Khare's problem thread - Engine mount and screeching noise page 15. EUROPE TRIP!

[VR6_Wherry]

sorted it out, the temp sensor did the job 

When can you close this thread off?  Is there anything left to do?

[Khare]

Being in a mk3 this thread will always be open 

[Khare]

Still go the dam idle problem 

It must be the wiring so I'll change the sensor loom. Does anyone know if a 1994 ABF is the same as a 1996 ABF? Same wiring?

Let me know as I'll pop down to the scrappy and get it as I saw a 16v the other day.

[Khare]

oh forgot to ask. Using a multimeter can I check the resistance in the plug and the wiring for the sensor?

[Khare]

Got some readings with multimeter

4.94 volts with ignition on
-5.79 ohms with ignition on (wouldn't get a + reading)
8.61 ohms with ignition off

Engine was warm, has been used about 40 minutes ago or so.

[rubjonny]

yes the sensor loom is the same, where are you getting the readings from?  what are the idle symptoms?

[Khare]

Readings are from the plug that goes into the temperature sensor.
Idle symptoms are the same, when warm the idle fluctuates. I had trouble starting it in the cold this morning, it wouldn't rev, just bog down.

[Khare]

OK, took the sensor loom off and wired in a new plug in perfect nick (scrappy). Idle is still fluctuating. It's an intermediate fault however, for example, it didn't do it for about 20 miles, then suddenly started doing it again. Is there anyway to check the loom from the multiplug to the ECU/fusebox?
I'm having trouble accessing vagcom so I can't check properly, but when I scanned it last week when it worked I had this fault.

00522 - Engine Coolant Temp. Sensor (G62): Break in wiring / short circuit to positive

Possible Symptoms
Difficulties with starting a cold engine.
Starting the engine when engine is warmish or warm, idle rpm immediately is 1200 - 3000 rpm.
RPM at idle is irregular.
With all engine temperatures seldom idle rpm will vary between 900 - 1000 rpm.
With engine warm (90 °C) the engine temperature suddenly drops (70 °C) and slowly comes back to 90 °C.
Bad acceleration during warming up.
Diesel: an indication is extreme long time burning time of the glow indication light.

Possible Causes
Wiring and/or connections faulty
Moisture in wiring harness of G62
Engine Coolant Sensor (G62) faulty

Possible Solutions
Check wiring and connections
Check / Replace Engine Coolant Sensor (G62)

I've replaced temp sensor with genuine VW one, so it must be the wiring... What resistance should the plug have when ignition is on? I got the following

Got some readings with multimeter

4.94 volts with ignition on
-5.79 ohms with ignition on (wouldn't get a + reading)
8.61 ohms with ignition off

Engine was warm, has been used about 40 minutes ago or so.

[danny_p]

do you rember the state of the loom from your donor car ?  i'm not  suprised it's being a problem really it was going to at some point !
think i told you that it would be a problem at some point when it went in. i defantly know the grounds in that loom are ropey as hell they looked it and the DMM confirmed it

only effective cure is replace the sensor loom as a whole for a servicable one.    where it's being soaked in oil round the side of the head the oil and heat will have knackerd the insulation on the wires over time.

[rubjonny]

http://vwtech.no-ip.info/downloads/g3abfecu.pdf

thats a full ecu wiring diagram, you can use it to trace all the pins back to the ecu.  I think it would be a good idea to strip all the loom tape/wrap off the engine loom and check all the wiring. as danny says wires dont like to be soaked in oil they go all brittle, the ecu code suggests they have cracked and are shorting together inside the loom tape somewhere.  if you're lucky the problem is inside the part of the loom clipped to the engine rather than the main engine bay loom