I just changed my radiator, and everything is working, but I found out that the tempuature is running about 10C higher than before in any situation. I am wondering if there is any bleeder that I need to bleed the air out after I replaced the radiator?

Did you replace the thermostat and clock it correctly?

I would

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Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

I did change the thermostate and clock it correctly.

How high is it? Maybe, the old thermostat is bad. I have replaced many MB thermostats which were running too cold.

David

Check the hoses including, heater hoses to see if there is a slow leakage anywhere. Make sure all clamps are secure but not overly tighten or loose. Also, make sure there is the right ratio of water and coolant.

What is meant by clocking the the thermostat?

Thanks

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Mike

I just had the radiator/thermostat replaced (Dec.2000) in my 84 300DT and experience the same simptons. Prior to change out temp always just a nudge above 80C, now is runs just a nudge below the 100C. Another curious thing, the pressure escaping when opening the expansion cap is dramatically less than before. The old radiator leaked at the top tank, thus the need for replacement, would this leak cause it to build more pressure in the system? Counterintuitive I know but it just seems odd.

Mark

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1987 300DT 127K
1987 300TDT 283K (Sold)
1999 528iTa 75K
1991 300D 2.5T 214K - Dead Tranny
1984 300DT 375K (Sold)

Mike,

The OE thermostat (after market product may not) has a small arrow mark which should be pointing up when the theromstat is installed. I think that is what Benzmac called clocking.

A new thermostat for 617 engine should keep the engine at around 85C at idle. Diesel engine does not produce much heat during idle. It is easy to trap air in the cooling system.

David

I experienced something similar lately when I flushed the radiator. The temperature was about 10% more than the usual. I also felt that the fan was not kicking in. Despite checking it, nothing could be found wrong. Then it happened yesterday when stuck in a jam - the temperature rose to 110C. I knew this is not acceptable.

Had the fans checked again and sure enough, the fan clutch was playing up. Replaced the fan clutch and the switch for good measure.

So far so good.

__________________
... Kerry

126 tailed by a 203, 129 leading the pack.

Thanks
be459

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Mike

slai,...assuming that correct coolant mixture was made and new thermostat was installed, ...please check if you can bleed the water jacket. Also, ..check the radiator cap,.. the radiator cap is not holding tight, ..please replace as required . Hope that this will help.

Actually I didn't measure the coolant mixture, I put 2 gallons of MB coolant and just a litte bit of water into it.( I thought it will be better, but will it cause this problem?). I will change the radiator cap to see if it helps. by the way, where is the water jack? and how to bleed it?

I would check the thermostat in a pan of water. Have had many a new thermostat not perform correctly. Putting it in hot water also cycles it which tends to loosen them up a little. Also you may need to bleed the air out. Sometimes takes several trips to get rid of all the air.

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Mark
82 300SD 110k
91 Caprice SS
92 Jetta TD
97 Cadillac Concours(300hp)
84 Celebrity 4.3L diesel

and "a little bit of water" could be, in my opinion, some of your problem. The excessive amount of coolant to water does not transfer heat as well as a 50% coolant/50% water mix does.
Jim
'85 300D
'95 E320
'97 CRV

I agree with Jim. Premix the coolant first 50/50. I usually put 1/2 gal of new coolent into an empty coolant container then fill them up with tap water. This way, you have two gal of 50/50 mixture. Label the container as 50/50 when I do not use up all the 50/50 solution.

David