Oil in my coolant tank. What could this be?


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

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 out of 2 people think this is helpful.
Colin Rivet

head gasket

1 out of 1 people think this is 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 out of 2 people think this is 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 out of 1 people think this is helpful.

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

1 out of 1 people think this is 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 out of 1 people think this is helpful.
Best Answer

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 out of 1 people think this is helpful.
Duane Foster

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..

Your Answer

Add photo

Related Questions


Looking for a Used Century in your area?

CarGurus has 1,292 nationwide Century listings starting at $3,295.


Search Buick Century Questions

Buick Century Experts

#1 John Saffrahn
John Saffrahn
Reputation 840
#2 Tom Demyan
Tom Demyan
Reputation 640
#3 LtColumbo
Reputation 300
View All

Related Models For Sale

Used Buick LeSabre"
16 Great Deals out of 2,600 listings starting at $1,450
Used Buick Regal"
190 Great Deals out of 10,616 listings starting at $5,900
Used Chevrolet Impala"
937 Great Deals out of 35,886 listings starting at $700
Used Ford Taurus"
348 Great Deals out of 23,127 listings starting at $1,400
Used Toyota Camry"
1,651 Great Deals out of 98,959 listings starting at $895
Used Honda Accord"
1,309 Great Deals out of 78,750 listings starting at $1,395
Used Chevrolet Malibu"
1,182 Great Deals out of 72,976 listings starting at $695
Used Pontiac Grand Prix"
27 Great Deals out of 4,393 listings starting at $1,972
Used Ford Focus"
1,215 Great Deals out of 57,389 listings starting at $1,495
Used Mercury Grand Marquis"
50 Great Deals out of 2,571 listings starting at $1,300
Used Toyota Corolla"
1,468 Great Deals out of 67,797 listings starting at $1,295
Used Nissan Maxima"
475 Great Deals out of 24,246 listings starting at $800