Thermostat Replacment
 

Regarding my 87 560 SL, my mechanic claims that as a matter of maintenance, one should replace the thermostat while doing a radiator flush. Should this really be done? If so, what is the parts and labor likely to be?

Thank you.

It may have more to do with the timing of the service interval.

If you are doing a radiator flush like every 50K miles for example, the thermostat may be due for a replacement at the second flush interval.

Replacing it won't hurt, regardless, as the part is about $30. I wouldn't replace it unless you are noticing signs of high operating temperatures lately...

As a matter of practice, I replace my thermostat when I change the coolant. The part is about $15 from Fastlane, and you have to drain out some of the coolant to replace the thermostat anyway. Once the coolant is out, all you do is loosen three bolts or so, take the old one out and put the new one in. So, I see it as cheap insurance.