A4sauce

Ok check it... my car seems is overheating if i pass a certain speed-after 50mph the temp gauge will climb, but if i slow down the gauge will drop back to normal?!?! what the heck is wrong? fluctuates relatively quick ...Weird thing is, the car doesn't overheat at idle or low speeds. any help? waterpump?sensor? t-stat?

stefano

it could be the pump or the thermostat too.

Bronze

My fan controller died at 45k. It did a similar thing. Dealer diagnosed it easily.

bhvrdr

Usually a bad fan controller will cause probs at idle, not at speed when you have airflow.

bhvrdr

Definitely get it checked. A bad WP is very good to catch right away. Usually a bad coolant sensor will have you read eroneously low and eventually will peg the needle at "C" all the time. Fan controllers generally will see overheating at idle and better temps as the car gets moving air over it. Like stefano said, it's easy and cheap ($15) to replace the coolant sensor so you could always just replace it to rule it out. Don't mess around with a bad WP though. If it sticks, it's big money. cheers! Mike

diagnosticator1

the impeller absorbs more power and the loose fit (the impeller is a shrink on fit by design} causes the impeller slip to increase, and unable to provide enough coolent flow at higher speeds. This is why you want a pump with a metal impeller, I am fairly sure the OEM impeller is plastic.

Bronze

until I put the heat on with the blowers on high. Then it steadily went down to normal. I was really surprised, and a bit skeptical when the dealer made the call on the controller, but they replaced it and I've had no issues ever since (two months ago).

I guess that temp gauge actually does work, and it's not a normal/not-normal dummy gauge.