Greetings Forum Members,

I could use your help in solving an ongoing problem.
The temperature guage creaps into the red zone only at highway speeds in my 1972 350sl.
I drive the car less than 2000 miles a year and the problem was first notice on my way to an auto meet last year at Limerock CT, almost half way there I had to turn off the interstate, let the engjine cool down and return to Boston.
I thought the problem was fixed after installing a new water pump and thermostat this year.
Yesterday, on a 15 mile highway trip the temp guage started heading towards the red zone again!
I don't see this happening driving around town..
The fan clutch seems to be ok, has resistance when tested at rest, turns at idle and when engine is reved.
I can feel air being pulled through the AC core into the radiator at idle.
Could it be inadequate system pressurization? Clogged radiator?
Has anyone had experience with this or a simular problem?
The car is grounded until this problem is solved.
Any and all help would be most appreciated.

Thanks,

Knarf

__________________
72 350SL #69
73 450SL Parts Car?
78 450sl Parts Car
79 450SLC - Sold
1985 280sl
87 190E 2.6 - Donated
90 300E-Junked
97 E420