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antifreeze leaking through cap when car warms up

1477 Views 7 Replies 3 Participants Last post by  zoltandy
Guys I need your help. I have a 2000 C 280 Sport with about 51,000 miles on it. It seems that when car is driven at slower speeds and in traffic, it pushes the anitfreeze out through the cap and starts to run hot (the guage moves past the middle into the red). On the highway it is fine and it operates at the normal temp (in the middle). I also noticed that the upper radiator hose has plenty of pressure (almost to much) and it is very hot, however the lower radiator hose is only luke warm. None of the hoses seem to be leaking, nor is the water pump. The only visible leak is through the radiator cap when the pressure increases past the middle on the guage. Has this happened to anyone else?

I am hoping it is something cheap like a thermostat or fan switch. Any suggestions?
1 - 2 of 8 Posts
The fan doesn't come on until close to 90C, if memory serves correct. I still think the culprit is your cap. A new cap should be pretty cheap.
1 - 2 of 8 Posts
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