erics944

It appears that prior to me owning my car, it might have had a blown head gasket. (Even if i had known this when I purchased the car I still would have bought it. I had my mind set that I was buying this car.) There was a little left over oil sludge left over in the coolant tank, which I didn't really think about. This weekend I changed the oil and took the coolant tank out to clean out the oil. When I removed the one of the hoses connecting the radiator to the coolant tank the inside of it was coated in sludge. My car lately has been running hot when idleing. I purchased a cooling fan switch and a new thermostat and I am going to install them next weekend. My fans don't ever run when i turn the car off when it is hot. However now I am thinking that the sludge in the cooling system may be a significant cause. Either way it is not a good thing. So to my question...How do I go about cleaning this out? I really can't afford to replace everything.

944CS

10 minute flush at auto zone

Dave in Chicago

When the oil-cooler on my 944 leaked, we filled the system with water and "Shout" laundry treatment, ran it, flushed it, repeated... 4 times!

Not fun, but that got almost every little bit of the "milkshake" stuff out. Still took the next year's flush/fill to banish the little globules forever.

It's a bear, but it can be done.

Dmitry S.

I would not use any off the shelf "flush" products - they are usually very acidic and will eat away at the cooling system even after you drain them. Try some laundry detergent and maybe some simple green like Dave said.

nine-44

We used Tide or some other laundry detergent at the dealer for the oil coolers that mixed. Always worked pretty good. Fill with water and a few scoops of detergent, fire it up and get it up to temp for a few mins and then drain and flush with water. You should see the mess when you mix oil with the Audi pink coolant, we had one sludge up so bad we couldn't blow air through it, even at full line pressure, like 140 psi!!! Had to repalce that one

nine-44

Simple green is acidic too, not reccomended on aluminum

Dal Heger

Tide. Laundry detergent.

Fill with water and tide, run it until hot, drain, rinse, repeat.

Rinse really well once there is no more oil/dirt coming out of the system. The water should be clear once it's rinsed really well. Then fill with a 50/50 mix of distilled water and your favorite coolant (mercedes/bmw/vw/prestone orange/dexcool/etc.)

Dal.

Yabo

If i have severe mixage, and car still runs but I need to rebuild the engine, and am going to before it goes back on the road, would you flush it before you take the engine apart? (i could still get the engine warmed up, it still runs fine). Reason is i'm going to replace the radiator/waterpump etc anyway, so i was thinking i wouldn't want to flush that stuff through my new stuff. What do you think?

nine-44

If it's been sitting for any length of time, all the rubber is going to be shot. If you are rebuilding, everything will get cleaned anyway, stll leaves little stuff and the heater core. I'd do a flush before and possibly after to be sure.

944CS

there is a 10 minute flush that has a water pump lube in it, that worked well when i drained my system

Yabo

All the rubber probably is shot, don't really care, replacing jsut about every seal anyway. I'll take your advice and do it before though, i thought that would probably be the best idea.