Nanocom Results / Rough Starting

I've not had a chance to do the seals yet, BUT not sure if this is relevant or not, or if it confirms injector seals, but if I turn on the ignition and put it into fuel purge I can hear a hissing noise from the top of the head. Does this confirm injector seals or suggest something else?

I got the seals changed today, genuine LR parts and the engine is just flooding itself - hydraulically locked and we had to take out a glow plug to release it.

Last time i done these seals on another vehicle I used all Bearmach parts and had no problems at all.

So I don’t know if it’s just the seals at fault, a cracked head or knackered injector(s). Has anyone any suggestions?

Read this and the link included TD5 injector seals not sealing

sierrafery said:

Read this and the link included TD5 injector seals not sealing

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And there was me thinking I was doing the right thing forking out on genuine LR and wishing I hadn’t put bearmach ones in the disco! If anything is leaking it’s the copper washers - we looked at the o rings with the rocker cover off and nothing was spurting up at us

BUT the injectors did go in rather easily

The copper washers are there to not let combustion gas into the fuel no way to hydrolock the engine due if they are leaking

Wishful thinking on my part! I think the o rings are ok as there’s nothing coming back, so it looks like the head

When I took the injectors back out the copper washers weren’t really crushed like I’d expect, virtually no marks at all.

Could diesel not get into the combustion chamber this way?

sierrafery said:

The copper washers are there to not let combustion gas into the fuel no way to hydrolock the engine due if they are leaking

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Are you sure fuel can’t get past these copper washers into the combustion chamber? Seems odd that since doing the washers (which still appear new as if they have not been compressed) the problem is 100 times worse than it was originally ...

Theoretically fuel can get through those washers ONLY if the injectors are not fitted well or the washers are wrong dimension and only while the ignition is on and the engine is not cranking or running cos the combustion gas pressure is much higher than the fuel pressure and once the engine is cranking or running the gas will go into the fuel not vice-versa ... the injector's end has a kind of edge all around especially made to bite into the copper as to seal well so if you dont see that trace even on a new washer which was once fitted something is wrong, did you tighten down the injector retainers to the recommended torque(32Nm)?

Yes, did it by the book and I check the torque settings with two different torque wrenches. I’ll try some other copper washers and see what happens. Purging of the fuel would have pushed fuel past the washers if they weren’t seated properly.

I've read that some people use the copper washers for the 300tdi - are these better quality ?

Did you take the fuel out of the engine before re fitting the injectors mate? Only saying this as it can bend a con rod or two if not

Discodevon said:

Did you take the fuel out of the engine before re fitting the injectors mate? Only saying this as it can bend a con rod or two if not

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Yes not that it’s made much difference as it would have just filled with diesel again!

I’m not sure why I bothered draining it I don’t normally bother and never had a problem!

Still no luck after reseating the injector sockets and using new washers, so at the moment i can only think the head is cracked

Question: If the engine was hydraulically locked due to excess fuel would I still be able to rotate the engine by hand?

tom1979 said:

Question: If the engine was hydraulically locked due to excess fuel would I still be able to rotate the engine by hand?

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Actually after a reasonably good charge the engine was turning over so I think that rules out any hydraulic lock. My only concern with that was that it was running after initially doing the injector washers and then it stopped itself (no dubious noises/sounds - it just stopped).

I just plugged Nanocom in to see the RPM whilst cranking - doesn't work just switches itself off as soon as I start to start the engine so a lot of use that is! Plugged the Lynx in and its showing 200rpm dropping to 184rpm as the battery voltage drops from 12.79v immediately down to 7v then down to 5v, at which point it wont turn over at all. Am I right in thinking the TD5 needs much more rpm to get started? If so what could be the problem? Whilst cranking I did have a charger on it, although not at full power.

My initial problem was a white smoke and roughness on start up, which once revved a bit disappeared and was fine until the next day. Replaced glow plugs (the original ones were fine but Allmakes so replaced with NGK). I then suspected copper washers on the injectors. Changed these as they looked pretty bad, even reseated the injector sockets and now its just cranking. There is the tiniest about of exhaust gas coming out while it's cranking.

Could just it be knackered battery? It's a Case 664 agricultural battery, I think 720CCA or thereabouts and about 3 years old. Is it worth trying a new battery? I can always remove it before setting fire to the motor

Well, I just started it and it ran perfectly. All I did was unplug the injector harness and plug it back in, and it had a good charge this afternoon. There were no fault codes for the injectors. It just started, with a bit of throttle. Plumes of white and grey smoke, ran it up to temperature and now it's just a bit of black smoke when it's booted a bit

I am now sure that there is an alternator problem, which was noticed from the nanocom readings at the beginning of the thread. With the engine running AND the trickle charger on it I was getting just over 13v. The test for the copper washers will be tomorrow or Monday when it's started again, but for now I am pleased not to be going down the route of a new head!!

This was after it had warmed up a bit:

Td5 needs around 10.5 volts while cranking before ecu will fire the injectors, so your battery was either low or is faulty

johnlad said:

Td5 needs around 10.5 volts while cranking before ecu will fire the injectors, so your battery was either low or is faulty

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Cheers yeah I think the alternator was at fault and the battery had got low. If you look at the nanocom results it was only around 13v whilst driving