No need to replace old glow plugs???

[joesco90vw]

A couple of VW diesel owners told me that after they installed a block heater, their glow plug light does not come on any longer as the coolant is nice and warm?
I am having a block heater install in my 90 Jetta 1.6d. It has about 109k miles and I would imagine the original glow plugs. Should I replace them at the same time I am having the block heater installed?
Thanks!

[vwkook]

If they're all still functioning, there's no need to replace them. If it gets cold and you're not able to plug your car in, you're gonna be SOL with out working glow plugs.

[82vdub]

A couple of VW diesel owners told me that after they installed a block heater, their glow plug light does not come on any longer as the coolant is nice and warm?

I've found on my A2 Jetta that the glow plug light does not stay on as long after the car has been plugged in for a couple hours before starting the car. I suppose it's possible depending on outside temp and how long the block heater has been plugged in that the glow plugs won't fire, but I have not personally seen this.

I am having a block heater install in my 90 Jetta 1.6d. It has about 109k miles and I would imagine the original glow plugs. Should I replace them at the same time I am having the block heater installed?
Thanks!

You don't necessarily have to do both at the same time. If the glow plugs check out ok, there should not be any need to replace them. If you do, only use Bosch glow plugs.

[Vincent Waldon]

Yup, a good block heater will warm things up enough that the engine will not ask for much of a glow cycle. In this last cold snap even at -30C my glow cycle went from 30 seconds to about 5 if the block heater was on.

However, in the immortal words of Clint Eastwood: Do you feel lucky, punk ??!!

In other words, there may come a day when you will forget to plug in... or someone will blow a breaker, or your extension cord will give out... and then you'll be glad you have 4 well-functioning plugs that can start the engine on its own.

For my, 16 bucks each is cheap insurance that I won't be stranded on the coldest day of the year... but then again, I'm not Clint Eastwood.

[Brian Rages]

How do you know there's going to be an outlet anywhere you might be going?


If you are planning on commuting to work in cold weather, your car can easily get COLD by the end of a typical workshift.

[Fatmobile]

If you have time and money to mess with the glowplugs, you can just change the 2 most difficult ones with new bosch duraterms.
I hate to waste old glowplugs that still work so I put them in the holes that are easy to change.

[joesco90vw]

Thanks for all the comments. After some additional research, I did the simple glow-plug test by turning on my dome light and the key in the first position (glow) and it did not dim a bit. The "dummy" light did turn off after about 8 seconds. I then tried to access each glow-plug while the key was in the "glow" position to see if they hot or warm, just plain old cold! All four seem to dead. This 90 Jetta, a Florida car with 109k miles might tell me that the glow-plugs might be originals.

I tried to locate the 50a fuse and the relay, but could not locate them. I have referenced the Bentley Shop Manual that I have for 1990 Jetta and there was a vague description of a location for a fuse panel to left section of the lower dash. SOL!!! Can someone lead me to the location of Jetta's fuse panel along with the glow-plug 50a fuse / relay location??? Would greatly appreciate it.

Now the million dollar question.... After spending about ten minutes reviewing the Bentley Shop Manual, I was surprised to find to glow-plug remove/install instructions!!! Based on their position, it sure looks like a labor-intensive chore. I am mechanical enough to be dangerous, so I farm this out to the local independent VW repair shop or give it a try myself?

What can I expect to pay a shop for the job. I see some pretty good deals for Bosh plugs on Ebay. Thoughts and opinions are greatly appreciated. Thanks!

[82vdub]

You can change each of the glow plugs below cylinders 3 and 4 in about 1 minute each, once you get the electrical bus bar out of the way. Those are the easiest one's to replace. To get at #1 and #2 blow plugs, the easiest way is to remove the injector lines, but others have posted that they have done it without removing them.

Make sure you use anti-sieze on anything you screw into aluminum.

[vwkook]

The fuse is on the firewall behindish the master cylinder. Pull the squarish plastic piece off and you'll see it. Definitely check this first.