hi I have a 2001 deville 88,000 miles car overheats in the city but on the highway it doesnt.I changed the waterpump, thermostat,radiator flush and changed the coolant.Radiator looks new.If i turn the car on leave it idle it takes about 10-15 minute to start overheating.No coolant smell in the tialpipe.Anybody can give me some hints?

 

sounds like an air flow issue ...

rad fans working?


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did you use dex-cool? if car originally started with dex probobly should continue..... heard of the same and guy took off brand coolant out and dex-cool back in and all was fine.... just a sugestion
rickyd

 

fans work. question can a clogged catalytic converter made the car overheat?

 

darn right it will.
but if it is clogged in the city, it is still clogged on the highway.

still sounds like the heat transfer from coolant to ambient air is not taking place.
are u sure the fans are working and working well?

on the highway, the ONLY difference is that the speed of the car pushes a lot of air through the radiator whereas in the city, the fans have to do it.





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Hi try to check if U have a right pressure in cooling system , does the coolant fluid go out when engine runs?