Intake manifold vs. head gasket

[someguy]

Hi,
Great site!

I have a 2000 Century (3.1) that just started leaking oil into the coolant. I want to confirm that this is due to the LIM gasket and have a few questions. The oil is clean and the coolant level is roughly right (but contaminated).

- If I run a block test, the results will show combustion gasses in the coolant due to the oil, which won't tell me anything - right?

- Will a coolant system pressure test tell me anything? I can't see any external leaks.

- I'll run a a compression test later, but what else should I be doing?

I (obviously) would rather not pull the heads is I can avoid...

Thanks for the help!

Josh

[pocket-rocket]

Hi,
Great site!

I have a 2000 Century (3.1) that just started leaking oil into the coolant. I want to confirm that this is due to the LIM gasket and have a few questions. The oil is clean and the coolant level is roughly right (but contaminated).

- If I run a block test, the results will show combustion gasses in the coolant due to the oil, which won't tell me anything - right?

- Will a coolant system pressure test tell me anything? I can't see any external leaks.

- I'll run a a compression test later, but what else should I be doing?

I (obviously) would rather not pull the heads is I can avoid...

Thanks for the help!

Josh

Combustion gasses in the coolant would probably be a head gasket, or like you said, from oil. Normally the 3x00 LIM gasket failures only goes coolant > oil, not oil > coolant. A coolant system pressure test would show you a LIM gasket leak though. Put your ear to the oil fill cap hole and listen for a hissing inside the valve cover (very close to the LIM gasket failure area).

[ForcedFirebird]

Take the radiator cap off, unplug the coil packs and turn the engine over. If there is coolant spewing out like mad, it's a head gasket. Take out the spark plugs one at a time and crank the engine to see what cyl blew. The one that blew out from the chamber into the coolant passage will NOT spew coolant when the engine is cranked.

I just diagnosed this a few days ago on a car, compression even will hold with a compression tester if the radiator cap is on...

[geoffinbc]

Cannot get oil in the coolant from a bad LIM gasket.

[Khipset]

Any reason to suspect a cracked radiator?

A while after getting into a fight with a curb and a while of diagnosing I came to conclusion I had cracked my radiator, the transmission cooler to be specific. Temp would stay fine, however the tranny would get real warm, and shift late with a lot of slip.

Saw a nasty substance floating in the coolant reservoir and on the top of the coolant cap. Hard to tell if it was Tranny fluid as the coolant was orange and the tranny fluid is red....

New radiator later, problem solved.

[someguy]

Thanks for the help!

I'll try the suggestions one night this week.
Thanks again...

[3400-95-Modified]

Just remove the trans cooler and put it in an aux one for a test, leave the ports open on the radiator and see if coolant leaks out of those ports. That will tell you if the radiator is bad. But yes this is the only way that I know of for oil to get into the coolant... Any other way the coolant is on the pressure side of things so it will be pushed into the motor, not the other way.

[primesuspect]

while your at it flush the death cool out and go green

[90tgpalex]

Head gasket or LIM

as for the diagnosis of a blown head gasket. Well today i pulled off my radiator cap and my coolant is nasty brown and contaminated with oil. I then did the test that ForcedFirebird suggested, where you unplug the coil packs and crank the motor with the radiator cap off but there was no coolant spewing at all. Would you think that it is just a LIM then?

BTW the car is a 2000 gtp with the 3800 in it.

Any advice would be greatly appreciated, Thanks a lot

Alex

[3400-95-Modified]

BTW the car is a 2000 gtp with the 3800 in it.

3800 is a 90* And they do not share the same LIMG failure as the 60*'s

[ProX]

as for the diagnosis of a blown head gasket. Well today i pulled off my radiator cap and my coolant is nasty brown and contaminated with oil. I then did the test that ForcedFirebird suggested, where you unplug the coil packs and crank the motor with the radiator cap off but there was no coolant spewing at all. Would you think that it is just a LIM then?

BTW the car is a 2000 gtp with the 3800 in it.

Any advice would be greatly appreciated, Thanks a lot

Alex

Nasty brown coolant doesn't automatically mean oil. It could be sludged up Dex Cool. I've seen them where you'd swear it was oil, but it wasn't.

[MidnightriderZ24]

3800 is a 90* And they do not share the same LIMG failure as the 60*'s

huh? 3800's are JUST as bad as 3x00's... i would do it anyways..

[90tgpalex]

My buddy who is a mastertech said he is almost sure it is the dexcool as well after looking at it