The dreaded No3 glowplug...

[Paul64]

Had the yellow light stay on after starting this week and just checked - no3 glowplug is kaput...
I have spares but, no 3 is the one behind the fuel pump. Having had a look, I can break off the connection and get a short socket onto it however, if I remove the fuel pump atmospheric correction chamber - 27mm I think - from the top of the pump, I can use a double-deep 12 and do it ‘properly’...
Question - does the chamber just unscrew or will I be damaging something within??

Look forward to hearing thoughts - I don’t want to break it with only 300k on the clock..!!

Paul

 

[clk320x]

Why not just leave it? Should still start fine with 1 out.

 

[Duff3103]

I'm sure i done a set of glow plugs in a w124 estate 300d when i was in the garage (assuming it is the 300d) and pretty sure it was a piece of piss? if i remember right all i had to take off was the intake trunking over the top of the cam cover and used 1/4 drive socket set with a wobbly end to get them all out? not 100% sure as its been a while but even taking off a fuel pump connection it just requires a rebleed anyway at the fuel filter housing

 

[Benzowner]

I have only 4 cylinders with one glow plug gone and the car still starts fine, has done since last service in March when I was advised of labour cost to replace the glow plug

 

[Paul64]

The car starts fine, though a bit lumpy now it's getting colder. I have spare glowplugs and am not bothered by the labour as I enjoy the work - it was more a question on the fuel pump chamber and whether it could be removed - to get onto the end of the plug with a 3/8 drive, which I suspect it might need having changed some of the others, the chamber would have to come off unless I get some 3/8 square bar for the end of the socket to make a square drive extension for a spanner. I think 1/4 drive might be too small for the torque required in this case - the others have been pretty FT when replaced...

 

[Duff3103]

Stick some release oil down the hole and let it work in then give it a try, sometime leaving the car running and getting some heat into it also aids removal, just a tip for up if it’s pretty tight

 

[Paul64]

Thanks for the tip - I did that last time when it was unscrewed but held in with the carbon build-up; it shot out and I lost it in a hedge nearby...! Good firing pressure I guess..!!

 

[Duff3103]

Iv only ever found mega build on glow plugs in modern engines, iv never had a bit bother on any older design diesels, dunno if it’s just good luck (which is few and far between) every time they have come out

 

[topdown]

I would stick to 1/4 drive as the the shear off TQ is quite low.

 

[Paul64]

Got the plug out last night - snapped the extended end off with a ring-spanner, gave it a couple of taps with a drift and used a socket - came out fine in the end. The new one went in after cleaning out the recess with a wire brush and tightened up with a couple of ring spanners with differing hex positions.
I did however, end up with a fuel leak after moving one of the injector leak-off lines when removing the HP pipe. As I replaced these about 5 years ago with original MB hose, it was a bit of a worry to find that the pipe had gone brittle after the pipe I replaced could well have been original... Looks like the rising % of bio fuel is degrading the hose early - I changed all the pipes with some new MB hose, just in case.
I also cleaned up the electrical connection on the oil pressure sender as the gauge had become a little unreliable and that seems to have done the trick. The loom trunking running vertically up the firewall had degraded and crumbled away to the touch too - I replaced the top harness when I bought the car but this section wasn't included. I just recovered the wires with suitable spiral-wrap which seems to have done the trick.
All good now, back to normal - ready for the next 300k....