Glowing doesn't work, desperate!

[weedeater]

Re: Glowing doesn\'t work, desperate!

The coolant temp sensor is color-coded. You have to get a replacement of the same color, even though the part numbers are the same.

There is still a 'short' here. The system is acting correctly when you unplug the sensor. Therefore there must be a short in the new sensor, wrong sensor, or a short in the plug when inserted into the sensor itself.

 

[DrBosa]

Re: Glowing doesn\'t work, desperate!

Thanks!
Even the part numbers weren't exactly the same. One sensor's part numbers ends with "501" and the other one "501A".

The color also differs on the two sensors (green and yellow).

I'll have to ask my spare part dealer if he can get me the right one.

Again, thanks!

 

[DrBosa]

Glowing doesn\'t work, desperate!

Hi!
I have a Passat TDI -94 on which the glowing doesn't work unless I unplug the coolant temperature sensor socket located on the coolant hose on the front side of the engine.

I have measured for voltage in all the glow plug sockets while turning the key and there is no voltage when the coolant temperature sensor socket is plugged in, but 12 Volts when the socket is unplugged.

I have now exchanged the old sensor with a new one, but no improvement.

What should I look for now? I don't think the glow plug relay is broken because then it would now glow at all...or?

I'm beginning to get desperate here, because I can't use the car now when the wheather is below freezing, and also, it would feel so much better to fix this problem single handedly and not take the car to the shop.

Anyone got any ideas?

 

[LUVMYTDI]

Re: Glowing doesn\'t work, desperate!

Just went through this myself for a 97 Passat.
Black/yellow sensor = 357 919 501A
Black/green sensor = 357 919 501
The colors green and yellow come from the little rings around the sensor. Dont forget to get the O ring too.

 

[DrBosa]

Re: Glowing doesn\'t work, desperate!

Ok, here's an update:

I did get the wrong sensor from the dealer, but the shop found out another problem too...

After the mechanic had plugged in the scan tool, he set the "basic setting" to "0" and then the diesel pump value said "0" instead of "50" as it is supposed to say. At least I think that's what he explained.

The diesel pump appearantly had the wrong setting which caused a timing error on the fuel injection. This of course made the engine very difficult to start in cold weather (which really was the first problem I wanted to solve).

The wrong diesel pump setting is due to that the wheel that drives the timing belt is loose. A pretty common problem the mechanic tells me.

Obviously the thing to do is changing the belt wheel and its bolt and adjust everything according to the factory service manual, and the problem should be solved.

 

[santacll]

Re: Glowing doesn\'t work, desperate!

So the infamous crankbolt strikes again... fortunately fixing it is pretty straight forward...

 

[First_VW_TDI]

Re: Glowing doesn\'t work, desperate!

Hello, I still -several weeks- have exactly teh same problem. Changed glow pugs, battery, coolant temp sensor. Stil no glow voltage when cold, except when sensor connector is disconnected. HOWEVER, they gave me a green colored sensor (357919501) in stead of the yellow one which was mounted (...501A). Today I bought myself a yellow one. The sensor had a metal top i.s.o plastic. Partnumber is ok. I will change the sensor tomorrow. Hopefully solving the issue at my end.

Question: By changing the sensor with the yellow one, was the problem solved? Or was the timing of the fuel pump the problem? Or both?

Thanks,
Pierre

 

[DrBosa]

Re: Glowing doesn\'t work, desperate!

The mechanic told me this:
A TDI engine should start easily with no glow time at all in at least -10 degree Celsius. Therefore it couldn't ONLY be the temp sensor that was broken. He was right. It was the crank bolt all along. The old temp sensor was working fine it turns out, and now after the crank bolt is replaced and the injection timing is adjusted, the engine starts without any difficulties with the old temp sensor.

So, my advice would be, have a mechanic check the fuel injection timing first, and if the timing is off, check the crank bolt.

 

[GoFaster]

Re: Glowing doesn\'t work, desperate!

For the record, VW fixed the problem with the crank bolt sometime around model year '96. The original post concerned a European model which was older than that.

Since my car was built in November '95, I check that bolt every time I'm in there for any reason. I have never been able to budge it.