Conflicting Symptoms... Need Help Please!
Thread Starter
Melting Slicks
Joined: Apr 2008
Posts: 2,343
Likes: 9
From: Lexington Park MD
I'm planning to pull the valve covers Saturday and it's nice to know what all to look for specifically.Did you only have to replace the springs or is there an underlying cause for something like that happening?
Instructor
Joined: Nov 2011
Posts: 137
Likes: 8
From: Dallas Tx
I just replaced the broken spring just to test if that would get rid of the P0300 DTC error. I'll replace the rest when a get a shipment in.
All I can say is the car has never run so well. I had changed the spark plugs, wires, cleaned the MAF and checked the fuel pressure. No improvement until that spring was swapped out.
It took $100 in special tools and some pretty sweaty minutes while I removed the keepers and then the spring. I had an air compressor running, putting air in the cylinder (100psi) to keep the valve from falling in the cylinder.
As a previous poster said, take it to someone that knows how to do it - if this makes you nervous.
Tech Contributor
Joined: Jan 2007
Posts: 19,472
Likes: 1,171
From: Dyer, IN
From reading the forum, there was a bad run of valve springs (guessing here) that happened around 2002-2003. Somehow my 2004 car got one (maybe more) and it failed at 95,000 miles.
I just replaced the broken spring just to test if that would get rid of the P0300 DTC error. I'll replace the rest when a get a shipment in.
All I can say is the car has never run so well. I had changed the spark plugs, wires, cleaned the MAF and checked the fuel pressure. No improvement until that spring was swapped out.
It took $100 in special tools and some pretty sweaty minutes while I removed the keepers and then the spring. I had an air compressor running, putting air in the cylinder (100psi) to keep the valve from falling in the cylinder.
As a previous poster said, take it to someone that knows how to do it - if this makes you nervous.
I just replaced the broken spring just to test if that would get rid of the P0300 DTC error. I'll replace the rest when a get a shipment in.
All I can say is the car has never run so well. I had changed the spark plugs, wires, cleaned the MAF and checked the fuel pressure. No improvement until that spring was swapped out.
It took $100 in special tools and some pretty sweaty minutes while I removed the keepers and then the spring. I had an air compressor running, putting air in the cylinder (100psi) to keep the valve from falling in the cylinder.
As a previous poster said, take it to someone that knows how to do it - if this makes you nervous.
Thread Starter
Melting Slicks
Joined: Apr 2008
Posts: 2,343
Likes: 9
From: Lexington Park MD
Regarding the compression test, don't we have an electronic throttle control? So should I remove the air bridge and manually hold the throttle body open or just leave it be and push the accelerator pedal down anyway?
Thread Starter
Melting Slicks
Joined: Apr 2008
Posts: 2,343
Likes: 9
From: Lexington Park MD
Did the compression test on the foreward most 6 cylinders (friend had to leave) and they were all the same, I'd say about 160-170psi. It's not that easy to read accurately.
So I threw in some new plugs and I want to say it is a little better when getting on the gas but honestly it may just be that now I am willing to dip the throttle a little deeper without thinking I'm going to break something. But the searching it does when winding down past idle is now worse.
Even though I'm sick I could definitely smell something with the hood up, maybe an exhaust leak? I would have thought that would be audible though. Revving doesn't seem to be an issue when WOT with clutch in, but it does shoot fuel or some clear substance out the exhaust tips.
And one more question. When pulling the #8 plug I knocked off this little cap in the pic below, so I tightened it down all the way. There was another one (see second pic) which was a little loose so I tightened it down all the way too. What are these and if they are some sort of vent should I loosen them back up again? I don't know what else to blame the problem of overshooting idle on. I can't see why new plugs would make it WORSE.
So I threw in some new plugs and I want to say it is a little better when getting on the gas but honestly it may just be that now I am willing to dip the throttle a little deeper without thinking I'm going to break something. But the searching it does when winding down past idle is now worse.
Even though I'm sick I could definitely smell something with the hood up, maybe an exhaust leak? I would have thought that would be audible though. Revving doesn't seem to be an issue when WOT with clutch in, but it does shoot fuel or some clear substance out the exhaust tips.
And one more question. When pulling the #8 plug I knocked off this little cap in the pic below, so I tightened it down all the way. There was another one (see second pic) which was a little loose so I tightened it down all the way too. What are these and if they are some sort of vent should I loosen them back up again? I don't know what else to blame the problem of overshooting idle on. I can't see why new plugs would make it WORSE.
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Instructor
Joined: Nov 2011
Posts: 137
Likes: 8
From: Dallas Tx
Even though I'm sick I could definitely smell something with the hood up, maybe an exhaust leak? I would have thought that would be audible though. Revving doesn't seem to be an issue when WOT with clutch in, but it does shoot fuel or some clear substance out the exhaust tips.
And one more question. When pulling the #8 plug I knocked off this little cap in the pic below, so I tightened it down all the way.
And one more question. When pulling the #8 plug I knocked off this little cap in the pic below, so I tightened it down all the way.
As for the smell - be a little careful. When my engine was misfiring (P0300), it was putting carbon monoxide. The garage door was open and the car was idling for a few minutes- and it set off a CO sensor with a high reading (110 one time). If it is over 50, you need to get out quickly. Note: carbon monoxide does not smell, but you can smell unburnt fuel (or whatever).
After the misfiring was fixed, the CO sensor does not read a trace.
Burning Brakes
Joined: Mar 2005
Posts: 800
Likes: 2
Did the compression test on the foreward most 6 cylinders (friend had to leave) and they were all the same, I'd say about 160-170psi. It's not that easy to read accurately.
So I threw in some new plugs and I want to say it is a little better when getting on the gas but honestly it may just be that now I am willing to dip the throttle a little deeper without thinking I'm going to break something. But the searching it does when winding down past idle is now worse.
Even though I'm sick I could definitely smell something with the hood up, maybe an exhaust leak? I would have thought that would be audible though. Revving doesn't seem to be an issue when WOT with clutch in, but it does shoot fuel or some clear substance out the exhaust tips.
And one more question. When pulling the #8 plug I knocked off this little cap in the pic below, so I tightened it down all the way. There was another one (see second pic) which was a little loose so I tightened it down all the way too. What are these and if they are some sort of vent should I loosen them back up again? I don't know what else to blame the problem of overshooting idle on. I can't see why new plugs would make it WORSE.
So I threw in some new plugs and I want to say it is a little better when getting on the gas but honestly it may just be that now I am willing to dip the throttle a little deeper without thinking I'm going to break something. But the searching it does when winding down past idle is now worse.
Even though I'm sick I could definitely smell something with the hood up, maybe an exhaust leak? I would have thought that would be audible though. Revving doesn't seem to be an issue when WOT with clutch in, but it does shoot fuel or some clear substance out the exhaust tips.
And one more question. When pulling the #8 plug I knocked off this little cap in the pic below, so I tightened it down all the way. There was another one (see second pic) which was a little loose so I tightened it down all the way too. What are these and if they are some sort of vent should I loosen them back up again? I don't know what else to blame the problem of overshooting idle on. I can't see why new plugs would make it WORSE.
Instructor
Joined: Nov 2011
Posts: 137
Likes: 8
From: Dallas Tx
Just got the shipment of rockers and springs today - so I can finish the job. I wanted to get the car running as it is my daily driver.
One question for the experts - do you use loctite on the rocker arm bolt? I did not see that step in the Service Manual.
One question for the experts - do you use loctite on the rocker arm bolt? I did not see that step in the Service Manual.
Thread Starter
Melting Slicks
Joined: Apr 2008
Posts: 2,343
Likes: 9
From: Lexington Park MD
I'm going to replace the AC belt tensioner pulley this week (I think that is the wine glass sound I had mentioned) and then pull the intake and valve covers this weekend. I think I'll pick up a can of Seafoam to try to decarbonize the cylinders too. What else should I check for this weekend?
Cruising
Joined: Jan 2011
Posts: 12
Likes: 0
From: Mukilteo Washington
went to where you suggested, gear chatter.com and couldn't find the DTC codes that my '99 C5 are displaying to me: G0 IPC U1160H, B0 RFA U1255H, U1096H, U1064H, U1016H, C2100 HC. I'm hoping to get rid of most if not all these codes when I replace the plugs, wires, O2 sensors, but would still like to know what all these codes pertain to???
Race Director
Joined: Jan 2007
Posts: 18,643
Likes: 14
From: Norman Oklahoma - The Only State in the Union with no Blue Counties!
went to where you suggested, gear chatter.com and couldn't find the DTC codes that my '99 C5 are displaying to me: G0 IPC U1160H, B0 RFA U1255H, U1096H, U1064H, U1016H, C2100 HC. I'm hoping to get rid of most if not all these codes when I replace the plugs, wires, O2 sensors, but would still like to know what all these codes pertain to???
96, 64, 16 are all ground related. Check the G105 ground located under the block, driver's size! Bet it is loose!
Thread Starter
Melting Slicks
Joined: Apr 2008
Posts: 2,343
Likes: 9
From: Lexington Park MD
went to where you suggested, gear chatter.com and couldn't find the DTC codes that my '99 C5 are displaying to me: G0 IPC U1160H, B0 RFA U1255H, U1096H, U1064H, U1016H, C2100 HC. I'm hoping to get rid of most if not all these codes when I replace the plugs, wires, O2 sensors, but would still like to know what all these codes pertain to???
Here's another DIC code list for you to search through in the future
http://forums.corvetteforum.com/1574463282-post2.html
Race Director
Joined: Jan 2007
Posts: 18,643
Likes: 14
From: Norman Oklahoma - The Only State in the Union with no Blue Counties!
To add to Silverbullet00's great advice, the C2100 is your left front tire pressure sensor
Here's another DIC code list for you to search through in the future
http://forums.corvetteforum.com/1574463282-post2.html
Here's another DIC code list for you to search through in the future
http://forums.corvetteforum.com/1574463282-post2.html
Thanks for the Kudos but I learned what I know here,,,Thanks again Bill Curlee!!!!!
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
To add to Silverbullet00's great advice, the C2100 is your left front tire pressure sensor
Here's another DIC code list for you to search through in the future
http://forums.corvetteforum.com/1574463282-post2.html
Here's another DIC code list for you to search through in the future
http://forums.corvetteforum.com/1574463282-post2.html
Thread Starter
Melting Slicks
Joined: Apr 2008
Posts: 2,343
Likes: 9
From: Lexington Park MD
Having some friends in one of your local Corvette groups it worth its weight in gold at times like this. If you have access to someone with a C5, swap wheels and tires with them long enough to evaluate the vibration issue. This would allow you to rule out wheel and tires. You mentioned in your first post that pushing the clutch in didn't change the vibration much, correct? I agree that you may have an engine issue, but if you turned the engine off and you still had one of maybe more vibration sources, you need to start ruling the easy ones out.
But I plan to take the intake manifold and valve covers off this weekend to ensure there is nothing that would suggest I shouldn't continue driving it for now. Should I pick up some new gaskets at Autozone for when I put it all back together? If so what do I need?
Last edited by Turbopower87; Dec 15, 2011 at 11:57 AM.
Race Director
Joined: Jan 2007
Posts: 18,643
Likes: 14
From: Norman Oklahoma - The Only State in the Union with no Blue Counties!
I just spoke to a guy at my work with an 04 and a scissor lift and we are going to see what we can do after the hollidays.
But I plan to take the intake manifold and valve covers off this weekend to ensure there is nothing that would suggest I shouldn't continue driving it for now. Should I pick up some new gaskets at Autozone for when I put it all back together? If so what do I need?
But I plan to take the intake manifold and valve covers off this weekend to ensure there is nothing that would suggest I shouldn't continue driving it for now. Should I pick up some new gaskets at Autozone for when I put it all back together? If so what do I need?
They will know!