Mechanics

LEAKING HEAD GASKET

2003 Buick Century

Engine Mechanical problem
2003 Buick Century Front Wheel Drive Automatic 174500 miles

The head gasket is leaking quite badly, I need to know how to fix it. Can you help with this in providing the neccessary schematics to do this job? Or suggest what to do.
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CASS2277
December 1, 2008.



98% its the intake manifold gasket leaking and not the headgasket
you should have it rechecked

BMRFIXIT
Dec 1, 2008.
Cylinder Head Replacement - Left
Tools Required
J 36660-A Torque Angle Meter. See Special Tools and Equipment.
Removal Procedure
Raise and support the vehicle.
Drain the cooling system.
Drain the engine oil. Lower the vehicle.
Remove the lower intake manifold.

mark each rocker arm and push rod .. to replace in the same exact place

Remove the valve rocker arms and the pushrods.
Remove the exhaust crossover pipe.
Remove the right engine mount strut bracket. Remove the oil level indicator tube.
Remove the left spark plug wires from the spark plugs.
Remove the left spark plugs.
Remove the left exhaust manifold.
Remove the left cylinder head bolts
Remove the left cylinder head.
Remove the left cylinder head gasket.
Clean and inspect the left cylinder head and the gasket mating surfaces.

Installation Procedure
Install a new left cylinder head gasket.
Install the left cylinder head over the locator pins and the gasket.

Install the new cylinder head bolts.
Tighten
3.1. Tighten the bolts in sequence to 60 N.m (44 lb ft).
3.2. Use the J 36660-A to rotate the cylinder head bolts in sequence an additional 95 degrees.
Fig. 192: Tightening Sequence Of Left Cylinder Head Bolts

Installation Procedure
Install a new left cylinder head gasket.

Fig. 190: Installing Left Cylinder Head Gasket
Courtesy of GENERAL MOTORS CORP.


http://www.2carpros.com/forum/automotive_pictures/266999_gasket_1.jpg



http://www.2carpros.com/forum/automotive_pictures/266999_bolts_1.jpg



Install the left cylinder head over the locator pins and the gasket.
Fig. 191: Installing Left Cylinder Head Over Locator Pins And Gasket
Courtesy of GENERAL MOTORS CORP.
NOTE:Refer to FASTENER NOTICE in Cautions and Notices.

Install the new cylinder head bolts.
Tighten
3.1. Tighten the bolts in sequence to 60 N.m (44 lb ft).
3.2. Use the J 36660-A to rotate the cylinder head bolts in sequence an additional 95 degrees.
Install the left exhaust manifold.
Install the left spark plugs.
Install the left spark plug wires to the spark plugs. Install the oil level indicator tube. .
Install the right engine mount strut bracket.
Install the exhaust crossover pipe.
Install the valve rocker arms and pushrods.
Install the lower intake manifold.
Fill the crankcase with engine oil.
Fill the cooling system.
Inspect for leaks.

Dave H
Dec 1, 2008.
Your reply is appreciated. But does the condition you mention leak the engine coolant? I never heard of that condition doing that.
Please reply.

Regards,
Mark

Tiny
CASS2277
Dec 2, 2008.
The manifold gasket will not cause it to loose water. But it will cause compression leakage which is what BMR was advising you to check? If your leaking water it is the head gasket.

Dave H
Dec 4, 2008.
I do respect every ones opinion
but if you are not sure, do not assume that I don’t know what IM talking about !

We do about 4 a week
check at top of tranny rear of engine for coolant leaking from the intake manifold gasket
check under the thermostat housing top of tranny by the intake manifold
very common
and if you decided to do the heads gasket you need to remove the intake out 1st just check the gasket corners at the coolant jackets
gasket will brake and separate, rubber from plastic
check it out

BMRFIXIT
Dec 4, 2008.
Respect to BMR on his knowledge of this fault. I have never come across it before?

Engine Oil or Coolant Leak (Install New Lower Intake Manifold Gasket)
TECHNICAL SERVICE BULLETIN
Reference Number(s): 03-06-01-010C, Date of Issue: April 08, 2008
Affected Model(s): 2000-2003 Buick Century; 2002-2003 Buick Rendezvous; 1996 Chevrolet Lumina APV; 1997-2003 Chevrolet Venture; 1999-2001 Chevrolet Lumina; 1999-2003 Chevrolet Malibu, Monte Carlo; 2000-2003 Chevrolet Impala; 1996-2003 Oldsmobile Silhouette; 1999 Oldsmobile Cutlass; 1999-2003 Oldsmobile Alero; 1996-1999 Pontiac Trans Sport; 1999-2003 Pontiac Grand Am, Montana; 2000-2003 Pontiac Grand Prix; 2001-2003 Pontiac Aztek; with 3.1L or 3.4L V-6 Engine (VINs J, E - RPOs LG8, LA1)
Supercedes: This bulletin is being revised to update the Parts Information and add an Important statement. Please discard Corporate Bulletin Number 03-06-01-010B (Section 06 - Engine).

Related Ref Number(s): 03-06-01-010, 03-06-01-010A, 03-06-01-010B, 03-06-01-010C
ARTICLE BEGINNING
Condition
Some owners may comment on an apparent oil or coolant leak. Additionally, the comments may range from spots on the driveway to having to add fluids.
Cause
Lower Intake manifold may be leaking allowing coolant, oil or both to leak from the engine.
Correction
Install a new design lower intake manifold gasket. The material used in the gasket has been changed in order to improve the sealing qualities of the gasket. When replacing the gasket, the lower intake manifold bolts must also be replaced and torqued in sequence to a specification.

Dave H
Dec 4, 2008.
BMR yes you are right about the coolant leakage as I am repairing my 1999 buick century custom atm. I have the manifold off. But where I live they dont have reliable mechanics with honest based knowlege and experience. I havent put the manifold back on as I have a problem with this design of the gasket. The rubber around the ports on the gasket itself being very thin and the gasket being plastic. The kit calls for ONLY placing silicone on the block front and back ends and where the pins/pegs on the gaskey go. I have a real problem with this it doesnt seem feasible that it will hold to me and some one here told me that their shop makes their own rubber gaskets for the front and back ends. But I need to know if your sahop does this. Because up til now all the engines I have rebuilt I always use RTV around the entire ends and around the block then on top of the gasket. I have never had an engine leak before, but this is a gasket I have never dealt with befor. Can you please advise if this man told me incorrectly as Im not sure about placing rubber there. Thank you for your help. Angelicabear

Tiny
Angelicabear
Dec 31, 2010.
Dave H

You are wrong in this case.I though this also, that was until two weeks ago when my sons Olds Cutlass started to leak water from under the plenum above the intake no water in the oil or vise versa. A cousin of mine who owns a garage quickly said the intake casket was the problem. So went to Auto Zone got the gasket kit and withing three hours had it changed. Fixed the problem

Thought ya might want to know this

Sam

> > > railroadsam@pennswoods. Net

Tiny
Samd74
Dec 15, 2012.