Pink Crud

It sure sounds like coolant - if you ever notice pink chaff flying about inside your cabin you'll know the heater core has gone to Heaven ;-)

I'd expect it's not normal to have coolant stains around the oil cooler, but might they be the result of sloppy topping-off?

/daytripper '00 s4 6spd

It *does* sound like coolant. Probably the hoses weeped a little at some point, and the crud has probably sealed it. As long as the coolant doesn't drop I wouldn't worry too much- check for any actual liquid leaking though.

Thanks for the responses.

This is not a stain. It's a lump o' crud, actually many lumps o' crud at the oil cooler. Since the oil cooler is just a block of something (looks like aluminum), there isn't anything to specifically top off.

Also, the crud is at both the inlet and outlet locations, suggesting to me that it is the nature of the thing to leak. If not, I would have expected maybe one or the other would be affected, but not both.

Perhaps it has something to do with the aluminum interface. A casual check around the rest of the engine compartment did not reveal similar gatherings of the crud.

Another possibility may have to do with changing the oil filter. The car was serviced by Audi for the first 50K miles of free service. Now that it's beyond the magic mark, I do the stuff myself. The first time I changed the oil filter, it was quite a job. Apparently, some gorilla socked it down real good and I had to contort it quite a bit before it broke free. The stress may have been transferred to the cooler lines and caused some weeping of the coolant. Hard to tell.

That problem is cured by tightening the oil filter hand tight. Doesn't leak and it doesn't take an impact wrench to get it off.

Another Audi item of note: the dealership consistently overfilled the oil. I, of course, do not.

Best,

Ken

Hola "KWS" escribió en el mensaje news:4JTwc.62647$Ly.24744@attbi_s01...

Thing is, the only thing going through the oil cooler is oil - coolant doesn't run through there. So why the oil cooler inlet and outlet would have coolant around them is a mystery unless the physical location of the oil cooler could make it prone to having coolant drop on it - I don't know the physical layout of your car.

Mike.

Mike,

This isn't another radiator. It's where the oil filter mounts. Apparently, cooling is done by exchanging heat from the oil, through what looks like an aluminum manifold, into the coolant that circulates through the manifold. On the A4 1.8T it is on the right side as you are looking at the engine from the front. It's under the coolant reservoir (which I move to get to the filter).

Best,

Ken