Glow Plugs, 5 or 7 volt?

Rrusse11 · **Posted:** Tue Oct 13, 2020 2:58 pm

So I believe my current failing plugs are the original 7v ceramic. Time for replacement, seeing as how they are starting to throw codes. No problems starting yet, but winter's on its way.
Various reiviews at IDparts of the 2 types offered, a 7v Etechno, and 5v Bosch, lead me to think that the 7v may not be the hottest option, several buyers complained that below freezing they had trouble starting. The 5v
reviews claim that while the voltage might be higher than rated for the plug, they will work fine in the cold.
Life expectancy may be a bit compromised, but they'll start the engine.
The other question is whether or not a glow plug harness is necessary. Worthwhile to replace after 15yrs and 250k? And I'll definitely go with the gasket option for the elbow.
Cheers!

uncaged · **Posted:** Wed Oct 14, 2020 1:46 pm

Having gone through this, here's my experience. I still have the original 7V controller that came in the beast. At about 10,000 miles (? or so - can't remember exactly) a ceramic tip broke off, made it clean through the exhaust valve train (thank heavens!) and wrecked the exhaust vanes on the turbo. Warranty replacement on the turbo, and I think they replaced the glow plugs (with more ceramics at the time) without mentioning anything. At around 100K I decided to replace the plugs and went with the steel 7V Etechnos. The thing wouldn't start for crap in the winter. Hated them. Replaced them in short order with the 5V Bosch and they've been great. I don't know about shorter life, they've been working for the past 45K miles through Vermont winters. I'd buy the 5V Bosch again for sure. They seem to work fine with the original 7V controller.

Rrusse11 · **Posted:** Wed Oct 14, 2020 4:02 pm

Uncaged,

Thank you sir! Just the kind of affirmation I've been looking for. I'll order the Bosch 5v and hope the harness is ok. It's going to be quite the exercise just getting to the little buggers.

Cheers! Appreciate the input.

CATCRD · **Posted:** Wed Oct 14, 2020 4:15 pm

uncaged wrote:

Having gone through this, here's my experience. I still have the original 7V controller that came in the beast. At about 10,000 miles (? or so - can't remember exactly) a ceramic tip broke off, made it clean through the exhaust valve train (thank heavens!) and wrecked the exhaust vanes on the turbo. Warranty replacement on the turbo, and I think they replaced the glow plugs (with more ceramics at the time) without mentioning anything. At around 100K I decided to replace the plugs and went with the steel 7V Etechnos. The thing wouldn't start for crap in the winter. Hated them. Replaced them in short order with the 5V Bosch and they've been great. I don't know about shorter life, they've been working for the past 45K miles through Vermont winters. I'd buy the 5V Bosch again for sure. They seem to work fine with the original 7V controller.

My experience with the different types of glow plugs mirrors yours almost exactly, except my turbo survived the ceramic one breaking. I'm currently running the 5V Bosch metallics, and while it seems like they aren't quite as good at cold starts as the original 7V ceramicss were, they get the job done, and I don't cringe at the thought of another breaking when I'm cranking the engine.

geordi · **Posted:** Thu Oct 15, 2020 12:48 am

The harness will be fine, and getting the plugs out will be much easier with the elbow kit to give you the access and also delete the EGR.

The "mismatch" won't be noticed by the computer, keep the 7V software and use the 5V Bosch plugs. They will last - people are into their 4th year with the mismatched plugs and they are starting great.

uncaged · **Posted:** Thu Oct 15, 2020 8:11 am

As an aside to easier starting, try waiting until the power-on chimes end before cranking the starter. It seems as though the glow plug heat up cycle lasts longer than the GP light would indicate.

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

uncaged wrote:

As an aside to easier starting, try waiting until the power-on chimes end before cranking the starter. It seems as though the glow plug heat up cycle lasts longer than the GP light would indicate.

This is good advice.

I'll also put forward a vote for 5V Bosch glow plugs on 7V programming. We've had this configuration for two years (as of next month) and about 40,000 miles at this point with zero problems.

Glow Plugs, 5 or 7 volt?

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