Overheating engine after replacing thermostat

[luckyboy1228]

I got the fault code P0128 saying the thermostat was stuck open. I replaced the thermostat last night, took it for a test drive today and made it 7 miles with normal engine temp. then it raised 3/4 of the way then dropped back down to normal then it started climbing again. I shut the car down before it red lined. I've got heat from the heater. When I first fired it up when the heater was running there was a gaugling sound coming from in front of the oil filter housing that's similar to the sound of a ball moving around the roulette table and hitting the tabs--but only if the heater was running, that sound disappeared in a very short time... I'm not sure what my next move should be.. :headbang:

 

[fixit man]

I got the fault code P0128 saying the thermostat was stuck open. I replaced the thermostat last night, took it for a test drive today and made it 7 miles with normal engine temp. then it raised 3/4 of the way then dropped back down to normal then it started climbing again. I shut the car down before it red lined. I've got heat from the heater. When I first fired it up when the heater was running there was a gaugling sound coming from in front of the oil filter housing that's similar to the sound of a ball moving around the roulette table and hitting the tabs--but only if the heater was running, that sound disappeared in a very short time... I'm not sure what my next move should be.. :headbang:

Hi,

sounds like there's air in the system !

 

[luckyboy1228]

I'll try that-- It's free!

 

[Maniac]

Isn't there a how to/puma type thing somewhere on this. Something about starting the car and holding it at certain revs for specific periods etc. .. Perhaps give the dealer a call for some advice?

 

[yg54sg]

remove the plastic cover over the top of the radiator and undo the bleed screw next to the coolant filler cap while the engine is running and up to temp... be careful as it will be hot... you should see air bubbles and coolant coming out, rev the engine a little and eventually it will turn to just coolant coming out. I did this a few times until all the air was out.

 

[luckyboy1228]

I haven't yet seen any antifreeze yet.... Waiting for the engine to cool off before trying again.

 

[Stuart Truman]

If you've got no visible coolant, shouldn't you be topping it up now?

 

[luckyboy1228]

I'm still having trouble. I replaced the thermostat again-- under warranty, and found it was dry inside the engine block. Wasn't letting anything past it. The temperature is still raising beyond normal. I didn't see the fan kick on that's next to the radiator. I turned on the AC and it kicked on, I'm thinking it could be a sensor now. I'm not getting any codes. There are no leaks. Anybody else have an idea what it could it be?

 

[slick]

The Water pump impellars are plastic and have been known to fall apart, no way of checking without taking the pump off the engine though ......thats assuming you dont have a leak ?

 

[luckyboy1228]

There is no leaking!

 

[jttaylor]

I'm having a similar prob. When I pulled up one day I heard a rattle noise from near radiator after engine was switched off. It lasted about 10 seconds and went. Thought it was water pump but realised it was water bubbling. No leaking, so bled the system and it's been fine for a few days and then today it happened again. I haven't replaced anything yet so where should I start?

New Z4 owner and not that technical and limited mechanic knowledge :-/

 

[yg54sg]

forgot to say on my previous post, do this while the engine is 1/4 warm not when fully up to temp as I believe the system works under pressure, i just heard air escape the bleed screw followed by water not steam under pressure

 

[luckyboy1228]

I ultimately had to park it off the side of a hill with the nose sticking up a lot to get the air work out of the system. when the hose flew off--i forgot to reattach the clamp, i had to start the process over again. Its running like a champ now. :driving: