Intake Manifold Gasket May Leak Coolant or Engine Oil on Chevrolet Lumina

Problem Description and Possible Solution

The intake manifold gasket may develop and external engine oil or coolant leak. In some cases, an internal coolant leak may occur causing coolant to mix with the engine oil. Our technicians tell us that operating the engine  with a coolant/oil mix can result in internal engine damage. Replacing the intake manifold gasket should correct these leaks.

Problem Data
RepairPal Verified
Average mileage: 137,033 (12,600–230,000)
Engines affected: 3.1L V6, 3.4L V6, 3.8L V6
9 model years affected: 1993, 1994, 1995, 1996, more1997, 1998, 1999, 2000, 2001
60 people reported this problem
Viewing 1 - 20 of 25 comments
Car is leaking coolant and is now leaking oil but not mixing. Car has not been running hot. Haven't smelled that coolant smell. Could it still be the intake gaskets?
I have been smelling a rather "hot" coolant and oil like smell for a short time and temp gauge would rise time to time in standstill traffic. I always kept my fluids level, and could not determine what it was at just the fluid checking step. I recently had trouble starting the car. I thought it was the battery, but was starter. Starter failed because of oil/coolant leak onto parts below; the buildup caused starter to malfunction. Coolant in reservoir very murky and oily.
Coolant is leaking, so I replace the water pump,it needed it anyway, to see if that was the problem. It still continues to leak underneath the serp. belt pulley. So I think it might be the intake manifold gasket. That sucks.
my oil is mixing with the antifrezze.
I checked my oil and it was a weird color and was rather high on the dipstick, i noticed a faint smell of gas.My daughters boyfriend says i have gas in my oil. I just got my oil changed about 2 months ago and do not drive alot of miles.
Engine oil getting into coolant. Mechanic diagnosed as intake gasket. Recommends replacing upper & lower gaskets.
Coolant leak due to deteriorating seals. Repair is $1050.00
common gripe.you can reseal the intake but the repair wont last more than 5000 miles.poor design by gm.
Internal coolant leak and external oil leak. Changing gaskets fixed it.
Lower intake gasket failure.
Water in oil mixture
Coolant leak from the intake manifold gasket.
Oil is leaking into coolant. I noticed coolant was milky, diagnosed as intake gasket leak :(
I drove 15 miles to a relatives house and my sister said my car had a puddle of something under it. It never ran out or nothing...
Oil mixing with coolant. No smoke
I was driving Sunday morning and I noticed the temp gauge going up. Pull to the gas station no problems. Leaving the gas station I started seeing smoke so i pulled over couldn't see where the problem was went back to the gas station put coolant in took off everything seemed ok . half way home started seeing smoke temp went up been parked every since.
There is gas in my oil
Haven't fixed it yet, did a block test, no combustion gases in the radiator. No external exhaust steam, and the only symptoms are coolant in the crankcase and loss of coolant. Changing the intake manifold gasket and oil and oil filter and re-check!
Engine oil was appearing in antifreeze. Mechanic said that intake manifold gasket needed replaced. $900.
The head gasket is allowing coolant and engine oil to mix.