Hello,
I have an 1988 4-Runner that is leaking (gushing) oil externally. The oil is also visable in the radiator so it is mixing with the coolant as well. The puzzling issue is if it was the head gasket, why is it leaking externally and internally. The engine is 3.0 V6. I ran a compression test and if it was the headgasket, steam would come out the tail pipe, and it is not. This is weird. I have not taken apart the engine so I cant see exactly where the leak is, but it is coming from the top part of the block on the passenger side. I am totally stumped. Any ideas?
Steve

 

If you've got oil and coolant mixing then either a gasket has gone, most likely the head gasket, or there is a crack in the block or the head. The fact that the compression is OK just means the gasket didn't go at one of the cylinders. You don't always get steam out of the tailpipe with a blown head gasket.

Do you have coolant in the oil as well.

 

When the engine is warm and running, try pulling the coolant tank reservoir top and see if exhaust is coming out. If it is, it's a head gasket.

 

I do have coolant in the engine oil as well. The location of the leak is such a pain, it looks like you need to pull the plenant to see. Plus the leak of oil is not immediate, but once it starts, it is pouring pretty good. Is this a common problem for the 3.0 just have the engine blocks crack for no reason?

 

It's likely that the HG has failed. The external oil leak may just be coincidental. You won't really know unless you pull the heads off and take a look.

Mike in AR