[Just4Kicks]

Car won't start randomly. Usually on short drives after I park but it could happen at any given time. Happened a few times while driving or at a stop light to. This is insane as Ive forked out so much money already, (not for this specific issue) what is life? its a 2000 Passat 1.8t ATW. One time I was going about 90 and my car lost power, epc light and battery light came on as I started to pull to the side of the road it regained power and I got back up to speed. Im not having any electrical problems with windows or lights, only thing I notice is when I roll windows up to the top and keep trying to roll them up, as I pull up on the buttons, the car idle jumps a lil bit... but Im pretty sure its always done that. Well the light inside the trunk doesn't work and the "boot lid open" indication on dash don't ever show up but I haven't been able to link that to the car not starting, cranks all it wants, just won't turn over. Any ideas? Alternator checked and good, timing belt recently done, battery should be good, MAF replaced with BOSCH, Premium gas always used, driver door lock module replaced... Sometimes I get it to start by undoing the battery terminals for a while but not always a solution.

 

[Profrmdover]

Crank position sensor also called ESS (engine speed sensor) .... just replaced mine. Car would crank but not start, EPC light, high idle (1100 rpms).

 

[wong93719]

Checked Crank breather hose. They tend to get brittled with age. It is attached to the end of the valve cover. It is a 3 way hose connector. Mine broke and it exhibit symtoms like engine stall at traffic light, slow start, EPC light on with high idle upon restart and it also showed intermittent engine speed sensor issue. I was about to change the speed sensor but I checked the resistance at the connector and it seems to behave fine. Then I noticed the big crack at the crank breather hose. It may still be the sensor but changing the crank breather hose is easier.

 

[Just4Kicks]

Oh yea I did the breather hose to already, where I took off the intake manifold to get to it.... the plastic L looking one that goes to the block and replaced the small three way plastic T (in-between coolant reservoir and engine) with a 30 dollar gold metal one from an audi dealer that I could of probably just replaced with a cheap auto zone replica but hey... Im leaning towards the ESS as well, would that cause the RANDOM no start tho? or would it just cold turkey not work?

 

[keithermadness]

Scan it for codes. If it's the Speed Sensor, it will show up probably as intermittent, but wont throw a CEL.

 

[FrescoGreen01.5]

This is classic Crank Position Sensor (ESS) failure behavior. It doesn't die, it just gets flaky. Replace it.

If you have a crank/no start again, try this: crank for 7 seconds continuously. If the ESS wasn't giving a signal, the ECM will go in to a limp mode after 5-6 seconds and go ahead and start without the ESS. The EPC light will be on and the idle will be higher than usual, but it will run and drive ok. Much better than being stranded.

 

[Just4Kicks]

Well, stalled out earlier today in left side turning lane, made a few people aggravated but I unplugged number 30 relay in the ecu box since i already had the screws off.. unplugged battery terminal and plugged it back in and it started right back up.. not sure what to gather from that trial. Still having trouble. Waiting on my bud to scan it but last time we checked nothing showed up. I wanna get it in its no start state and scan it it just been hard to time it right since its random for the most park. Will check back soon, thanks for the help.

 

[Just4Kicks]

FrescoGreen, I did try that one and it didn't cut on after about 10sec of cranking... was hoping that worked to.

 

[Tomvw]

You haven't provided much useful info to go on, but I suggest you replace the ECU Power Supply Relay. (In the ECU box)

 

[Just4Kicks]

Would a tiny leak from the fuel injector O-rings cause this sort of problem? I don't hear air compression when I take off the gas cap like I used to. Passenger side front tire is a little wobbly to... Just thought id add to this. Went to Oreilys to and apparently they don't check codes for people.

 

[Tomvw]

Would a tiny leak from the fuel injector O-rings cause this sort of problem?

No!

 

[John_E]

This is classic Crank Position Sensor (ESS) failure behavior. It doesn't die, it just gets flaky. Replace it.

If you have a crank/no start again, try this: crank for 7 seconds continuously. If the ESS wasn't giving a signal, the ECM will go in to a limp mode after 5-6 seconds and go ahead and start without the ESS. The EPC light will be on and the idle will be higher than usual, but it will run and drive ok. Much better than being stranded.

Thanks for the tip. My elder son has been going through this with his 2002 A4. I didn't know about the 7-second rule, but he may have been doing that subconsciously.

Anyway, I bought him an ESS, and this morning he and his brother finally got around to installing it. Their advice for an AMB 1.8T is to drive up on the ramps and have one person under the car and one above it while threading the ESS lead down from the plug-in point under the coolant recovery tank. They were done with the remove-and-replace in less than 30 minutes.

 

[FrescoGreen01.5]

Anyway, I bought him an ESS, and this morning he and his brother finally got around to installing it. Their advice for an AMB 1.8T is to drive up on the ramps and have one person under the car and one above it while threading the ESS lead down from the plug-in point under the coolant recovery tank. They were done with the remove-and-replace in less than 30 minutes.

I bet they were less sore than I was! I did mine alone, from above, working blind, but was still done in an hour or so (but it's been a few years). Glad to lend a (figurative) hand.

 

[Tomvw]

Did you get this fixed ?
Your issue is typical of a faulty ECU power supply relay.

 

[John_E]

Did you get this fixed ?
Your issue is typical of a faulty ECU power supply relay.

Good point -- been there, done that, as well.

In hindsight, our first warning of a failing ECU power relay was a couple of strange CEL codes, but it did not throw any codes when it finally failed.

 

[dublove88]

Good point -- been there, done that, as well.

In hindsight, our first warning of a failing ECU power relay was a couple of strange CEL codes, but it did not throw any codes when it finally failed.

hes right i had this same problam on my b5 it was a relay i reolaced the one under the dash and in the ecu box

goodluck