WTF! 2.8 liter GP running hot oil and coolant light

[gtp_05]

Well my girlfriends car decided it wants to run hot. not sure why. thought it might be a head gasket. the oil and coolant lights are coming on so classic head gasket problem right? no oil in coolant and no coolant in oil. what the hell..... its an 1988 Grand prix 2.8L 100,000 miles anybody know whats going on? any help would be greatly appriciated. I dont want to tear the heads apart if i dont need to. Thanks!
Cold garage no heat= crabby ass boyfriend.

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[EmersonHart13]

Have you checked the thermostat? Fans? Although it is cold cars can still overheat from the common things.

 

[gtp_05]

yeah i actually bought a new thermostat and there was no change. took the thermostat out and the car stayed cool. im thinking it is a head gasket. i also noticed when it gets hot the heat stops working and it started blowing cold.

 

[gtp_05]

seems like the fan is working okay too

 

[Bob Kazamakis]

Don't the 60* engines suffer from head gasket problems?

That's my bet.

 

[gtp_05]

yea probably. still in denial though.

 

[Bob Kazamakis]

My parents 3400 Montana had a head gasket and intake manifold gasket failure with about 100k on it.

 

[EmersonHart13]

It probably is the gasket, just hoping for something simple for you!

 

[Oreif]

yeah i actually bought a new thermostat and there was no change. took the thermostat out and the car stayed cool. im thinking it is a head gasket. i also noticed when it gets hot the heat stops working and it started blowing cold.

This particular problem is common with GM 60* V-6 engines (2.8L, 3.1L, or 3.4L) when someone previously replaced the waterpump and used one that had a plastic impeller. What happens is the impeller is slippling on the shaft under pressure. As the cooling system warms up it build pressure and the impeller starts slipping. This reduces coolant flow resulting in running hot. No flow = no heat at the heater core. When the engine runs hotter the oil thins and the oil light will kick on if it drops below 10psi. A 100k 2.8L running hot will drop as low as 9psi thus setting off the light.

My advice is to change the waterpump (make sure the replacement has a metal impeller), flush/fill the cooling system, and do an oil change.

All will be fine then.

 

[EmersonHart13]

What a weird problem. . .

 

[gtp_05]

well thank you very much. i will try that and if that isnt the problem i'll know its the intake gasket or head gasket

 

[Bob Kazamakis]

I guess it makes sense if you don't have coolant in your oil.