What is the normal temp for a 3.5 on a warm day (80-85). My car seems to run hot around 180-220, in stop and go traffice even hotter. Can anything be done to keep the car running cooler?

Thanks,

Dave Benson
71 3.5 Coupe

Like what section of Phoenix do you live in?

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

aux fan turning on? Rad full? T-stat new? Last coolant flush?

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

The aux fan is working, actually I have made a bypass switch that allows me to turn it on manually. Radiator is full, have not checked coolent, will this help much??

Dave Benson

Just checking the coolant level will not help. However, if you have to add a quart or two, it might help a lot. Does your car have a coolant recovery tank. I think it does. All you have to do is look at it, quite carefully on an old tank because they do fog up with age. But if there is coolant in the recovery tank, then your system should be full.

__________________
Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

I had a similar problem in my '72 280SE 4.5. Turned out to be a bad fan clutch. Replacing it made a huge difference in reducing engine temps overall.

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1972 280SE 4.5

I'd recommend flushing the system, if you haven't done that lately. Use M-B antifreeze, and distilled water. Check the thermostat, water pump, hoses, belts, the works. Don't let it overheat! I had a serious overheating problem brought on by using stopleak on a slightly leaking radiator. Bad move, cost me an engine rebuild. Agree that it could be a malfunctioning fan clutch too. They can be rebuilt. Ned

Number one 180 to 220 is not running too hot. Dont go crazy replacing parts. Make sure the radiator cap is new and the proper pressure for that car. Verify the front of the radiator is not covered with road debris, bugs, animals etc. that would restrict in coming air. Pull the shroud off around the fan and flush the back of the radiator. Then drive it. Your main concern is that the temperature is relatively stable. Gets to 180 quickly and stays there unless you're creeping thru traffic, then it should go to 210/220 at which time the aux fan turns on and lowers the temp 10 to 15 degrees. A weak fan clutch could be an issue but an expensive gamble. When my 4.5 fan blade broke years ago, I put a non fan clutch blade on it from , I believe, a 240D. Ran it a week till I got another blade. Noisy, but temp remained stable. A simple test for a fan clutch is to blow compressed air against the fan blade normal rotation at idle, effectively stopping the fan from rotating. Once the eng. temp gets to a hi enough temp the clutch will engage the fan and the air will not hold the fan from spinning. If the fan remains stopped and the gauge says 200, the clutch is faulty. Quality of coolant and as close to a 50/50 mix will help stabilize temp as well. Too much water, not enough coolant will run warmer. If its over 2 years old replace the coolant as insurance. Do your best to get to a 50/50 mix.

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81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.