2000Disco TD5 running rough, now won’t start at all

My mechanic & I are running out of ideas.
Problem began with a clattering/rattling noise that built up over about 10 miles with some loss of power so car was recovered by breakdown truck.
Tickover not as quiet as it should be, & rough. Some vibration noticeable. Noise increases dramatically when revved & excess grey smoke emitted. No strong smell of fuel in smoke on tickover.
Hawkeye faults 3007 ambient pressure low 3014 airflow low 3046 airflow fault Ambient pressure 101kpa, manifold pressure 100kpa. Same reading
MAF sensor 0v.
Same results when MAF sensor replaced with one from a fully working Disco.
Wastegate checked ok.
Hose MAFS to turbo looks ok.
The s- hose turbo > intercooler replaced 18months ago. A hole approx 2cm x1cm was found in this where it had rubbed against the car body so has now been replaced. No improvement.

Tests so far: ran injector test with Hawkeye. At no 4 engine started making a loud knocking, suggestive of u/s big end. A commercial mechanic friend with many years' experience thought that an injector was pumping excess liquid fuel into the cylinder, the knocking being caused by the consequent hydraulicking. Injector 4 has been replaced with a s/h one from the local LR garage. The knocking has stopped but the engine is still rough & smoking & the MAFS giving 0volts.
When entering the replacement injector code it was noticed that the other injector codes showing on both Hawkeye & Autel were different to those on the injectors in the engine! Yet it had (apparently) been running satisfactorily with those codes!
Checked the HP pump on switching on the ignition & got 13mv across F10 - Engine NOT running.
Borrowed an unused Bearmach pump from a mechanic friend & got about 18mv across F10 & still no improvement. Engine still running very rough & producing lots of grey smoke. Another used MAFS was fitted - this one gave normal readings.

Decided to replace the fuel filter, on a Saturday afternoon. The water sensor was removed & the filter drained. As I couldn’t find my filter wrench the replacement didn’t get fitted until Monday morning when I got the required tool. It would then not start at all, sounding rough on cranking, as though 1 or 2 cylinders only were firing, & emitting a small amount of grey smoke. Repeated fuel system purging has had no effect. Checks were made for possible faulty connections allowing in air - none apparent. Tried starting with small squirts of ether – unsuccessful.

All 5 injectors clicked on test firing, but no 3 returned ERR when attempting to read the code so this was replaced with the one removed earlier from No 4. All 5 codes can now be read, but still not starting. Copper washers & seal rings have been replaced on injectors 3 & 4.

Have cleaned the air bleed unit in the rear r/h (return to tank) union on the filter housing; still not starting. No DTC codes present on either Hawkeye or Autel.

I’m told that the filter housing could be causing the problem, since I disturbed it when changing the filter. It does not appear to be seriously corroded. Do the forum members have any thoughts about this? Or possibly the fuel regulator? Any other suggestions would be most welcome please

I can't say what the problem is in your case exactly, but don't forget the crank position sensor. After a clutch change I forgot to screw mine down fully and I got a very rough start with lots of smoke and a load of faults showed up on the Nanocom. I cleaned it and its seat and screwed its retaining bolt down tight and things were much better thank goodness.

It sounds like you might have some other problems like injectors or a worn big end bearing, but check out the crank position sensor or give it a spin with a known good one in to rule it out.

Thanks - we'll check the sensor, tho' there are no DTCs on either Autel or hawkeye. Another mechanic chum who listened to it yesterday suspects low fuel pressure - after cranking for 3-4 secs it fires internittently & emits a little grey smoke, probably unburnt fuel. Another fuel pump has just been lent by the local LR breaker/specialist to try. A fuel pressure testing kit arrives tomorrow or Monday.

Still baffled! Pump pressure in the fuel line going in to the regulator is 4 bar; less on cranking. The oil level has risen to about 6ml above the dipstick full mark. We think this may be due to the fuel draining in when injectors were twice removed & replaced.
To recap - problem started with a clattering noise & loss of power. Back home after recovery it would start & run rough, emitting lots of grey smoke. During test- firing the injectors it developed a loud non-metalic knock, thought to be excess fuel hydraulicking. As this occurred when, I thought, testing no. 4 that, was replaced with a s/h injector which made no difference to running but the knock disappeared. A further DTC check showed no 3 code unreadable so that was replaced from the injector from no.4. All Injector codes could then be read. The engine still ran very rough. The fuel filter was then replaced. Because it took over 24hours to obtain the necessary tool, the fuel system was allowed to drain, the water sensor having been removed.
After that the car would not start. Atfer 2 or 3 seconds cranking it starts to fire intermittently, emitting a small amount of grey smoke. There are no DTCs. Further suggestions will be most welcome.

Draining the fuel may have skewed the diagnosis as any air still in the system will give problems of its own.
Is it a 10p or 15p engine, either way, does unplugging the MAF make any difference?
The working D2 you got the MAF sensor from, was that 10p or 15p? The reason for the question is that the MAF on a 10p does little other than control the EGR valve. If the donor D2 was a 10p then the MAF could be defective without much apparent affect on the D2, but could have a significant affect on yours if it is 15p.

All your injectors are black or blue aren't they?
Maybe you could also change the seals and O rings on the other 3 injectors too. If your oil level has risen, I doubt it's because of removing injectors. 6mm is quite a lot spread out over the whole sump.
I suspect that you're getting fuel in the oil from a dodgy seal or crack in the head.

Injectors are black. it's a 10p engine.
As the borrowed MAFS had to be returned another used one was obtained from the local LR supplier - he wasn't sure if it was working but the ECU thinks it is.
My mechanic thinks a significant volume of diesel drains into the sump whenever injector(s) are removed. Some may have got there from earlier occasions when it was cranking & not firing. However we don't know if this is enough to increase the oil level by ~6mm
Injector seals could be leaking - we will probably replace them all, check for cracks & see how much the oil level rises when we do.
I am still at a loss as to the source of the clattering noise heard when the trouble began. Could a faulty injector cause this? It built up slowly over about 10 - 15miles.
Re air - we undid the fuel cooler exit pipe - a few small bubbles appeared ,then pure fuel. I shall suggest to my mechanic that we flush the system further with more fuel. If that doesn't work, we will replace the remaining injector seals & check for cracks. After that, a further pressure test will be carried out, to see if it gives 4 bars while cranking. A few quick squirts of ether were tried unsuccessfully, furthe indicating that therewas not enough fuel being delivered to the injectors.

If yours is a 10p then a faulty MAF would not cause a starting issue. The MAP sensor might if it were very dirty, well worth a clean and test with Hawkeye.
Battery voltage? If the voltage is low the ECU lacks the power to fire the injectors and the engine will just turn over without firing. If the voltage is good are the terminals tight?
Crank Position Sensor/Wiring/Interference would all cause your symptoms, but should show on Hawkeye.
ECU Top Switch would cause this, but again should show on Hawkeye.
If you have 4 bar at crank then fuel pressure is not stopping it starting.
Air in the fuel sounds like it may still be possible, but unless there is a big leak, it should have purged by now.

Without hearing it a rattle could be from almost anything - high end tappity or low big end knock? Are you sure it was engine and not ancilliaries driven off the belt?
Camshaft timing? You might want to check the chain tensioner, make sure the hydraulic tappets are working properly are not loose and the gap is correctly adjusted and consistent across them all - their oil ways can get blocked which throws them out. Also gives you a chance to check that the rocker lock bolts are properly torqued down.

BTW I don't think that I have ever seen a noticeable amount of diesel enter the sump when changing the injector seals.

Before you pull the injectors you can take off the fuel pressure regulator which will get most of the fuel out of the head, but even if you dont then as you pull the injector any fuel goes down into the cylinder when you lift the injector off the copper seal, I dont think this is the reason why the oil level has increased, I think it would be wise to look at exactly why this has happened.
I hope it's not, but you cant rule out a crack.

Found it hope this helps

Thanks everybody. We are still baffled. The non-return valve & air bleed valve in the filterhead have been renewed. The filter head does not appear noticeably corroded. The timing has been checked, in case the chain had jumped a tooth. The pressure on the HP side of the pump is a steady 4.1 bar when cranking. Earlier we connected a clear tube to the air bleed-to-pump pipe at the pump end & pumped a litre or so of fuel through. A lot of air came out initially, followed by pure fuel. We also collected a litre or so from the outlet side of the cooler. This was free of air, but looked a bit cloudy. We haven't checked the remaining injector seals or looked for cracks yet. Any further suggestions will be most welcome.

Have you figured it out yet? I had similar experience last year, loss of power and a thud, pulled over and then ran extremely rough. Got recovered, then every time I started it got increasingly worse, eventually failing to start at all. I had a screeching noise develop when cranking. Literally did all of the checks you've listed, before taking the sump off. I found lots of metal shavings, and the oil pump bolt was loose / sprocket wobbly. Didn't look good so replaced engine. Recently got around to inspect the problem- found most of the bearings completely f*****, so stemmed from oil circulation problem. May be worth checking oil pump bolt and big ends/Conrods of youve run out of ideas...

Have had to put the repair job on hold whilst repairing a van which has just gone u/s. The well-known oil pump bolt problem occurred & was fixed last year. When the oil pressure light came on I stopped almost immediately & had the car recoverd, so no damage was done.
A mechanic friend found a post in another forum or magazine about the ECU losing the security code when the battery has been disconnected for some time. This will be the next check when I've found the card with the code. If I can't, anyone know the procedure for obtainig it?

Hi, did you manage to get to the bottom of the issue you were having?
My friend has recently bought a 10p Discovery TD5, we bought it with a fuel pressure regulator issue, we have changed the pressure reg and then realised it was immobilised, sorted that out and got it running, it ran quite rough as if it was running on 4 cylinders. Took the fuel pressure regulator back off, triple checked our work. Fire back up and still the same. Fuel pump is fairly quiet when ignition is switched on, although my 15p TD5 is very loud when priming. Removed the rocker cover and coded all the injectors as noticed some were different on the system. Still runs rough. Finally took the pressure regulator off again to check once more, now will not start at all, sounds like it’s coughing as if it wants to start but no good. When it was running it sounded low on compression as if injector seals need changing so we’re going to do that next but your symptoms are very similar to ours so curious if you ever got to the bottom of it. Thank you in advance!

I want to provide the td5 with torque and speed so that it can get up quickly. You see many providing it through the computer and the turbo.

Kodrey194 said:

I want to provide the td5 with torque and speed so that it can get up quickly. You see many providing it through the computer and the turbo.

Click to expand...

Is this a kind of a blow job through the wastegate actuator?

Sorry my friend, I don't understand what you mean

I've seen some TD5 owners supply accelerometers via their computer