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: 144,443 (46,000–250,000)
Engines affected: 5.7L V8, 7.4L V8, Gasoline
11 model years affected:
1990,
1991,
1992,
1993,
more1994, 1995, 1996, 1997, 1998, 1999, 200026 people reported this problem
Purchased a brand new crate engine replacement for my 1999 chevy 3500 silverado. Been chasing an engine miss for over a year now. could not believe that the gaskets were leaking until coolant was noted as being low during a fluids check after an oil change.
I took it to the dealer as the engine is still under warranty. they will only replace the gasket. i guess I have to live with the engine when she blows as the ccoolant has probably been leaking into the engine since the miss started.
I wish I could buy a Toyota 1 ton truck in this country. I have had enough of this chevy crap. Why they got a bail out is beyond me! no pride in their products or what!
Yeap, went out to check my oil level and saw that it was way overfilled and discovered I had a bad lower intake manifold gasket leak. Spent most all the weekend replacing the lower intake manifold gaskets and that fixed the problem for me. That was completed back in November 2012 and today as I am writing this passage is 25 February 2013. So all is good and my oil level after the gasket change is staying the same level.
Chevy wonders why the import market got so strong, it's simple, people don't like to spend hard earned money on junk!
Fleet mechanic and have two trucks with this aparent problem, mostly seems this or head gasket cuz the oil get milky choco latte' . Radiators also leak which may have caused the gasket failure... still under investigation.