MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: HandyAndy on July 28, 2016, 10:36:05 pm

Title: Oil in my coolant expansion tank.
Post by: HandyAndy on July 28, 2016, 10:36:05 pm

I have been topping up my expansion tank with coolant for ages now and it's gone from every 500 or so miles to every 200 or so miles.

I topped it up tonight and noticed little blobs of black in  the tank. I have assumed this can only be oil contamination and I'm getting worried. It's cost a fortune so far this year and has now got around 178000 miles on the clock.

I have seen in some other forums that it's the oil cooler and it fixes it by changing it, but takes a lot of flushing through.

Any ideas please

Title: Re: Oil in my coolant expansion tank.
Post by: Neil 54 on July 29, 2016, 06:39:09 pm

Possibility its your head gasket had this problem on an old car of mine and it turned out to be that you could get a compression test done although not sure if that will show up if the leak is between a water and oil way or only if the leak is into a cylinder

Title: Re: Oil in my coolant expansion tank.
Post by: Octoparrot on July 29, 2016, 07:22:32 pm

Symptoms sounds like head gasket failure to me I'm afraid!

Title: Re: Oil in my coolant expansion tank.
Post by: Scottymon on July 29, 2016, 07:38:16 pm

It's the usual suspect unfortunately

Title: Re: Oil in my coolant expansion tank.
Post by: r5gtt on July 29, 2016, 08:23:17 pm

Doesn't sound promising unfortunately mate. What's the tempreture needle like?.

First I thought water pump as you were topping up a lot  but as I read on I realised it's worse.

Title: Re: Oil in my coolant expansion tank.
Post by: HandyAndy on July 30, 2016, 02:24:51 pm

Hi all, I have looked this morning and the water is not showing any signs of oil contamination. Although the level was low again. I had a compression test done earlier this year and it was OK. The water pump was replaced last May when the cam belt was changed, circa 30,000 miles previous.

Temperature wise the needle is right in the middle all the time when it reaches temperature, so once it reaches temp it's ok and doesn't move.

I'm thinking it might be worthwhile getting the headgasket done and checked for cracks or any other faults then.

Title: Re: Oil in my coolant expansion tank.
Post by: r5gtt on July 30, 2016, 07:29:55 pm

Get a compression test done and also get a leak test done to confirm where the leak is coming from.

Title: Re: Oil in my coolant expansion tank.
Post by: neiller on August 05, 2016, 02:44:15 am

Could be the oil cooler ! Did you get you the bottom of the problem ?

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