How Necessary To Ream Glowplug Hole?

[beaulieub]

What is this accomplishing and how important is it to do?

Bert - NH

My understanding is that if you don't ream it, the next glowplug you put in will quickly fail.

[BenzDieselTuner]

i never reamed mine when i changed them, and havent had any trouble at all.....

[carnut]

Its much like cleaning soot from a chimney. The built up carbon can break off and get under a valve or the new glow plug will have a hard time threading in. Most times there are no issues, but Murphy's law can prevail! you simply run a tap of the proper size to clean the threads.

[TheDon]

Originally Posted by carnut

Its much like cleaning soot from a chimney. The built up carbon can break off and get under a valve or the new glow plug will have a hard time threading in. Most times there are no issues, but Murphy's law can prevail! you simply run a tap of the proper size to clean the threads.

i recomend using the reamer.. but in a pinch the tap will have to do.. the reamer is used for a reason since it catches alot of the crud that is reamed out

[DieselAddict]

I've never reamed mine, but what I've done is to crank the engine for a second or so with the glow plugs out. This will blow out any carbon in the glow plug holes.

[Jadavis]

I didn't ream mine this time. I thought I didn't have time to buy one before I put the car back together. Turns out I would have if I would have ordered when I first realized I needed one.

I did turn the engine over with the glow plugs removed.

We'll see how it goes.

-Jim

[F18]

I have never reamed a single glow plug hole on any one of my past or present diesels. Never had a single pre-mature glow plug failier or siezed or broken plugs...... But it could be because I do almost all highway miles???
I would imagine that there is alot more carbon build up with vehicles that do almost all stop and go city driving and sit Idling for extended periods.

In the K1500 TD Blazer I had the same original 8 glow plugs from the factory in it when it turned 300K miles. I felt guilty about it...so I changed them out and found the originals still in perfect condition (very little erosion)..their resistance was still right on the money. On the MBs I use to get about 150K on a set of glow plugs.

I think it really all depends on the vehicles use....either city or highway.
If its city then may be its a good idea to ream them and inspect the glow plugs more often.

hmmm

I only got 10k out of my last set and I did ream them. This time I pull them I am going to pull the prechambers and have the injectors rebuilt.

[beaulieub]

"pull" the prechambers? They are removable?

[83-240D]

the carbon can build up and short out the plug making you think you need new plugs when a good screwing in the hole was all your car needed.

Originally Posted by beaulieub

"pull" the prechambers? They are removable?

With the correct tools, yes. ~$100 for the two tools (total). I have them, and anybody in the Portland Metro area can borrow them.

EDIT- And I have the reamer too.

[Hit Man X]

Smart? Yes.

Necessary? No.

[dieseldiehard]

Originally Posted by 83-240D

the carbon can build up and short out the plug making you think you need new plugs when a good screwing in the hole was all your car needed.

well, that statement is not applicable to the pencil type GP's (including the '83 240D) its a carry over from the series connected GP's

I've never reamed mine. No issues yet. My glowplugs last an average of 8 months to a year.