contact148

My 003 c240 wagon the engine temp is in C you have 80 a space then a line a space then 120C

anyways when driving it usually stays around about 1/2' after 80C today it was 5C outside I was in stop and go traffic for about 45 mins and the engine temp got up to allmost the line betwwen 80 and 120c

ive never seen it go that high ever as soon as I got away from traffic it went back down to just above 80C BUT everytime i stopped at a light it went back up to allmost the line between 80C and 120C

NO coolant leaks no steaming no malfunctions

so is this normal temps??

Oh when i got home I put the winshie;d defrost on and the rad fan did come on so that works

LILBENZ230

~87C is the normal operating temperature, I believe.

glocati

That is the ~temp. my 04 c240 runs.

contact148

hmm well If it dose it agin ill try and get a picture of it

Glyn M Ruck

87/89 deg C is thermostat opening temp. The 240 should sit just below that center line in normal operation

contact148

by center I guess you mean the line between 80 and 120 c??


as mine usually sits just a hair above 80c

jcnash

Thats a pretty healthy temp.

You have problems if it stays at the 100C line or goes higher than that regularly.

87 deg is the absolute optimal operating temp but anywhere between 80-100C is normal, because lots of external factors influence engine temperature such as ambient temperature, traffic conditions etc.

acr2001

This question has been answered so many times. The proper temp is just over the 'half way mark' on the temp gauge. Please search

Glyn M Ruck

I do

contact148

ok got pics tonight



this is where it stays when im driving NO traffic. IE 15 min drive to work



this and the one below was after on the hywy for 20 mins at 120km then 5 mins city no traffic and 2 mins at idke for the pic



its never gone higher then the above 2 pics and to be honest ive had this car for 7 months and i never notuced it go above 80 and a hair before

samaritrey

could be a bad thermostat

Carsy

The temperature risefall seems to be related to engine load & the amount of air flow through radiator which is to be expected.

I do not know the engine but could I ask a few of questions.

Do the fan/fans run when the engine temp guage is reading high?
At what temp does the fan cut in.?
Has the temperature guage been calibrated?.
Has the radiator been back flushed , degreased & descaled ?.
Are the radiator external heat transfer fins in good condition?
Is the radiator operating at the correct pressure ?.
Is there a difference in temp readings when the thermostat is removed completely?
Can you see/feel a good coolant flow anywhere in the system ?.
Have you always used a corrosion inhibitor ? Heavy scaling of engine jackets can limit heat transfer.A jacket water descaler could help but be careful of blockages occurring.
Is the coolant of the recommended consistancy ? ie too much additive can cause less heat transfer& higher temps.

I hope someone else can come up with a few suggestions.

Glyn M Ruck

I don't know how well these temp gauges are calibrated. All your readings are in the very safe zone & slightly cool. My 240 is & always has been rock solid & very, very slightly higher than your highest reading. (56,000Km now)

I think that your thermostat is getting lazy - Benz thermostats fail wide open & you will get a P0128 to tell you that the car is running too cold. If it worries you change the stat. Otherwise wait for a CEL.

contact148

well the coolant is orig from what i know of the cars history

coolant last checked by MB in jan 07 car manufactured Dec 02

coolant appears to have some yellow (exact same colour as the coolant) goo in it

Now at 1st I thought maybe oil in the coolant but its not oil like its yellow and will disolve when run thru your fingers

car has 116,000Km on it I plan on doing a rad flush in the spring too cold right now

My coolant and oil levels never move

are the m112 engines know for head gasket problems??

Glyn M Ruck

M112's never have head gasket problems. You need a coolant flush & change - sounds like you have some gel formation. Your car precedes the 15 year coolant change & does not have the silica gel sachet in the surge tank to release silicates.

contact148

thanks alot Glyn youve been very helpfull!

Carsy

I would sack the MB Service if your coolant has not been changed for 8 years & therefore allowing a cheese buildup.

What does your service book say on coolant change servicing?

I would do a flush immediately.The cheese could be beginning to block your radiator.

contact148

book says 250,000km or 15 years.....

id love to do the flush now but its -10C here and my ****** jeep takes up my garage which is also unheated so the flush has to wait till it warms up Im going to do the t-stat at the same time

samaritrey

ok so i was stuck in traffic two days ago and remeberd your thread. ok so it was about 40F out and i was stoped to about 20mph and my temp was the same as your 2 and 3 picture. i did get a new thermostat about 1 1/2 ago.

genius

where is the thermostat loacted?

Is it hard to change? Is it in a tight spot? Does anybody have a picture where it is located?
Mine has a clear fluid in it. what is the fuild called? where would be the cheapest place to buy it?

Do you just add the fluid in the white contanier? At what level in the containier should the fluid be at?

thank to all that help

Glyn M Ruck

See item 53 - easy to change


I recommend using Benz genuine coolant or Zerex GO5

Dealer or rmeuropean
Zerex at most parts stores

Filling & level instructions in owners manual. If you don't have a manual download from forum. Fill to black top line on surge tank.

Bennzy

There is a half way mark between 80 and a 100, I believe it is 90. Your temp will fluctuate between the two but never gets to 90. You should be fine.

tammuz

Hello, I know this is an old thread but I am having issues with my temp, It is too low it is usually at 60 when driving at a normal speed on the highway, it does get to 80 but only if the car is not moving.

I just replaced the Thermostat and the coolant temperature sensor but no luck.

Anyone has any idea what could be wrong?

The car is a 1999 CLK 320.

Thanks