Mercedes SLK World banner

Status
Not open for further replies.
1 - 14 of 14 Posts

·
Registered
Joined
·
50 Posts
Discussion Starter #1
My 2004 SLK200 Automatic does not get above 70 degrees, even in slow moving traffic it fails to reach 80 degrees. I assume it should be in excess of 90 degrees!
What temp does everyone else's run at?
Hoping for a reply.
Chris:grin:
 

·
Registered 2014 SLK250
Joined
·
1,001 Posts
Do not rule out the sender unit though - in fact many will change the sender along with a thermostat as a matter of course, and as they are a doddle to put in, many try this first. But probably right that it is a thermostat open.
 

·
Registered 2006 SLK280
Joined
·
1,274 Posts
Hal & Beppi are right; it's almost certainly the thermostat that's failed in the stuck-open position.

One thing strikes me as odd with you guys running the SLK200...you don't get a CEL lighting up with this, do you? On my SLK280, when the thermostat failed it threw a CEL. It doesn't make sense to me that one engine family lights up a failure indicator and another does not; Mercedes is usually more consistent than that.
 

·
Registered 2006 SLK200
Joined
·
629 Posts
Hal & Beppi are right; it's almost certainly the thermostat that's failed in the stuck-open position.

One thing strikes me as odd with you guys running the SLK200...you don't get a CEL lighting up with this, do you? On my SLK280, when the thermostat failed it threw a CEL. It doesn't make sense to me that one engine family lights up a failure indicator and another does not; Mercedes is usually more consistent than that.
If the thermostat is stuck open there is no warning from the cel, there is no danger driving with an engine temperature between 70C and 90C degrees. I drove quite q while before noticing the temperature was low. However the car responds better now at 90C degrees.
 

·
Registered 2006 SLK280
Joined
·
1,274 Posts
If the thermostat is stuck open there is no warning from the cel, there is no danger driving with an engine temperature between 70C and 90C degrees. I drove quite q while before noticing the temperature was low. However the car responds better now at 90C degrees.
Agreed that there's little danger of overheating with a stuck-open thermostat, and not surprised that the car runs better when it gets to the proper temperature. What mystifies me is why my M272 V6 SLK280 is programmed to throw a CEL when the thermostat fails, as mine did last year, and your M271 I4 SLK200 does not. There's no reason that I can discern why the two engine management systems should respond differently to the same failure mode.
 

·
Registered 2006 SLK200
Joined
·
629 Posts
Agreed that there's little danger of overheating with a stuck-open thermostat, and not surprised that the car runs better when it gets to the proper temperature. What mystifies me is why my M272 V6 SLK280 is programmed to throw a CEL when the thermostat fails, as mine did last year, and your M271 I4 SLK200 does not. There's no reason that I can discern why the two engine management systems should respond differently to the same failure mode.
I think that car has a different thermostat with different compartments. I also has a heating element to heat up the thermostat so it will open. Much more evolved set up.
 

Attachments

·
Registered
Joined
·
84 Posts
"Who would have thought that a nuclear power plant could be so complicated!" -- Homer Simpson

Looking at the cooling system in the R-272 with its electrically controlled multi-plate thermostat, separate recirculation pump, & washer fluid heat exchanger, I am reminded that German engineers are the only people in the world who use 5 lines to draw a triangle.:laugh:
 

·
Registered
Joined
·
50 Posts
Discussion Starter #12
"Who would have thought that a nuclear power plant could be so complicated!" -- Homer Simpson

Looking at the cooling system in the R-272 with its electrically controlled multi-plate thermostat, separate recirculation pump, & washer fluid heat exchanger, I am reminded that German engineers are the only people in the world who use 5 lines to draw a triangle.:laugh:
You are quite Reich:laugh:
 

·
Registered 2004 SLK200
Joined
·
647 Posts
I'll piggyback that thread.. it looks fresh ;-)

My new toy (R171, 200 kompressor, 2004) never reaches more than 50 deg C - I guess thermostat stuck wide open is not unusual? I didn't have time yet to check if the radiator gets warm shortly after start.
 
1 - 14 of 14 Posts
Status
Not open for further replies.
Top