230K
MB Enthusiast
- Joined
- Jun 1, 2003
- Messages
- 2,190
- Location
- Belfast
- Car
- 09 E320 cdi Sport Estate, 98 E300TD Estate, 99 SL 500
Hi
I had a call from a firend yesterday with a 1998 C250 Turbodiesel, he explained his car was boiling over and that it just happened all of a sudden.
On the phone i told him what was most likely the cause.
He was able to limp the car to my house hoping for help!!!
After a cup of tea and a natter (allowing her to cool) I removed the thermostat housing and released the tension on the belt and poked my finger in at the back of the impeller and spoked the front pulley to see if i could feel the impeller turning and sure enough it wasnt and hence the cause of the overheating.
This seems to be a common problem on the 605 and 606 engines in the 202 and 210 models and can be wrongly diagnosed as the head gasket, viscous fan etc etc.
My advice if you have any over heating on these engines is to check the impeller by simply removing the thermostat housing, 2 bolts!! and check to see if it is turning in time with the pulley.
The impeller gets brittle with age and seems to fail in hot weather when car is running that little bit hotter than usual, photograph below of how my pump looked when it failed in 2006.
Hope this helps someone.
230K
I had a call from a firend yesterday with a 1998 C250 Turbodiesel, he explained his car was boiling over and that it just happened all of a sudden.
On the phone i told him what was most likely the cause.
He was able to limp the car to my house hoping for help!!!
After a cup of tea and a natter (allowing her to cool) I removed the thermostat housing and released the tension on the belt and poked my finger in at the back of the impeller and spoked the front pulley to see if i could feel the impeller turning and sure enough it wasnt and hence the cause of the overheating.
This seems to be a common problem on the 605 and 606 engines in the 202 and 210 models and can be wrongly diagnosed as the head gasket, viscous fan etc etc.
My advice if you have any over heating on these engines is to check the impeller by simply removing the thermostat housing, 2 bolts!! and check to see if it is turning in time with the pulley.
The impeller gets brittle with age and seems to fail in hot weather when car is running that little bit hotter than usual, photograph below of how my pump looked when it failed in 2006.
Hope this helps someone.
230K
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