It depends. You can either have coolant in the oil, or oil in the coolant. Look for overheating of the engine, check the coolant fill level, and check your oil. That the only way you will know.

 

look on the side of the inake where the powersteering pump is and the otherside where the throttle body is. if it is damp with oil or gooey with coolant then it needs to be changed befoe the gasket blows. there is a metal gasket made by felpro i dont remember the pn but the revised torque is 18 ft lbs on the diadonal bolts under the power steering and throttle body if yours isnt leaking then you can try to retourqe these bolts and hope for the best that it wont leak.

i just did my friends 3 weeks ago and found the outer bolts were already loose and he has 62,000 original miles on his 02 ls 3400. the gaskets were weaping so we changed them before they blew. they were cracked already. damn plastic!!! also get a set of lower injector o-rings from gm as i tore 1 o-ring and no parts store has them. so we makeshift a o-ring for now and it held, so in the spring i will change it to a new o-ring.

ive done about 100 intake gaskets on these w body cars over the past 5 years even though gm will say "is there flat tappet or roller lifters" they are all roller lifters.

 

ya i thought all of them engines had that problem at like 65,000 or so mine and both of my brothers did... hoping the 3800 has less issues with it

 

in the shop where i work we got a 03 grand prix 3100 with 75,000 on it and the gaskets are gone, customer complaint is burning oil and loosing coolant. both lights are on, low coolant and low oil. oil dipstick had nothin on it and only 1.5 qts came out of oil pan but not milky but rad is chunky. another one bites the dust....

 

black04monteSS

well sort of the same as the black upper intake where the throttlebody is. after the tb there is a egr passage, when the pipe that goes into the plastic upper manifold gets hot it expands and when it cools it contracts, as it does this alot the upper manifold cracks and coolant gets into the motor but filles the lower manifold first. $200 for the upper manifold and $50 for the lower gaskets. common with these engines. another leak is the throttle body gasket $20, the lower part gets eaten by the coolant and will make a leak. my dads 94 buick lesabre 3800 had this leak and there is a thicker gasket gm makes so this doesent happen its a grey color gasket as the factory one is orange and thin.

 

tons of discussion about this all over the internet. i have a 1998 Lumina (base) with 3.1 litre. noticed a little oil on driveway floor. looking under thorttlebody i could see oil running down. felpro(metal) gasket set is the way to go. be sure you have a good experienced mechanic dothe job. important note == the little spot(plug) where the disturbitor used to be has a weak "o-ring". be sure to change it at this time when you do the intake manifold gasket. my mechanic did it with some aftermarket "o-ring" and developed a leak and had a heck off a time curing that problem. be sure to flush your cooling system and also change the oil .

 

I have seen and worked on many 3.1 and 3.4 engines, they all pretty much have the same intake gaskets problems, a friend of mine has 3 montes a 95, 96 and a 03 ss they all have roughly the same milage give or take a k or two, the only one that didnt need to have gaskets replaced was the 3.8 in the ss and in sayin that I know a few people that have had 0 problems with there 3.1 or 3.4 and they have well over 150k on them, its a crap shoot guys.

 

My '97 LS had to have the intake manifold gasket replaced. The car had about 180,000 miles on it at the time, though.

 

Just replaced mine in my 2000 monte carlo with 86,000 on it ,it's been leaking about 20,000 though,

 

I just did my upper/lower intake gaskets on my 3800 last week. A friend of mine is a good mechanic so he helped me out. The sign that I saw other than the seeping of fluid through the gasket is severe condesation and a white/yellow substance on the bottom of the oil cap. Fortunately we caught the leak early and there wasn't any damage to bearings. GM had a TSB on '99 Montes with 3.8 Liters for intake gaskets, so my car already had Felpros in it, but whoever did the first job sucked it up and they weren't seated right. They are now though!