Discovery 2 Misfire

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Depending on mileage , ref the coolant going down by half a cup, you could have a small leak somewhere. I take it you have checked for coolant under the vehicle. ( a god place for a hidden coolant leak in at the rear of the oil cooler under the turbo ).

Ref the fuel pressure , I was thinking more of at the FPR, where your temp sensor goes in. Iirc I saw a kit for about £20 on bay of flea.

Cheers
 
neilly said:
Depending on mileage , ref the coolant going down by half a cup, you could have a small leak somewhere. I take it you have checked for coolant under the vehicle. ( a god place for a hidden coolant leak in at the rear of the oil cooler under the turbo ).

Ref the fuel pressure , I was thinking more of at the FPR, where your temp sensor goes in. Iirc I saw a kit for about £20 on bay of flea.

Cheers
Click to expand...
Hi
Yes I had that bloody job to do a few months ago, had an oil leak from the gasket of the oil cooler so gave all of that a good sort out while I was there.
I'd had a look at the fuel pressure gauges and there a few in the market but I think the more you pay the more fittings come with it. I guess it's worth the investment. Think I'll also have to find a suitable compression tester for the TD5 engine.
First though test the wastgate modulator in the morning.
Will keep you informed
 
smac02 said:
Hi
Yes I had that bloody job to do a few months ago, had an oil leak from the gasket of the oil cooler so gave all of that a good sort out while I was there.
I'd had a look at the fuel pressure gauges and there a few in the market but I think the more you pay the more fittings come with it. I guess it's worth the investment. Think I'll also have to find a suitable compression tester for the TD5 engine.
First though test the wastgate modulator in the morning.
Will keep you informed
Click to expand...
I assume then, you have completely discounted the chance of fan wobble as the source of vibration?
 
Bobdog said:
I assume then, you have completely discounted the chance of fan wobble as the source of vibration?
Click to expand...
Hi
Ive been trying to chase down the problem again today (as well as pruning trees).I knew there was a bit of play in the fan bearing and had removed it before to see if things were quieter but it didn't change things much. Tried it again today and yes it is a touch quieter but no effect on the vibrations. So I'm going to add a new fan to the list of parts as I don't think the bearing is replaceable.
Steve
 
Hi all,
Been at the Disco again today. Removed the viscous fan (with known worn bearing) ever so slightly quieter but no change to lumpiness in revs or vibration. Did the workaround the waste gate by linking piping to cut out the modulator, sadly no change in engine lumpiness.
I am strongly suspecting the fuel pump as the culprit and as mine looks like the original it is way past it's sell by date. The one on my first disco packed up at less than 80,000 miles. Symptoms were a few moments of fuel starvation over about ten miles then kaput. Had it transported home and sure enough it started and got to the garage, who just didn't have a clue. All sorts of injector faults codes etc. Soon realised fuel pump was shot. Replaced it and all was ok. Soon after a friend with a Disco 2 came by and was having strange occasional misfires, cut out's etc. We changed the pump and again all was well.
My point being I'd forgotten how often the fuel pump is the problem and gives no specific indications of the problem and can struggle on for miles and miles.
So I've ordered a cheapy fuel testing gauge to see what reveals. I will though be changing the fuel pump before it lets me down badly.
I'm also told that when the injector copper washers start to fail they let soot through from the cylinders into the fuel chambers and back into the tank which slowly kills the pump. When I replaced my rear quarter chassis I dropped and cleaned the fuel tank, which was full thick with black sooty slime. So every chance that my pump is on its way out. (Injectors washers since changed by the way)
Will let you all know how it goes in the next week..
Thanks for the tips by the way.
Going to try and post todays live data from Nanocom if anyone wants to try and understand it and let me have feedback.
Steve
 

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smac02 said:
Hi
Ive been trying to chase down the problem again today (as well as pruning trees).I knew there was a bit of play in the fan bearing and had removed it before to see if things were quieter but it didn't change things much. Tried it again today and yes it is a touch quieter but no effect on the vibrations. So I'm going to add a new fan to the list of parts as I don't think the bearing is replaceable.
Steve
Click to expand...
Have you tried the fuel system cleaner route? I put a bottle of Cataclean (as recommended by my MOT garage) through mine and it got my emissions down from 8.4 to 0.14 so it must do some good. No harm in trying, sometimes it's the simplest solution that works!
 
Bobdog said:
Have you tried the fuel system cleaner route? I put a bottle of Cataclean (as recommended by my MOT garage) through mine and it got my emissions down from 8.4 to 0.14 so it must do some good. No harm in trying, sometimes it's the simplest solution that works!
Click to expand...
Hi
Been using Archoil and BG244 for months but noticeable effect
 
smac02 said:
Hi
Been using Archoil and BG244 for months but noticeable effect
Click to expand...
I assume you meant "no" noticeable effect lol. I put redex in mine about a month ago and it made no difference. This Cataclean stuff obviously did the job for me. I suppose though if it's a mechanical issue then no amount of cleaner will have any effect.
 
Well today I received a cheap fuel pressure gauge and managed to bodge together some fittings to take a reading from the fpr. All is good with fuel pump as I was getting a full 4bar pressure across the rev range.
Now have a used set of injectors on the way and a compression tester with an adapter for the TD5 to fit into the injector holes in the head so that all 5 cylinders can be tested.
I was also thinking maybe a broken valve Spring could be the problem, though previous experience of this on others motors has given a misfire at idle upwards.
 
Well the engine is now sorted and the lumpy misfiring gone, at great expense. I bit the bullet and pulled the head. Straight away I could see that the exhaust manifold top stud on number 1 pot was sheared. Also the manifold was badly warped, again at number 1 pot. Sure enough my engine being a 10p was still using the plastic dowels and of course they were both half sheared. I could also see that in the past the head had moved and the exhaust valves had been cuting a groove into the cylinder wall but with no obvious wear or damage to my valves I'm assuming this had happened in the past and had been rectified. Luckily when this happens the damage is above the top compression piston ring so the engine us still usable.
When I stripped the head there was no obvious signs of cracking across the head or in the ports. Nevertheless I decided to change the head for a refurb one as there was some damage in the injector seats on both number 1 and number 2 (might have been me on e last change of copper washers). Took the chance to change the glow plugs and water pump too, found to be weeping at the weep hold and the bearings were a bit lumpy.
Thankfully all is good so far, fingers crossed. It's a pain in the arse job and there's no cheap way of doing it as the gaskets, head bolts and water pump alone came to £250. Plus the cost of the head of course. But I saved £480 labour and vat that was quoted me.
The eBay engine hoist at £100 was a good buy too as it made the job possible as even with two people the weight of head and manifolds would have been a struggle. A nice addition to my garage tools though.
Gonna run with Nanocom for a whole to watch the engine temps but feeling confident it was a good fix and another D2 remains alive and well.
 
Hi Spong
Certainly in my case it was one or even two of the cylinders not pulling their weight. I think they were both still firing but leaking into each other. I had done a pressure test on the car using a dummy injector which showed a leak from cylinder one into cylinder 2 but I still cannot confirm where that leak was.
Added to this the badly warped exhaust manifold and the bust manifold stud, also the fact the head had moved on the plastic head dowels. It's surprising it ran at all really.
I had run a mild economy/power ecu tune for some months and possibly that was the death knell for the head, given that I tow a heavy caravan and a fully loaded vehicle now and then.
I tried everything I could think of to nail down the fault before removing and replacing the head butt none of the tests were conclusive.
There is a very slight vibration at 2500 revs under load that feels to be in the transmission but that can wait until the mot is out of the way.
Hope this helps
 
Hi
Yes I'd tried that. My original pump was a little low on pressure so replaced it with a brand new one but no improvement.
 
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