Express 1500

Intake Manifold Gasket May Leak Coolant or Engine Oil on Chevrolet Express 1500

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. Running the engine with a coolant/oil mix may result in engine damage. Replacing the intake manifold gasket should correct this issue.

Problem Data
RepairPal Verified
Average mileage: 110,150 (50,000–200,000)
Engines affected: 5.0L V8, 5.7L V8, Gasoline
7 model years affected: 1996, 1997, 1998, 1999, more2000, 2001, 2002
39 people reported this problem
Viewing 1 - 17 of 17 comments
Upper intake manifold gasket leaks. I had a cracked radiator which I replaced but the leak moved to the back of the engine block. Found out that the gaskets are made of plastic and possible corrode due to the antifreeze chemicals. It is a huge job to replace. My mechanic suggested trying the radiator sealing tabs first to see if it would fix the problem. It did. I talked to another buddy of mine who is a service technician and he believed that even brand new, they put those tabs in... faulty design!!!
Noticed a smell of Antifreeze and thought the lower radiator hose was bad. Took it into the repair shop and after some searching they found the Gasket to the INtake Manifold was leaking. With this many reports, there should be a recall.
Had a substantial antifreeze leak (about a quart on the floor) attributed to a ruptured intake manifold gasket. Mechanic said that these failures were not uncommon but that they usually occurred around 100K miles. Installed a steel gasket with an insert. No further problems since 2005.
During the summer of 2015, I had a coolant leak from intake manifold gasket onto the back of the engine block. I temporarily fixed it with radiator stop leak. That repair was good for 7000 miles. Afterwards, the intake gasket failed and dumped the coolant into the oil. At this point the engine had 173,000 miles. The engine died within 8 miles of my residence, so I had it towed home. I have done some research on repair. The consensus is to use a FelPro Intake Manifold Gasket. I now have the gasket, but have not started the tear down for replacement. 02/25/2016
intake manifold gasket failed, coolant got into combustion chamber fouling plugs and valves, had to get a valve jog done. HOWEVER, to get a valve job done, I had to have the engine pulled, heads sent out, and the whole thing put back together...cost was over $3,000 because a $10 manifold gasket failed...BTW, GM had notoriously bad intake manifold gaskets for years
Intake gasket failure leaked coolant into oil & burned up bearings. Replaced with salvage yard engine which ALSO failed gaskets and burned up bearings. ENGINE NUMBER THREE has new intake gasket and new crankshaft & bearings!

What genetically defective idiot at GM decided that plastic intakes could radiate heat properly away from the gasket surface?! The intake gaskets simply burn up after ~~100k miles.

Next van = Sprinter!
Leaking very slowly, thought it was a leaking water pump but turned out to be intake manifold gasket, was quoted around $1000 to repair with 7 hr labor. Not sure if I am going to do it yet.
Loosing antifreeze, engine overheating. Poured gasket sealant in radiator to solve the problem. I don't think in really worked well
Oil pressure dropped and discovered coolant was in oil. Not sure if damage was caused to the engine, so repairs have not been done.
Gasket leak had come back after replacing the spider assembly. Threw in the coolant tabs again and everything seemed fine but then went for a long road trip (+1000 miles) and, fortunately, when I got home it came back with a vengeance! It is a heck of a job... should have done it when I did the spider assembly.
Blown intake gasket, fixed it myself, now it has two error codes and will not pass emissions, one is a random multiple misfire, the other is a cam code