Overheating and need help STRANDED OK CITY!!

[Johann2.7t]

Hey everyone, need some advice and counsel.

Im enroute Albuquerque via Boston and stuck in OK City on a sunday!

Car is overheating and coolant is not circulating at all.

I replaced all the major coolant components about 6 months ago including a metal fin water pump https://www.ecstuning.com/ES8146/

Yesterday when driving i noticed the car would overheat towards the 3/4 mark on hill climbs or under high loads. It would return when in cruise or downhill. It will overheat even at idle given enough time.

Because Ive replaced everything I was under the impression I had air in the system even though ive previously bleed using an ECS Pressure bleeder system.

This morning I cracked the hardline bleeder and coolant comes out (engine running/and off when cold) I also tried bleeding via heater hose and nothing comes out at all (no circulation it seems). The fluid level in the reservoir backs up and will overflow given enough time at idle. The upper hose is hot to the touch and the lower hose is cold.

also replaced within 4 months the lower temp sensor and entire electric thermostat assembly and J plug.

Any ideas on how to test the various components involved?

PS doesnt leak or burn any coolant what so ever.

[imnuts]

Sounds like the water pump may be bad and it isn't circulating coolant anymore. Sounds like you checked everything externally, so the only stuff left is going to be tearing it down to look at it. There have also been several people on here recently with WP failures and all of them have been the metal impeller water pump.

[Militant-Grunt]

Did you replace the thermostat? Let the car heat up, see if you have heat, also touch the bottom coolant radiator hose under the coolant tank. Assuming this is a 1.8t?

[diagnosticator]

Looks like you will be in OK City overnight. You will need to replace the coolant pump, either yourself or at an indy Audi shop? I use only OE Audi coolant pumps from the Audi dealer. You can get the same pump from a VW dealer for less money usually. An aftermarket coolant pump will get you to Albuquerque.

[Johann2.7t]

Hey guys so I took both hoses off the heater core and ran the car. Some fluid (not a massive stream) was coming out and it was pretty cyclical so I'm assuming the pump is working? Is that a dumb assumption?

I have temporarily joined them together bypassing the heater core in case that was clogged and somehow preventing flow although I know not all the outlet flow of the engine goes into the heater core?

I've ran the car at idle with the AC running and it didn't over heat. Guess I'll try driving ?

Is there anything I can check with vag?


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[diagnosticator]

The heater core cannot stop coolant flow through the engine even if it is plugged or air bound. That cannot be the problem. Based on the description of all the symptoms, the coolant pump has failed and is not circulating coolant. It is likely that the impeller is slipping on the pump shaft, and the amount of slip is dependant on the coolant temperature. More slip when hot. If you try and drive with the failed pump, the fit of the impeller on the pump shaft will only get looser. Ignore this advice at your peril.

[diagnosticator]

I am 100 percent certain the impeller is slipping on the pump shaft, in case there was any doubt about what is wrong with the pump.

[old guy]

Is there anything I can check with vag?

I tend to agree with Diagnosticator that the problem is with your coolant pump. But to answer your question, yes there are things you can check with VCDS. Here's an explanation as to how it all interrelates. Clicky click® and Clicky click 2® You will have to fully understand what is going on between the sensors and thermostat heater to make use of the logged information.

The example provided was for a thermostat sticking in the open position. The functionality works both ways.

[Militant-Grunt]

I tend to agree with Diagnosticator that the problem is with your coolant pump. But to answer your question, yes there are things you can check with VCDS. Here's an explanation as to how it all interrelates. Clicky click® and Clicky click 2® You will have to fully understand what is going on between the sensors and thermostat heater to make use of the logged information.

The example provided was for a thermostat sticking in the open position. The functionality works both ways.

A stuck closed thermostat will cause him the same issue. Like I said, make sure the hose that comes out of the thermostat is actually hot. If it is then it is likely the pump failed. If its not, you have an issue with the thermostat. Also, is your cooling fan kicking on? Its the fan on the driver side. AC fan is on pass side.

[old guy]

The problem is that you can't check the temperature of the coolant coming out of the thermostat because it flows directly into the block. That's why you have to monitor the conditions exiting the block at the back and the conditions entering the thermostat from the lower radiator hose to determine if the system is working properly.

[Johann2.7t]

Hey guys! the local oreillys had a pump albiet shady quality.

Will be spending the afternoon in the hotel parking lot.

Fingers crossed!

[old guy]

I gotta tell ya, although I said I tended to agree with diagnosticator, I am not 100% convinced that it's the pump. As the 'grunt pointed out it could also be a sticking thermostat.

[A4orce84]

Johann2.7t,

I'm originally from OKC, and there is a pretty big Audi/VW group in town. Check out the following:

1. http://wetdub.com/phpBB3/viewforum.php?f=7
2. FB Group --> https://www.facebook.com/profile.php?id=15887400601

Unfortunately, I'm located in Texas now....but still have a lot of friend's in the area. If you still have problems or need another set of hands, feel free to post up and I'm sure someone can offer some assistance.

Good luck!


Thanks,
Asif

[diagnosticator]

A stuck closed thermostat will cause him the same issue. Like I said, make sure the hose that comes out of the thermostat is actually hot. If it is then it is likely the pump failed. If its not, you have an issue with the thermostat. Also, is your cooling fan kicking on? Its the fan on the driver side. AC fan is on pass side.

Conceptually, a stuck closed t-stat seams like a reasonable possibility, however T-stats are designed to fail open, it is very unlikely the t-stat will fail closed. (fail safe design principle)

[Johann2.7t]

Conceptually, a stuck closed t-stat seams like a reasonable possibility, however T-stats are designed to fail open, it is very unlikely the t-stat will fail closed. (fail safe design principle)

Hey guys, just finished replacing the water pump and it wasn't that. Original pump seemed fine and the new one has no impact. Is still overheating with any driving what so ever. The upper hose is extremely pressurized and the lower is cool to the touch.

T-Stat next? I have already replaced that 4 months ago but who knows...

[old guy]

That's about the only thing left.

Good luck!

[diagnosticator]

Hey guys, just finished replacing the water pump and it wasn't that. Original pump seemed fine and the new one has no impact. Is still overheating with any driving what so ever. The upper hose is extremely pressurized and the lower is cool to the touch.

T-Stat next? I have already replaced that 4 months ago but who knows...

That really makes no sense. The cooling system can't have high pressure in the upper hose while the lower hose is not pressurized the with the same pressure. In addition, the t-stat can't cause a no flow condition in the cooling system. Even if the t-stat is stuck closed, the coolant will circulate in the engine and heater. Does the heater put out hot air?

If the t-stat was stuck closed there would be a cooling system fault DTC stored, and the CEL would be ON. Also the cooling fan should be running even if the t-stat was stuck closed.

[diagnosticator]

I regret the bad advice, but we can only interpret your situation based on the information you provide. It's not possible to see any overlooked relevant detail not being there. The only consolation is that you did not try and drive out of OKC and get stranded in the middle of nowhere.

Despite the conflicting technical symptoms, I agree with OG, that the t-stat is the only possible point of failure remaining.

[diagnosticator]

Now I am worried about the high cooling system pressure you described. Does the tank cap release pressure and gasses? I am concerned about the head gasket considering the overheating that has occurred. I mention this for your awareness, but don't be to worried before the t-stat is replaced. I am conflicted about bringing this up, I hope my concern is without merit here.

[Johann2.7t]

I just meant hi pressure in terms of the hose was very firm after temp must have expanded the coolant?

If I unscrew the coolant cap after running air and expanded coolant will escape. This is normal with a warm engine though no?

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[diagnosticator]

After loosening the tank cap, and releasing the normal system pressure, the cooling system should not push coolant out of the tank with the coolant at normal operating temp. IF the system is in a state of over heating then it is likely some coolant will be pushed out of the tank, because with lower system pressure, the coolant can boil and the steam produced will expand and exceed the volume of the tank.

When refilling the cooling system, it is extremely important that enough time is allowed for the added coolant to fill the system completely. IF the refill is rushed, then system will have air pockets that will expand when the engine warms up causing coolant to be forced out of the tank when the cap is loosened and over heated localized areas in the head jackets, messing up proper cooling function from the start. Expect to use about an hour for the system to fill from the tank, while keeping the tank topped up. When the coolant level in the tank stops dropping over a 10 min period, replace the tank cap and start the engine and run at 2000 RPM for 2 min. Stop the engine and allow the system to cool down before loosening the tank cap, then top up the coolant level in the tank.

[Seerlah]

Any update? Been watching this thread, curious of the outcome.

[crazyquik22023]

Hey guys! the local oreillys had a pump albiet shady quality.

Will be spending the afternoon in the hotel parking lot.

Fingers crossed!

Hey guys, just finished replacing the water pump and it wasn't that. Original pump seemed fine and the new one has no impact. Is still overheating with any driving what so ever. The upper hose is extremely pressurized and the lower is cool to the touch.

T-Stat next? I have already replaced that 4 months ago but who knows...

The first post says you went and purchased the water pump around 11:57 AM and you posted that you finished at 2:39 PM. And you did that all in a hotel parking lot..pretty impressive.

[Militant-Grunt]

Conceptually, a stuck closed t-stat seams like a reasonable possibility, however T-stats are designed to fail open, it is very unlikely the t-stat will fail closed. (fail safe design principle)

We see it from time to time, more prevalent on 2.0t FSI's, but Ive had a few 1.8t's with this issue. He could also just have air preventing the thing from opening, hence I asked if he had heat.

Hey guys, just finished replacing the water pump and it wasn't that. Original pump seemed fine and the new one has no impact. Is still overheating with any driving what so ever. The upper hose is extremely pressurized and the lower is cool to the touch.

T-Stat next? I have already replaced that 4 months ago but who knows...

When the coolant was refilled, was a coolant bleeder/ filler used or did you guys just fill it back up? 1.8ts are absolutely notorious for air when you open up the coolant system.

I'll say it over again, do you have HOT heat? This is your number one indicator. (Assuming there is nothing wrong with heater core)

[diagnosticator]

I gotta tell ya, although I said I tended to agree with diagnosticator, I am not 100% convinced that it's the pump. As the 'grunt pointed out it could also be a sticking thermostat.

As convinced that I was, I had a small doubt about the situation as well. Relying on the symptoms described, associated with the functional characteristics involved, was a good fit considering the physics and specific operational facts involved. My wrong conclusion prevailed regardless.

[Johann2.7t]

As convinced that I was, I had a small doubt about the situation as well. Relying on the symptoms described, associated with the functional characteristics involved, was a good fit considering the physics and specific operational facts involved. My wrong conclusion prevailed regardless.

so I just finished installing and running the car with the new thermostat assembly and J plug with no change in symptoms.

The car still overheats and really just seems like its not circulating coolant. When idling the coolant level will back up in the reservoir and eventually overflow. The upper hose is very hard and hot while the lower isn't.

I am totally lost here. Any suggestions?

[Johann2.7t]

The first post says you went and purchased the water pump around 11:57 AM and you posted that you finished at 2:39 PM. And you did that all in a hotel parking lot..pretty impressive.

unfortunately didn't fix it! I guess being able to replace parts isnt as important as being able to diagnose problems accurate. Damn my lack of skills.

[Johann2.7t]

We see it from time to time, more prevalent on 2.0t FSI's, but Ive had a few 1.8t's with this issue. He could also just have air preventing the thing from opening, hence I asked if he had heat.





When the coolant was refilled, was a coolant bleeder/ filler used or did you guys just fill it back up? 1.8ts are absolutely notorious for air when you open up the coolant system.

I'll say it over again, do you have HOT heat? This is your number one indicator. (Assuming there is nothing wrong with heater core)

I do not have consistent heat and have been refilling by just filling the reservoir. I currently do not have a compressor to run my power bleeder. I have bleed the car via the upper hardline but cant bleed the heater core before the reservoir overflows.

[A4orce84]

Are you still in OKC?

[Militant-Grunt]

I do not have consistent heat and have been refilling by just filling the reservoir. I currently do not have a compressor to run my power bleeder. I have bleed the car via the upper hardline but cant bleed the heater core before the reservoir overflows.

There are two bleeders on your engine, one on the coolant hard pipe and the other on the upper heater core hose (a little hole). Ignore the one on the hard pipe, and use the one on the heater core hose. Get the car Hot up until right before it overheats, pull back the upper heater core hose while the car is running, enough to expose the hole. Get a second person to rev up the motor and hold at 2500-3k, hold the hose pulled back enough to expose hole to flow and wait till it starts geysering out coolant through that hole. You will have to do this a number of times until you have consistent hot heat and the car is not overheating.

If its starts overheating, give it a 5 min break, and get back into it. Its a painful drawn out process sometimes, but it is the most effective way to get rid of air in the system without a power bleeder.

[Johann2.7t]

Are you still in OKC?

no i trailered the car the rest of the way to my new home in Albuquerque NM!

[crazyquik22023]

unfortunately didn't fix it! I guess being able to replace parts isnt as important as being able to diagnose problems accurate. Damn my lack of skills.

I just meant even changing the water pump in 2 hrs in a hotel parking lot is pretty quick..it can definitely be done though.. Why don't you take the small hose going to the expansion tank off, hold it over a bucket, start the engine have someone rev it up to 2500 or so, there should be a steady stream of coolant coming from the hose. If it is unsteady you might have air still or a slight blockage in the system, if there is no flow at all then you have a blockage somewhere or a failing water pump, but its obviously not a failing water pump since you just changed it.

[Johann2.7t]

I just meant even changing the water pump in 2 hrs in a hotel parking lot is pretty quick..it can definitely be done though.. Why don't you take the small hose going to the expansion tank off, hold it over a bucket, start the engine have someone rev it up to 2500 or so, there should be a steady stream of coolant coming from the hose. If it is unsteady you might have air still or a slight blockage in the system, if there is no flow at all then you have a blockage somewhere or a failing water pump, but its obviously not a failing water pump since you just changed it.

should hose be level while doing this? If i point it down there is a good stream.

Also when im bleeding the heater core house should the coolant reservoir cap be on or off? Ive been doing this with the cap off.

It to me seems like a definite blockage but what could block it? Does the rear coolant flange have any common failures other than leaking?

What would happen if I unplug the thermostat sensor, what role does it play?

Thanks guys so much

[crazyquik22023]

should hose be level while doing this? If i point it down there is a good stream.
You should get a strong stream no matter which way you hold it.

Also when im bleeding the heater core house should the coolant reservoir cap be on or off? Ive been doing this with the cap off.
That is correct

It to me seems like a definite blockage but what could block it? Does the rear coolant flange have any common failures other than leaking?
Cracking and coolant temp sensor going bad

What would happen if I unplug the thermostat sensor, what role does it play?
It won't effect the thermostat from opening. Its not a sensor that is in the housing, its a heater that makes the thermostat open quicker when it needs to. You could give it a try but I don't really see the need or any benefit in doing this.

Thanks guys so much

I thought you put a new thermostat in already?

[Johann2.7t]

I thought you put a new thermostat in already?

yes I just finished putting a new one in but really seems there is a blockage pre thermostat

[john_gonzo]

There are two bleeders on your engine, one on the coolant hard pipe and the other on the upper heater core hose (a little hole). Ignore the one on the hard pipe, and use the one on the heater core hose. Get the car Hot up until right before it overheats, pull back the upper heater core hose while the car is running, enough to expose the hole. Get a second person to rev up the motor and hold at 2500-3k, hold the hose pulled back enough to expose hole to flow and wait till it starts geysering out coolant through that hole. You will have to do this a number of times until you have consistent hot heat and the car is not overheating....

[heywier427]

If you feel there is a blockage, there is only 1 way to check.

Unhook all the hoses, and flush the rad, engine, heater core, individually.

Loop the pesky heater core and take it out of the equation.

Use the old thermostat, gut it, and re install. See if either the old and new therms are bad, or your car is not telling the therm to open.

Now that your home, can you log anything? Whats the coolant temp sensor saying?

[Johann2.7t]

If you feel there is a blockage, there is only 1 way to check.

Unhook all the hoses, and flush the rad, engine, heater core, individually.

Loop the pesky heater core and take it out of the equation.

Use the old thermostat, gut it, and re install. See if either the old and new therms are bad, or your car is not telling the therm to open.

Now that your home, can you log anything? Whats the coolant temp sensor saying?

The coolant temp is reading well into 108c before the fans kick on and the needle will start to move.

By looking at the old thermostat (4 months old) it is in the open position. Not sure what would tell it to stay shut?

I have been bleeding the heater core and fluid does come out of the hole so is that confirming the water pump circulating to that point?

Does anybody have a good diagram of the cooling system so I could try and figure out where the blockage/bubble might be.

The car is still overheating. UGGH

[heywier427]

How many miles on car?

How soon does the coolant flow out of the reservoir when cold?

This just started happening? You didnt do any other work. You didnt run low on coolant and top if off?

Crazy.

Did you try lifting the reservoir up as high as you can? Try when cold. use a bungee and hold reservoir up as high as the hoses will allow. Add as much coolant as you can. Close it.

Always add coolant (open the system) with a cold engine. Like over night cold. If you still get bubbling at the reservoir when you open the cap, it was not cold enough.

[jschmidtjordan]

seconding the motion on headgasket.
if you start the engine from cold, does the rad hose get cock hard before engine temps are even up? could show signs of a cracked headgasket.
and there are combustion leak testers you can use to verify.