runs hot when stopped in traffic?

[mjulaw]

first time caller here…

'95 C280. temp gauge goes up when driving, but only when stopped. my common sense tells me this may be a fan problem...that there's plenty of air flow at higher speeds, but not enough when stopped.

i'm always of the mindset to troubleshoot with the easiest / cheapest and move forward from there. radiator flush, thermostat, are definitely on the short list, but if it's the thermostat, am i correct in assuming it would also run hot at higher speeds too?

i know the fan kicks on, i hear it when i crank the car in my garage. but maybe it's not kicking in to 'high gear'?

p.s. this one has 75k miles. i also have this same car at my mechanic's place with 245k. (we're gonna get it moving and donate it. told him it's our 'karma project') anyway, i'm almost 100% sure it has two fans, while the one i'm driving now has one. anybody have a clue on this? both '95. both C280. no 'sport model' etc.

mike

[wichipong]

have you checked the thermostat?

[mjulaw]

have you checked the thermostat?

that's the question i'm asking...is the fact that it doesn't run hot all the time an indication that it's NOT the thermostat? in other words, wouldn't a thermostat problem present itself all the time, whether moving or stopped?

but no, i haven't checked it yet.

[Abbaso]

It's the viscous fan that's not operating at it's full potential. Had the same problem on mine. OEM part from dealer was just sick and the pirate parts make too much noise sound like an airplane. So I drilled my oem part and filled it with EP90 gear oil. It's been good now for a year or so.

Right oil would be silicon oil found at hobby shops. Mine was out of it and didn't know when they would get some.

[sicelo]

I used Toyota silicon oil, doing the same thing as Abbaso. Works good :)

[andy_1100]

Check 2 things:
1. thermostat - has to be a 87 deg C openning
2. fan clutch

Had same problem, it develops slowly. Ended up changing the fan clutch, first got a KOOLman from Amazon - garbage, turned the car into a leaf blower, returned it and got a URO clutch. Works better, but I don't think its 100%. It's still noisy a bit.