[itrdc2]

Hi guys, I'm trying to fix my girl friends 2000 beetle 8 valve. It over heated on her. It looks like the oil cooler seal went out and we got oil in the coolant, sounds pretty common from what I've read and it fits the description(thick brown coolant).
We replaced the bad water pump and warped water neck, next will be the seal and maybe the radiator fan switch.
Some of that thick brown coolant was layered up on the inside of the radiator fan switch and I was wondering if that would make switch not read a accurate temp. and not kick on the fans?

Any input is greatly appreciated, thank you

In the pic the left side is dirty and the right side had been wiped clean

 

[red99]

The seal for the oil cooler keeps oil from leaking to the exterior of the engine. It does not seal between the oil and the coolant. It oil is getting into the coolant there the cooler itself must have rusted through internally.

"Thick brown coolant" is also a description of what happens when an incompatible coolant (ie. almost anything else) is added to the VW G12 coolant. Could it be that something else was added to the coolant?

From the looks, I think your temperature sensor will be OK assuming it still works electically. Problems with the radiator fans are fairly common. See this:

http://newbeetle.org/forums/questio...3260-summers-coming-here-check-your-fans.html

 

[D2Beetle]

I concur with red99; however brown coolant can be caused by either of these events ...

1) Mixing any department/parts store coolant with G12
2) Bad head gasket

 

[janitz]

Yah, the seal won't be the cause of oil in the coolant. That would only occur if the internal components of the oil cooler failed and allowed the two liquids to mix.

But the thick gunk is more likely to be caused as they already mentioned by mixing the wrong coolants.

I would thus advise you to flush the radiator and coolant system fully using distilled water until it comes out clean and then add new 50/50 mixed G12 or better (G12+ or G13 being common now). Remember when flushing that you have to not only empty the radiator with the convenient drain located near the sensor you pulled but also from the block by removing the lowest hose from the engine block and draining from there.

How is the Air Conditioning system in that Beetle? It seems to me that more issues with radiator fans seem to be caused by AC issues than other sources of problem. I know on my car that once I fixed the AC the not quite normal operation of the radiator fans fixed itself.