thermostat

[mark.t]

Covering a few question with ths one, my temp gauge is ok at 78/82 max, and my e300 td has a tow bar (mb factory fit) so has an extra oil cooler, would this keep the temp of the engine down as i beleave most diesel run at about 85/90, is ths right . and do people have to take this into account when checking there temp.

 

[NormanB]

I am no expert but though the extra cooler was for transmission oil?! The engine thermostat should control engine water temperature to spec with ot without this additional cooler in the circuit.

 

[Ian B Walker]

Mark It would help if you could post a pic of the cooler in question as I have a feeling that it could be a transmission cooler. I have spoken with a guy once who claimed that he had an oversize radiator fitted for towing and an extra cooler for his transmission.

 

[andy_k]

if it is an oil cooler then yes it would cause your engines temperature to run lower than normal - oil not only lubricates but cools the engine (at least as far as I understand).

It's more likely the additional "radiator" is there to cool the auto fluid which wouldn't affect the engines temperature.

Fitting a new thermostat may be worthwhile although the temp on most of the engines will vary according to outside temperature and how you are driving it - does the temp climb when you sit in traffic? Through the winter our petrol W124 temp has hardly got above the 80 degree mark when driving but in the summer it hovers around the 90 mark

what temperature are your auxillary fans cuttting in? (don't put your hands in there -there's a relatively simple test to see if these are working properly using a carrot ). If they are permanently engaged then that would cause a drop in temperature.

Andy

 

[NormanB]

if it is an oil cooler then yes it would cause your engines temperature to run lower than normal - oil not only lubricates but cools the engine (at least as far as I understand).



Andy

Andy

I have no experience of this setup but I cannot agree with (respect) your theory. The engine thermostat should control within its tempertaure range and specification. If additional cooling is effectively being done elsewhere (lubricating oil) then all things being equal and the assuming the thermostat is not defective - then the thermostat will close up proportionately to the additional cooling and the status quo restored.

Norman

 

[mark.t]

temp

Thanks for the replies, having posed a similar question on temperature I know 78/82 is ok because Dieselmans run the same, although I don,t know if he has a tow bar fitted, ill get a pick of what I believe to be the extra cooler. Also in stationary traffic it dose climb to 80 never seams to go over even when doing over a ton, I don;t think there's a problem just interesting to find out if people think they have a problem with temp running lower than normal,i will also check my fans

 

[jimmy]

I recently noticed my C250TD was running cool, barely getting above 60-65. I fitted a new thermostat and it sticks right on 78-80 all the time. I have a tow bar and was advised to fit a transmission fluid cooler. When I looked I saw that mine already has a transmission fluid cooler, so that was one less thing to worry about.

Towing a fully laden trailer has never caused my car any problems, the temperature gauge never moves above normal. As Norman has said, extra cooling in the form of oil coolers or radiators or fans should not make any difference to the engine temp, the thermostat keeps it constant unless it is faulty.