X250 Engine earth fault

[John52]

Robbo - 2017-07-14 4:10 PM

 

John52 - 2017-07-14 1:47 PM

 

The original earth strap on my 2008 model was plain copper. My understanding is that tinned copper is beter because its less susceptible to corrosion. If you want to replace it you need a short (9" is ample) strap with 8mm holes both ends. 25mm is adequate - link: (see original post)

But thicker cable is always better,

link: (see original post)

 

 

Can't read unfortunately - is it possible for the OP to shorten the long links ?

 

Unfortunately not as you can't edit a message after 30 minutes.

They are just links to an ebay site illustrating earth straps.

There should be a slider at the bottom of your screen you can hold and drag to the right to read the whole page?

[Keithl]

Robbo - 2017-07-14 4:10 PM

 

Can't read unfortunately - is it possible for the OP to shorten the long links ?

 

John,

 

I have edited them for you :)

 

Keith.

[Robbo]

Keithl - 2017-07-14 4:32 PM

 

Robbo - 2017-07-14 4:10 PM

 

Can't read unfortunately - is it possible for the OP to shorten the long links ?

 

John,

 

I have edited them for you :)

 

Keith.

 

Many thanks Keith :-D

[Willum]

I'm guessing/HOPING!! that I'm seeing symptoms of the same earth strap problem that started this thread.

 

I have a 2008 Ducato X250 Maxi 3.0 litre 160 BHP

Yesterday the dash lit up like the usual christmas tree, lights went out as usual except the glowplug kept flashing and engine fault lights stayed on. Turned the key and initially all I got was a click as if the battery was flat. It isn't, it's on constant maintenance charge. Neither is the weather cold.

Turned all off, on again and the same lights but the engine started and ran perfectly well. The glowplug light went out, as did the engine fault light.

About 15 minutes later, I noticed the idle speed increase to about 1100 rpm. It didn't go back to normal and I stopped it about 5 minutes later - at home, happily - and left it for 20 minutes.

Similar result when trying to start it again, glowplug light flashing, engine fault light on and a click first attempt to start. Several more attempts to start and not even a click, nothing.

It's a try with a jump lead engine block to chassis first, then into the battery compartment for a look.

I've heard there is also case of wiring looms in the engine compartment wearing through and producing strange results and warnings. I pray it's not - but I'm going to look regardless

Will ;-)

[euroserv]

Hello Will,

 

It sounds classic earth fault to me. Try the jump lead test (from the block or lifting eye to the jump start stud above the grille (if you have one of those) and see if it solves the problem. The increased revs signify either a poor earth or an issue with the alternator charge rate; in either case, the ECU is not seeing sufficient current and is trying to compensate.

 

An additional earth lead is pretty much a necessity on vehicles over 3 years old. Nobody should wait for a problem if a little preventative work can remove the chance.

[Willum]

euroserv - 2017-09-27 4:53 PM

 

Hello Will,

 

It sounds classic earth fault to me. Try the jump lead test (from the block or lifting eye to the jump start stud above the grille (if you have one of those) and see if it solves the problem. The increased revs signify either a poor earth or an issue with the alternator charge rate; in either case, the ECU is not seeing sufficient current and is trying to compensate.

 

An additional earth lead is pretty much a necessity on vehicles over 3 years old. Nobody should wait for a problem if a little preventative work can remove the chance.

Would the flashing glowplug light be a symptom as well, or just coincidence?

[Willum]

A bit more:

Tried a (cheap-and-a-bit-nasty) jump lead from the earth stud to the engine. Glowplug light continued to flash.

Engine turned over VERY slowly, so slowly it didn't start. Jump lead got quite warm, so I quit!! A bit worried about what other earth path it might decide to use if the existing earth straps and the jump lead weren't providing enough.

Checked the battery voltage. It had been off hook-up for a day and the off load potential was 12.6 volts Not good. Plugged in to hook-up and the voltage went up to 13.7. 12 hours later, it's at 13.6 volts, plugged in. I'll unplug and see where it drops to.

Methinks, looking at the level the starter battery dropped to in 12 hours, I have a failing starter battery to add to the mix - and confuse the issue a bit more.

I'll clean all the battery terminals and replace the earth strap, then see what happens.

Am I right in thinking the gearbox-to-chassis strap is about 225mm (9 inches, for us 'more senior' types) long? Halfords (local, instant and easy option) seem to have quite a selection.

I only ask the length 'cos it's raining and I would prefer not to stand in the rain, pulling the headlamp and air cleaner out to measure it :-(

Will ;-)

[euroserv]

The hot jump lead was more than likely because the conductor was too small, but it kind of proved the point because it turned over slowly rather than not at all. An earth strap should sort this if your starter battery is fit and well. I get my earth leads made about 15" long. This gives you some flexibility over where to attach it. You can always 'pigtail' it if it's too long but just one loop. Don't want to make a coil out of it!

 

The glow plug problem is a common one and won't give you any trouble. It may well be an intermittent 'feature' going forwards but you need not worry about it. The cost, complexity and potential heartache of it actually being a defective glow plug, when they are barely used by the engine anyway; it too much to bear thinking about on an otherwise perfectly good engine.

 

N

[Robbo]

Suggest you leave the existing earth strap in place and add a supplementary strap.

 

This is what I did. Connected to the engine block at the lifting bracket. The bracket is connected to the engine with 2 bolts. Remove one of the bolts and replace with end of cable connected. The other end of the cable goes to a convenient chassis point. I found an existing pre-tapped hole in the subframe which accepted something like a M6 or M8 bolt.

 

I used a Halfords negative battery cable 60cm (24"). I did initially try the 45cm version but found this a tad too short.

 

PS. I did originally consider replacing the existing strap but found that access was extremely difficult in my engine compartment, based on an A Class van.

[Willum]

RESULT!!

It's fixed :-D :-D

 

Got hold of aforementioned 24" Halfords strap and fitted it from one of the starter motor mounting bolts, conveniently 8mm, back to the point where the original earth strap attaches to the chassis. The reasoning behind using the starter motor as the engine end mounting was:

a. the lifting eye on the 3.0 litre is a bit awkward to get at, has a 25mm diameter hole in it and dictates that the strap runs either to a redundant bulkhead stud, or through all the pipes/cables, etc across the top of the engine. I have a secondary living area heating circuit from the engine to a heat exchanger (Alde system) so there are extra sizeable pipes crossing the top of the engine. As a result the option of using the mounting bolts for the lifting eye as a fixing point require you to have12" long, double-jointed fingers and the ability to work backwards and blindfold.

b. the starter is the thing that imposes the big current load, so I reasoned that earthing directly to it 'cuts out the middle man'.

 

As Robbo suggested, I left the original strap in place and put the new one under it, direct to the mounting point on the chassis, with a good coat of Neversieze (nickel-based equivalent of Copperslip) on the threads and terminals. I used a nice, new, stainless steel nut and washer - which probably makes little or no difference but it's less to corrode.

I did remove the original strap and have a look at it. It's tinned, flat, braided copper, with what looks like steel terminals and some sort of anti corrosion coating (passivation) on the steel. I'd guess the high resistance is as someone suggested within the terminal crimps, as there is no real sign of deterioration of the braid visible. There's no external sheath on the braid.

 

Bottom line: It LOOKS perfectly OK but obviously isn't.

 

It now starts, like a good 'un again and all the dash lights go out where they should. The battery was left on charge for 36 hours before I started doing the mod and only dropped to 13.2 volts when left disconnected from the charger for a couple of hours whilst I worked on the vehicle. With the engine running at idle, it sits at 14.3 volts. Happily, that's the end of any concern about the starter battery being faulty.

 

Initially the glowplug light did the same trick of flashing and continued to do so after I started the engine first time but then went out after a few seconds. After that it hasn't done it again, so has probably decided to forget about the fault it thought it had, along with the rest of warnings.

 

The wiring harness around and underneath the fuse box was checked and mine is fine, no damage and the majority of it covered in hard plastic, ribbed, split conduit all around that area.

 

Total cost of the modification? Less than £7, plus a trip to Halfords (other retailers are available ;-) )

Result? All those nasty, frightening, lights have gone away and everything works the way it should

 

A note of caution reference said earth strap. I'd ordered two - just in case - and they were collected for me. They both had identical labels and identical barcode numbers but one was decidedly thinner than the other, about 8mm diameter, including sheathing, as opposed to 12mm for the one I used. That's a significant difference in cross-sectional area. The thin one doesn't look man enough for the job, to me. Even the thicker one looks no more than adequate when compared to the cables supplying the starter motor and jump start touch point. The thin one is going back.

 

Finally. My sincere thanks to all who replied, especially euroserve for the original thread and advice and Robbo for the advice and pointers. I'm naturally a 'glass-half-full' person but the sight of that dash full of lights and the Ducato's reputation for wiring harness and ECU horrors had filled me with a bit of dread, especially since we are contemplating changing the camper.

Anyone want to buy a nice, sorted, Burstner Argos A748-2? :D :D

 

Will