Coolant leaking into oil on a bastard T5 (99 S70 T5m)

[Levinicus]

My son's 850 transmission was ruined because coolant got into his transmission through the radiator. A turbo radiator has oil, coolant and transmission fluid going through it...any one of these breaches and you have problems. How old is your radiator? That would be my guess if the other suggestions come up wrong.

On mine (1999) the oil cooler is strapped to the side of the oil pan... I don't believe the radiator has oil going to it. I would be delighted to be wrong though. I REALLY don't want to mess with the block or head.

[wizechatmgr]

Try draining the coolant and pressurizing the cooling system with shop air to pressure cap spec and seeing if you can track down the hiss - hopefully you will get a hiss you can hear. Hopefully it isn't something that is small enough not to leak with the engine cold but leaks only when it warms up to operating temp.

It will be a bear to track down as far as time required, but you should be able to do this without a mechanic. Heck, you already performed a leak-down test so this is relatively easy in comparison...

If all else fails and you're about to junk the car *gasp* you can try stop leak products. I figure if you're going to junk it anyways you have nothing to lose for $20. Obviously you wouldn't want to do this if you intended on keeping the car long term....

[Levinicus]

Does anyone know the exact model of turbocharger on the 99 T5 2.3? I would like to look at a diagram if I can find one. [EDIT] Sorry, nevermind. It's the TD04 16t.

I will attempt a pressure test on the coolant system. I would, however, still be interested to know if it is possible for coolant to leak into the oil in the turbo WITHOUT the turbo generating smoke. The turbo does put out black smoke at high boost and RPM, but it has done that since I bought it.

[wizechatmgr]

I suppose it could if the turbo bearing housing were to crack just right/wrong internally. If it were to it could leak into the oil supply and straight down the return. From the all knowing google search I see half of the world saying it can never happen, and the other half saying they've seen it but it is rare.

Wish someone made a sight glass for the oil supply/return on turbos similar to those in refrigeration... Would really eliminate the mystery while troubleshooting...

Are you currently developing any boost? Has the turbo's operating noise or performance changed any?

If you have time, change the oil with something cheap for testing, refill with coolant, pull the oil return and direct it into gallon or so bucket. Run the car for just long enough to see what's going on. Mind your oil level as it drains since we're not returning it to the crankcase, we don't want to cause more damage. That may rule the turbo out if the oil is pristine... If it suddenly looks like a milk shake after having no issue, check the dipstick. If the dipstick is milky and the turbo return line wasn't running into the oil pan, then the issue cannot be the turbo. However, if the dipstick isn't milky but the return suddenly is... Turbo it may be

[FLXC90]

Do the bastards use a heated PCV like P2s? maybe through that system? But I don't think there is actual contact there is there?
Sorry, but my bet is warped head.

[wizechatmgr]

http://www.audizine.com/forum/showthrea ... ant-in-oil
One case where the turbine wheel detached and the shaft lodged where it shouldn't, allowing coolant and oil to mix. Not the right vehicle but the thread may help for troubleshooting ideas...

[abscate]

Do the bastards use a heated PCV like P2s? maybe through that system? But I don't think there is actual contact there is there?
Sorry, but my bet is warped head.

D

Well done!

The bastards indeed have a coolant pipe ( to heat the PCV line. I forgot about that

Worth checking.

It's two banjo bolts , one hard to get to under the intake manifold , left side of engine (towards front of car) and one on back of block. If that coolant pipe let go into the PCV somehow, it would go into the crankcase.

Never heard of that happening but a thing to check

[rspi]

Ooops!

[Levinicus]

The bastards indeed have a coolant pipe ( to heat the PCV line. I forgot about that

Worth checking.

It's two banjo bolts , one hard to get to under the intake manifold , left side of engine (towards front of car) and one on back of block. If that coolant pipe let go into the PCV somehow, it would go into the crankcase.

Never heard of that happening but a thing to check

Do you know if it's possible to remove that pipe without removing the intake manifold? I would like to locate the problem before I dive into a full PCV job.

[abscate]

I would say not.

It is really crowded under there and not easy to see what you are doing

The coolant pipe is also bonded to the PCV so you would be trying to break that free without cracking the fragile PCV pipe, very tough.