I need help!!! 2009 tdi jetta overheats when driving and AC is on

I own a 2009 Jetta TDI, last November I had my intake manifold replaced not even a week later engine light comes on for clogged egr cooler. My car has been serviced at this same volkswagen dealership since I purchased it 7 years ago. I took my car to vw about the egr cooler problem and after a few days they finally told me I needed a new egr cooler and a new fuel rail pressure sensor. I got this replaced after they ordered the wrong egr cooler and delayed my car getting fixed for a week. The very next day after finally having my egr cooler replaced and the fuel rail pressure sensor replaced my engine light came on yet again. So I took my car back to vw and they then told me there was an electrical problem with the fuel rail pressure sensor they installed; they said they could not fix it that day and that I needed to bring it in a week later. Well when I went back I learned that I actually had a broken engine harness and that was the reason the fuel rail pressure sensor went bad. I had to wait a while before the part came in and vw told me it would not be a problem to continue driving my car, so I did and my engine light came on yet again. I decided to take it to Autozone for a engine light read and they told me I needed a glow plug replaced, this same day I was driving when my air got warm and my car started overheating. I had no choice but to drive my car and when I took it to vw for the engine harness (which was a 5 hour labor job that turned into a 4 day job) I also requested a coolant system flush because I had **** floating in my coolant reservoir and when I went to pick up my car I also learned they had to replace the engine coolant temp sensor. They promised me the problem would be fixed but yet again they were wrong. My car has been sitting at vw since the 21 or 22 of June and they have still yet to find a problem. They told me they checked the head gaskets for leaks and that it all checked out ok. They have absolutely no idea what is wrong with my car and told me that my car is only overheating when you drive it that they had it running in the shop for 4 hours with the air blasting and it was not overheating. I really need help I am only 18 and can not rent a car so vw has me screwed.

Did you drive it after they replaced the engine coolant temp sensor and have it overheat again? If the temperature sensor was malfunctioning, are you sure it actually over-heated?
I don't know the details on the electrics of a 2009 (my car is ten years older), but a condition of over-heating should cause the A/C compressor to get cut off. So if the computer in the car thinks it is over-heating because of a bad sensor, it would cut off the AC, thus the warm air being blown. Possibly also the warm air was blowing because it is a way to help cool down the over-heated coolant if the radiator fans quit, again something the computer would be switching on.

Yes I drove it after the sensor was replaced, I finally got my car back from them Tuesday of last week and that is when they replaced the coolant temp sensor and the sameday it had overheated but not into the red nothing was beeping or anything. They've had it ever since and they said that they were parking it and it started overheating I asked if the air was on and they said it was but now they're saying that it's only overheating when it's being driven and the ac is on. They also said that they had it running in the shop for about 4 hours with the ac on and it never overheated.

It also only blew the warm air the very first time it started overheating, but after that the air would stay cold and it would overheat but honestly after it started overheating the first time I didn't ride with my air on too much more I just stayed ready to blast the heat in case it started overheating. After they replaced that sensor I noticed my car ran at a little over 190 maybe 215 or so if i had to guess where as before it always ran at 190 warm and the first time it overheated after they replaced the coolant temp sensor it very slowly started overheating and when I turned on the heat it didn't cool down and i had to pull over before it got too high but before that sensor was replaced along with my engine harness I could blast the heat when it would start overheating and it would cool down while I was still driving and I wasn't forced to pull over on the side of the road. But when I did have to pull over I was pulled over for 10 minutes or less before it was cool enough to drive again. I keep saying overheated but my car only truly overheated once but I got the car turned off before it got in the red and started beeping every other time it's gotten up to about 3/4ths of the way before I either pulled over or the heat cooled it down

Did they not replace the thermostat? There is a coolant/engine temperature sensor (what drives the display, sends data to the ECU, etc.) and a thermostat, which is a mechanical device that opens at a certain temperature, e.g. 190°F, allowing the coolant to flow through the engine to the radiator.

Things that can fail, and cause over-heating:
1. Radiator fans or the controls for them or fuse (and fuse holder, which on older VWs overheats, melts, and then doesn't make contact). This one is obvious-- if the car is overheating and they aren't spinning furiously, there is the problem. Also, at least in my car, driving at speed without pulling a heavy load, the engine never overheats, even without working fans and AC on (I know from experience, and actually am about to go poking around to see why the fans aren't working, but it only overheated this time while going up a mountain pass pulling 1/2 ton in the trailer with the AC on!).
2. Something blocked in the cooling system. If you saw a lot of gunk in the coolant, I guess this is quite possible.
3. Thermostat failure. If the water doesn't ever circulate through the radiator, because the thermostat never opens, then there is the problem.

If blasting the heat cools it down, then that indicates that the water pump is working and coolant is circulating.

The thermostat can be checked by putting it into water heated to the temperature at which it should open. Certainly recently boiled water (212°F) should open it, if you don't have a thermometer to measure the water temperature. Don't throw it in the pot and leave it on the stove though while the water is heating, just after the water has been heated and the eye is off, otherwise direct metal-metal contact will mean it probably gets hotter than the water.

Really, if the dealer is competent, then they should have done these checks. But one can't be sure about dealer competence, especially with what I suppose a dealer would consider an "old car".

To my knowledge they havent checked or replaced the thermostat I will be taking this information to them today they have told me that they have contacted vw of America and they told them some things to check but that they still didn't find anything and that some other technician would be coming between Monday and Wednesday to look at my car but here it is Wednesday and still no answers

Yeah and this dealer isn't the best had my oil changed and checked under the hood and the idiots put a screw in wrong and didn't even take it back out to correct it just left the screw hanging out of the hole

These are some of the reasons why I do-it-myself. Not everything, but much of the stuff. It is a question of time available, and what you could be using the time for otherwise, and interest, of course. And whether it saves you money as well.

I wish I had the know how to fix my own car it would be so much easier than my car sitting at their dealership going on 3 weeks now

just take the buy out when it comes around, get a nice Honda accord or something

That's my plan if they even buy back my car, I was talking with the service manager of the vw dealership I go to and he said it's looking like they're only going to buy back cars that were leased and mine was not it has since been fully paid off so my car would not be apart of the buy back. Hopefully with this ruling just coming out maybe something will have changed and they'll buy mine back too

If you do end up keeping the car, then just start with the simple things, like oil changes. Get a repair manual. Basic tools and a jack, wheel chocks, and jackstand are needed at first (or even just Rhino Ramps for oil changes). You have an advantage being in the US that Autozone at least lends out specialty tools, a service I took much advantage of in highschool and college from the (then) open-24-hours-a-day Autozone in Smyrna. I did have the advantage of a retired Delta Airlines mechanic neighbor with huge toolchests and a similar Honda as mine to help me through a lot of early repairs and lend the odd socket or other tool I may have lacked (RIP Joe M.).
With the simple stuff you get the certainty that e.g. the right oil was used, the filter really was changed, the oil plug was tightened down to the right torque, etc. And the more familiar you are with the mechanical state of the car, the better position you are in if taking it to a mechanic to get fixed. For instance, instead of saying "The A/C isn't working, please fix it" you might already have diagnosed where the problem is, and would be telling the mechanic "Please replace the electromagnetic clutch on my A/C compressor".

Jettatdi2009 said:

That's my plan if they even buy back my car, I was talking with the service manager of the vw dealership I go to and he said it's looking like they're only going to buy back cars that were leased and mine was not it has since been fully paid off so my car would not be apart of the buy back. Hopefully with this ruling just coming out maybe something will have changed and they'll buy mine back too

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totally incorrect on the only leases part, but you'll find out eventually. never rely on a VW dealership for proper info

http://forums.tdiclub.com/showthread.php?t=463038

http://forums.tdiclub.com/showthread.php?t=463015

have info on the buy back.

so you purchased the car when you were 11?

how many miles on it?

it almost sounds to me like your radiator could be the issue, either internal, or clogged with some leaves and dirt and such where the air goes through.

Lol no my grandfather bought it but gave it to me when I moved in with them, it has close to 160,000 miles on it he bought it because of the awesome gas mileage

Turns out I have a blown head gasket and its another 1300 almost 1400 to have it fixed on top of that they can't fix it until 2 weeks from now. Not sure if I should fix it and keep it or just trade it in for something else, or waiting until more news on the buy back comes out.

Vw supposedly tested my coolant and determined there was gas in it, is this a problem from the blown head gasket or could it be something else?

if there's gas in your TDI's coolant you've got other problems...

Jettatdi2009 said:

Turns out I have a blown head gasket and its another 1300 almost 1400 to have it fixed on top of that they can't fix it until 2 weeks from now. Not sure if I should fix it and keep it or just trade it in for something else, or waiting until more news on the buy back comes out.

Click to expand...

No one in their right mind will take that car in trade with a blown head gasket. Park it until the dust settles on the buy back.

I bought a block tester kit recently and tested my coolant and turns out it shows that my head gasket is fine, I finally have my car back and turns out Volkswagen allowed it to overheat so much that the coolant reservoir boiled out. I am going to have my boyfriend start taking things out and checking on them, but I am not sure where to start first other than the thermostat and I'm not entirely sure where that's even located on my car. I also think they didn't put something back together correctly because when my car is started there is a loud ticking sound, this sound happened occasionally before it was worked on but was never this loud or persistent it would die out once the car was warm usually. What else should I start looking at to fix it?

I don't know how much I'd believe your block tester kit. Diesel head gasket breaches can often hide from pressure tests because the cylinder pressures required to open the breach are very high. Most low-pressure tests simply don't have the oomph to cause the breach expose itself.

Diesel head gasket breaches will cause combustion gasses to enter the cooling system, which causes an air bubble to form. That air bubble then leads to the cooling system not circulating correctly, and eventually overpressurizing the system and forcing coolant to overflow out of the vent. Once that happens, your coolant level drops and you're left with a partially empty cooling system that can't cool the engine.

In my opinion, your best option is to park the vehicle and wait for a buyback. There are lots of inexpensive used vehicles on the market that can tide you over while you wait. It sounds to me like further diagnostics on your TDI are simply throwing good money after bad, especially if your VW dealer is doing those diagnostics.

Please stay away from the VW dealers. Depending on just where you are in GA, you might find someone on this list who can help you: http://www.fixmyvw.com/recommended/

Make sure the radiator fan is coming on when it should, and is pulling enough air through the radiator when it does to cool the coolant. If that's not happening, you can get a delayed runs-too-hot effect . It might only show while driving the car because driving loads the engine more and generates more heat.

You can also have runs-too-hot effects that come and go if the thermostat sticks partially closed until it gets really hot, then suddenly snaps open. Sometimes it'll even cycle, sticking partially open, snapping open, then closing back down and sticking again.