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Discussion Starter · #1 ·
I posted this over in the general Jetta III forum and thought I'd repost here.
My car, a stock 98 GLX with 90k, has a problem with warm starts. After the car has been driven for a while and then parked for about 15 minutes or more, it will not start. The engine kicks over fine but doesn't start. When this happens I know the fuel pump is not pumping. After the car sits some more (some times up to an hour or more) it will start as if nothing happened. The car drives fine when it does start.
This started out of nowhere about two years ago and happened for about 5-6 months. Took it to a few mechanics but the problem never happened while it was in the shop and although the check engine light goes on after this happens, no codes are stored. Then it mysteriously stopped for about a year and a half, but just a few weeks ago it began happening again.
After taking it to another mechanic who couldn't figure it out, I took it to the dealer. They ran a diagnostic and found a faulty ignition switch so they replaced that (for $330). Of course, that didn't fix it and the car wouldn't start the very same night after I drove it home.
Went back to the dealer for a bitch session about being charged $330 for something I didn't need and they looked at it again. Ran the diagnostic and came up with nothing. The mecahnic then drove it for about a half hour and went to lunch. When he came back to the car 30 minutes later he said it started fine so he drove it back to the dealer. He dicded to scan for codes, even though the engine light was not on and he pulled code 16706 which is no signal from the engine speed sensor.
He then called me and said his theory is that when the engine shuts off, it continues to heat up (he referred to this as heat soak) and it heats to the point that it causes the sensor to not send a signal. Then after a long enough period of time, the engine cools down to the point that the sensor will send a signal and the car starts. He thinks it's a faulty sensor and wants to replace it (for $450). I asked him if he could just test the sensor first to make sure it was bad but he said he would have to test it when it was not sending a signal and that even if the sensor was good, it might give a bad ohm reading anyway (?).
I would like to replace the sensor myself. So my question is this, where is this thing located and how difficult is it to remove and replace? Do I need to remove the oil pan (or anything else)? The Bentley is not much help at all.
Also, if someone could give me a good definition of heat soak I would really appreciate it. Thanks.
 

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Re: warm start/engine speed sensor (dunno)

Quote, originally posted by dunno »
I would like to replace the sensor myself. So my question is this, where is this thing located and how difficult is it to remove and replace? Do I need to remove the oil pan (or anything else)? The Bentley is not much help at all.

The Crankshaft Position (CKP) / Engine Speed sensor is on the front side of the VR6 motor.
If you get underneath and look at the oil filter housing, it's right next to it on the engine block.
It's a black, single wire sensor that has a 6mm allen wrench bolt.
Removal can take some time, since you DO NEED patience to remove it so it does not break.
Pictures available upon request; best of luck!
- Erik
 

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Discussion Starter · #3 ·
Re: warm start/engine speed sensor (bluefox280)

Thanks erik, found it earlier this morning and pulled it off. Tested it with a multimeter and it's out of spec at 940ish. VW dismantler has one for $25.
I did a much thorough search on the forums and found a lot of info and this sounds like it's my problem. The heat soak from the engine is causing the sensor to not send a signal, although I'm going to test the ECU terminals to make sure it's not that.
 

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Re: warm start/engine speed sensor (dunno)

Quote, originally posted by dunno »
Thanks erik, found it earlier this morning and pulled it off. Tested it with a multimeter and it's out of spec at 940ish. VW dismantler has one for $25.

I think you found your culprit! Replace and let us [me] know...
Sorry that I couldn't help out an sooner. Best of luck!
- Erik
 

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Re: warm start/engine speed sensor (dunno)

Man, that's highway robbery! I replaced my crank sensor on my car in five minutes! I was troubleshooting my computer to see why the car would not start with a '95 computer but would with a '96 computer. Buy the sensor from the dealer or [email protected] 1800 VWPARTS( ask for Tom or Erik) and change it yourself! Good luck.
 

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Discussion Starter · #6 ·
Re: warm start/engine speed sensor (wardrp)

Quote, originally posted by wardrp »
Man, that's highway robbery! I replaced my crank sensor on my car in five minutes! I was troubleshooting my computer to see why the car would not start with a '95 computer but would with a '96 computer. Buy the sensor from the dealer or [email protected] 1800 VWPARTS( ask for Tom or Erik) and change it yourself! Good luck.

I was really pissed when I found the sensor and it took me about 15 minutes to take it off (the allen bolt was tight and I didn't want to force it, so that took some time). He quoted me $250 on the part so the other $200 was for labor, and it would probably take them 5 minutes to swap it out. Anyway, I'm picking up a used one tomorrow for $25 and I'll put it on this weekend and see if that solves the problem.
 

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Re: warm start/engine speed sensor (dunno)

I have the same symptoms on my 1.8t passat. It has been very intermittent but is happening a lot more than ever before. Somtimes there was no fault stored, sometimes it was 16706. Did this fix your problem? Anyone that can help point me to where to find it on a 2002 Passat 1.8t so I can replace it? Thanks!
 

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Re: warm start/engine speed sensor (jaclyn)

Quote, originally posted by jaclyn »
I have the same symptoms on my 1.8t passat. It has been very intermittent but is happening a lot more than ever before. Somtimes there was no fault stored, sometimes it was 16706

* VW DTC P0322 (universal 16706) - Ignition / Distributor Engine Speed Input Circuit No Signal
Yeah, it could be the very same thing.
Yes, he did fix this problem; there was a double post and he informed me there.
However, to find it on your Passat, I would ask the 1.8T and Passat forums.
- Erik
 

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Re: warm start/engine speed sensor (bluefox280)

That's good news! This problem has been driving me crazy for a year! I will post a question in 1.8t and Passat forums to try and get more information on location of the part and the part number. Thanks for the info!
 
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