Question: 87 Running out - Oil turning milky / oil in coolant

[87C4Wagner]

87 Running hot - Oil turning milky / oil in coolant

Alright, got a 87 with the 350 TPI - has 149,xxx miles ... Got this knowing it has the water in the oil .. Recommended first take on what I should do? Pretty sure its the head gasket, just looking for any advice if anyone has done this already on this model? Thanks a lot

 

[ecss]

Alright, got a 87 with the 350 TPI - has 149,xxx miles ... Got this knowing it has the water in the oil .. Recommended first take on what I should do? Pretty sure its the head gasket, just looking for any advice if anyone has done this already on this model? Thanks a lot

Go to an Autozone and borrow their radiator pressure test kit. You remove the radiator cap install the proper cap and use the hand pump to apply around 18 psi or less of pressure. The pressure should hold.

If you are leaking or burning coolant the low coolant indicator light on the Driver Information Center should come on indicating low coolant in the radiator. You also may see white smoke out of the exhaust.

Pull each spark plug and they should be a tan color. Any plug that shows a dark wet look indicates it could be the cylinder with the head gasket leak. Usually cylinders 7 and 8 are the most likely to have a head gasket leak.

Could also be a leak between the intake manifold and head dumping antifreeze into the engine valley and draining into the oil pan. That may show up when you pressurize the system.

 

[87C4Wagner]

Go to an Autozone and borrow their radiator pressure test kit. You remove the radiator cap install the proper cap and use the hand pump to apply around 18 psi or less of pressure. The pressure should hold.

If you are leaking or burning coolant the low coolant indicator light on the Driver Information Center should come on indicating low coolant in the radiator. You also may see white smoke out of the exhaust.

Pull each spark plug and they should be a tan color. Any plug that shows a dark wet look indicates it could be the cylinder with the head gasket leak. Usually cylinders 7 and 8 are the most likely to have a head gasket leak.

Could also be a leak between the intake manifold and head dumping antifreeze into the engine valley and draining into the oil pan. That may show up when you pressurize the system.

Okay definitely sounds like a good start ... Thank you ... ill keep the updates , hopefully its nothing too expensive.

I found the original owner on Facebook and I guess it has been like this for awhile .. meaning years

 

[Wegone]

You may also want to run a compression check.

 

[DonB]

Does it run HOT in slow traffic or idling in Park? If so,... I'm pretty sure you have a blown head gasket if NOT a cracked head too. it is a common issue with those engines because they run hot from the factory. As mentioned a compression test or a cooling system pressure test would be in order. But,....If you have oil in the water and worst yet, water in the oil you have major issues. More than likely it is time for an engine overhaul and then install the new temperature sensor kit discussed here on the forum from Corvette Central with a 160* thermostat. The sensor kit turns the fans on at about 185* instead of the factory setting of about 230*. Way too hot in my opinion. I did and mine runs cool even in Chicago's hot and humid summer days with my A/C cranking. Good Luck

 

[chevyaddict]

I started a thread today with the same issue. Here is my question about the compression check - How can a compression check differentiate between a blown gasket and a head/block crack? I just replaced my head and intake gaskets 30,000 miles ago so likely this is not my problem... I did overheat it about a year ago. Could a crack take this long to leak into the block? I'm just trying to find out the easiest way to differentiate a crack versus gasket without having to pull the engine completely apart again, replace the gaskets, and then find out it was a crack all along....