I've been getting a tough time starting since the weather got colder here (Winter in the UK, so still not mega-cold conditions, down to around 0oC was as bad as it got so far). So I suspect one or two glow plugs have failed making it hard work to start (Turning over a few times and starting on a bit of white smoke).

So today I checked the system out, tested the relay first as that's nice and easy at the front of the engine bay, all OK there (For reference I used a multimeter to test continuity between the terminals when 12v was applied to the coil terminals).
So went on to test the glow plugs. Who on earth designed where they go on these 2.8CRD engines! Counting from the left of the block, plug 1 is behind the alternator, so couldn't even get to the lead to take it off and test resistance. Plug two is behind the power steering fluid bottle, plug three is behind a metal intake/exhaust (can't remember which) mounting and plug 4 is probably the easiest behind the sensor.

Anyway, I tested the three I could get to reasonably easily, and all three are totally open circuit! (Testing resistance against the chassis and the tip of the plug) So no wonder it's struggling to start.
(I also did a further test on one of them using my current sensing meter, lead to battery +ve and then to the tip of the glow plug to see if it pulled any current. Not a thing!)

Going to order some glow plugs and set to changing them probably next weekend. Any tips or hints? Looks reasonably straight forward once I've gained access to them. Plug 3 looks like if I loosen the metal intake it'll split and the split in the middle should give me enough room to fit the socket inbetween and get at it!
Probably an easy one to you seasoned professionals but just the awkward positions of them amazed me. I'll probably leave the one behind the alternator as that'll just be a challenge too far!

 

You sure the white smoke is not coolant due to headgasket leak?

 

Reasonably sure, I do have a water leak at the moment (Looks like at the left corner of the radiator, the seam is leaking) but don't think it's gasket. White smoke is just when initial starting, at heavy load, kickdown, etc don't get any. Also it's just a small puff at first start when very cold, if it's warm it seems all fine, so suspicion isn't head gasket, at least not at the moment!

Planning on doing the plugs next weekend as I know they need doing, then need to either get it in or get a new radiator and change that before anything else I guess.

 

CRD's with a good battery are usually good starters in spite of glow plugs. A battery is a 100% check for the earthed plug itself varying between red-tip of tip only 50% and red-most of tip 100% efficient. Ditto the same glow test between terminal and tip for circuitry continuity and relay switching. At the moment you seem to be saying there's no voltage at the plug tip are you ?

 

Thanks for the diagram QinteQ, that confirms the relay I tested was the right one and was fine.

I've not tested the socket for voltage at ignition on, I've tested the glow plugs themselves in-situ and get totally open circuit (Between chassis and the glow plug tip itself) so looks like the plugs are completely open, no resistance so think they're shot.

*edit* Ah, I just spotted where I was a bit vague:

What I meant there is I tried to power the glow plug manually by jumping from the +ve on the battery straight to the actual tip of the glow plug (i.e. bypass the car relays, wiring, etc) and test what current draw it pulled using my meter. It didn't pull a thing which makes me conclude it was a shot plug.

And yes, I guess they are good starters regardless of plugs as the way mine are looking, all 4 have given up over time (Remember, I've only had this GV about a year and it's past ownership haven't been good on replacing/maintaining)

 

on the top of the triangular metal plate above the alternator there is the cabling and a nice connector for the glowplugs (square 4 pin) which makes a good point for initial testing.

Regards
Richard

 

Voltage counts, old school would be a direct voltage, these days mucho potential for other control bits to interfere so I suspect No1 is somehow causing the other 3 to read as open circuit by not opening a ground circuit - PCM/ECM finds no feed shuts of ground ? [a guess] go voltage IGN and forget the DVOM for the minute.

I know one plug never gets changed but dig out any and test #4 then any others you get get at. As for the one that no one wants to do I've never done them on a GV but many have reported a 1/4 drive and wobble end works with perseverance. If any single one tests ok with voltage and earth applied direct [see mage below] then the No1 is going to have to come out like it or not and be subject to the same test. Best of luck.

Amount of red tip

 

Did you only check continuity on the relay , remember to check volt (power supply) the fuse might be blown.

Glowlight in dash is still working if glowplug fuse is blown !.

And it's quit easy to remove alternator to get access to no.1 plug.

 

∀ndy, two or four ... all gone ... simultaneously is a long shot as was my #7 'open circuit' theory. What you need is a confirmation that a glow plug does not glow. Take any one out of circuit and apply a jumper lead each to the 18mm threaded top and M14 threaded body

 

Is the glow plug relay on 2.5crd 2001 model meant to be grey or black? Does anyone have the right part number? Mine is a black one and a few articles i have read all say grey. I am beginning to suscpect its wrong relay