Spewing Coolant
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CLK320
Spewing Coolant
My '98 CLK320 just started spewing coolant from the coolant reservoir, through the overflow tube. The temp is normal (about 85C) and it still spews. I changed the thermostat, but that didn't help. Before you know it, I have a good puddle of coolant under the car! What next? Water pump maybe?
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From: Bay Area
02 clk 55, 13 GL 450
pressure check cooling system with the motor running. If your leaking combustion compression into the cooling system you'll get coolant out the cap. When was the last time you replaced the cap? could be just a bad cap too 
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CLK320
Bought a new cap and ran for a while. Shortly after, the low coolant light came on and shortly after that, it overheated. Saw alot of condensation coming from the exaust and car had a really rough idle. There were no signs of coolant leaking anywhere, so where can it be going? Into the exhaust system?
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From: San Diego
02 CLK430
How "shortly" after was it, in minutes/miles? Whats the ambient temp while this is happening (outside temp.)? Is your car equipped with the electric fan or the fan clutch fan? Does it start overheating at idle or while driving, is the temp ok while the car is driving at cruising speed?
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CLK320
The coolant warning light came on within 10 minutes ( never left driveway). I was waiting to see if the expansion tank would start spewing. The tank never spewed...The electric fan kicked on immediately. The ambient temp was 92 deg in the shade. it took about 15 minutes for the temp guage to "spike" to 120 C. It happened quickly and I saw it and turned off the negine and let it cool before I checked coolant level. Once I did, I found that coolant was low again.
Before I filled level in reservoir, I purged all the air by squeezing upper radiator hose. I did this ubtil there were no bubbles. Topped it off and closed new cap.
Before I filled level in reservoir, I purged all the air by squeezing upper radiator hose. I did this ubtil there were no bubbles. Topped it off and closed new cap.
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S65
You... do realize that you only think you purged ALL the air out of the cooling system, yes?
A proper air purge on a MB engine (at least the ones I'm used to), requires a venturi pump to put vacuum on the cooling system.
It's not an air pocket that's your problem. You have all the classic symptoms of a blown headgasket. I'm sure this is not what you want to read, but it is what it is.
A proper air purge on a MB engine (at least the ones I'm used to), requires a venturi pump to put vacuum on the cooling system.
It's not an air pocket that's your problem. You have all the classic symptoms of a blown headgasket. I'm sure this is not what you want to read, but it is what it is.
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S65
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From: San Diego
02 CLK430
You can get a block test kit that you place over the opening of the expansion tank. You fill it with a liquid that once mixed with exhaust gases (blown head gasket ) it will change color
http://www.blockchek.com/kits.htm
http://www.blockchek.com/kits.htm
Last edited by Ruination Fan; Aug 22, 2010 at 08:09 PM. Reason: added link
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CLK320
Well, the Benz is running like crap. Almost won't stay on (very rough idle) and will not get up to speed. Saw what looked like coolant dripping from the tail pipe. Blown head gasket? Think so.... @#*$&^@($!(
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CLK320
Sathinas - The thermosat is brand new, and did not solve the problem initially. I never suspected that it was bad out of the box, so I moved to the possible thing that was recommended (expansion tank cap). Got that new as well but no change. Actually got worse. See my previous post.
Ruin - Thanks for the post. That block chek tool is pretty cool. It's a must have.
Ruin - Thanks for the post. That block chek tool is pretty cool. It's a must have.
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From: San Diego
02 CLK430
Sathinas - The thermosat is brand new, and did not solve the problem initially. I never suspected that it was bad out of the box, so I moved to the possible thing that was recommended (expansion tank cap). Got that new as well but no change. Actually got worse. See my previous post.
Ruin - Thanks for the post. That block chek tool is pretty cool. It's a must have.
Ruin - Thanks for the post. That block chek tool is pretty cool. It's a must have.
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From: Bay Area
02 clk 55, 13 GL 450
All is not doom and gloom yet.. No need to pressure check the cooling system now, but have you pulled the dip stick yet? If the oil still looks like oil and not a choc milkshake then could be a "simple" gasket failure. At any rate I wouldn't attempt driving it at all and these are not the motors you want to "learn" on regarding teardowns. You could try pulling some plugs to see how many are wet but those heads are gonna have to come off at the least.
