[EagleScreen]

I often find this kind of oil in the coolant resevoir:

But the engine oil seems to be in good condition so i doubt it to be a problem with heads gasket or engine block.
What do you think?

 

[Daytrepper]

What engine is in the car?

 

[peva]

One possibility: Some aftermarket coolant additives and stop-leaks are oil based. Someone may have put some in your system. If so, it can be hard to get out.

Are there certain leaks between oil and coolant systems that would only leak in oil-to-coolant direction? I don't know. Seems like you'd get water in your oil after shutting down with coolant system pressurized and oil pressure zero, unless the leak is acting like a check valve.

 

[Daytrepper]

What Peva said, and, If its a 2.7, a bad water pump can cause this;

If it is, stop driving it immediately, dont even start it until the water pump is checked out. Usually when they are to the point where oil/coolant is mixing, the bearing has failed in the water pump pulley, and it may or may not be running hot/overheating.

If the water pump is the issue, and oil/coolant is mixing (which is what you have) it is ready to fail catastrophically at any minute; it will either let the timing chain loose, or wash the bearings---in either case....engine will be done, and need to be rebuilt.

PCV system being plugged up can cause it in extreme cases.

Whatever the problem is, the cooling system will need to be completely flushed with an oil removing cleaner after the problem is fixed.

 

[EagleScreen]

The car is Intrepid with 3.2L engine. It has 160,108 kilometers.
The radiator brake in year 2017 (40,000 km ago) and that time the engine oil entered in the coolant system. Then i put a new brand aftermarket radiator. But that time was different, all the colant was quickly tinted of black color. I used radiator cleaner products and flushed several times and also replaced the coolant reservoir, but after that incident, the reservoir was never be completely clean again. But this time is different, in these 4 years i had never seen the white fatty material and the coolant in the rafiator or in the bottom of the reservoir seems clean and pink.
Dude: is it possible in any way transmission fluid (ATF) to mix with coolant in any part of the vehicle?

 

[peva]

Yes - transmission fluid flows thru a heat exchanger loop in the driver's side end cap of the radiator. If a leak developed in those heat exchanger tubes, you'd have exchange of ATF and coolant. What does your ATF dipstick look like?

 

[EagleScreen]

Hello, this is the aspect of the trans fluid. It seems to be in good condition for me, what do you think?

 

[Daytrepper]

Dude: is it possible in any way transmission fluid (ATF) to mix with coolant in any part of the vehicle?

Yes, there is a cooler in the radiator that can leak, fot both the engine, and transmission.

The trans and engine oil fluid pressure is always higher than the pressure in the cooling system when running, so it will generally not leak back into either in large amounts, unless its a huge leak. It will also not lose much oil if it is not a serious leak.

You could tell by pulling the radiator, and having a radiator shop test the coolers.

If thats the case, change the oil, or flush both the transmission, and cooling system, and install a new radiator.

 

[EagleScreen]

Updated photo. After seing this, i have stopped using the car.

 

[Ronbo]

Definitely Fooked there!

Time for a new radiator and engine/transmission flush and fill.

 

[EagleScreen]

So do you think it is a radiator issue?
What is exactly a transmission flush?

 

[Daytrepper]

So do you think it is a radiator issue?
What is exactly a transmission flush?

It is hard to tell here without tests. But the trans cooler in the radiator is the most likely suspect.

Normally you would have a radiator shop test the oil and transmission coolers, and the radiator itself.

Or just replace the radiator.

As far as a trans flush, when coolant/trans fluid mix, you'll have to take it to a shop with a flush machine. That machine will physically remove all the nasty contaminated fluid, and wash the trans out with clean fluid. Wont be able to get it out any other way. Not something to attempt at home.

Otherwise, you risk damaging your transmission.