1998 S70-oil in water, water in oil

[Cincyken]

As a comment, my 1998 S70 T5 has oil and transmission cooler connections on the radiator even though it is a 5 speed manual. Only the oil cooler is connected. I really like the idea of converting to the later model oil pan. My 1995 T5-R has had the "o" rings at the engine repaced 3 times in 5 years, and they are dripping again. I may replace the lines and "o" soon or just do the oil pan conversion.

Thank y'all for the great advice. I will post a note as what what the final outcome is. I am lucky, i have 3 volvos (and a fully restored 1971 Triumph TR6) so i have time on my side and do not need to have the car back on the road right away.

[rspi]

When my daughters 98 S70 GLT had a bad head gasket, the compression numbers were good. Didn't do a leak down or coolant test but it was clear to me that the coolant was being forced out of the coolant reservoir. No fluid mixing.

If a head is taken to a shop to be made true, they do check (hopefully) to make sure the the head is not cracked or have leaking valves.

Maybe a leak down test can show an issue with the block but maybe not if the issue is below the top of the piston because they raise the piston before they pressurize the cylinder if I'm not mistaken.

[burnout8488]

I used a product called AutoRX that stopped the leak in less than 5 miles of driving. And my leak was huge - all my coolant would be blown out of the radiator within ten miles of driving. True, the repair only lasted a year, but if it will last a year in a diesel engine it will probably last forever in a gas engine.

AutoRX is an engine cleaner, it has absolutely no sealing properties, especially for a head gasket. (When it fixes oil leaks, it fixes them at rubber seals that have degraded) Whatever happened on your diesel must have been a coincidence, or another sealing product. Are you sure this was the same stuff? AutoRX isn't $100 last time I checked.

[kiss4afrog]

The "Block Tester" is really handy and as said you can get it as a loaner tool from most parts stores.

Stop leak is something an owner uses or chooses instead of the correct repair but shouldn't be any mechanics fix for a problem. If you were give a quote and balked at it, being presented with a stop leak as a very temporary solution to the problem is understandable as long as it was clear it might not work at all and if it did it was temporary. No mechanic should use stop leak to band aid a car unless it's the owners choice to do so.
IMHO Any customer is better of with a leaking car sitting at a shop where the customer is safe and warm rather than having it open up in a day, week, month ... and be in traffic and or far away from home.

How to on the block tester:

[abscate]

As a comment, my 1998 S70 T5 has oil and transmission cooler connections on the radiator even though it is a 5 speed manual. Only the oil cooler is connected. I really like the idea of converting to the later model oil pan. My 1995 T5-R has had the "o" rings at the engine repaced 3 times in 5 years, and they are dripping again. I may replace the lines and "o" soon or just do the oil pan conversion.

Thank y'all for the great advice. I will post a note as what what the final outcome is. I am lucky, i have 3 volvos (and a fully restored 1971 Triumph TR6) so i have time on my side and do not need to have the car back on the road right away.

Ken..my 1999 T5 manual did not have connectors on the radiator for the transmission oil cooler..I wonder if that radiator of yours is a replacement?

[Cincyken]

It's been a while but i am now back on with my project....oil in my coolant.
Step 1..I disconneted the oil cooler and pressurized the cooling system to 10psi. It held pressure for 5 minutes, and there was no coolant visible coming out of the oil cooler connections. Radiator is not the problem.
Step 2...I did the block test (looks for exhaust gases in the coolant). It passed.
Step 3...At this point I really don't think i have any options but to pull the head all over again, and have the head presssure tested and checked for flatness.
A couple comments:
The local Volvo dealer said it could also be the turbo causing the oil in my coolant. I am not sure how that could be but if it did happen, i would think I would have found exhaust gases in the coolant.
They also warned me that it can be very difficult to remove all the oil from the coolant system once it gets in there, and that they felt it would be wise to flush the cooling system again, before i pull the head. They think it is possible the oil I am seeing in the coolant could possibly be residual from last year.
Step 3A...So, that will be my next step. Flush the cooling system again, if the oil returns in my coolant......pull the head (Step 3 above).
I shall keep you posted.

[erikv11]

Oil and coolant can indeed mix in the turbo without involving exhaust gases.

Doing a very thorough flush sounds like a good idea.

If that doesn't solve it: if it was my own car I would then swap in another turbo, that can be done pretty easily in one day. If you have to pay a mechanic for that, you'll have to find out the cost and weigh the options, but pulling the head is drastic and I would almost never do it without exhausting all options.

Is this car a GLT or a T5?

[Ozark Lee]

In order for oil and coolant to mix in the turbo there would need to be an actual crack in the in the turbo housing. The two systems are isolated by the casting itself and not by seals or O rings. It is not a common problem but it can happen.

...Lee

[Cincyken]

Like so many other Volvo owners, i always have a spare part or two in my garage.
I have a spare 16T that was rebuilt by Cherry Turbos (that i have never used), if flushing does not work, that will then become my next step.

[erikv11]

In order for oil and coolant to mix in the turbo there would need to be an actual crack in the in the turbo housing. The two systems are isolated by the casting itself and not by seals or O rings. It is not a common problem but it can happen.

...Lee

This is good info that I was unaware of, thanks Lee for posting.