3.8L (3800) Head Gasket Replacement Advice

A few weeks ago while driving home from work on the freeway I had some major engine problems. The car was very sluggish, loud, kept loosing speed until I had it pulled to the shoulder were it shut down and I had to coast to a stop. Alot of white smoke was coming from the engine compartment. Well after it was towed home (thank you AAA) I later discovered it was a blown head gasket. I pulled the front set of plugs out, turned the motor a couple of times to see a mixture of fuel and orange coolant get collected in plastics bottles I set in front of the engine.

So now that I know what is wrong with the car I started tearing apart the top end of the motor. Currently all is off the top of motor except the rear heads. These are the pictures how it all looks currently...

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1815.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1818.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1819.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1820.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1817.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1816.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1821.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1822.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1823.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1825.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1827.jpg

http://i602.photobucket.com/albums/tt101/gordon_Gjs/DSCN1828.jpg

I know it pretty dirty right now, but I plan on cleaning it up. Judging by the way the heads look what would some of you experts recommend I do?

I called a 2 local shops and the 1st one quoted the following...
A. Shave and run the heads in the cleaner would cost $80 bucks each
or
B. Shave, run the heads in the cleaner, do a valve job and install new seals would cost $165 each.

The 2nd one quoted the following...
A. Trade in old heads for rebuilt ones - $150 each
of
B. Get old ones rebuilt, includes valve job, new seals, cleaning and shave for $150 total for both.

I heard somewhere that it is better to rebuild the orignal part then it is to put a rebuilt different part on it. So I am leaning towards B. at the 2nd shop.

Is there anything esle I should worry about when putting it back together?
What is the best way to clean the top of the cyclinder and get a smooth surface to ensure no leakage when put back together?
I also plan on getting the complete felpro head gasket kit from rockauto along with new head bolts.

with fixing the old heads if possible................

shaving the heads must be done to both heads exactly the same. then you must get a head gasket kit to replace this cut material..gasket will be thicker.

not doing this your combustion chamber will be smaller. this will require the use of higher octane fuel..

they the cutters and you must comunicate so that you can get the gasket for what ever they plan to cut.

If you got stretch head bolts, don't forget to replace all the head bolts.

with fixing the old heads if possible................

shaving the heads must be done to both heads exactly the same. then you must get a head gasket kit to replace this cut material..gasket will be thicker.

not doing this your combustion chamber will be smaller. this will require the use of higher octane fuel..

they the cutters and you must comunicate so that you can get the gasket for what ever they plan to cut.

If you got stretch head bolts, don't forget to replace all the head bolts.

I mentioned that to the guy at the shop, he ensured me that there will be so little taken off it will not affect the compression ratio and nothing special would be required. Maybe he told me resurface the heads. Is there a differance between shaving and resurfacing?

Also, my parts list includes...
- Felpro complete head gasket kit
- Head bolts
- Heater Core (old one is leaking)

and intake/exhuast valves if needed.

I just notice that I wrote Advise at the end of the title instead of Advice...
3.8L (3800) Head Gasket Replacement Advise

Is there a way I can edit this?

I mentioned that to the guy at the shop, he ensured me that there will be so little taken off it will not affect the compression ratio and nothing special would be required. Maybe he told me resurface the heads. Is there a differance between shaving and resurfacing?

Also, my parts list includes...
- Felpro complete head gasket kit
- Head bolts
- Heater Core (old one is leaking)

and intake/exhuast valves if needed.

cleaning and shaving is different. any material removed will make the combustion chamber smaller. If this is being done because of the coolant entering the cylinder caused a distortion I would get heads off a scrap yard vehicle or new heads. you will need higher octane fuel and may find other issues with the heads cut/shaved and not adjusting for this. like more compression in the cylinders. could be engine not designed to handle this ..

My question to you is did you find the bad spot in your head gaskets? ie: where it allowed coolant to fill the cylinders?

If not, take a peek in your upper intake plenum near where the EGR stove pipe goes. Look for melted plastic.

Part of my thinks pulling the heads was overkill as the Upper intakes on these motors fail causing coolant to fill the cylinders. I just hope for your case you didn't bend a connecting rod from possibly hydrolocking it.

Good luck!

My question to you is did you find the bad spot in your head gaskets? ie: where it allowed coolant to fill the cylinders?

If not, take a peek in your upper intake plenum near where the EGR stove pipe goes. Look for melted plastic.

Part of my thinks pulling the heads was overkill as the Upper intakes on these motors fail causing coolant to fill the cylinders. I just hope for your case you didn't bend a connecting rod from possibly hydrolocking it.

Good luck!

I will check the upper intake plenum when I make it home today, but when I pulled the upper intake plenum off half a year ago I dont recall seeing any melted plastic.

I pulled the heads off because the middle front cylinder was blowing coolant and fuel when I removed the spark plugs while the others were not. The heads have also been leaking oil near the headers and I have also had an external coolant leak from somewhere near the heads.

How could I tell if there is a bent connecting rod?

In the last few pictures I posted you can see some pictures of the head gaskets, they are in pretty bad condition (from what I can tell). The coolant ports look almost completely sealed over. I could be wrong on this as this is my first time going this deep into the motor.

Currently the heads are at the motor shop being rebuilt and I hope to get them back tomorrow. If all goes like planned then I hope to have it together by sunday.

Also the coolant system on this car was neglected for many years before I got a hold of it. I have been trying to get it back to normal for awhile. Hopefully after this it will be almost back to normal. Somebody posted somewhere that running CLR instead of coolant flush cleans much better, is this true and safe?

I recieved the heads and lower intake manifold back from the shop today all rebuilted and cleaned up. I will post pictures of how they turned out.

Also, Does anybody know if there is suppose to be a pencil size hole in the rear valve cover? I will also post a picture of this...

There should be no hole in the rear valve cover.

Your oil leak you mentioned in post 8 sounds like the bad valve cover gaskets, or the hole you mentioned above.

The external coolant leak could be numerous places, if it was puddling up near the injectors, more than likely your lower intake gasket.

To check for a bent connecting rod, if you still have the motor tore down, would be to rotate the crankshaft and watch the pistons move up and down to see if all of them reach the top of the block. If you put the motor back together already, I guess just hope for the best.

There should be no hole in the rear valve cover.

Your oil leak you mentioned in post 8 sounds like the bad valve cover gaskets, or the hole you mentioned above.

The external coolant leak could be numerous places, if it was puddling up near the injectors, more than likely your lower intake gasket.

To check for a bent connecting rod, if you still have the motor tore down, would be to rotate the crankshaft and watch the pistons move up and down to see if all of them reach the top of the block. If you put the motor back together already, I guess just hope for the best.


Thanks for the info on the valve cover, I sealed the hole over with a rubber plug and some gasket sealant. I just wish I knew what put the hole there in the first place. I also rotated the crankshaft and all the pistons reached the top of the block.


This question here is for anybody who can hopefully answer it...
When the motor is unhooked from the front struts and is tilted backward or pulled foward, is it suppose to leak engine oil or transmission oil?

Well I have eveything installed and when I try to start it just sputters for a second or so, back fire alittle and dies.If I hold the gas pedal alittle and start it will sputter and running alittle longer. Does anybody have any idea of what might be wrong?

I checked the IAC,throttle posistion sensor, all 6 exhuast pipes are hot.
I will check more stuff on it tomorrow, If anyone has any pointers please post or pm me ASAP! I need the car running by tomorrow night! Thanks!!!

Verify the spark plug wires are going to the right cylinders. Make sure the MAF is plugged in and you didn't forget to hook up your brake booster vacuum line. Check for Pending or Stored DTC's if you have an OBD2 Scanner. Just the things that come to the top of my head.

If all else fails, pull the plugs and look for coolant and run a compression check.

Verify the spark plug wires are going to the right cylinders. Make sure the MAF is plugged in and you didn't forget to hook up your brake booster vacuum line. Check for Pending or Stored DTC's if you have an OBD2 Scanner. Just the things that come to the top of my head.

If all else fails, pull the plugs and look for coolant and run a compression check.

Yes, I finally got it started sunday afternoon! It was such a relief! I was sitting down thinking what could this be... I remember about the brakebooster. I plugged it in and it started right up. Now I am just fixing minor coolant leaks. I bought new coolant hoses today because the old ones are leaking. I also stripped one of the threads for the coolant thermostat housing. But I fixed it yesterday with a helicoil. Other then that the car seems to sound and run great. Here are some other pictures I took before putting it together...


http://i602.photobucket.com/albums/tt101/gordon_Gjs/IMAG0328.jpg
http://i602.photobucket.com/albums/tt101/gordon_Gjs/IMAG0326.jpg
http://i602.photobucket.com/albums/tt101/gordon_Gjs/IMAG0325.jpg
http://i602.photobucket.com/albums/tt101/gordon_Gjs/IMAG0324.jpg
http://i602.photobucket.com/albums/tt101/gordon_Gjs/IMAG0327.jpg
http://i602.photobucket.com/albums/tt101/gordon_Gjs/IMAG0323.jpg
http://i602.photobucket.com/albums/tt101/gordon_Gjs/IMAG0322.jpg
http://i602.photobucket.com/albums/tt101/gordon_Gjs/IMAG0320.jpg
http://i602.photobucket.com/albums/tt101/gordon_Gjs/IMAG0321.jpg
I also found out were the hole came from on the valve cover. When I replaced the alternator last year I must have switch one of the longer bolts with the shorter one and it went thru the cover. But its fixed now.
Thanks for youre help!

Sounds Good and Good Job :bigthumb:

That machine shop sure did a good job on your heads. Makes me almost want to change out my head gaskets just to get my heads to look like that.

May want to keep an eye on that back valve cover though as different materials expand at different rates and could cause your epoxy work to pop off. I don't think a replacement valve cover would be too spendy from a slavage yard should you ever want to replace it.

Sounds Good and Good Job :bigthumb:

That machine shop sure did a good job on your heads. Makes me almost want to change out my head gaskets just to get my heads to look like that.

May want to keep an eye on that back valve cover though as different materials expand at different rates and could cause your epoxy work to pop off. I don't think a replacement valve cover would be too spendy from a slavage yard should you ever want to replace it.


Taking the car apart was a piece of cake, I think I used my air tools to remove almost every bolt and nut. I bagged and label every bolt, nut and part I removed. I also cleaned all the parts before installing. Putting the car back together was very nerve-wracking and alot more time consuming. I had never replaced heads on a motor, so we will see how this holds up.

As for the valve covers, I drilled the hole to were it was nice and smooth. I took a rubber grommet and smeared gasket sealant around it and fitted it into the hole. I then took a plastic plug that was made to plug the rubber grommet and smeared gasket on that and fitted it into the grommet. So it is not just a hole filled in with gasket sealant. I dont see this thing leaking. But I will check on it every now and then to make sure.

So 14 months later how is it running? Did you re-use you upper intake/plenum?

I just removed the intake upper and lower from my 98 Buick. I found the issue in the plastic upper where the EGR pipe goes though. The machine shop told me to check it. I appears that it was leaking pretty bad. I can't understand why the coolant dead heads around the EGR pipe, and could I just plug the hole that allows coolant to circle to the EGR pipe from the throttle body.

or try to reseal around the pipe, or find a new upper.

It has to be replaced....

So 14 months later how is it running? Did you re-use you upper intake/plenum?

I just removed the intake upper and lower from my 98 Buick. I found the issue in the plastic upper where the EGR pipe goes though. The machine shop told me to check it. I appears that it was leaking pretty bad. I can't understand why the coolant dead heads around the EGR pipe, and could I just plug the hole that allows coolant to circle to the EGR pipe from the throttle body.

or try to reseal around the pipe, or find a new upper.



I had the intake manifold fail [hole] egr portion. very common problem.

like was mentioned new intake required.

1998 monte carlo 3.8L @125,ooomi.

So 14 months later how is it running? Did you re-use you upper intake/plenum?

I just removed the intake upper and lower from my 98 Buick. I found the issue in the plastic upper where the EGR pipe goes though. The machine shop told me to check it. I appears that it was leaking pretty bad. I can't understand why the coolant dead heads around the EGR pipe, and could I just plug the hole that allows coolant to circle to the EGR pipe from the throttle body.

or try to reseal around the pipe, or find a new upper.

It is running great... well the top end is at least!!

It seems to have a new issue, which I am looking into right now. It leaks transmission fluid, lots of transmission fluid. Enough to make the car not go into gear the next day until I top it off.

It seems to be leaking from the passenger side and its looks to be axle seal (I think). So I will be looking into this in a few days when I get some time.


Now the EGR Pipe issue you mention makes me wonder if mine is going? How can you tell if it is bad?

So I am pulling the heads to do a head gasket replace on a 98 intrigue. I know its the head gasket, it burns coolant, but not visible leaking. It also over heats. It isn't the upper intake or its gaskets as they have been replaced. It also bubbles at the radiator mouth when I take the cap off and start the car, and it has oil in the coolant. So anyways, I got the intake and valve covers off and im down to the head studs and headers. How in the heck does one get the rear bank's headers off without cussing? Is it humanly possible? I am looking at the front bank of headers and know im in for a bit of tedious wrench turning. Any tricks? thanks!