[Tin Injun Tom]

A friend recently aquired an '01 Alero with a suspected blown head gasket. There was quite alot of milky slime on the dipstick, and inside the tappet covers. In spite of that, the towing outfit that sold the car to my friend reported that the previous owner didn't drive the car long before they 'discovered' the problem. I have to question that it would have to be driven a period of time for the coolant would mix with the oil to the point of omnipresent slime. I'm not sure if it was found via low coolant at this stage, either.
Regardless of those circumstances, this car is pretty nice, and well optioned, and my friend speculated that it would be worth repairing the engine and flipping.

This afternoon I helped him start the teardown. As we worked on getting the upper intake off, we noticed there was a puddle of antifreeze on top of the transmission. Then when he put a socket on the lower intake bolt/drivers side rear, the bolt was only 'finger tight'. I had been starting to wonder if it was possible for the intake gasket to leak in a spot where it could allow copious amounts of antifreeze into the oil.
I've read here or somewhere that GM 3100 and 3400 have developed intake gasket leaks with age. Am I remembering correctly??? This has 107K miles BTW.

I decided we should do a compression test on all cylinders before we crack the head bolts loose. I pulled all the spark plugs and none seem to be 'washed' clean, or excessively wet. That was about quitting time for both of us. We are going to check the compression first thing tommoro.
My friend says the car runs smooth without missing. He drove it (gently) the 2 miles from where he bought it to his shop. I have not yet heard it run. Also as I think about it, I didn't ever look in the tail pipe to see if there was telltale moisture.
I wanted to ask the techs here if there is any type of head gasket failure that would NOT show up in the compression. Any way a cracked head would alow coolant into the oil? I think this is an iron block, so is it safe to assume the water jackets don't crack like they do in a sleeved aluminum block? The latter was the case on a 2.3 Ecotech motor we tore down a year ago. I want to cover all the bases before I suggest to my friend that we can abort the head gasket replacement.
My main question(s) would be, are intake gaskets known to be a common failure, and do they allow coolant into the oil? Will a compression test diffinitavely rule out a bad head gasket?

Thanks for all input!!!
It would certainly be a relief if 'we' can get this ship shape with just the intake gaskets.
Even though I do not intend to shoulder any burden on this project.

[KO]

Intake gaskets are very common. I just did a 3400 Olds minivan but I also did the head gaskets just to be safe and there was evidence of gasket erosion around the water ports. The intake gasket is hard plastic with silicone or rubber rings around all the intake and water ports, the rings deteriorate with time. The fact that it has over 100K I would do head gaskets because you are more than halfway there (you have to remove the pushrods to replace the intake gaskets becaue the intake gasket doubles as the pushrod guide plate) and do not mix up the pushrods, they are diferent from intake to exhaust. Good luck and have fun.

[mike nixon]

unless it as overheated do the intake and drive it.

[BDHABT]

Do the intake AND headgaskets.Many of our cheap customers wanted us just to do the intake;we do only what they ask,then the car comes back overheating.Guess what,headgaskets are bad;and of course,it`s our fault that we didnt do the headgaskets the first time.The 3100 and 3400 heads like to crack too,so have`em checked if you pull them off.
Also,if there`s alot of coolant in the oil,it will wash the rod bearings.

Mark.

[engineer]

class action suit was settled on these engines with intake manifold gasket issues.

[mike nixon]

@ 107k and a second owner The suit settlement won't help him.

[Region Warrior]

Unless it over heated, proply just the intake.
Most head gasket leaks are at the rear head, and external, not internal.
And like you said, the plug would be clean.
Be sure to replace and correctly torque all the intake bolts.

[judgethis]

There was a bulletin for these engines for the intake gaskets. GM redesigned the gaskets. They have a kit now which includes the gaskets and bolts. The part number for the kit is 19169127. Also get the O-ring for the distributor plug. Its a plug where the disributor would go. They get hard and leak and as long as you have it apart it will be easy to replace.

[Tin Injun Tom]

Cylinder #6 had 135 psi while all the others had 175 or 170. I thought it was a bad exhaust valve, because I could hear a croaking sound on each stroke, out the open exhaust log. When I put my hand over the exhaust dump, I felt considerable suction which coinsided with the croaking noise. Only heard it when the comp tester was threaded into that cyl. We don't have the right tool to do a leak down test.
Just went ahead and pulled the head. The gasket was breached from the cyl to a tiny water port. Very small, but it was there. The back head had a simmilar breach in #1 cyl. which was even harder to spot.
I believe all the coolant was getting mixied with the oil from the intake gasket though. My theory is it got hot when the coolant level was depleted and that caused the head gaskets to fail.

Thanks everyone for the opinions. Lots of valuable input makes it easier to decide what to do.

[Blown 69]

Was the oil milky too or was there just a milky residue on the inside of the valve covers? If the oil looked like milky snot I would suspect washed out bearings. I have seen a dozen or so of these engines have the cam seize in a cam bearing and result in a broken cam and usually alot more damage. The cam siezing happens after the head gasket or intake gasket repair. I would start and warm it up and the change the oil and filter again before driving it!

[Dens71TA]

I did a similar job on an '01 Grand Am. GM has an upper gasket kit just for this job. It includes updated head gaskets, valve guide seals, and intake gaskets. The '01 head gaskets are a very poor design and rot out even with more than required coolant changes. The updated gaskets are a completely different material and are graghite coated.

The updated valve guide seals have extra material on the bottom so it touches the top of the valve guide so oil can't be sucked under the spring seat/valve guide seal. I know on the engine I did just about every spring seat had a puddle of oil under it and the engine went from burning a quart of oil every 3000 to hardly anything with the new design seals.

Now would also be a good time to replace the O-ring on the oil pump drive distributor plug as those like to leak. There is actually a secondary seal available now that goes between the block and the top of the plug.

[daduck]

The filing deadline for Dex Cool Litigation is October 27, 2008 for Missouri residents. It covers GM vehicles from 1995-2004 w/ 3.1, 3.4, 3.8, and 4.3 liter V-6. I just sent my paperwork in yesterday.
www.DexCoolSettlement.com/Missouri