The Sound of Solenoids

Technical questions and answers concerning all models of VW diesel vehicles.

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Thomas M
Diesel Freak
Posts: 158
Joined: Sat Dec 11, 2004 5:54 pm
Location: Vancouver, WA

The Sound of Solenoids

Post by Thomas M »

My car: 1991 MK2 1.6 diesel, NA

The injection pump was recently rebuilt by a reputable diesel specialty shop in Portland, OR…..Diesel Fuel Injection Service. I has the two solenoids; fuel shutoff and cold start.

They look the same, but have different Bosch part numbers.

The fuel shut valve will make an obvious “click” when energized with a 12 volt lead.
The cold start valve makes no such sound. Thinking the wire to it might be temperature controlled, I jumped directly from the battery…….still no click.

I tried to remove the cold start solenoid using a large crescent wrench, but it felt too tight and I didn’t want to break anything. The aluminum housing doesn’t look to strong. I put some WD-40 on and left it till tomorrow.

One of the techs at DFIS told me that some of the Bosch solenoids cannot be heard very easily.

Should the cold start solenoid make an audible click when energized with 12 volts directly from the battery???
If not, can I take that as a sign to replace it??

Picture of what I call the "cold start solenoid"........some pumps don't have it.
Image

It's in there pretty tight and that housing is dainty....I suppose I could grap the aluminum housing with a padded pair of channel lock pliers and put a little more twist to it? ?

I just want to know if I should be able to hear it activate. If yes, I might have to replace it.

The car has a cold start pull handle to the left of the steering wheel.
:roll: 1991 Mk2 Jetta non-turbo, 1.6 Diesel, engine code ME, hydraulic lifters,
5 Speed 020 AWY 04120 Transmission
320,000 miles, Original Owner; Vancouver, WA

Located in: Vancouver, Washington
Still Looking for Engine Rebuild Options in Portland, Or Area as of August, 2021
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