Intake gasket failure, 'W' 4.3L V6 engine

[JHZR2]

Hi,

 

Oil analysis is showing Na, K and positive glycol. My 98 ZR2 has 40K and has been driven pretty lightly. I doubt a headgasket is the problem, but definitely feel that the intake gasket could certainly be the culprit, since they are typically weak on these cars.

 

Can anyone give me some insight as to how to tell if mine is bad. Also, is it usually the upper or lower that has the problems? Should I replace both, or is it better to leave as much original as possible?

 

How much am I going ot end up shelling out for this?

 

Thanks,

 

JMH

[blue2kzr2]

On my 94, haven't done anything but whatever has to get done to fix the no-start (possible dead battery) on the 2000, the upper gasket had to get replaced in order to do the lowers. The upper plenum had to come off to get to some of the lower manifold bolts. Dunno how the newer ones are set up, but it may be the same thing.

[chevroletmb]

the 94's had the old style gaskets and yes the upper intake had to come off to get at the bolts for the lower. but 98 and newer don't require the upper intake to come off at all. as for how to tell if they're leaking? visual inspection or coolant pressure test.

[JHZR2]

well, I had it into the dealer, and they said that they tested it and had no indication of any leaks... they put a fluroescent dye into the coolant, so ill come back in 1k miles and see... Plus ill do oil analyses to check it out as well.

 

Seems so odd that I would have the coolant in the oil though, if this isnt bad. They did do a CO2 test to check that it wasnt the headgasket, as well.

 

Could pressure flushing cause the coolant to leak into the oil from a spot that othewise doesnt leak? I know the readings were high after getting the coolant flushed, thermostat replaced, and oil cooler lines replaced. Maybe it was sloppy work or too much pressure causing seepage?

 

JMH