Problem with the new glow plugs on W211 OM642.

[Dino_Cars]

I had to replace the glow plugs as instructed by my old foxwell scanner every time the light remained on after starting up; in all, it took six weeks to replace three glow plugs, but it fixed the problems. This happened to me a few times in the past few months. In anticipation of having to purchase new glow plugs, I made good use of some old ones.
At last I placed an order for replacement glow plugs. Upon arrival, I fitted the new beru plugs and immediately saw that cylinder 5 went open circuit. I replaced it, and everything was back to normal. However, now the #1 cylinder has gone open circuit as well. I have replaced it again, and everything is back to normal.
My concern is, is there a reason why my glow plugs keep failing, or do I just have faulty new ones? I was experiencing the same problem before I installed the new ones.

In the past, I've seen that whenever the scanner has shown a glow plug, it has actually been the glow plug becoming open circuit.
Even though I've read that glow plug relays sometimes malfunction, I'm not seeing any error messages related to this particular component. Please, I would greatly appreciate it if our om642 specialists could weigh in on this. Thank you in advance.

[LiamTheGreat]

Curious that they are going open circuit when their regular behaviour is to increase resistance when they fail. When properly installed, the resistance between the glowplug's tip and the adjacent head should be about 2 ohms; however, when they malfunction, this resistance typically increases to 40 to 60 ohms.
That was a failure.

[killiomop]

It seems like the light plug relay could be the culprit; because you mentioned that the problem existed before you installed the new plugs, it's likely that the timer inside the relay is stuck on and is causing the glow plug to burn out because it stays on.

[LeeStu]

Additionally, I would swap out the relay before proceeding.

[rawadmika]

Given that the glowplug circuit is fused at 225 Amps, I would be surprised if further issues arose if the relay became jammed and all six plugs were permanently on.

Changing the plug might be a quick remedy for a connector or wiring issue that's causing an open circuit. Is the status of the plugs you removed still unknown?

[maturo99]

Do we have two options for glow plugs for our engine? There are some that are 12v and others that are 4.5v.
Are you currently using various types of engine plugs? I'm not sure if it would do anything.
Unless you've altered the gp relay before, it won't last forever.

[Dino_Cars]

Apologies for the delayed response. After replacing the glow plug, I encountered an additional issue with the car. It was determined that the culprit was the exhaust back pressure sensor, which was causing it to exhibit abnormal behaviour. True, I checked the plugs after removing them and found that they were open circuit. I initially suspected the relay would be to blame and, to this day, I still have that suspicion.
I did the relay around three years ago, but if they keep burning out, I will be looking for a new one. Currently, I have all beru in them save for a couple of old decent ones, and everything appears to be going smooth.

[GURU4U2BUY]

Take care that the glow plugs' voltage is in sync with the relay's output.

[Dino_Cars]

The right glow plugs for my engine are 4.4v beru. The best course of action would be to keep an eye on things to see whether the problem continues; if it does, then get a new relay, even though the current one is supposed to be the right one.

[maturo99]

Which brand of relay is it?