Oil in my coolant tank. What could this be?


Asked by Jul 30, 2014 at 11:34 AM about the 2002 Buick Century Custom Sedan FWD

Question type: Maintenance & Repair

When I had my oil changed 2 weeks ago, they said I should have my coolant flushed since they saw some oil in it.  They do the flushing.  I have an appointment with my dealer's service department Friday, but am nervous about what this could mean.

9 Answers


Lots of things. From a cracked block to a bad gasket some place. How's it running?

2 of 2 people found this helpful.

head gasket

1 of 1 people found this helpful.

Do you trust the people that told you that? Do you know for FACT it has oil in it? I agree with those guys, BohoMark and Colin but it's possible the dealer is trying to take advantage of you, spend money on a flush you don't need. If it is indeed a head gasket, you really ARE blowing money, a big waste to flush it before fixing it.

2 of 2 people found this helpful.

It runs fine. Not hot and no apparent problems. Oil Can Henry's is where I have my oil changed and they are the ones that told me. I saw it when my son checked it for me. Almost definitely was oil and quite a bit. The oil, however, has not gone done since the last oil change and doesn't appear to have any water in it. Thanks for your help. Please keep responding.

1 of 1 people found this helpful.

The first paragraph I wrote should have said "they (Oil Can Henry's) DON'T do flushing".

1 of 1 people found this helpful.

Are you lossing oil?If you are,then check head gasket,if you are not,flush it,and see if it return,s.If it doe,s then you defenatly have a head gasket problem.

1 of 1 people found this helpful.
Best Answer Mark helpful

Not losing oil. Oil looks good and is still at full line since last change.


This is an odd situation, usually coolant ends up in the oil pan. If the engine has been overheated I guess there could be a cracked block or maybe you've lucked out and it's just a head gasket. Either way, I'd use a mixture of 50/50 water and white vinegar, it will cut through any sludge that's developed and when you've found the problem buy straight antifreeze and cut it 50/50 with distilled water otherwise you're paying 6 bucks a gallon for the water in the premixed stuff, distilled water is only around $0.69 a gallon. You want to used distilled because there isn't any mineral in it. Happy Motoring! Good Luck.

1 of 1 people found this helpful.

Have you added any radiator stop leak..That will look like oil in the coolant reservoir...Sometimes a cloudy buildup occurs if you have not flushed in a long time also..and of course the old you need a flush routine..

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