Td5 Fuel Knocking Sound

[maxthomas]

So I have a 2006 Td5 Defender with 220,000km. I replaced the fuel pump about 2 years ago at 186,500km with a VDO in tank pump. In the past 6 months the fuel pump has become noisy and doesn't seem to ever stop running even when the ignition is on II without the engine running. At first I thought it must have had air in the line and tried to bleed it many times. It then blew two relays over a few months and everytime you touch the relay while it is running they are very hot. I have noticed the vehicle seems to have lost a bit of pulling power slowly over time.

Yesterday driving the vehicle home from work it began making a heavy knocking sound when under load up hills etc, it sounded almost like big end bearings. So I pulled over and let the engine rest for awhile and checked all fluids etc and noticed the engine oil sitting a little high and it smelt a little like diesel but may be my imagination.
I did some reading online including this forum and it appears that the cause might be the injectors leaking around the washer or O ring.

Has anyone else experienced a similar issue and am I heading on the right track. I have ordered a set of washers and O rings hoping that is the issue at only $38 for a full set.
Is removing the injectors and fitting new seals a big/difficult job? I am quite mechanical and happy to give anything a go but i've never worked with injectors in the past.

Thanks,
Max

[Tombie]

Sounds like a couple of issues may be at play..

Good idea to check the washers / o'rings...

May want to consider doing Harness whilst in there - and you'll need a cover gasket.

[maxthomas]

Sounds like a couple of issues may be at play..

Good idea to check the washers / o'rings...

May want to consider doing Harness whilst in there - and you'll need a cover gasket.

Thanks mate. Yeah I have a new rocket cover gasket to fit

[DazzaTD5]

Just some more info as the job may well have been done already....

*I generally only recommend using genuine copper seals and o-rings, if either leak again due to a cheap alternative then it will be a re-do the job over again. I dont use genuine anymore because I've taken the time to match up a o-rings and copper seals that are perfect.

*DO NOT wire brush the injector tip.

*I'm sure myself, JustinC or someone else has mentioned, when the injectors are all out to, pull the fuel pump relay (under seat, I think from memory its the second yellow one from the front, if unsure just pull all 4) and give the engine a couple of turns on the start to push out any diesel that WILL have drained into the cylinders.

*I normally throw something over the top of the engine like an old vehicle guard cover so diesel doesnt spray everywhere, although a few weeks back was doing this job and talking **** to my Dad and forgot all about the cover, No 5 cylinder obviously had a bit of diesel in it, i was standing next to it and said to my dad, "yeah give it a turn"..... myself, my hat, my tool box, work bench, computer screen, just about half the workshop in fact was covered in diesel.....

*Take care when removing and fitting the injectors, touchy touchy nice and gentle, once injector is fitted back, give the side of the injector (where the clamp bites down on it) a little tap to ensure it has seated fully.

*I'm almost tempted to say replace No 2 injector, its the one that always seems to have a solenoid failure (shrugs).

*Change oil and filter.

Here is a step by step guide, I'm sure there is prolly one on AULRO here as well. (its everything that is in the workshop manual)
www.discovery2.co.uk / TD5 Engine - Injector Seal Replacement (http://www.discovery2.co.uk/Injector%20Seals.html)

Regards
Daz

P.S and yes new rocker cover, fit clean and dry, no sealant, make sure the half moon at the back is spotlessly clean and torque down. Replace injector harness and common practice is on the plug end to remove little clip in cover on back of plug, squeeze some automotive sealant into it, clip back in cover. Then on the o-ring side of plug to run a generous bead of sealant around the o-rings (while technically thats the wrong thing to do on an o-ring, it will seal between the plug and the head and prevent oil from running down into the female plug).

[maxthomas]

So quite a bit has happened since my last post. I'm not sure if it is all connected but i'll put it here anyway.
After replacing the injector o rings and copper washers and setting the adjustments correctly it was all running fine.

I drove it a few hundred km's before it had complete lack of power heading up a steep hill and would not start again. It felt like it had run out of fuel (full tank of diesel), I pulled over and tried to prime the fuel pump and did a few general checks under the engine bay but couldn't find any evidence of the cause so I assumed the noisy fuel pump must have finally bit the dust. I put the car on a towtruck and sent it home.

I replaced the fuel pump with a new VDO unit, primed it and all seemed fine. Took it for a quick test drive - no worries. Parked it for a week while riding my motorbike to and from work. Tonight I jumped in and went for a short drive and it cut out again heading up a hill with the exact same symptoms as before I replaced the fuel pump. Hawkeye diagnostic comes up with no errors.

Anyone have any idea what is going on? What is causing the engine to 'shutdown' when under load? It hasn't had enough run time to notice an increase in diesel in the oil if that is still occurring? Could there be another fuel leak causing it to run out of fuel when under load?

I am a little worried as we plan to head off around Australia in about a month and with most businesses shutting down over Christmas I don't like my chances of getting it repaired if I can't fix it myself.

[harro]

You mentioned in your first post that the fuel pump relay was getting hot.
If that is still the case check the connections to it.

Cheers, Paul.

[maxthomas]

I took a short video to try and explain the noise I am getting from the fuel pressure regulator. When I put me hand over the regulator it changes sound. Is this normal or does it appear to be faulty?
Its hard to see if it is diesel or oil around that area.

https://youtu.be/eAQuRpHvfCY

[DazzaTD5]

The change of note is you blocking / unblocking air flow (huh from where?) all I can think is there is still air in the fuel system.

So far...
*fuel pump replaced with a VDO unit.
*Injector seals done, and seem to be fine, as in if you have balls up the job they leak pretty badly and will stall, hydra-lock a cylinder (wont turn over).
*Pump continues to run and is noisy, which is fine that its making a noise, so we know its working correctly, its often when the pump makes very little noise its a problem.
*So your saying with ignition on (engine off) that after 30 odd seconds the pump doesnt turn off? (which is by design),

To do:
*Change out the fuel pump relay as I dont remember them ever getting that hot as you mention.
*Change the fuel filter, and when you go to fit the new filter make sure you havent left behind the old seal on the centre thread, also dont over tighten the filter, just firm as they will leak if too tight.
*I'm unsure about that fuel regulator, generally they leak fuel so its obvious, from my point of view, I'd change it out, as I keep them on the shelf.

Regards
Daz

[maxthomas]

Thanks Daz,
Yes it appears to sound like the change in sound when I put my hand over the regulator is air but you cannot feel the movement of air. The fuel pump does run through the cycle (not sure on how long for - I haven't timed it) but in that video the pump stops and then kicks back in again (around 0:25 on the attached video). Everytime the pump kicks in you can here "air" purging through that side of the engine, its difficult to hear where exactly but appears to be coming from the regulator region.

I can't see or feel any diesel below the regulator, just the usual oily grime. I'll fit a new fuel pressure regulator and see how that goes.

I did fit a new Mahle fuel filter when I replaced the fuel pump but I will recheck the seals etc on that.

I will fit a new fuel pump relay and see if it makes any difference.

I am worried that it could be a cracked cylinder head causing the diesel to end up in the sump. Is there any other ways for the fuel to end up in the oil? I haven't driven far since replacing the injector seals (approx 300km) but the oil does appear to have risen slightly on the dipstick and smells like diesel but I could be just fearing the worst. Is there any way of checking for a crack without removing the head?

Am I dealing with two separate issues:
1. engine cutting out under load
2. diesel in the oil

Or are these both consistent with a cracked head?

At this point the engine will wind over but will not start. Today I got the following error on the Hawkeye diagnostic:
Fault 3065 Fuel Pump Drive Open Load Logged

[manofaus]

Did you try a blot test for the diesel in oil? You could even have a dud injector that's flooding a cylinder. Any smoke?

[maxthomas]

I haven't tried a blot test but I will give it a go.
I did have white smoke when I got it going this morning.

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