I bought a '97 Thunderbird with the 4.6 V8 in it about a month ago. When I was looking at it, I didn't check the coolant bottle, got home and checked it a few days later and it had a bunch of oil mixed in with it. Brown and nasty looking. I flushed it all out real good, but it's mixing oil back in the new coolant. There's no coolant getting in the oil, car doesn't overheat or smoke. Runs and drives fine.

I've had three mechanics look at the car, and here is what each of them have told me:

1. Told me it was trans fluid, and to change radiator. (To me it looks NOTHING like trans fluid, if you stick your finger in it, it's milky brown, not red at all).

2. Told me it was engine oil, but that it wasn't any big deal as long as the car runs ok, and just not worry about it.

3. Said it was engine oil, and that it's coming from a cracked head. Head will need to be replaced.

So, I'm looking for opinions guys. What does it sound like to you?
Is it possible to have a cracked head, and have this be the only symptom?

Thanks.

 

Ask a mechanic to verify it is oil....you can do this as well...take a drop and place it on a counter or flat piece of of metal, etc....if it separates, the oil raising to the top it is oil...if it doesn't it could be Barr's stop leak or juct radiator grime- if its grime, flush the rad and fill with fresh coolant.

 

There is an adaptor on the left lower portion of your engine where the engine oil and coolant come very close to each other. The gasket that the adaptor mounts to has O-rings bonded into it that collapse over time and heat cycles. Oil can enter the cooling system at that point as the oil pressure is usually 25 to 60 psi and the coolant has a pressure of about 15 psi. You should check there first.

 

I've flushed the cooling system several times, both with radiator flush and just plain water. Whatever this is, it always comes back. And it gets nastier the more times I drive it. If it's just gunk or grime, it sure is being a pain to remove. I'll try putting some of it on a piece of metal tomorrow.


That's a very good suggestion, but the dealer I bought the car from said that he had someone change that gasket when he bought the car. He said it was leaking oil really bad around that adapter. I'll check it again, he might not have done the job right. That would be great if that was all that needs fixing.

Here's a couple pics I took of the coolant. I had to use my worklight to light up the reservoir so the camera could focus.

 

It looks like engine oil. I think the adaptor may be the cause of the problem.

 

Is there any way I can test the adapter other than removing it? How hard is it to remove?

 

If there is an internal leak as I suspect, there is no way of seeing it without removing the part for an inspection and at that time you will need the gasket anyway so you should just have the gasket on hand. Take it off the block look for evidence of a leak and put it back together. The most you might see is a pair if flattend out o rings. Of course you will need to drain and flush the cooling system or the oil will still show in the coolant and you won't know if it was a fix or not.
The r&r is not too hard on the trucks but it is pretty tight in the T-Birds. I did it a few years ago on my Mark VIII and it took less than an hour. If memory serves, you will need a couple 1/4" extensions, a flex socket or universal and either an 8mm ot 10mm socket as well as an inch pound torque wrench.
Good luck with it and let us know how it works out.