Got an issue of minimal voltage reaching plugs.

Swapped over the glow timer: relay unit (mental blank on proper name..)

No change .. and donor car starts on the swapped one..

The bad one had blown the 50A maxi fuse on battery terminal.. so I thought the timer contacts may be stuck.

I have full 12volts on good car..holding stable.

Poor car flickers to 1 volt for a second before nothing.

So I suspect damaged wiring.. what else could pop a 50a fuse..and still stop power flow now

Strangely the dashboard glow signal seems uneffected (NORMAL)..

I have since changed 2 glow plugs.. but MES says 'short circuit'

So must be damaged wiring.. AFTER the glow relay box..

Any other suggestions.?

A quick look on ePER seemed to put the short wiring section...@£550 .what I paid for the donor car..!!

I think you are better off tracing the glow plug wires from both ends back along the loom.

Either there will be visible external damage or the damage is internal in which case you will just have to unwrap the looms external covering looking for the fault.

Mid loom repaires are not that difficult do. Only get tricky when the damage is right next to the connector ends.

Next plan

Hoping to get to the bottom of it tonight..

MES should at least tell me if the fault is rectified.

The 50 A mega fuse is a pain to obtain also.

Using household fuse wire as a temp fix.
5 minute walk and 50 pence.

Update..

IT RUNS.


Having checked I still had 12 volts on the flylead from battery terminal..through maxi fuse.. to the glow relay timer box.

I pulled all 4 plug leads off.. and got 12 volts reliaby.

(I had perfomed previous tests singly..)
so I summised the 'dead short' predicted by MES may be the last glowplug.. No.4

It had only turned 1/4 turn.back and forth... so I left it.. but I replaced the others..

Guessing this plug may have failed internally..

I just connected to plug No.s 1 and 3.. started well.

Left idling for a minute.. a quick look confirmed all appeared well.
So switched off.. tucked the 'spare lead' from No. 4 out of the way..and refitted plastic boxes.

Started again and had a 2 monute drive.

Will aim to use for work in coming dsys.. getting HOT enough to withdraw that last plug.. then repair the dodgy cable ends..

Hopefully before more cold weather..

Trying to remember where we are up to with this but have you ruled out the possibility that a glow plug has gone short circuit. A simple multimeter may not be able to resolve the difference between 0.9 ohms and 0.0 ohms.

0.9 ohms will pull 13 Amps, time 4 = 52 Amps. This will not blow a 50Amp fuse due to the short duration vs the fuse's 50 Amp continuous loading ability.

A meter with a "zeroing" function will eliminate its leads. Even then measuring resistances below 1 ohm is always an interesting game.

Looks like our posts crossed over at the same time

Thanks.

I had made several attempts measuring tesistance.. but nothing conclusive.

My decade+ diesel experience starting with the 1929 TDs.. found that when swapping struggling plugs.. 95% would still glow cherry when sat on a battery.

So suspected poor conductivity..

This is the 1st occurence of a shorted plug for me.

Thanks again. Charlie

Todays basic test rig-

Short piece of cable.. fron glow plug body to engine bolt.

Good earth.

Then plug coupled to a power lead.. working along the cylinder leads.

With this I could see the plug glow cherry from thr drivers area


Having got power.. had the confidence to rebuild

How did you manage to get the last plug out without snapping it off? I have changed 3 out of 4 glowplugs but can't get number 4 out.
90% sure I will snap it off if I try harder...I don't even have a clue what to do when that happens.

Detroitdiesel said:

How did you manage to get the last plug out without snapping it off? I have changed 3 out of 4 glowplugs but can't get number 4 out.
90% sure I will snap it off if I try harder...I don't even have a clue what to do when that happens.

Click to expand...

Not out yet..

I kept a can of penetrant lubrican in car.. everytime I stopped with a HOT engine..

I sprayed around the plug threads.

As you will know some are better accessed than others.. airbox is in the way


I got the motor HOT and loghtly sprsyed the plugs.. to effectively SHRINK them slightly.

Will do the same with the other 2..

Plugs 2and 4

Ok.

Got to take car to work.. starting well enough on 2 new plugs.
Gave a good soaking of the 2 plugs when arrived at work.. an opportunity for the fluid to 'creep' into the threads.

Got nice and hot on way home..
Stripped away the airbox and got the 2 remaining old plugs moving. 8mm single hex deep socket. 100mm extension bar.. and a 200mm 'handle'

Got a nice amount of 'feel' through this..and worked things loose before switching to a ratchet

No.4 was still the tightest fit.. but was moving ok.. did 2 turns.. then sprayed with release old and wound back in.

Seemed happier coming out on 2nd attempt.

Got both plugs out with this method.

Started both new plugs by hand.. did @3 turns before stiff.. then wound in with a ratchet..

No.4 was giving resistance all the way.. but it was steady : uniform

So felt 'right'

Obviously judging when it has bottomed on the seat is tricky.

I think these BERU plugs have been in for a LONG time

I had a hard time getting the wiring connector away from the worst corroded plugs. One snapped at the solder joint..

And will be awkward to repair

Probably best to get replacement short stubs
and solder back inline.. with a little 'slack'..
as the factory leads are relatively tight on length

varesecrazy said:

I think these BERU plugs have been in for a LONG time

I had a hard time getting the wiring connector away from the worst corroded plugs. One snapped at the solder joint..

And will be awkward to repair

Probably best to get replacement short stubs
and solder back inline.. with a little 'slack'..
as the factory leads are relatively tight on length

Click to expand...

I changed the plug's on my 09 500 last year the one nearest gearbox took a bit of back and forth to get out cleanly but came out after a short while
They were of cause nothing like the state of yours minimal rust build up
Looks likes they have been getting wet a fair part of there lifespans

varesecrazy said:

I think these BERU plugs have been in for a LONG time

I had a hard time getting the wiring connector away from the worst corroded plugs. One snapped at the solder joint..

And will be awkward to repair

Probably best to get replacement short stubs
and solder back inline.. with a little 'slack'..
as the factory leads are relatively tight on length

Click to expand...

As the kids say these days - Respect to you for getting those out!

Was more about finding the time ..
At least it has proven worthwhile.

Detroitdiesel said:

How did you manage to get the last plug out without snapping it off? I have changed 3 out of 4 glowplugs but can't get number 4 out.
90% sure I will snap it off if I try harder...I don't even have a clue what to do when that happens.

Click to expand...

Did you get them out?

I got well practiced in removing air filter for access.

Once up to full operating temperature..
3 minutes later airfilter was removed..cables off

The stuck plug moved ok.. stiffly but steadily worked out.

varesecrazy said:

Did you get them out?...

Click to expand...

I din't try anymore. First I want to be sure that the stuck one is actually the one not working. Going to order a non-crappy ELM327 and test them with multiecuscan to be sure which one it is. Even then I might wait till next winter since it currently starts on all 4 when the temperature is >5C.

Luckily the stuck one is cylinder number 4, the only plug easy to reach without dissembling anything. (not even the air intake needs to come off on my engine)

I'll keep your experience and tips in mind though, when I do try to pull it out the engine will be fully up to temperature. :slayer:

Just lately I've come across a couple of google entries describing air impact wrenches which are specifically intended for use on glow plugs. I tried to see what was on you tube and found a number of quite detailed videos. The guns can be adjusted to deliver 10, 20, 30 or 40 newton meters of torque. There are a couple of very impressive videos showing it being used to "crack off" seized caliper bleed nipples. I can well imagine that these devices may work well at this due to the hammer effect they deliver.

As I work on older vehicles and machinery where corroded fittings are always a problem (seized bleed nipples being a frequently encountered "pain") I find this particularly interesting - Pity they cost so much! Now I have my CP I wonder if I can find a way to "throttle down" my old Clarke impact gun? Now that sounds like an interesting challenge and project?

Its nice to have some 'feel' though.

Rather than ..

Dial in a Figure.. and pray..!!

varesecrazy said:

Ok.

Got to take car to work.. starting well enough on 2 new plugs.
Gave a good soaking of the 2 plugs when arrived at work.. an opportunity for the fluid to 'creep' into the threads.

After removal :

Started both new plugs by hand.. did @3 turns before stiff.. then wound in with a ratchet..

No.4 was giving resistance all the way.. but it was steady : uniform

So felt 'right'

Obviously judging when it has bottomed on the seat is tricky.

Click to expand...

I will have to revisit this plug..

Sods law says this is causing my fumes..