Vy Overheating issues

[Amy Winslade]

Hi everyone, I'm new to the forum. I have some questions about my car.

I have a 2003 Holden vy acclaim. I have recently replaced alot of parts. Most recently the thermo stat, plugs and leads, air filter (switched to k&n) and the altenator.

As of yesterday, my cars temperature sits where it always does, then as I drive around for a little while the temp goes up a little bit. Just below hot. Then if I stop anywhere, traffic lights etc, the temp drops back down to normal....

I also noticed last night that even though I had used my air-con in the car that day, when I used it last night, the temp gauge instantly hit overheat. Turned the air-con off and the temp dropped but this time it only dropped to just below redline..

My question is, what could cause this. Thermostat has been replaced, coolant was bled all done about a month ago... Etc etc

Help pleaseeeee!

 

[Lex]

Hi
Welcome to the forum.
Maybe water pump? I'd start with that. I'm assuming radiator is good?

 

[Amy Winslade]

Blonde moment. Didn't think of the water pump. That would be it is assume, radiator is fine as far as I know. Thankyou

 

[PlenumBiscuit]

could have air pockets in your coolant, give it a bleed maybe

coolant temp sensor could be faulty and i would spray the plug with contact cleaner, in fact spray up all your sensor plugs clean off gunk

radiator cap could be old but it would piss out your coolant, just something i would look at if was mine

i personally would reset ecu take battery off for half hour, may or may not help

 

[Amy Winslade]

I just bled the coolant. Was alot of air in there but I've noticed there's a bit of movement in the pulley to the water pump... Will try and upload a video of possible. Also how would I know if the radiator cap needs replacing? Any noticeable signs?

Sorry for any stupid questions, Im Learning here so bare with me haha

 

[PlenumBiscuit]

just if the cap is old n crap. but its only faulty if you notice the radiator has dropped half your coolant on the road. its worth replacing for the long term but but only small chance it will fix your issue

 

[Amy Winslade]

Thankyou evbenji..

Don't think that's an issue. I have just disconnected the battery like you said to reset the eve. Will see how it goes later on otherwise it's looking like the water pump unfortunately.

Thankyou for all your help

 

[Amy Winslade]

Hi again everyone.

Still having over heating issues.

I have had the heater tap replaced as it was buggered and also the water pump. The coolant has been bled twice in the last fortnight in case of airlock bit that's not the case.

Just wondering what else it could be? Could it be the coolant/water temp sensor?

 

[Immortality]

Sorry to hear the problem hasn't been fixed.

Seeing as you recently fitted a new K&N filter I would start by cleaning the MAF. Oiled type filters have a habit of contaminating the little wires inside the MAF that can make the engine run lean which will contribute to any overheating issues that may be present.

It still sounds like there is an airlock in the system, try running the engine with heater on full hot preferably with the car parked on an incline with the car facing uphill. The radiator cap is a crucial part of the cooling system, as the system heats up the coolant expands and the radiator cap will allow some coolant to bypass it into the expansion tank to maintain the correct pressure and then once the engine is switched off as the engine cools a slight vacuum is created in the cooling system (as the coolant contracts) and the radiator cap will allow the coolant to pass back into the radiator from the expansion tank. Old or tired radiator caps tend to not seal the system 100% so they will allow the coolant to bypass into the expansion tank but don't seal well enough when things cool and instead will allow air to enter the system instead.

Another possibility is that your new thermostat is faulty. Start the car and let it warm up. Monitor the top radiator hose and as the engine gets up to operating temp the top hose should heat up as the thermostat opens. If the thermofan comes on and the top hose isn't piping hot than the thermostat is probably faulty.

 

[Amy Winslade]

Thank you for the advice I will try that and see how I go fingers crossed!!!!!