Daddylonglegs
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| posted on 22/10/12 at 06:24 PM |
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Landrover Discovery Issue
Any Disco experts out there?
Just forked out for a new tyre for the truck as I'm getting her sorted ready for the winter time, went to start it as I hadn't used it for
a week, and got a loud knocking from the engine. Intermittent then it seemed to go away for a few seconds, then came back again. It seems to lessen
with revs but I am reluctant to give her too much throttle until I know what it might be 
I drove it round the yard and the noise was still a little intermittent. Seems to be worse when I drop the throttle so my fear is that the Big ends
are the culprit 
I'm not 100% and I always thought that they would give a gradual increas in noise and not go suddenly?
Anyhow, anyone got any ideas?
I might try and record the noise tommorrow and put it on here to let folks know what it sounds like.
Any help really appreciated.
Thanks guys & Gals 
It looks like the Midget is winning at the moment......
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locoboy
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| posted on 22/10/12 at 06:57 PM |
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200tdi?
300tdi?
Td5?
TdCi?
Or petrol?
Service history?
any other symptoms such as smoke, loss of power, loss of coolant, loss of oil
ATB
Locoboy
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Daddylonglegs
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| posted on 22/10/12 at 07:08 PM |
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Doh!! What a muppet, I am so miffed at it going wrong I forgot to say!
It's a 300TDi, was auto with EDC pump and fly-by-wire throttle, but I had so many issue with the elcronics, I replaced the pump with a
mechanical one and fitted a cable throttle. She's been runnig fine since I did it, (last summer), but today started this knock
I have noticed it was down on poweer but seemd to be sweet enough running until now.
I do have to top up the coolant a fair bit but I put that down to the leak at the top of the thermostat housin (there is a cap that screws into it but
I need to replace it). Not drastic but annoying.
JB
[Edited on 22/10/12 by Daddylonglegs]
It looks like the Midget is winning at the moment......
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Wheels244
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| posted on 22/10/12 at 07:15 PM |
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Is it firing on all four cylinders ?
Stuck injector/s ?
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Daddylonglegs
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| posted on 22/10/12 at 07:17 PM |
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quote:
Originally posted by Wheels244
Is it firing on all four cylinders ?
Stuck injector/s ?
Good point, well presented, but how do I check chap?
It looks like the Midget is winning at the moment......
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locoboy
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| posted on 22/10/12 at 07:32 PM |
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That was going to be my first suggestion ref the miss-fire.
In my experience the injectors don't really give that much trouble.
Can you check the timing yourself?
These engines can often 'chuff' from the back of the cylinder head, it's a common place for gasket failure, it doesn't blow
into the water jacket so doesn't manifest in overheating. at tickover it could be mistaken for a knock and at higher revs could go unnoticed due
to the general increase in engine noise.
can you get under it when it is running? that would make it a lot easier to establish if it is a bottom end knock or not.
ATB
Locoboy
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Wheels244
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| posted on 22/10/12 at 07:35 PM |
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The easiest way would be to swap them over with a known good set to see if that's the problem.
Do you know anyone with the same engine that you could borrow a set from ?
Or whip them out and get them tested at a diesel specialist.
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Daddylonglegs
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| posted on 22/10/12 at 07:38 PM |
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I've still got the set I had from the EDC engine setup, I guess I could try replacing them one at a time (the #4 is a special sensor injector so
cannot use that one). I know they are OK because I had them tested when I had the original fault.
It looks like the Midget is winning at the moment......
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locoboy
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| posted on 22/10/12 at 07:39 PM |
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Have you got rid of the number 4 injector with the EDC wire that is an auto specific injector?
maybe you have a conflict with this injector and your manual pump? potential problem with the EDC wire maybe chaffing and causing a miss fire?
ATB
Locoboy
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Daddylonglegs
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| posted on 22/10/12 at 07:44 PM |
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Yep, like I said, I changed the pump over from the EDC to a mechanical, and I also changed all the injectors for the reason you state. All the gear
came out of a fully working non-EDC motor and has run fine since last summer.
Sod's law says it will play up just before the weather when I will probably need it on the road 
It looks like the Midget is winning at the moment......
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Wheels244
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| posted on 22/10/12 at 07:47 PM |
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As you've got a good set, I would try the swap first - cost neutral.
With a bit of luck that might sort it.
Keep us posted.
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Daddylonglegs
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| posted on 22/10/12 at 07:53 PM |
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Will do, tommorrow's job sorted then...
It looks like the Midget is winning at the moment......
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ElmrPhD
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| posted on 22/10/12 at 09:55 PM |
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Check if your turbo is leaking. A ruptured membrane in the turbo's valve will cause the symptoms you describe.
Steve, in the NLs
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Daddylonglegs
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| posted on 23/10/12 at 11:22 AM |
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Well, it appears it's not quite as drastic as I first thought.
The noise seemed to be coming from quite high up in the engine, so I removed the aux belt and the noise stopped!
So, it's either alternator, water pump or power steering pump. I doubt that the water pump would make such a loud noise but cannot guarantee it.
nothing seems to have excessive play, but I have had a squeaking for a few weeks which seems to have lessened so maybe a precursor to something
related?
I found the power steering reservoir cap loose too so I must not have tightened it down last time I checked the fluid, and the reservoir was quite
low, so now I am thinking that maybe I've foobarred the pump running it low? After I put the belt back on, the noise seemed to have gone, but
then as the engine started to warm up a liittle it is still there occasionally. It seems worse on the overrun. With my hand on the alternator I can
definitely feel the knocking, but that doesn't necessarily mean the alternator is at fault because the steering pump is directly mounted along
with it so could be knocking through the bracket?
So, what is the general concensus, alternator or steering pump, and would the fluid being low (about 1" down in the reservoir) knack the
pump?
cheers guys
It looks like the Midget is winning at the moment......
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Mr Whippy
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| posted on 23/10/12 at 11:37 AM |
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tbh I can't imagine how either makes a knocking noise, does the noise get louder when you put on all the lights/heater/back window demister etc
and load it up. Or the steering pump when you turn the wheel lock to lock?
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David Jenkins
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| posted on 23/10/12 at 11:42 AM |
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Are all the aux belt pulleys on tight? None coming loose? Belt in good condition? (turn it inside out - did that to a cam belt once, and all the
teeth were delaminating off the backing!)
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Daddylonglegs
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| posted on 23/10/12 at 12:00 PM |
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quote:
Originally posted by Mr Whippy
tbh I can't imagine how either makes a knocking noise, does the noise get louder when you put on all the lights/heater/back window demister etc
and load it up. Or the steering pump when you turn the wheel lock to lock?
You got me thinking there. After I refitted the belt I assumed that it was the reason for the noise returning. So I just removed the belt again, and
this time the noise is still there (intermittently) but as loud as ever
So it looks like it is something more sinister
Not sure where to try next? I'll try the injectors as suggested but not holding my hopes up
Edit: Managed to record the racket! around 11secs to 30 secs then again from around 1:10 to 1:40
[Edited on 23/10/12 by Daddylonglegs]
It looks like the Midget is winning at the moment......
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