read multiple sources and videos this is the most conclusive write up I came across.
A big thank you to @2003C5Z06DEC the Author of this article.
I used air on most valves, but a couple I just couldn’t get the air hose threaded so I end up using rope, then turning the engine until it wouldn’t turn anymore, and I was unable pull the rope out, that indicated the piston was up. I swapped the springs, then turned the engine the opposite direction and pulled the rope out.
Buy the LS valve spring compressor it’s worth every Penny of the $85 dollars. (See picture)
From start to finish took me about 12 hours. (About 1 hour was probably spent cleaning engine components, valve covers, coil packet etc)
LS Spring Compressor Tool
Last edited by rlwagner1975; 05-15-2023 at 03:15 PM.
whenever i did valve springs with compressed air the pressure of the air would push the piston to bdc if you should loose air pressure when changing the spring you also dropped the valve
whenever i did valve springs with compressed air the pressure of the air would push the piston to bdc if you should loose air pressure when changing the spring you also dropped the valve
What I did to stop the piston from going down, I put a wrench on the crank bolt and wrested the wrench against an engine brace. (I think it was a radiator hose or something like that) this prevents the engine from turning. Just in case you have disruption to your air. I have to say, though, I was surprised how little air leaked, moving at a normal pace, replacing two springs and two valve stem seals, I lost about 25 pounds of air per cylinder. I could do 4 springs total (I was pressurized at 50 pounds) before the compressor even kicked on.
whenever i did valve springs with compressed air the pressure of the air would push the piston to bdc if you should loose air pressure when changing the spring you also dropped the valve
per my comment in post #5, I set the piston at TDC and put the car in gear. That way, if the air pressure is lost, the valve doesn’t drop into the cylinder.
per my comment in post #5, I set the piston at TDC and put the car in gear. That way, if the air pressure is lost, the valve doesn’t drop into the cylinder.
That would have been a lot easier. I somehow missed that comment before doing the job.
12-25-2017, 12:41 AM
My DIY Valve Spring Replacement; 2003 C5 Z06 42K Miles
