Mayo in Expansion 😞

Hi guys

Just joined and I'm getting straight in with questions, hope you knowledgeable bunch can help?

I have a 1997 S70r manual, as the title says I've Mayo in my expansion tank

It happened this morning, thankfully on my way home and almost in my drive!

Water over pressurised, steam clouds and mayo oozing from an expansion cap....grrr

Engines done 117k and has a great well maintained history, engine runs very well, no misfiring, no steam from the exhaust, no signs of any mayo on the oil filler cap or the dipstick.

So there's obviously an issue here!

Is there a possibility that it may be the rad/oil cooler or the dreaded HG?

Any advice would be greatly appreciated 😀

Could well be the rad/oil cooler, the head gaskets rarely go, although it can happen.

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Originally Posted by stribo

Could well be the rad/oil cooler, the head gaskets rarely go, although it can happen.

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Yeah that's where I'm at really, I know they can go but it's pretty unusual on a unit with 117k and excellent history

What kind of cost are the oil cooler/rad units? I've had a mooch on line but can't seem to id the right one ��

You need to get the water dipped for exhaust gasses & possibly a compression check just to make sure what it is. With the system pressurised & over heating I'm thinking head gasket as mine never pressurised, it just turned my water to Mayo sludge.

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Originally Posted by stribo

Could well be the rad/oil cooler, the head gaskets rarely go, although it can happen.

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This would be my first guess. Of the possible causes, it's one of the preferable ones. A new radiator and a flush and you're good to go again.

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Originally Posted by Biff

You need to get the water dipped for exhaust gasses & possibly a compression check just to make sure what it is. With the system pressurised & over heating I'm thinking head gasket as mine never pressurised, it just turned my water to Mayo sludge.

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I'd be checking along these lines too.
Compression test and sniffer in the exhaust to check for a HG leak.

That much mayo in the expansipon tank would suggest a bigger leak than the HG and there isn't anywhere else (apart from the turbo) where oil can get into the water.

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Originally Posted by Dangerous Dave

That much mayo in the expansipon tank would suggest a bigger leak than the HG and there isn't anywhere else (apart from the turbo) where oil can get into the water.

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That's where I'm at with my logic, HG would surely degrade a lot slower, in the space of about 1 minute my expansion looked like the magic mayo pot!! The stuff kept on bubbling out. Surely points to a larger breach than HG failure?? Again if the HG had failed to that extent then wouldn't there be any other noticeable running issues? She ran perfectly before and after, a very clean exhaust, no smoke or steam, no mayo on dipstick or cap, temp gauge in the middle, no slight misfire.....nothing, hope that's a good sign!

When it happened I felt the bottom of the rad and it was warm but nowhere near as hot as you'd expect with your expansion doing a Vesuvius! Could it be that so much mixing had caused a lot of crap to sit in the rad and effect flow/temp?

I've just spent a fair bit getting the front struts/lambda and a few other bits done so I'm really hoping it's not the HG!!

Also in my experience a HG failure tends to be failure around the cylinder sealing ring and not between the oil and waterways (unless the cylinder head has started to corrode which is unlikely, only seen that on my brothers old 940 due to lack of antifreeze. So if it was a HG failure I'd expect mayo in the sump and not in the expansion tank plus some cooling system pressurisation dependant on how bad the HG failure is.

This is the one you want:
http://www.partsforvolvosonline.com/...oducts_id=3619

Quote:

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Originally Posted by stribo

This is the one you want:
http://www.partsforvolvosonline.com/...oducts_id=3619

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Cheers stribo :B_thumb:

Quick update re my mayo issue!

The oil mixing was caused by the rad/oil cooler corroding and holing not the HG :B_thumb:

Cheers guys for the help and advice, rad's on order and she'll be back on the road by the weekend......hopefully

Order yourself some oil cooler pipe clips. They probably won't be re-useable after removing them. Get some new rubber gaskets all from Volvo dude. Make the job much easier for £35.

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Originally Posted by Biff

Order yourself some oil cooler pipe clips. They probably won't be re-useable after removing them. Get some new rubber gaskets all from Volvo dude. Make the job much easier for £35.

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Thanks Biff :B_thumb:

I'm all for making things a little easier, appreciate your help mate :)