[alfaitalia]

Especially for the four or five of us on here with CRD models! I have noticed that my WJ is slow to start when its below freezing so I tested the glowplugs in situ and three of the four I could reach failed the test....so that explains that then!

Five new Falcon glow plugs bought for £27 inc delivery from eBay arrived at my door a couple of days ago and here is how I fitted then today.

In a lot of cars this would be no more difficult than changing a set of plugs....but not on this one. firstly the fuel rail and its fuel lines and wiring are in the way and secondly, since this engine has been stuffed into a vehicle it was never designed for, access to the rear most (cyls 4 and 5) is limited to say the least. So here goes. I apologise for poor photos and the fact that I forgot to take some at all!

Before you start the engine MUST be up to full operating temp (about 90c)...if not there is a very real chance that the old glow plugs could snap off in the head...meaning head off....expensive. They only take about 20nm to fit and cant take much more than that on removal without shearing so be careful.

Firstly remove the engine cover...pull firmly upwards and off it comes.

This is what you will find underneath.

Remove bracket that hold cover on and locates dip stick tube....this will enable removal of fuel rail fixing bolt.

Remove fuel system bleed valve so fuel rail can be lifted out.

Remove fuel rail pressure sensor.

Remove plug from fuel pressure regulator at far end of rail. Tight but possible with normal size hands! Upper middle of this picture.

Remove main rail fuel supply (links rail to high pressure pump). 14mm spanner (wrench in US!).

Remove all five injector feeds from rail. No need to disconnect them from the injectors but doing so from cyls four and five will give you more room when removing their glow plugs. 14mm

Remove the three bolts that secure fuel rail to head. This is the rear one....tight to access due to fuel return pipe running across it but not impossible. You could remove this pipe from fuel filter to gain more space. I didn't.
Pull rail as far to left as possible to clear space to access glow plugs. There is no need to unbolt 'excess pressure return valve' from end off rail....just make sure you don't over stretch the pipes going to and from it.

Remove glow plugs caps....a pair of needle nosed pliers was my weapon of choice....not much space around the plugs.

Remove all glow plugs slowly and carefully to avoid snapping. Should take no more than light hand pressure on a 3/8 drive socket with a deep reach 10mm socket to get them moving....if it does not budge either leave that one or apply some localised heat if you can. I though number 5 would be the most difficult due to access but it came out easily albeit with a bit of skin loss and only a small arc of movement on the ratchet. Number four was a pain due to the plastic shielding that protects the injector wiring and the engine hoist mount fitted nearby getting in the way. But a bit of patience and they were all out. Hooray!

 

[alfaitalia]

3 old and nasty glow plus and one sparkly new one. The round thing is one of the grommets that hold my engine cover in place. I lost that about the first time I removed the cover....never thought I would see that again. Been lodged against number four glow plug for about four years!

Fifth glow plug came out easily but not much space foe tools or extraction of old plug....looks more space than there really is in this picture!

All five out. Four on the left are dead....only one functional on right. No wonder she did not like sub zero starts!

Having put it all back together..not forgetting to replace caps on the glow plugs. Remove cap from bleeder on top of cylinder cover and insert 8mm pipe all the way in then retract about 5mm.

Other end of pipe goes here. Best £8 I've spent on tools. Use it for this (priming fuel system after any fuel system work) as well at topping up difs, changing power steering fluid etc.. Do not try and bleed system just by cranking over with key. It probably wont work and could damage both your fuel pumps. I know this from first hand experience! Pull fuel through until just about bubble free. Should start first time then.

She starts sharp as you like now although I will be waiting for a properly cold morning to be sure. Cold tick over is better too. Unlike a lot of diesels the glow plugs stay on (in low power) for quite a while after the glow plug light has gone off on the dash to speed up warm up and smooth out idle and low speed running...that was not happening on mine. They can stay on quite a few minutes after you start up if its cold enough.

So there you go. As always if you have any queries, comments or criticisms Id be happy to here them.:thumbsup:

 

[alfaitalia]

Success....it was minus 2 c this morning and she started within a second of turning the key. Would have been a four of five second crank before the new glow plugs. Satisfying when you get the right result....I knew several of them were faulty but there is always that element of doubt in the back of your mind that the problem might be being caused by something else.....usually it is!!

 

[ChrisHager]

Added to the FAQ!

 

[alfaitalia]

Thank you! Makes all the trying to take notes and pictures on a windy day at about 2c over freezing all worth while!:thumbsup:

 

[MadderThanMax]

Well Done you.. Great write up, Bovril & a pie to you (Or is that a pastie??) to heat you up..

Good stuff..:thumbsup:

 

[BlueJc]

Great write up Alf, What did you use to test your plugs? (A multi meter on ohms looking for continuity?) What readings did you get on the bad plug in relation to a good one?
My jeep takes five cranks/cycles 2-3 seconds then starts right up (on first turn of the key). obviously when the heat light goes out. This was at -2C.

 

[alfaitalia]

Get a multi meter and test the voltage of the battery. Then leave the positive lead of the meter on the positive terminal of the battery and place the negative or the tester on the terminal of the glow plug (remove glow plug cap first or course!). The voltage reading should be within a couple of tenths of a volt of the reading you got from the battery test. 3 of mine read zero volts and one about 5 volts the fifth one read 12.4 volts (battery was 12.5) so I've kept that one as a spare!

 

[davidmarais]

Nice write up, how many miles did you get on those old glow plugs? Mine is on 102700miles and still starting like a champ on cold Surrey winter mornings but effectively know the time is coming to replace mine in the future.

 

[alfaitalia]

121,000.....and even then it was only noticeable on the sub zero mornings. I while ago I removed both glow plug relays to try in a friend's jeep and to be honest, in the warm weather mine still started pretty much instantly with no relays and therefore no glow plug heat at all. Only really needed in winter in sub tropical Sussex (and nearly as warm...but a lot posher! ....Surrey!). The key is having a battery and terminals in top condition. A fast turnover speed from cranking will generate enough heat from compression alone to almost render the glow plugs redundant.

Sent from my SM-T310 using JeepForum

 

[lemioux12]

Nice write-up here , can someone please point out with a picture where the glow plug relays are exactly located ?
Thanks !

 

[BlueJc]

I changed mine for new when I had my leaking injector #5

Nice write up

 

[alfaitalia]

Nice write-up here , can someone please point out with a picture where the glow plug relays are exactly located ?
Thanks !

Fuse board under the bonnet near the battery....long black plastic box.

 

[tahoeJeep]

As long as this post has been resurrected. . .

If a glow plug fails, do you get any kind of indication other than hard starting? Check engine light or trouble code in the OBDII? Last winter here in Minnesota, the WJ would start at -15F. This winter it is harder to start, even above zero. 193,000 km on the odometer which translates into ~119k miles.

Great post, BTW! I know it will someday come in handy!

 

[alfaitalia]

Obviously no glow plugs in the petrol models you get over there...but no. No warning lights and no fault codes for faulty glow plugs.

 

[tahoeJeep]

FYI, my WJ CRD was assembled in Austria, spent 12 years in Italy, then "returned" to the USA. I purchased it in Arizona. Sprinters have the same basic engine, and I believe their engine control computer gives an error code on a bad glow plug. When mine gets too hard to start in the cold, I'll replace all 5.

So there are a few WJ CRDs over here. I sure like mine!

 

[alfaitalia]

Interesting.....did not know you had any over there. Mine never threw a code.....not saying that none do though. The only code I know is for no power getting to the plugs....rather than actual plug failure. Most hard starts on these, in my experience, are worn injectors allowing too much leak back....similar symptoms as failing glow plugs.

 

[Johnny-DK]

Do I just pull the glow plug connector straight up or, do I need to twist or squeeze it a bit? Don't want to break any of them.

 

[alfaitalia]

Straight up. I needed to use some point nosed pliers to get enough pull on it.

 

[fuseblower]

Very useful write up. Thank you for taking the time to photograph and explain. I have plenty to tell but for now how do you get the fuel bleed plug out? I am reluctant to put a lot of force on a piece of plastic. Advice please
thank you in advance