I just had my water pump replaced and a coolant flush. 35 miles later, my MAL light came on and my mechanic said my thermostat needs replacement. Should this have been done with the water pump work, or could the work have caused the thermostat problem?
I agree with Scott.Truth is though the water pump is a completely different issue than a thermostat.The only relation they have is both are part of the cooling system.If it had been me doing the water pump i wouldn't have changed the thermostat either
My philosophy on thermostats is if I don't have a reason to suspect trouble with it I don't change it. Thermostats don't have any particular life expectancy - the one in my daughter's Accord is 18 years old and works better than new aftermarket thermostats I have tried. I haven't replaced a thermostat in about 15 years. They are often blamed but (until recently, with the introduction of fail open thermostats) rarely at fault. EDIT - I also agree with BR549, although for a different reason. Professionals have to work somewhat differently than DIYers because of where the costs fall. I would rebuild a starter and it would be a lot better than a store-bought rebuilt, but a pro would be taking on unnecessary risks if he didn't replace the starter. His perspective splits the question in two: should the thermostat be replaced during coolant service, and should a professional mechanic replace the thermostat during coolant service? I answer no to the first and yes to the second. The replacement may actually be a step down from the one we know works, but it is also the safer way for a pro to go.
Anytime I replace a water pump, intake gasket, or anything else where the coolant needs removal, I always suggest to my customers that we change the thermostat as well. Many times I just change it anyway. I tell the customers, but really don't offer an option! (of course if they say don't I will honor that, but no one has ever said that!) It is possible that during a flush some trash/scale got into the thermostat causing improper operation. With the thermostat removed, there is no restriction in the cooling system making flushing easier and more thorough. Now to answer your question, It is my opinion he SHOULD HAVE. That is not only an up-sell (even though I hate creating extra work) it is just an added value to the customer. He should also check belts and hoses, changing them (via customer approval) if needed. As a mechanic, the last thing I want is a comeback such as yours was because I at the very least didn't suggest a proper service!
Yes he should have replaced it. It was pretty stupid for him not to replace it. Everything was taken apart and the thermostat was right there. Now he's going to undo everything he did, have you pay more for gaskets and coolant, replace what he should have replaced in the first place and then put it back together while your without a car for a few more days. If I were you I'd find a competent mechanic.
Yes an no. Is it a good idea? Yes. Especially if the vehicle overheated. Is it required? No. It will be extra labor to replace the thermostat. He did not cause the problem but he probably should have recommended it to you. It would have cost you the same extra money then as it did now. Just would have saved you time.
