Blown head...

[mikroman]

I'm a handy kind of guy but I have never really got into cars. I found out recently that my 1995 Seville has a blown head and the dealer wanted 2500.00 to fix it. I called a machine shop and they only want 300.00 to mill the heads and do a valve job. So that means the labor would be 2200.00. I'm going to try and save some money because the Caddy has been nickel and dimming me to death over the last year.

Are there any pitfalls that I should watch out for when replacing the head gaskets? Should I buy anything different or new while I'm at it? Any suggestions would be helpful to a newbie...

[Scotty]

This is not really a DIY job. The engine has to be time-serted, this is NOT just a matter of pulling the heads replacing the head gaskets. If you want to continue after reading up on time-serting, there are a few here that have done it. If you don't pull the engine out you will probaby need a 90 degree drill but the job is harder with the engine in place. I personally would be hard pressed to do this job myself knowing that the engine had to be pulled out and I have done valve jobs about 10 times on Chevys, Cadillacs Olds and an MGB-GT.

http://www.timesert.com

[KHE]

You don't need to do a "vave job" on these engines or mill the heads. If you have confirmed that the head gaskets are blown (via pressure test) then removing the heads, installing timeserts and replacing the gaskets and headbolts with the OEM parts is the proper way to go.

Some have installed timeserts with the engine in the car - I think it was Barry94.

[Bob D]

Mik…even if your absolutely sure it’s the head gasket (are you?!) it’s really not a job for the average DIY’r, unless you have the facilities to pull the motor (and trans with it..) and everything you need for Timeserting. I guess it’s been done with the engine in the car, but that’s REALLY no easy trick, especially when you’re timeserting, a process which cannot be skipped.

[Barry94]

You don't need to do a "vave job" on these engines or mill the heads. If you have confirmed that the head gaskets are blown (via pressure test) then removing the heads, installing timeserts and replacing the gaskets and headbolts with the OEM parts is the proper way to go.

Some have installed timeserts with the engine in the car - I think it was Barry94.

Yes, I have done the head/timesert with the engine in the car.

Actually twice.

The first time was for a burned exhaust valve in #5 cyl.

The second time was a couple years later because I didn't timesert the block.

Three head bolts had pulled the threads from the block.

It can be done in the car, however it takes awhile.

I have a few "tricks" that I have learned.

If you attempt the job with the engine in the car, I'll pass along my experiences.

Barry

[crich8136]

Question for Barry:

I have the overheating problem and have been suspecting a head gasket for some time. Tonight I am reading the site for the first time (on this problem) just to understand what my options are.

You mention your experience timeserting the engine in the car. Have you posted that anywhere? Otherwise would you please post it or send it to me?

Also, I suspect that my problem may be in the front head. Is it foolish to replace the gasket on that head and ignore the rear one (assuming that the pressure test confirms the problem only in the front)? Will the rear one likely fail soon anyway?

Thanks for any advice you can give.

Claude

[jhall]

mikroman,

Have a look at the Timersert process at http://caddyinfo.ipbhost.com/index.php?sho...796&hl=timesert

This should show a pallette of shots from my 4.6L '97 Deville that I am currently rebuilding from a blown head gasket (130K miles). Heads are due back from the shop this weekend so more assembly pics and details will follow in a couple of weeks.

Before you embark on this type of job, you need to make darn sure that it is the head gaskets. Symtoms include misfiring cylinder(s), exhaust smell and cold engine pressurization in the reservoir tank, overheating, leaking at the water pump seal, overflow from reservoir tube, etc. Not all of these symtoms may appear and overheating may be from other causes. Give more details on this forum and maybe you'll save yourself a lot of time / money.

The Timersert kit along is about $300 and will take 4 - 5 hours to install. You will also need to buy a GOOD repair manual so you have proper torque specs and other assembly details. Skip the Chilton and Haynes manuals. They don't have the details you'll need.

Good luck.

[Barry94]

Question for Barry:

I have the overheating problem and have been suspecting a head gasket for some time. Tonight I am reading the site for the first time (on this problem) just to understand what my options are.

You mention your experience timeserting the engine in the car. Have you posted that anywhere? Otherwise would you please post it or send it to me?

Also, I suspect that my problem may be in the front head. Is it foolish to replace the gasket on that head and ignore the rear one (assuming that the pressure test confirms the problem only in the front)? Will the rear one likely fail soon anyway?

Thanks for any advice you can give.

Claude

Claude,

Here is a list of all the things (that I can remember) that may be helpful.

- Removing the rear exhaust pipe/crossover bolts can be a pain, have lots of

extensions.

- Subframe: Since there is little "working" room under the hood, access to

some bolts is very tight.

To facilitate this, remove the two top "dogbones", and the cooling fans.

The subframe is held to the car with approx. 10 bolts. (4 or 5 on each

side).

Almost totally remove the front pair of subframe bolts. Then loosen the next pair a bit less.

The next pair less again. Last pair is barely loose.

This will cause the subframe to "hang" down in the front. This will "shift"

the engine forward about 2".

Rear bolts on the engine are now much more accessible.

Do the reverse to gain better access to the exhaust/crossover bolts in the

rear.

The rear head can be removed without the removal of the exhaust manifold.

- I "locked" the flywheel in place with a steel bracket. Easier to remove

the balancer bolt.

Also, since the engine is locked, I marked all the timing chain/sprocket

locations with a dab of paint. When I reassembled it I just matched all

the paint marks. I didn't try to use the original timing marks. (Hard to see all the original marks on the sprockets with the engine in the car).

I used a 3/8" air ratchet (as a drill) to drill out the rear head holes as

I didn't have a 90 degree drill.

A second person is also handy to have when you torque the heads.

One doing the pulling, and one reading the torque angle gauge.

- Not much else worthy of mention. It just takes a while to do the job.

I'm sure I have forgotten some "shortcuts", however if you have questions,

let me know.

As for doing both heads (while you're in there) I think would depend on the reason the head failed. If it was from lack of coolant changes or from overheating, then likely the other head has a high chance of failure as well.

If the gasket failure is from a previous head removal and the bolts have pulled, then doing the other head may be optional.

I hope this helps.

Barry

[crich8136]

Barry:

Thanks for the helpful info. I tested my car today and found cylinder #2 totally blown. When I applied 120 psi the coolant gushed out of the holding tank. Didn't test any other cylinders on the front head.

The back head was tight on all cylinders.

I got the carfax report to see if it told me anything about prior repairs on this car -- it told me nothing.

Presently I am thinking to do the front head without pulling the engine and just waiting until the back one fails. I don't know whether the front head has ever been pulled. The engine has overheated ("Engine Hot -- Turn off engine!!") maybe 4-6 times in the 16 months I have owned this car. The first times caught me by surprise. Usually if it gets to 235-240 degrees I will turn it off before the warning.

I don't know if that helps to try to predict whether the other gasket might fail soon. I figure I am not out much if it does. I can still pull the engine later.

Any advice you have will be welcomed. Thanks for responding to my prior questions.

Claude

[Scotty]

Good Luck with this Claude

[Barry94]

Barry:

Thanks for the helpful info. I tested my car today and found cylinder #2 totally blown. When I applied 120 psi the coolant gushed out of the holding tank. Didn't test any other cylinders on the front head.

The back head was tight on all cylinders.

I got the carfax report to see if it told me anything about prior repairs on this car -- it told me nothing.

Presently I am thinking to do the front head without pulling the engine and just waiting until the back one fails. I don't know whether the front head has ever been pulled. The engine has overheated ("Engine Hot -- Turn off engine!!") maybe 4-6 times in the 16 months I have owned this car. The first times caught me by surprise. Usually if it gets to 235-240 degrees I will turn it off before the warning.

I don't know if that helps to try to predict whether the other gasket might fail soon. I figure I am not out much if it does. I can still pull the engine later.

Any advice you have will be welcomed. Thanks for responding to my prior questions.

Claude

Claude,

Sounds like you found your problem head.

The front head is much easier to do while in the car.

As far as the rear head is concerned, if you are absolutely sure there is no leak into the coolant, then likely doing the front head only could solve all your problems.

When I pressure tested mine, I only had a small leak on the rear head.

Just the sound of bubbles in the tank, nothing visible.

Good luck with the repair.

Barry

[OynxSTS]

Question for Barry:

I have the overheating problem and have been suspecting a head gasket for some time.  Tonight I am reading the site for the first time (on this problem) just to understand what my options are.

You mention your experience timeserting the engine in the car.  Have you posted that anywhere?  Otherwise would you please post it or send it to me? 

Also, I suspect that my problem may be in the front head.  Is it foolish to replace the gasket on that head and ignore the rear one (assuming that the pressure test confirms the problem only in the front)?  Will the rear one likely fail soon anyway?

Thanks for any advice you can give.

Claude

Claude,

Here is a list of all the things (that I can remember) that may be helpful.

- Removing the rear exhaust pipe/crossover bolts can be a pain, have lots of

extensions.

- Subframe: Since there is little "working" room under the hood, access to

some bolts is very tight.

To facilitate this, remove the two top "dogbones", and the cooling fans.

The subframe is held to the car with approx. 10 bolts. (4 or 5 on each

side).

Almost totally remove the front pair of subframe bolts. Then loosen the next pair a bit less.

The next pair less again. Last pair is barely loose.

This will cause the subframe to "hang" down in the front. This will "shift"

the engine forward about 2".

Rear bolts on the engine are now much more accessible.

Do the reverse to gain better access to the exhaust/crossover bolts in the

rear.

The rear head can be removed without the removal of the exhaust manifold.

- I "locked" the flywheel in place with a steel bracket. Easier to remove

the balancer bolt.

Also, since the engine is locked, I marked all the timing chain/sprocket

locations with a dab of paint. When I reassembled it I just matched all

the paint marks. I didn't try to use the original timing marks. (Hard to see all the original marks on the sprockets with the engine in the car).

I used a 3/8" air ratchet (as a drill) to drill out the rear head holes as

I didn't have a 90 degree drill.

A second person is also handy to have when you torque the heads.

One doing the pulling, and one reading the torque angle gauge.

- Not much else worthy of mention. It just takes a while to do the job.

I'm sure I have forgotten some "shortcuts", however if you have questions,

let me know.

As for doing both heads (while you're in there) I think would depend on the reason the head failed. If it was from lack of coolant changes or from overheating, then likely the other head has a high chance of failure as well.

If the gasket failure is from a previous head removal and the bolts have pulled, then doing the other head may be optional.

I hope this helps.

Barry

Very Cool Technique Barry…

If I ever have the misfortune to “blow a gasket” I’m going to give this a try!