So I'm new to this whole forum thing and i hope I'm in the right spot. I've got an 89 pickup with the 3.0 v6. I've now got 275000 miles on it and I'm starting to see oil in my coolant. i have no leaks on the engine and have never had an issue in the past. is the oil in the coolant a result of the head gaskets failing or is their another issue as well that anyone on here has seen in the past? Any input would be much appreciated.

 

How much oil are you talking about here?

Small amounts float - not uncommon.

Large amounts could be head gasket or a crack somewhere.

Does your oil look milky or have coolant in it?

 

The oil looks fine and I know with this many miles it is kinda normal for the engine to use a little. In about two weeks the engine will use about a half of a quart. From what I can see the overflow reservoir for the radiator is maybe 15 to 20% oil. I'm expecting it to be something else but I don't really know how this engine is configured so I thought I would ask. I've also got a 3.4 that I'm going to eventually swap the 3.0 for. I just wanted to get all I could out of the 3.0 first.

 

If your engine is burning that amount of oil in 2 weeks, there must be a major leak or it is possible one of your cylinders has a cavity or trench. Is there any black or white smoke coming out the pipe?

 

It's not smoking, knocking, missing, or leaking externally. That's why I'm sorta stumped. I mean the engine has had a great run and I'm planing on tearing it down anyways I'm just trying to troubleshoot before I get started so I know what I'm getting into.

 

That's a lot of oil in the reservoir! There's no trick to this engine; the only place the oil gets near the coolant is in the cylinder and the cylinder head. You could have a crack in either, but most likely you've got a leaky cylinder head gasket.

Or do you? Lot of folks think "Yeah, bad head gasket, I'll throw a new one on Wednesday afternoon and I'll be good for another 200,000 miles." Once you start taking an engine apart (especially a, uh, senior engine) you will find all sorts of tiny problems. Your wednesday afternoon will stretch into December, 2015 (if you keep working on it).

If you have a 3.4 swap already planned, I wouldn't worry about wringing the last few miles out of the 3.0. It's a good engine, but you need to prioritize.

 

Yeah I don't see why people knock them. I mean 275000 miles is a pretty good run.