While replacing an alternator a shop (not GM ) says there is oil in the coolant and visa versa. They would have fixed it for $1500 replacing both intake manifold plenums. They say the lower one has a gasket leak.
I told them perhaps latter and drove it home.
I then looked in the coolant overflow tank and it looked sorta normal with some sort of scum on it that I had thought was a result of the coolant (Dex___) reaction with aluminum and normal deteriation. I stuck a paper towel in it and it was indeed "oily" but there was no odor.
They did an oil change so I can't tell by looking at that, yet, but two weeks ago when I last checked the oil level it looked normal for oil overdue for a change.
I once had a 56 Chevy with water in the oil and the Regal's oil looked nothing like that.

Any advice? Thoughts?

Don
Union City Ca.

The Upper Intake Manifold (UIM) and lower manifold intake gaskets is a known problem on the 3800 Series II NA. If coolant is in fact in the oil, the oil will appear to be milky. Plus there may be an increase in your oil level. The other symptoms would be driveability problems and overheating or the engine temperature staying above the half mark continually.

On the coolant overflow it's probably Dexcool sludge. The overflow tank is not airtight and therefore it is a common reaction when Dexcool is exposed to air.

The best to do is continue to monitor and inspect the oil and do a complete cooling system flush to get the old Dexcool out. Try using Prestone Extended Life coolant which is 100% Dexcool compatible.

BTW - $1500 is too high for that type of repair bill.

However, if there is coolant contamination in the oil, the crankshaft bearings and camshaft bearings will probably fail.






http://i5.photobucket.com/albums/y186/lizzywiz/regalgs.jpg

Thanks bnaylor3400 for the response.
First a minor correction. My Regal is a 96.
Yeah, Dexcool sludge, the reaction with air. That is what I was trying to say.
About the $1500. I called the Buick dealership and thier estimate was about the same. Yeah, high, but I don't know who else to trust with this.
But then the work may not be needed if the shop misunderstood the sludge. I will be monitoring the situation carefully.
I am also considering taking the Regal to the Buick dealership for a cooling system flush. If there is a problem, they will certainly notice it.

About the 56 Chevy I mentioned. It had a very bad head gasket leak putting water, I didn't believe in coolant or preventive maintenance back then, into the oil, big time. Each saturday morning after siting overnight alowing the oil and water to mostly seperate, I would drain water out of the crankcase untill I got oil. Then I would add a quart or so of oil so I would be good for another week. The compresion got so bad on the V8 that at low RPMs it only fired on 6 cylinders. It died after a 6 cylinder run over the grapevine. I was stuck behind a slow truck without enough power to pass. An hour later the mains siezed. I droped the pan and two rod bearings were pounded out to about 1/3 normal thickness. Yes, it clatered badly before it siezed. I sold it. the buyer and I got it push started and he drove the one mile to his home where he rebuilt it.

If you think that there might be anti freeze in the oil have the dealership get an oil analysis done.

About the 56 Chevy I mentioned. It had a very bad head gasket leak putting water, I didn't believe in coolant or preventive maintenance back then, into the oil, big time. Each saturday morning after siting overnight alowing the oil and water to mostly seperate, I would drain water out of the crankcase untill I got oil. Then I would add a quart or so of oil so I would be good for another week. The compresion got so bad on the V8 that at low RPMs it only fired on 6 cylinders. It died after a 6 cylinder run over the grapevine. I was stuck behind a slow truck without enough power to pass. An hour later the mains siezed. I droped the pan and two rod bearings were pounded out to about 1/3 normal thickness. Yes, it clatered badly before it siezed. I sold it. the buyer and I got it push started and he drove the one mile to his home where he rebuilt it.

Interesting story on your '56 Chevy. I had a '70 Dodge Challenger R/T with a 440 Magnum back in the old days. One of the connecting rods let go at the dragstrip. That is not a good sound to hear.

Good luck and hope you get the problem, if any, with your Regal resolved.







http://i5.photobucket.com/albums/y186/lizzywiz/regalgs.jpg