Oh, nooooooo!!!!!!

[sedwar05]

Need some help! I just had the timing belt/water pump (metal impeller)thermostat and serp. belt replaced a few days ago, and now my bug is over-heating again...

Mech. is coming out tomorrow morning, what should I have him look for to trouble shoot? I'm reallllllly nervous that this happened and I need my car for work!

ANY ideas or suggestions would be most appreciated!

[raymondlee]

could somethign as small as flushing the coolant to get out air pockets.

or as bad as replacing fans/ fan module.

[sedwar05]

Maybe a bad temp sensor?

Or a fan switch?

I'm outta ideas for my baby right now, I'm so stressed about it!

[Pseudotropheus]

Restriction in the radiator, will cause the pressure to rise higher then normal. Also, need to check for the thermostat being installed backwards.

Very common mistake people make... Also, you are in Arizona. Whats the temperature been running there lately? Cars have alot of overheating issues in Arizona.

[sedwar05]

Originally Posted by Pseudotropheus

Restriction in the radiator, will cause the pressure to rise higher then normal. Also, need to check for the thermostat being installed backwards.

Very common mistake people make... Also, you are in Arizona. Whats the temperature been running there lately? Cars have alot of overheating issues in Arizona.

I'll have him check those too, thanks. Maybe a bad hose?

I live up in the mountains, so it's been in the 70's & low 80's so far. We only hit in the '90s a few days, and she was OOC for that. I know it's more of a common occurrence in the Valley (Phoenix) where 110+ temps are the norm...

[Smileybug]

Is it actually overheating or is the coolant light just coming on solid red? If its solid, check your coolant levels. You likely just have some air in the lines that has burped out and made your coolant level under the min mark. That happened to me about a week after getting mine done. Topped it off and then I was good to go.

[sedwar05]

I wish it did that... It's blinking the temp light and the coolant is actually boiling over...

Ok, so I was so stressed last night, I forgot to mention that when I topped off w/coolant, I drove her the 3 miles home with the fans on and the temp light went out for a few moments. I'm starting to think it's a fan or sensor problem now...

[sedwar05]

Just started her up and checked the fans. A/C is running nice and cold, luke-warm on the heat.

Fan comes on for the A/C but turns off when the A/C is disengaged...

[Canadianbugin]

Originally Posted by sedwar05

Just started her up and checked the fans. A/C is running nice and cold, luke-warm on the heat.

Fan comes on for the A/C but turns off when the A/C is disengaged...

Any CELS....????

[sedwar05]

Nope, no CELs. Mech. is coming out to check the voltage, he thinks it "might" be a relay that got loose from the pump install from one of his techs...

We'll see though...



I just want my car back...

[sedwar05]

Update:

Well, we switched out the temp sensor and have the problem narrowed down to a faulty fan control module.

No more over-heating since I've topped off the coolant (I'm going with the "burp" suggestion), so we'll switch out the module and hopefully she'll be good to go...

Thanks to all for the input!

- Stacey

[simonsi]

Originally Posted by Pseudotropheus

Restriction in the radiator, will cause the pressure to rise higher then normal.

OK, no it won´t. Engine circulation pumps are designed to provide flow, not pressure, if there is a restriction you won´t get more than a fraction of a psi pressure rise from the pump.

Second, if it did cause the pressure to rise, well higher pressure causes an INCREASE in the boiling point of the fluid under pressure (High School physics???), so that would be a GOOD thing if it happened, but it doesn´t.

I agree that a restriction in the radiator could cause overheating but this mechanism you suggest is just rubbish.

Why post crap, it doesn´t help the OP (other than help them sound stupid if they repeat it)?

[JaceyMelissa]

unfortunatly when mine did that in 08 and I had to have the head gasket replaced It would not overheat while idleing but at cursing speeds when the turbo was kicked in it would create excessive pressure and blow exaust into the coolant causing it to boil. Whatever you do don't just let anybody touch your car I did that and ended up rebuilding the head plus outher parts that did not need to be replaced good luck

[sedwar05]

Originally Posted by JaceyMelissa

unfortunatly when mine did that in 08 and I had to have the head gasket replaced It would not overheat while idleing but at cursing speeds when the turbo was kicked in it would create excessive pressure and blow exaust into the coolant causing it to boil. Whatever you do don't just let anybody touch your car I did that and ended up rebuilding the head plus outher parts that did not need to be replaced good luck

Understood and will keep that in mind if the problem persists....

My mech. is one of the best in the area for VWs and has been working on them for 20+ years, so I trust him... Plus, he does house calls, LOL

[Pseudotropheus]

Originally Posted by simonsi

OK, no it won´t. Engine circulation pumps are designed to provide flow, not pressure, if there is a restriction you won´t get more than a fraction of a psi pressure rise from the pump.

Second, if it did cause the pressure to rise, well higher pressure causes an INCREASE in the boiling point of the fluid under pressure (High School physics???), so that would be a GOOD thing if it happened, but it doesn´t.

I agree that a restriction in the radiator could cause overheating but this mechanism you suggest is just rubbish.

Why post crap, it doesn´t help the OP (other than help them sound stupid if they repeat it)?

pressure was the wrong the term to use I agree, however...

I just had the same scenario just happen on a XR-7 Mercury Cougar turbo charged. The Coolant lines in the radiator were contaminated and causing a restriction to flow, therefore it constantly overheated.

I can guarantee restriction in his radiator will cause an overheating issue!

[simonsi]

Originally Posted by sedwar05

Need some help! I just had the timing belt/water pump (metal impeller)thermostat and serp. belt replaced a few days ago, and now my bug is over-heating again...

Mech. is coming out tomorrow morning, what should I have him look for to trouble shoot? I'm reallllllly nervous that this happened and I need my car for work!

ANY ideas or suggestions would be most appreciated!

Back to your problem, you say overheating again, what were the circumstances of it overheating before??

[simonsi]

Originally Posted by Pseudotropheus

I can guarantee restriction in his radiator will cause an overheating issue!

Yes it would, whether that is his actual problem is another matter hence my question as to what were the original circumstances. After all having your water pump replaced doesn´t suddenly cause internal blockages unless the wrong coolant types were mixed.

[Pseudotropheus]

Looking at a tech tip in my book.

When fluid heats up, it expands, causing the pressure to build up, on systems with radiator caps, there is also a spring that is meant to get rid of pressure, typically once these spring loaded caps reach 15 PSI, they bleed out the pressure.

[simonsi]

Originally Posted by sedwar05

Update:

Well, we switched out the temp sensor and have the problem narrowed down to a faulty fan control module.

Did you switch out the coolant temp sensor in the black plastic flange assembly on the engine or the thermal switch in the radiator (the thermal switch is the one that triggers the radiator fans.

Did you need the water pump and belt replaced in any case by time and mileage?

[simonsi]

Originally Posted by Pseudotropheus

Looking at a tech tip in my book.

When fluid heats up, it expands, causing the pressure to build up, on systems with radiator caps, there is also a spring that is meant to get rid of pressure, typically once these spring loaded caps reach 15 PSI, they bleed out the pressure.

The spring actually holds in the pressure up to the value set by the manufacturer, VW set the NB system to 15psi, other engines and manufacturers have different values by design. The cap also contains a valve to prevent the system going to vacuum when it cools.

Your point is? Did your Bentley turn up? (sorry couldn´t resist )