2004 VW Jetta TDI Wagon starting problems

Hi I have a 2004 Jetta TDI Stationwagon. I lived in Minnesota and about a month ago moved to NW Wisconsin. In January it started having starting problems. The car would crank but not fire. After about 8-9 tries it would fire. MOstly does it first crank of the day (whether morning or afternoon). Mechanic #1 said it was the fuel filter and changed it. But it still had starting problems. Then Mechanic #1 said it was a sensor and changed it. Still had starting problems. In February, Mechanic #2 said it was the fuel pump. Changed the fuel pump. Still had starting problems. Then Mechanic #2 said it was the crank sensor. But when he checked the crank sensor was brand new (apparently Mech #1 changed it in January). Still had same starting problems. Mechanic #3 said he received the Crank sensor diagnostic error too but he checked it and it was brand new! He told me to take it to the dealer. I did. Dealer said no it wasn’t the crank sensor it was the new fuel pump installed in April was defective. Took off the brand new fuel pump that was installed another brand new fuel pump. Next day car started fine but two days later didn’t start again. Took car back to the dealer. They said after all it wasn’t the fuel pump it was the crank sensor. After a couple days they said it wasn’t the crank sensor but it was the EGR valve that was clogged with carbon. They changed the EGR valve, cleaned it out and gave the car back to me. Today the car doesn’t start again! I tried it about 7 times! Dealer is going to haul it back and try to figure it out! But I am frustrated! What could it be? Any ideas! Help! Thanks in advance.

I’d really like to know what fault codes are stored, but I’m going to make an assumption or two and take a shot at this one anyway. There will be some guessing involved, as there often is.

There’s clearly been some guessing going on. Dying fuel pumps can be tested for and should have been before changing it. But all told, it sounds like it’s having difficulty getting a rich enough mix in the morning. That would make me want to test the temperature sensor. That tells the ECU that it’s cold out and that the engine needs a richer mix. My guess is that the “sensor” he changed was the oxygen sensor, as it too provides information to the ECU on how much fuel needs to be sprayed…however it is intentionally ignored when the engine is cold in order to allow a richer mix. Replacing it will not fix a “cold start” problem.

A clogged EGR valve will not prevent starting a cold engine. That was IMHO a wild guess.

My guess is the temp sensor. And, as with other things, that can be tested. Let us know what the shop finds out.

Have the glow plugs been checked? You might want to post on tdiclub.com, I’m sure they will have some answers.

How many miles on the car and any history of overheating?

Just wondering if the compression is dropping as a diesel can get cantankerous when this happens.

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

You may need tdiclub.com if what was suggested here does not work for you.

Thanks All. I am waiting for the dealer tech to call me back. I live 3 and half hours away from the dealer, where the car is now. So, I have to wait for them to send me the codes. I do believe that all the mechanics are guessing. The first mechanic had said something about the temperature sensor which I conveyed to Mech #2, #3 and the dealer. I guess I should ask them again. I will have to wait for the dealer techs to send me a list of the codes that are coming up on the diagnostics. I will also get on tdiclub.com. Thanks again everyone.

Oh I forgot the car has 110,000 miles on it. I bought it new and have been the only owner. Oil changes and other stuff done regularly. REcently in January 2013 I had timing belt changed and other brake work done. The starting problems started about 2 weeks after that. (I don’t think it’s related but I am just throwing out stuff at this point). Also, in Feb 2013 I installed a block heater. When the car was hooked up it would only take two cranks to start it up in the morning. Again, not sure if that tidbit is relevant. The mechanics have heard all this too! Once again Thank you very much!

Perhaps the timing is off by one or more teeth . . .

I would certainly hope the dealer mechanics double checked their work, since the problems started 2 weeks after THEY replaced the timing belt.

Actually it wasn’t the dealer that changed the timing belt it was Mechanic #1 (who does VWs only). But I will speak to the dealer tech and tell him to check that. I did tell them that the timing belt was changed in January. But I will remind them to look. Thanks so much!

HERE’S AN UPDATE! Today the dealer tech called and said that there was frayed wires that were breaking the circuit and wouldn’t let the car start!!! I hate to say this but I am totally ignorant about cars and car mechanics (I guess girls my age were never encouraged to learn cars). However, I remember asking all mechanics if it could be electrical and all of them focused on the fuel, fuel pump, crank sensor etc.! So, now after two brand new fuel pumps, new sensors, a new EGR valve we find out that it was frayed wires!!! I will keep looking for a mechanic who knows his stuff. THANK YOU EVERYONE for your input. I will use this forum more and I am surely starting to learn my car better. I will post again if the frayed wires weren’t the problem.

Maybe it is just the cold? That is the only time I can’t start, like this morning after -10 degrees last night. I just ordered a dipstick heater for mine.

I know this is an old post, but someone else posted recently, so:

“REcently in January 2013 I had timing belt changed and other brake work done. The starting problems started about 2 weeks after that”

DING DING DING

Whoever did the timing belt job botched it. This is extremely common with TDI’s. Dealers screw it up, ‘Euro’ car shops screw it up, even VW specific mechanics screw it up if they don’t regularly work on TDI’s. In the future, never take the car to anyone (even the dealer) unless they own or regularly work on TDI vw’s.