Question
300TD
Hi Robert,
I recently purchased my Mercedes 300TD. With little knowledge of diesels, I'm still getting to know her ways! Question -- it seems when idling with the air conditioner on that sometimes the engine temp goes to the maximum. Also, do you know any Mercedes experts in Maine?
Thank you!
AnswerHello Lisa,
You did not indicate the mileage on your vehicle, but you may need to have the cooling system checked.
There should be no connection with the AC temperature rise and being a diesel.
I would be sure to use the proper weight oil and make sure it is topped off. The Oil help remove heat from the vehicle.
All shrouds around the fans should be in place.
This vehicle may have an axillary fan in addition to the belt driven fan.
The electric axillary fan should be operating full time when the AC is on.
The engine drive fan must have a belt that is properly tightened, not slippage.
The engine drive fan clutch should be in good condition.
This is a fluid clutch that engages with rise in temperature to increase air flow through the radiator.
I would have the AC checked by a competent technician. If the AC is building too much head pressure it can damage the compressor.
The AC condenser on the front of the radiator and radiator veins should be clean and the radiator tube need to be in good condition as well. You may need to have the cooling system chemically flushed. It is also important that the coolant be of the correct mixture. At least 50/50 %. Make sure that your radiator cap is holding pressure and that your coolant recovery tank has coolant at the proper level.
If the coolant in this tank get too low, your radiator will pull in air and air bubbles in the circulation system cause excessive hot spots. The recovery tank hose should always be covered with coolant. This allow any air bubbles in the system to escape and water to be drawn back into the engine.
I would try to locate a local Mercedes Benz club in your area. There are many resources through a club.
I would try to locate an independent Mercedes mechanic.
You should check out www.benzworld.org/forum .
There are hundreds of on line members and there is an are that will cover your vehicle.
Because of expense, a dealer should be your last resort.
Good Luck. Let me know what you find out.
Robert
