normal running temp for 300CE?

[Nik_Codling]

Hi All,

I've noticed recently that the temperature on my '89 300CE is a little higher than it has been. The needle always used to sit around the 80 mark on the gauge, but has recently crept up a bit from there - approximately half way up the gauge. What's normal for this type of car?

I do seem to have a very slight coolant leak (I believe where the expansion hose goes into the top of the radiator) atlhough I haven't cheked thoroughly elsewhere.

I recently topped the coolant tank up with water, and although the anti-freeze still seems to be doing it's job I should imagine the coolant could probably do with changing? It's not been changed in a little over 20,000 miles.

Any advice on obvious things top check on this type of model would be appreciated.

cheers,

Nik

 

[Spike]

If you have a 'slight ' leak, the system will not be able to maintain the pressure adequately which in turn will mean that your temperature will rise above normal.

Only cure is to get the leak fixed.

 

[Orlando 300E]

May be the answer

My 91' 300E had a plastic thermostat housing, that had cracked where the top radiator hose connected, creating a leak.
the replacement I got, now comes in alloy, with a bleed screw. Seem to remember less than a tenner plus only ten minutes to fit.
good luck,
Orlando

 

[Nik_Codling]

running temp

Thanks Spike. Makes sense. I'm going to get it pressure checked.

One thing that occured to me - when i start the engine from cold it takes a few seconds for the engine to catch. Is it possible that a slight leak from the head gasket could be allowing coolant into one or more of the cylinders? There's no evidence of leakage in the coolant or oil, but maybe a very slight seapage could cause this? It's ok when the engine's warm, so it would seem to go along with this theory, or am I talking bollards?!!!

I'm sure my ignorance must be highly amusing to those of you that know what you're talking about, but if i don't ask I won't learn, so stick with me!

cheers,

Nik

 

[sunil sood]

the normal gauge behaviour should be as follows:

the needle usually rests just above the 80 mark while driving along.

during periods of idling or in long traffic queues -the needle usually creeps up to midway between the 80 mark and the next mark on the temp gauge-(think this is the 100 mark).then the fan usually cuts in to maintain temp around the 90 mark.

i would get the leak sorted out as this could contribute to the rise in temperature,and also make sure you have the correct coolant mixture -ie deionised water and antifreeze in the correct propotions for your particular model.

hope this helps.

 

[Nik_Codling]

running temp

Thanks Orlando, I'll check the thermostat housing later today.

On that subject, how often should one expect to replace the thermostat?

Cheers Sunil, to be honest your running temp sounds exactly the same as mine. I've not found it to be running alarmingly hot - it never even gets near 100, just that it's been slightly higher than normal recently. Odd, as it's bladdy cold, even on the south coast!

cheers guys, this forum is great!

Nik

 

[Matt Crooke]

Re: running temp

On that subject, how often should one expect to replace the thermostat?


Nik

i dont think there is a set period when it should be changed. Generally they get changed if a fault occurs and the car starts to run too hot, or takes forever to warm up. This can usually be narrowed down to a stuck thermostat.

Also, for the sake of 15 squids or so a new one wont hurt, and it wont break the bank either!

Cheers

 

[Nik_Codling]

thermostat

Thanks Matt.

Can anyone tell me if I get the thermostat housing when i purchase a thermostat? Sounds like a daft question, but I've heard of some cars where you get both. I know I need to replace the o-ring, and though as I have the plastic housing it might be good to upgrade to the alloy one.

Nik

 

[Spike]

I cant remember for sure but I think when I bought mine, the housing was about £15 and the thermostat and the 'O' ring were about £5.

Changing them is a doddle...just three screws I think et voila. Just remember to try to bleed the system of all the air you can when you are done.

 

[AHJ]

HI NIK

IT MAY BE WORTH CHECKING THE RAD. I HAD A SIMILAR PROB ON MINE!

WHEN THE ENGINE IS WARM AND ENGINE OFF, CHECK THE HEAT IN THE MIDDLE OF THE RAD.

ON MINE THE RAD GOT BLOCKED AND THE MIDDLE IT WAS COOLER THAN THE SURROUNDING AREA, THEREFORE NOT LETTING THE HEAT THROUGH TO WARM THE OIL IN THE FAN AND THEREFORE FAN WAS NOT WORKING PROPERLY.

JUST AN IDEA

 

[Spike]

PARDON? :wink: