Hot 560sl!

[mattcara]

Hey all.

I am reaching out to 560SL owners! i think i need some good advice and maybe to start a poll here!

I have an 88 560sl 80k mls. really in tip top shape.

but! the damn thing runs hot and i dont know if its normal to run hot as hell in traffic or what? the gauge goes way down when driving.. and when im sitting in traffic it shoots right up and then back again,. and so on and so on,.

i love my SL and want to use it daily but its stressing me out now..

can some of you. or all of you ,,,, please post for me..


thank you!

[Walrus]

Matt,

Seems you have been having trouble from some time... As I recall, several have tried to re-assure you 107's can run around 100C, maybe slightly above at times. If you are experiencing temps above this, you indeed do have a problem. From your description today, I would guess your fan clutch is shot. I asume you have done all the other troubleshooting and remedys, and may have addressed the fan, but you did not say in you post.

How hot is it getting? Have you flushed the cooling system? Have you had the radiator cleaned and flow tested? Is the thermostat good or replaced? is the coolant tank cap seal good? Is the a/c condenser clean and free of debris? Is the fuel mixture correct? is the timing correct? how abut the oil... the correct viscosity? hows the tranny... All these thiings can affect engine temperature.

Post back with your results....

[mattcara]

Hey Rory,

My thermostat is new. cooling was flushed. and the temp gauge stays at 100.c

my frustration is that even tho I hear the fan on, and see a normal temp reading..

I am not crazy.. the car is hot.. hot.. hot.. fan buzzing too much,.

i can not accept the fact that this little high end SL is supposed to run soo damn hot!

I will once again look into this and ill post my final outcome..

Its just un acceptable.. my lexus is always cold engine and quite perfection..

how could people have bought these cars new and ran around with hot engines..

no no no no no this is driving me crazy/......

[ericdee]

Wow 100c, that's hot, sometimes the thermostat sensors read hot.

Take it to a Tech and have them take an infrared laser thermometer read on it.

[mattcara]

Eric,,

I took it to one guy and he said nothing was wrong.. i have to go again to someone else.. my gut tells me its too hot.

Have you ever touched the hood after a hard ride and almost burn your hand? that to me isnt normal..

I just want my SL to drive cool.. i sound like an old lady now..LOL

no offense anyone.. im just making a joke!

[ericdee]

Well it's a big motor, they do throw off a lot of heat. And yes my hood does seem to get really hot.

[Walrus]

Matt,
I ask again, Have you checked your fan clutch? The viscous clutch may not be locking in at temp, which would xplain your heating in stop-and-go traffic. These clutches are set to lock in at approx 90% engine speed at or above 105C, any other temp, or rpm above 3600, the clutch allows the fan to "free-wheel". I understand you hear the the fan "buzzing"... are you talking about the electric aux fan? It is set to come on when the a/c is on, and at temps above 105C... It is a two-speed fan, with the a/c-on slower than high temp. Mine typically runs 85-95, but I have seen 100 pulling a grade at speed, or a/c on in stop and go traffic. No worries there. Another question... Is your hood pad still in place? My hood does not get too hot to the touch, as you have described. I have always thought the car ran too hot, but have been assured it is running as designed. I even tried to get a cooler thermostat, but could not find one anywhere.

Eric,
Why do you think 100C is hot? The thermostat begins to open at 85, but is not fully open 'til 95C... After-all, 100C is only 212F. Not boiling if proper coolant mix, and radiator/coolant tank cap seal is good.

It took me a bit to get used to this... I am used to detrot iron running 180-195F.

[ericdee]

212.F is on the hot side not the cool side.

[mattcara]

Wal,


are you telling me that there are 2 fans? the one im hearing and another one?

I dont even attempt to put on my a/c, with the engine temps shooting up..

I did have it on yesterday in traffic, and then it blew out cluody air and dripped alot of water on my feet..!

so after the ride. my engine temp gauge read about 105c. my hood gave me second degree burns when i touched it, and my feet were wet.

dont get me wrong. the car didnt over heat.. no steam came out of the engine compartment..

but i just hate the way my 560SL is behaving.. do you really just think a fan clutch can be the problem here?

i didnt think so.. because i hears it on and i saw the temp gauge going down..

its the simple fact that the fan is soo loud, and i smell and feel the heat...

this cant be the german engineering. designed here...

[Walrus]

Matt,
No offense, but have you spent any time under the bonnet of your SL? There is indeed two fans... one electric auxillary fan mounted in front of the a/c condenser, and one engine-driven fan as with any 80's vintage automobile. It is driven via a v-belt and the crankshaft, and is equipped with a viscous clutch. The engine-driven fan is the primary cooling fan for the engine, with the electric to help out in high load situations and when the a/c is on. Next time you go for a drive, after shutting down the engine, raise the hood and spin the fan with your hand. it should NOT spin freely (no more than a half to full turn). If it does, prepare to spend $200US to procure a replacement.

Secondly, why is your hood so hot? Is the insulation pad not in place on the underside of the hood? It should be there to protect your paint!

Thirdly, is your fan shroud still in place and centered on the fan? If not, you must get a replacement!

Good Luck!

[Walrus]

Maybe these pics will help you...

[Walrus]

eric,

I understand 212 is hot by most standards, but not the 107SLs... It is no accident the aux fan, as well as the viscous clutch are set to operate at 105C, which means neither are employed at temps below that.

[mattcara]

i did not know there are 2 fans. i only see the one..

is the engine fan the loud one you always hear?

the hood pad is new, the previous owner must have put it in.

i live on the east coast, and i bought my SL on the west coast. so the car comes from a hotter climate.

all kidding aside guys, this is upsetting to me , that a perfect clean looking mercedes. would be giving me soo much trouble. I am going to try a professional mechanic and hopefully get it right.

but even after all is said and done, i dont know if i will be able to daily dive it, around NYC where i live if its going to be a hot running car..

Help! lol....

[mattcara]

thanks guys for letting me vent,,

i will definately keep you all posted on my final outcome..

i think you all desevre to know..

let me ask you all one last thing? does any of your A/c systems drip water on your feet?

[Walrus]

Perform the test I decribed... Then write back. A professional MB mechanic is a good idea. Many things come in to play; fuel mixture, valve timing, ignition timing, exhaust system (stopped up catylitic convertor), transmission, water pump, thermostat, radiator cap, hoses, etc.

Let us know how it goes...