Hello guys,,i own an SL500 '93....it has done about 110 000 miles,,,i live in a very hot country,,tempreatures afternoon reach 114-116 F,,do u think its normal that when i turn on my AC car over heats to 100 or a little above? some ppl told me that i need to change the HEADS which is a very expensive thing,,and some told me that a 500 in my place its normal to overheat at bad weather.....thank u all

 

Politely ask these people to STOP giving advice to you or anyone else.

Absolutely. Just make sure the auxiliary fans in front of the radiator are running.

 

thanks mate,,i just made the radiator fans work faster..by adjusting some electrical thing,,,do u think its ok to make them fast all the time? or should i put them back to normal speed? thankss ....

 

Another thing to do is 0 time your coolant, did you buy the car used?, you may not know how long the coolant has been in the car and it is a cheap fix to drain it, flush it with a hose, and reinstall the correct coolant in the correct ratio. If you still have your owners manual you can see when this last service was done if your car had been maintained by the dealer. If not, just do it yourself.
I am big on only using what Mercedes originally put in the car so follow the service manual if you have one, but I do not either so here is some background if you do not want to call the dealer and ask. NOTHING cools better then straight water but you have an aluminum engine and straight water will cause corrosion so you will have to run an approved additive to prevent this. Anti freeze is also required even if you live in a hot climate as it also has (the best brands) a anti corrosion additive and a water pump lubricant. NEVER add more then 50% anti freeze to the water in your system or it WILL overheat, that is another good reason to drain and flush your system as you are probably not sure what is in there now.
Go to Mercedes first and use what they recommend, barring that, buy some premium anti freeze and a good anti corrosion lubricant and do it yourself, your cylinder heads are probably fine, this is a 300,000 mile engine in a car that cost $75,000 new, it has only the best parts, if it has never been seriously overheated, your engine will be fine. Von