td5 misfiring update

hi all, 2000 td5 disco 2 is still misfiring between 1500 and 2500 revs only when cold have noticed it when disco is stationary in park and just revving the engine. so far i have had it on a diagnostics and no faults found (how ever just a normally garage diagnostics not full landy one). I have checked the waste gate all seems to move freely, no oil in the ecm (red plug) wiring harness has been changed. now i have checked and cleaned the MAP sensor and also switched it for a good one no difference, how ever if i just unplug the MAP sensor it DOESNT MISSFIRE??? I know the ECM is probe going to default mode but why would it work ok in default mode if the diagnostics didn't pick anything up!!! i still have the erg however i did try to change it but the bottom bolt snapped another thread!!!!! any help would be great......

any suggestion on the above thread please help im at a loss for ideas now!!!!!

jay572 said:

hi all, 2000 td5 disco 2 is still misfiring between 1500 and 2500 revs only when cold have noticed it when disco is stationary in park and just revving the engine. so far i have had it on a diagnostics and no faults found (how ever just a normally garage diagnostics not full landy one). I have checked the waste gate all seems to move freely, no oil in the ecm (red plug) wiring harness has been changed. now i have checked and cleaned the MAP sensor and also switched it for a good one no difference, how ever if i just unplug the MAP sensor it DOESNT MISSFIRE??? I know the ECM is probe going to default mode but why would it work ok in default mode if the diagnostics didn't pick anything up!!! i still have the erg however i did try to change it but the bottom bolt snapped another thread!!!!! any help would be great......

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Sounds like you have a faulty MAF. New ones can be bought from Ebay from about £30 for an after-market one (which is working well in my car) to £80 for an LR one.

Without diagnostics though you really are working in the dark.

Jay,

Have you made any progress recently about this issue? My TD5 behaves exactly as you describe and I'd love to find a solution. Had it at a local indie who after many hours couldn't pin down the problem. Talked to a someone who believed that it was some hydraulic springy thing under the tappet/camshaft cover that becomes sticky with age and produces this "misfire".

Oh, should mention that mine has EGR blanked off and still produces the issue, so you can likely ignore that for now.

And another thing. The person that identified the spring thing also said you would be able to hear a kind of popping noise from the engine, which is actually true in my case. I can hear it more clearly under load at about 2000 RPM.

just something to check is it completely full of coolant i had one with misfire bled top hose while filling , cured it ,presumably temp sensor was giving intermitent signal

Hmm interesting idea. I'll definitely try that. My heater matrix leaks and I've had to top up coolant occasionaly a while back. Now I run with the aircon set to Lo, seems to stop the leak, but there could be an air trap in there already. Did you run the engine while bleeding the coolant?

no and then yes

Mmm, have just found this thread, have posted my own last night about the same fault! Really don't think it will be your MAF, i put a brand new genuine Landrover one on mine and it made no difference. Interesting about the MAP sensor though, will try that on mine tomorrow. Also the coolant loss, mine drops about an inch in the header tank over a month or 6 weeks, don't know where its going, once its dropped that much it does'nt drop any more, don't think its going internal though, would be more problems i think. Will keep an eye on this thread, and will let you know if i find a cure first!

hi i had it back to the landy specialist today MAF sensor made no difference, have swapped MAP sensor for a known good one still no difference, landy guys are going to have it in next week, how ever they did mention something about something sticking under the camshaft cover so it could be... still have no idea i have read somewhere of a faulty coolant temp sensor that has caused faults when cold so i might change that as well.... my coolant level drops about 10mm when i top it up and then stays like that forever same as yours td5silver i don't worry about it as i docent drop any further weird and wonderful TD5's

UPDATE so far i have had it back to land specialist they have had it from cold now when it misfires and have said cylinder no.4 is high As far as i can gather the rest are between -8 and +8 and no. 4 when cold or up to 2000 revs is at +17 now when it gets warm or you go past 2000 revs it drops down the the same reading as the rest (normal). They said the would have it in and swap no.4 injector with another to see if its the injector or other then that the head would have to come off to see if its a bent con rod or something else.... I am not going down the route of getting the head off... but they are going to swap the injectors and do the washers, just wondered if im opening a can of worms by doing this or does anyone have any more ideas.. diagnostic still shows no faults injector harness has been changed MAF and MAP have been changed no oil in ecu or red plug....

Its interesting to read that another report of something sticky under the camshaft cover. I had a diagnosis that pinned that as exactly the cause of the problem. Apparently only replacement of that part fixes it, a cleanup helps, but only temporarily. I'd really vote for having that replaced first.

Quadiago said:

Its interesting to read that another report of something sticky under the camshaft cover. I had a diagnosis that pinned that as exactly the cause of the problem. Apparently only replacement of that part fixes it, a cleanup helps, but only temporarily. I'd really vote for having that replaced first.

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I know there is a valve on the RR diesel engine but I don't recall seeing anything of this nature under the last two TD5's I've had the cam cover off?

I have to admit I'm not sure what springy thing I'm talking about either. All I know is that someone quickly diagnosed the "misfire" based on experience. For all I know, it could be on the TDi engines. He did also say that the problem will be accompanied by a popping sound, which I actually started hearing before the judder became noticeable.

An interesting turn of events for my situation. The landy was at a local indie for the last couple of days and I collected it today. They found that there were 2 missing and 2 broken bolts on the bellhousing. My bellhousing was damaged when my front propshaft gave out about 8 months ago :doh:. This seemingly was the cause of a lot of the vibration.

However now I have a strong droning sound at about 2000RPM under load

mine doing this to
the only spring i can see is the valve springs
just put the middle Exhaust box back on to see if it the eng getting carbon up see how i go
as any off u done any exhaust mods ?

Bent conrod same symptoms as mine

Well the TD5 Injectors have springs fitted to them.