Hello all, My 240D has been running up to 90C everyday after I flushed the entire cooling system and that is with the heater on full heat. My auxillary fan does not kick on at all, I removed and tested the T-Stat which works but did hear some squealing coming from the water pump. I removed this without any difficulty. I used spray on gasket remover and a razor blade to remove the old material. I coated the pump with blue RTV and put the gasket on and coated the other side of the gasket. I put the pump in place and hand tightened all the bolts but when I began slowly tightening each in a criss cross fashion the right upper area of the pump pushed out and ripped the gasket (I replaced with an aftermarket WP as MB wanted $124 as opposed to $32). Do you think that some residual gasket remover caused this or am I doing something wrong? Does anyone know when the auxillary fan is supposed to kick on and does it run after the engine is stopped? I have been reading about the liklihood of the radiator fins being clogged and I will clean those as well but what is the most efficient way to flush out the inside other than a prestone liquid flush. Any help would be appreciated on this. Thank You.
Noel Smith Morrow, Ohio
1981 240D Euro 146k on clock but non-functional.

It is not deigned to come on when the engine is hot.

You did something wrong by using RTV on the gasket. Use a new gasket without anything on it.

Okay, thanks for the info on the fan. I should only use the gasket and no sealer? Thanks

Yes, perfectly clean mating surfaces and the paper gasket only.

I've never seen a $32 water pump...was it german or china made?

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Cheers,
Robert

Be sire to Clean all the RTV gasket material that has squeezed into your system out if possible.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Hi All, Well, No problem with getting the water pump back on, thatnks for the advice ForcedInduction and Robert. The pump came from Autozone with a lifetime warranty, states made in USA and foreign countries so don't know for sure where it is made. I do still have a problem with it heating up to 90C and will climb a bit higher when not accelerating. I used concentrated degreaser and coated the entire radiator and trans cooler, let it sit for about 1 hour and thoroughly sprayed it down. Is there anything else that I should be doing to correct this? The highest the temp was prior to this was 80C and that was for at least a year of my driving, Thanks again, Noel

90C isn't too bad.

Mine climbs to 90C in driving and idling, it'll climb to 100, then sit there. Previously would climb to 115-120 on the highway, and around 100 in the city.

That's after a brand new radiator and a full coolant flush...not sure why it's running a little bit high but its way better than before.

The odd thing is, I think my temp sender is slightly broke -- the temperature needle eventually will jump around a little bit and then peak at like 110C and then stay there until the car is turned off. I've replaced the sender, so I Think it must be the panel grounds.

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1983 Mercedes-Benz 240D
Automatic, A/C, Power Sunroof, Power Right Side Mirror
231K Miles FOR SALE MAKE OFFER

The last post jogged my memory. What if your temperature indicator has aged a little and is giving you a slightly false reading? Happens. On a 240d as long as it never boils over everything is probably okay. Or technically car is serviceable. This is of course with not running the heater motor.

Engine may be a little more efficient at slightly elevated temperatures. With engine up to temperature. Try a very llong hill if you have one locally. If engine does not loose coolant or boil over I would forget about it and just drive the car myself.
A completly different set of rules apply to the later engines with aluminium heads. You have the boat anchor engine instead that is all cast iron. I have a couple of 240ds myself.