Oil in the Coolant Tank? Please help

[Doc.Doug]

I have a 1.3 Ford Aspire, 5-speed manual transmission, 90,000 miles.

At my last oil change, I observed oil in my coolant expansion tank. No coolant appeared in the oil. Since this is the case, I assume that the oil is under pressure where it leaked into the coolant. Having said this, I suspected the head gasket was cracked where the pressurized oil makes its way to the top of the engine. I pulled the head only to find no obvious head gasket cracks or stress. The head and block, where they meet, looked good too.

I am stuck. Should I replace the head gasket not knowing if the head gasket was going bad or replace the head and gasket? I guess another consideration is that the block could have a problem around the oil pump or passage?

One final thing to add. Over the winter, when the car sat for more than 10 hours, one of the hydraulic tappets sounded like it was sticking. After re-starting the engine several times, when this occurred, the tapping would stop. This happened 8-10 times, in total. (Probably not related to the oil in coolant?)

The car ran great , 39 - 44 mpg, and exhibited no symptoms other than oil in the coolant expansion tank.

HEEEEELLLLP. Thank you, Doug

[roycehof]

I'm not sure about the Oil in the expansion tank, But the valve tapping on these engines is very common and not of any concern unless it last for more than 30 seconds on start-up. This was information that I got from a Mazda mechanic. I have noticed it on occasion on very cold days after the cars sit for a long time and there has been no detrimental effects.
You might want to elaborate on how much oil you found in your expansion tank. I little slick on the top on the antifreeze probably is not a issue and could be caused by the water pump seal starting to fail. I would siphon it out and see if you continue to get oil in the antifreeze.

[Doc.Doug]

roycehof, thanks for the reply.

The tapping would probably continue indefinitely unless I shut the engine off and restarted it several times. As far as the oil in the expansion tank, the oil was about 1/4 - 1/2 thick at the top and had started to cause the rubber coolant over-flow tank lines to turn soft and mushy.

The water pump that I removed when I pulled the head shows signs that leakage occurred and some coolant leaked out the small tube on the pump for this purpose. Probably no big deal as the coolant level never dropped to the eye.

I will probably pull the camshaft and rocker arms from the head and have the head tested and milled before I reinstall.

Thanks again for the info.

[roycehof]

That is really strange - that seems like a lot of oil. I never had the head off of my engine but I wonder how close the oil and water passages are on the head gasket. Since oil pressure is usually higher that coolant pressure, perhaps there is a small leak in the gasket, but that would only be if they pass by each other fairly close. I would be interested in whatever you find.
Good Luck!
Oh yeah, they make a little replacement hydraulic assembly that goes in the rocker arms and when the oil leaks from these this is the tapping noise you hear. They sell replacements. If I understood the mechanic correctly, there are little O-rings in these assemblies which start to leak and hence the tapping on start up. More pronounced when it is cold due to shrinkage. No matter what, eventually the tapping should stop once oil gets in there. Starting and stopping probably has no effect The part are call hydraulic lash adjuster also known as HLA's. If you get into this engine you probably either want to rebuild these or replace them.
And Again - Good Luck.

[dahodges]

If the head is off the engine. Go ahead have it checked and rebuild. I don't think if cost more than a hundred dollars. And of course use a new head gasket.

David