No Glow? Hard cold start? Check coolant temp sensor.

Jimmy

Veteran Member
Joined
Feb 24, 1999
Location
Canada
There are several threads regarding glowplugs and hard starting. Yes, if your glow time is too short and it is cold, it will be very hard to start. Last summer I noticed the temperature guage intermittanly falling back to zilch when the car was obviously warm and running. No one makes coolant that good! So off to a dealer for a new sender unit, and after a small loss of coolant, and two trips to the dealer for a part that actually fitted my car, the new sensor was in, guage working.

Then fall arrived, and the car became steadily more difficult to start as the temperature dropped. It did not take a Sherlock Holmes to figure what to suspect. "Watson" could have solved that one. A peek at the indicated coolant temp with a VAG-COM when the car was left overnight at 5 deg C showed that the computer was told it was a lovely tropical 30 DEG C!!!! So I had the wrong part in for 2 months.

According to one parts counter, there are two to three possible models of coolant temperature sensor for the ALH engine. One has a very different connector from mine (built Mar 99) and is cheap - $7Cdn. The first "parts" counter indicated I needed the "$18" one - and was the wrong type. A third trip to a different dealer yielded the correct part (and new rubber O-ring) at $45. Tip: Make a note of the color of the connector. If you remove the unit, coolant will start to drain out (Duh!).

Note that this sensor is actually two in one unit - one half provides for the instrument guage and the other for the ECM.
 
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dieseldorf

Top Post Dawg
Joined
Oct 11, 2000
Location
MA
TDI
ex- 1996 wagon, ex-2000 Jetta
VAGCOM ROCKS! No VW owner can afford to be without !!
 

MOGolf

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Joined
Jun 27, 2001
Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6.
17-Instruments will never show you a coolant temperature below 30C. That's the low point on the gauge. I hope your reference to "the computer was told" was in reference to a reading in the ECM, not the cluster.

The rest of your thread has been posted numerous times.
 

greenskeeper

Top Post Dawg
Joined
Mar 10, 2003
Location
USA
TDI
1998 Jetta TDI
That's one of my projects I havn't gotten around to. Manually operated glow plugs off of a switch. Did it to our truck and havn't looked back since.
 
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