C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

blown head gasket on '87

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Old Jul 1, 2013 | 03:34 PM
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Default blown head gasket on '87

Hello everyone.

I had been getting a low coolant light for several days,so I added a little coolant and went through the burping procedure that I learned here.I did not drive the car yesterday,but started it this morning and white smoke is pouring out of both tail pipes. I am assuming the head gasket is broken/blown. I am writing to seek advice from you guys especially those who have had this problem.My 'vette is nearing 110K in mileage,and I don't know whether I should consider replacing the gasket or finding another engine.I am a shadetree mechanic and am great at tearing things apart ,but when the time comes to put them back together,I am in deep,deep trouble.I don't relish the thought of trying to adjust valves,etc,plus I'm an old fart and like to look for the easy way out of problem areas.When you guys find the time,would you mind giving me your thoughts as to what you would do? I am in Columbia,South Carolina in case any of you guys/girls are in this area.

Thank you

tankman
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Old Jul 1, 2013 | 03:46 PM
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doing an eng swap is just as much work as doing the gaskets...

Its #7 btw.

As common as the sun rise.

Pull the heads, get 'em checked, buy good quality gaskets and reassemble.
Go BUY a FSM set BEFORE doing ANYTHING and do some reading. Gain confidence. Do not set time limits....do what assembly YOU are comfoprtable with and walk away for the day. It WILL get put back together as long as you do something each day...

Not a real big deal. I gotta do the same thing soon. Except I'm swapping heads and doing performance, but the same work and I'm disabled and stupid so I have a REAL disadvantage.
Not to worry, it can be done.
Good luck.
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Old Jul 1, 2013 | 03:50 PM
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I would remove the heads, have them checked for cracks, and rebuilt. Use a FelPro blue gasket putting it back together, and if you do this I'll explain how really easy it is to adjust valves. You might consider adding 1.6:1 Proform self aligning roller rocker to give a slight increase to a pretty famous L98 cam.

I used to have a solid lifter 302 car, and got really good at running through the valves. I's really easier than most think.
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Old Jul 1, 2013 | 03:55 PM
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More than likely #7 or #8 cylinder. Pull the spark plugs and look at them? Exceptionally clean might mean a blown gasket.

Replacing the gaskets is not too difficult. Just be sure to label each bolt, wire and hose your remove without exception. It will keep you out of trouble trying to find where this and that went....and asking for help on the Forum to identity parts. In many cases there are different size bolts, so be sure what came from were.

You just need basic tools and a torque wrench.
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Old Jul 1, 2013 | 06:17 PM
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Originally Posted by leesvet
doing an eng swap is just as much work as doing the gaskets...

Its #7 btw.

As common as the sun rise.

Pull the heads, get 'em checked, buy good quality gaskets and reassemble.
Go BUY a FSM set BEFORE doing ANYTHING and do some reading. Gain confidence. Do not set time limits....do what assembly YOU are comfoprtable with and walk away for the day. It WILL get put back together as long as you do something each day...

Not a real big deal. I gotta do the same thing soon. Except I'm swapping heads and doing performance, but the same work and I'm disabled and stupid so I have a REAL disadvantage.
Not to worry, it can be done.
Good luck.
Thank you to leesvet, MrWillys, and John A. Marker. I do have the FSM and tools. I think it's going to take a while before I gain enough confidence to begin,but you all have got me thinking. MrWillys,I'll take you up on the valve adjustment offer if/when I get that far. Thanks again to all of you.

tankman
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Old Jul 1, 2013 | 10:19 PM
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I was doing a compression check because my car was running funny. Water blew out of the spark plug hole on #7 so I knew what the problem was.

You might try pulling all the plugs and spinning the engine to see if you get any water.
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Old Jul 1, 2013 | 10:35 PM
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I agree that pulling an engine is a lot more work than pulling the heads, especially on a C4. The transmission bell housing mount bolts are not fun to get at to remove and a bigger pain to install when putting the engine back in.

My 90 started losing water, wasn't leaking on the ground, just disappearing but I didn't see any white smoke. The oil was a little discolored but nothing really indicating a water leak. I also had an oil leak coming from the back of the intake manifold so I decided to tear into it and see what were the problems. The water loss had just started so it probably didn't leak much into the oil. The oil leak was the oil pressure sending unit, not the rear seal on the intake manifold. When I took off the intake, the gasket between the intake and head didn't look good and was suspcious on the passenger side rear of the intake. I thought that the intake gasket was the cause of the leak but I didn't want to take a chance and install a new gasket and it be the head gasket that was leaking. Pulled the heads and the head gasket also looked suspect but didn't look like it was leaking but the condition of the gasket indicated that it would eventually give out. Sent the heads to a shop for checking and rebuild, turned out the heads weren't warped so it was probably the intake leaking in the first place. While the heads were in the shop I got to thinking that the gaskets in the block were just as old as the head and intake. Decided that I would pull the block, check the bearings and install new gaskets/seals. Bearings were fine, almost looked new, and the engine didn't use any oil so I didn't rebuild the block. Then I had to put it all back in. Any way, all I have to do now is reinstall the fuel rails, runners and plenum and I'm done.

If you don't have a decent digital camera, get one! Take all kinds of pictures of the engine, engine bay and all the wiring before you start disassmebly. Take pictures as you disassemble everything. You will really appreciate this when it's time to put it all together again. Get a box of sandwich baggies and a marker. Put all your bolts and nuts in baggies and label where they come from, ie. water pump, alternator mount bolts, etc. There are too many of them to try and remember where they go. Get a 2 foot length of 2X4 and drill holes in it to place the pushrods into in order of taking them out of the heads. You can slide the rocker and pivit down on the push rod and this will keep them together.

I'll be 66 next month and have arthritis in every joint in my body and I have done all this work by my self, only had a friend help me wiggle the engine back into place when I reinstalled it. I'm not bragging, just pointing out that you don't have to be 18 (it sure helps though) to do the work. I just work a lot slower now and take a lot more breaks. Had I taken this to a shop I know it would have been close to $2,500 for the work.
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Old Jul 1, 2013 | 10:59 PM
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Hi, head gaskets are easy, and I believe these cars use hydraulic lifters so no need for valve lash adjustments! pull the heads, get new head bolts/studs, an accurate torque wrench, a new head gasket, and send the heads out to get shaved. Put it all back together, following torque specifications and patterns, set the timing and fire it up. Should take more than like 2 days to complete. Good luck.
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Old Jul 1, 2013 | 11:07 PM
  #9  
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Originally Posted by Cliff Harris
I was doing a compression check because my car was running funny. Water blew out of the spark plug hole on #7 so I knew what the problem was.

You might try pulling all the plugs and spinning the engine to see if you get any water.
I went out tonight and tried to move it to the garage,it would barely move. I shut it down, White smoke was billowing from the tailpipes.
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Old Jul 1, 2013 | 11:14 PM
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Originally Posted by George Dickel
I agree that pulling an engine is a lot more work than pulling the heads, especially on a C4. The transmission bell housing mount bolts are not fun to get at to remove and a bigger pain to install when putting the engine back in.

My 90 started losing water, wasn't leaking on the ground, just disappearing but I didn't see any white smoke. The oil was a little discolored but nothing really indicating a water leak. I also had an oil leak coming from the back of the intake manifold so I decided to tear into it and see what were the problems. The water loss had just started so it probably didn't leak much into the oil. The oil leak was the oil pressure sending unit, not the rear seal on the intake manifold. When I took off the intake, the gasket between the intake and head didn't look good and was suspcious on the passenger side rear of the intake. I thought that the intake gasket was the cause of the leak but I didn't want to take a chance and install a new gasket and it be the head gasket that was leaking. Pulled the heads and the head gasket also looked suspect but didn't look like it was leaking but the condition of the gasket indicated that it would eventually give out. Sent the heads to a shop for checking and rebuild, turned out the heads weren't warped so it was probably the intake leaking in the first place. While the heads were in the shop I got to thinking that the gaskets in the block were just as old as the head and intake. Decided that I would pull the block, check the bearings and install new gaskets/seals. Bearings were fine, almost looked new, and the engine didn't use any oil so I didn't rebuild the block. Then I had to put it all back in. Any way, all I have to do now is reinstall the fuel rails, runners and plenum and I'm done.

If you don't have a decent digital camera, get one! Take all kinds of pictures of the engine, engine bay and all the wiring before you start disassmebly. Take pictures as you disassemble everything. You will really appreciate this when it's time to put it all together again. Get a box of sandwich baggies and a marker. Put all your bolts and nuts in baggies and label where they come from, ie. water pump, alternator mount bolts, etc. There are too many of them to try and remember where they go. Get a 2 foot length of 2X4 and drill holes in it to place the pushrods into in order of taking them out of the heads. You can slide the rocker and pivit down on the push rod and this will keep them together.

I'll be 66 next month and have arthritis in every joint in my body and I have done all this work by my self, only had a friend help me wiggle the engine back into place when I reinstalled it. I'm not bragging, just pointing out that you don't have to be 18 (it sure helps though) to do the work. I just work a lot slower now and take a lot more breaks. Had I taken this to a shop I know it would have been close to $2,500 for the work.
Thanks for responding and the advice. I'm not looking forward to this. Tonight I wanted to move it to the garage but it would hardly move.I think I'm going to put it under the carport if I can get it there. I do have a good digital camera. Thanks again.
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Old Jul 1, 2013 | 11:16 PM
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Originally Posted by DanielRicany
Hi, head gaskets are easy, and I believe these cars use hydraulic lifters so no need for valve lash adjustments! pull the heads, get new head bolts/studs, an accurate torque wrench, a new head gasket, and send the heads out to get shaved. Put it all back together, following torque specifications and patterns, set the timing and fire it up. Should take more than like 2 days to complete. Good luck.
No way will I get this done in two days. I'll be lucky to get it done in two months,but thanks for responding.
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Old Jul 1, 2013 | 11:22 PM
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Originally Posted by DanielRicany
Hi, head gaskets are easy, and I believe these cars use hydraulic lifters so no need for valve lash adjustments!
So please expound on what you do to set these hyd lifters. Does Harry Potter wave a magic wand, or do you just tighten down the rocker nuts to a given torque? Or must you rotate the engine following a sequence and bring them to lash plus 5/8 to 3/4 of a turn?
Please tell us?
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Old Jul 1, 2013 | 11:56 PM
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I know that MrWillys is giving the poster a hard time.
You do have to adjust the valves...no if's or shortcuts.
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Old Jul 2, 2013 | 11:11 AM
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tankman, I don't blame you on not looking forward to the job, it is a lot of work. If you are retired take your time and when you get frustrated and want to break things, walk away and take a breather. May want to wait a couple days before getting back to it, that's what I've been doing. I hope to finish it today or tomorrow, weather has cooled down and I won't have to worry about heat exhaustion. My workshop is a metal building and it gets like an oven on hot sunny days and a refrigerator in the winter. One of my retirement projects, insulate the work shop. Hang in there man, you can do it and the feeling of accomplishment when the job is finished is great.
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Old Jul 2, 2013 | 11:34 AM
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Originally Posted by George Dickel
tankman, I don't blame you on not looking forward to the job, it is a lot of work. If you are retired take your time and when you get frustrated and want to break things, walk away and take a breather. May want to wait a couple days before getting back to it, that's what I've been doing. I hope to finish it today or tomorrow, weather has cooled down and I won't have to worry about heat exhaustion. My workshop is a metal building and it gets like an oven on hot sunny days and a refrigerator in the winter. One of my retirement projects, insulate the work shop. Hang in there man, you can do it and the feeling of accomplishment when the job is finished is great.
Hello George,
Thanks. I got it into the garage this morning,pulled the 5 and 7 plugs and they are dry. I pulled the dipstick and it's still only oil,no water or milky color. I'm starting to wonder if something else is causing this because I really don't want to start.
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Old Jul 2, 2013 | 04:12 PM
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Originally Posted by tankman
Hello George,
Thanks. I got it into the garage this morning,pulled the 5 and 7 plugs and they are dry. I pulled the dipstick and it's still only oil,no water or milky color. I'm starting to wonder if something else is causing this because I really don't want to start.
I'm not sure if this is a fact, coincidence, or luck. Maybe it will help you. I defintly had some white smoke out of my tail pipe on the 89. I knew my intake was leaking(low coolant light also). I saw antifreeze pooling by the injectors. As you assumed I thought it was my head gasket. I replaced the gaskets on the intake manifold, plenum, tb and cleaned the living day lights out of all parts. My white smoke stopped. I just assumed they where so dirty it was polluting my exhaust.
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Old Jul 2, 2013 | 07:56 PM
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Originally Posted by guno89
I'm not sure if this is a fact, coincidence, or luck. Maybe it will help you. I defintly had some white smoke out of my tail pipe on the 89. I knew my intake was leaking(low coolant light also). I saw antifreeze pooling by the injectors. As you assumed I thought it was my head gasket. I replaced the gaskets on the intake manifold, plenum, tb and cleaned the living day lights out of all parts. My white smoke stopped. I just assumed they where so dirty it was polluting my exhaust.
Hello guno89,
Thanks for responding.I haven't found antifreeze on anything yet,but it does smoke & smells like coolant or the radiator.I guess I'll get started tearing into it. I purchased injectors over a year ago and they are still on the shelf,so I guess I'll be replacing injectors while I'm at it.
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Old Jul 5, 2013 | 06:14 PM
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Pulling the heads isn't normally a real big problem. I've done it on a Couple of LT1 C4's. It will take some time, but no one single step is very difficult.

The biggest issue in my experience is normally rusted bolts on the exhaust. Plenty of penetrating oil on the bolts, and give the oil some time to work it's way in. Take your time. Having an air impact wrench (or an electric impact wrench) can make the job a bit less of a Pain, but eventually, the bolts that hold the exhaust manifold on have to come out, and the bolts that hold the pipes to the manifolds have to either come off - or get broken off. If they get broken - they can be replaced "fairly easily" (as compared to drilling a broken bolt out of the aluminum cylinder heads)

As for your question about adjusting hydraulic lifters after reinstalling the heads. It's NOT hard to do, and the adjustment isn't hypercritical. Let's say you are going to adjust the valves for cylinder #1 (and let's assume you have a stock camshaft - nothing with tons of duration). Bring cylinder #1 to top dead center. Slowly tighten the first rocker arm adjusting nut while twirling the pushrod for that roker arm with your fingertips. You'll be able to feel when the "slop" in the pushrod travel is all taken up. Tighten the adjusting nut 1/4 - 1/2 turn past the point of the slop being taken up and guess what... You're done! Repeat for the next rocker. That cylinder is now done. Move on to the next cylinder. The FSM will probably say to tighten 1 turn, and some of the forum posts will say to go barely past the point that the slop is all taken up. The hydraulic lifter operates within a certain "range" to automatically take up any slop in the valvetrain. You are tryng to get the plunger of the hydraulic lifter somewhere in it's operating range. Some guys like to leave the lifters right at the top of their operating range (very little room to take up slack) because if they accidently over rev, and the valves "float" (where the lifters loose contact with the cam), the lifters will try to take up the play, and the valves won't be happy - but let's not worry too much about that for right now..... Let's worry about getting the motor back together and getting it running. 1/4 - 1/2 turn past the point all the slop is taken up will work just fine. IF, you want to be a purist about it, once the motor is running. - redo the adjustment. Warm up the motor and pull one valve cover, start the motor, and quickly back off each rocker (one at a time) to the point you hear valve noise, then tighten it back a quarter turn past the point the noise stops. Then repeat on the other side. This procedure will work extremely well, but unless you have a spare set of valve covers that you want to cut up - it will make a horrible mess.

The key thing is to no be afraid - this is not rocket science - it's all nuts and bolts stuff, you're just removing and re-installing a bunch of parts......

GOOD LUCK !!!
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Old Jul 5, 2013 | 06:30 PM
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I prefer to think of it this way:

Turning the engine in the direction of rotation (clockwise if in front of harmonic balancer) watching the number 1 cylinders exhaust valve. When is starts to move up, you adjust the intake valve for the cylinder. While tightening the the rocker arm nut you twist the pushrod with your other hand. Just when you feel pressure being applied that is zero lash. I've always been sucessful with 5/8 to 3/4 of a turn past (not claiming the other poster is wrong, but what has worked for me). Now following the sequence of the firing order complete the other 7 intake valves.
Now watching the intake valve on #1 come up, and almost all the way back down, you adjust the exhaust valve. Following the sequence of the firing order for the remaining 7.

This is the method I've used for 30 years after watching my dad do it running getting oil everywhere.
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Old Jul 5, 2013 | 07:17 PM
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What Mr. ****** is saying about looking for movement of one valve is a more correct way to do the adjustment. I suggest the TDC method - because when you're putting the heads back on - you are starting with no rockers installed - so trying to figure out when one valve just starts opening / closing is quite difficult. Finding TDC is quite a bit easier for someone who isn't that familiar with the inner workings of the valvetrain.

The differences in procedure are next to meaningless for stock type builds. If you were to look back at a 1970's Factory Service Manual - they would say that on hydraulic lifter cams - you can do 8 valves at a time from one crank position, meaning that all the valve adjustments can be done from just two crank positions.

The difference between 1/4 - 1/2 turn in and 5/8 to 3/4 turn in - is purely a matter of taste. There is no one right answer - both options will work just fine.
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