S350 engine running to hot

[rekatt]

Hi there. Last time I drove my car, like three days ago, I noticed that the temp had gone up to 100 ºC, after that I stoped the car for like 30 minutes and the front hood was real hot. This never happened before.( Actually just once but then this guys that test drove my car stepped on accelerator as hard as he could, and that was uphill). After 30 minutes I drove it again and just so I test it I pressed on the accelerator real hard and the temp went 105ºC.After that I just parked the car home and I haven't driven it since. I consulted some buddies and they told me to turn the engine on and after it gets at working temperature open the radiator cap and see if the water is circulating, if it is the water pump is good. Then grab the water hose and if it is hard and you arenot able to squeeze it then it is the thermostat, not letting the water go through. If both of these work then its either the fans or a clogged radiator. Please advice

[pentoman]

Originally posted by rekatt
temp went 105ºC.After that I just parked the car home and I haven't driven it since.

105 degrees is fine - the auxiliary fan should cut in at around this point and bring the temperature down. Check that it does.As the system is closed, it won't boil the water at this point because the pressure prevents it from doing so. You may also want to search/post in the diesel forum assuming this is a S350 turbodiesel.

I consulted some buddies and they told me to turn the engine on and after it gets at working temperature open the radiator cap and see if the water is circulating

I think that is a most insane idea..

IMO, when the engine is at running temp, you should put your hand on parts of the radiator and check it's not cool in any areas. That would check for a clogged radiator. Otherwise, if you haven't had a coolant flush and replacement recently, do that

more suggestions?

[sixto]

Originally posted by pentoman
I think that is a most insane idea..

Are those people beneficiaries on your life insurance policy?

In the first place, your car doesn't have a radiator cap, it has a pressurized reservoir cap. There is no discernable flow through the reservoir.

Another thing to check is the thermostatic clutch on the belt driven fan. I don't know how to check it other than to listen for it to engage when it should.

Sixto
91 300SE
87 300SDL
83 300SD