Brown Sludge on Radiator Cap

Kiwi Cortina · Post by **Kiwi Cortina** » Sun Jun 28, 2015 8:34 am

I have now done nearly 700 miles on my MK2 rebuild and the other day I was doing a fluid level check and notice a brown sludge like substance on the radiator cap. The radiator is new. Also I am having trouble with the oil cap/ breather on top of the rocker, it lets oil blow out and some times the cap blows right off. Any suggestions.

Thanks

Post by **peteleo** » Sun Jun 28, 2015 12:28 pm

Brent,

It sounds like the crankcase ventilation is plugged. Check the PCV valve first. The plunger needs to be spring loaded.
Most likely the canister is the culprit. It is sometimes neglected. Usually inside will have slug causing the oil return baffle to plug. Soak it in degreaser for a day which should loosen all the slug. The canister after that will weigh half as much as before. Pete

Kiwi Cortina · Post by **Kiwi Cortina** » Sun Jun 28, 2015 12:55 pm

Thanks Pete. Pulled it off and put it in degreaser and already crap is coming out. Now that should help with the oil cap, but will it help with the brown sludge in the radiator?

Post by **peteleo** » Sun Jun 28, 2015 7:17 pm

Are you using a stop leak chemical in the radiator ?

Kiwi Cortina · Post by **Kiwi Cortina** » Sun Jun 28, 2015 8:02 pm

Post by **peteleo** » Sun Jun 28, 2015 8:14 pm

I suspect some chemical is reacting with the coolant. There may be some crap left over from the heater element.
I would flush the system with clean water and then drive the car around for a couple of days and see if the problem comes back. If it doesn't, you can then add coolant.

Kiwi Cortina · Post by **Kiwi Cortina** » Sun Jun 28, 2015 10:29 pm

Thanks Pete. I will give that a try.