Oil in the coolant tank...opps

[Pastymunchingxc70]

So today I bypassed the oil cooler with pipe connects filled it with water. And ran it. The oil cooler poured oil out. So new oil cooler it is.NOTE to anyone who buys one secondhand *replace the cooler* it may save you in the future. I did on my last 2 v70s didn't think to do it on this one.... Well I will learn.

[Georgeandkira]

Lots of European vehicles used the dark blue coolant.
What changed was the metallurgy of engines and cooling systems throughout the industry.
Nothing particular to Volvo.

I've used dishwasher packets with success but better would be one of the many cleaners which contains Diethylene glycol monobutyl ether along with surfactants.
"Purple Power", "Simple Green" and "Fast Orange" are some of the brand names here in No. America.
Similar products must be available over there.
Just be sure to rinse thoroughly as these cleaners are corrosive to aluminum if let to set.

Just get yourself warmed up and be quick about it. Using them on the fouled, plastic coolant reservoir can be done more leisurely.

[Bob Meadows]

Central heating cleaner/descaler is good and far better than any so called engine flush:~
Bob.

[Simmy]

Originally Posted by Pastymunchingxc70

My plan is... Now is bypass the cooler clean the coolant system then run it with no coolant pipes on the cooler and see if it leaks... Fingers crossed it does. Then drain oil renew cooler, clean again the coolant system then connect cooler and then pray to the swedish gods it works.
Lemons ermmm would cheap ones do or do I have to be posh and get m&s ones😂😂.

lemon juice is far less harmful to engine parts some use dishwasher tablets but have you seen what they do to aluminium pans i just prefer the less corrosive route it entirely up to you what you use just dont wreck your engine:regular_smile :

[Clan]

Originally Posted by Pastymunchingxc70

What's the best way round my issue.
Clean out expansion tank,drain all coolant,remove thermostat,bypass cooler and flush system. Then refit thermostat.
Or bypass cooler clean it and see if I still get oil in it. If I do... Panic.

I've had to sort out 2 of these over the years No its not common but a rare chance it could happen to you . There is a Volvo special tool for testing oil coolers.
Its a very long job, every single rubber hose must be changed as the oil will have penetrated the rubber and softened it through the inner layer of rubber, Including the heater hoses going through the Bulkhead and any inside the car. 10 years ago a set of hoses was well over £200 . If you don't change every single hose the ones you don't change will burst sometime in the future when you have forgotten all about it !
Once you have drained the system out it needs to be flushed out with an Emulsifier fluid which enables the oil to mix with the water. you will have to do this several times, a drive for about 20 mins will flush out what it can then drain and refill with the emulsifier fluid and go for another drive.
When you are happy plain water is staying clean change to genuine Volvo Coolant which is the best quality and also the best Value as it lasts for many many years. Good Luck !