P38A Leaking Injectors, freshly refurbed

Hi everyone,

Just making a post on here to figure out what is the best course of action for my problem.

I have a 1999 P38 with the M51 diesel. I sent away its injectors to be refurbished by a reputable company, they cleaned them, installed new nozzles and tested them.

I just spent the morning installing them, they work great and the engine runs well.

About 5 mins later, I notice diesel on the joint between the upper and lower half of the no.1 injector collecting. I then inspected the rest of the injectors and pretty much every single one was leaking from this area.

I have checked the fuel pipes and leak off pipes... It is not leaking from these - very specifically from the joining of the upper and lower half of the injector.

I turned the engine off, wiped down the injectors, and sure enough in about 2-3 mins of running there was diesel leaking out from the same area again.

At this stage I can only assume that this is the fault of the rebuilder, I literally just took them out of the box and stuck them in.

What is the best course of action here? I'm assuming the company will take them back and fix them but what's to say they do it right the next time? (for reference, none of them were leaking before hand, I just heard it was part of good maintenance to have them refurbed every 60k miles - since mines got 230k I figured it was about TIME they got refreshed!)

Is there anything I'm missing here, from what I have researched - if they are leaking from this area there is nothing else that can be done other than removing them and taking apart again etc.

Just a bit frustrated as I really went to the trouble of finding the best, most well rated diesel engineering specialist to have this work done and straight away they are leaking. It took me 3 hours to get them installed and it looks like I'm going to have to take it all apart again, along with having the P38 sitting up for at least a week

I have attached some pics for reference.

MikeFl4 said:

Hi everyone,

Just making a post on here to figure out what is the best course of action for my problem.

I have a 1999 P38 with the M51 diesel. I sent away its injectors to be refurbished by a reputable company, they cleaned them, installed new nozzles and tested them.

I just spent the morning installing them, they work great and the engine runs well.

About 5 mins later, I notice diesel on the joint between the upper and lower half of the no.1 injector collecting. I then inspected the rest of the injectors and pretty much every single one was leaking from this area.

I have checked the fuel pipes and leak off pipes... It is not leaking from these - very specifically from the joining of the upper and lower half of the injector.

I turned the engine off, wiped down the injectors, and sure enough in about 2-3 mins of running there was diesel leaking out from the same area again.

At this stage I can only assume that this is the fault of the rebuilder, I literally just took them out of the box and stuck them in.

What is the best course of action here? I'm assuming the company will take them back and fix them but what's to say they do it right the next time? (for reference, none of them were leaking before hand, I just heard it was part of good maintenance to have them refurbed every 60k miles - since mines got 230k I figured it was about TIME they got refreshed!)

Is there anything I'm missing here, from what I have researched - if they are leaking from this area there is nothing else that can be done other than removing them and taking apart again etc.

Just a bit frustrated as I really went to the trouble of finding the best, most well rated diesel engineering specialist to have this work done and straight away they are leaking. It took me 3 hours to get them installed and it looks like I'm going to have to take it all apart again, along with having the P38 sitting up for at least a week

I have attached some pics for reference.

Click to expand...

Are you sure it's not trickling down from the pipe connection?
You could try tightening the top half but personally I would send them back.

Datatek said:

Are you sure it's not trickling down from the pipe connection?
You could try tightening the top half but personally I would send them back.

Click to expand...

Hi, Yes, I am sure that its not from the fuel pipe, to confirm this 100% I wiped off the injector no.1 - started the engine and just sat and watched it for a few minutes. You can see it slowly seep out from the connection between the upper and lower half.

Also, yes, I contemplated trying that - tightening the top half - but it would be just as much work to disassemble everything again to tighten it - as it would be in order to just remove it and send it back.

I made this post mainly to check just incase there is any weird situation where its "normal" for them to leak on the first startup, then maybe after heat cycling or carbon build up they stop leaking etc? I know it sounds kind of silly I was just hopeful that I wouldn't have to do everything again

MikeFl4 said:

Hi, Yes, I am sure that its not from the fuel pipe, to confirm this 100% I wiped off the injector no.1 - started the engine and just sat and watched it for a few minutes. You can see it slowly seep out from the connection between the upper and lower half.

Also, yes, I contemplated trying that - tightening the top half - but it would be just as much work to disassemble everything again to tighten it - as it would be in order to just remove it and send it back.

I made this post mainly to check just incase there is any weird situation where its "normal" for them to leak on the first startup, then maybe after heat cycling or carbon build up they stop leaking etc? I know it sounds kind of silly I was just hopeful that I wouldn't have to do everything again

Click to expand...

There was a sealing washer in the one I took apart (needle lift sensor) so if fully tight they shouldn't leak. No carbon deposits in there.

Datatek said:

There was a sealing washer in the one I took apart (needle lift sensor) so if fully tight they shouldn't leak. No carbon deposits in there.

Click to expand...

Good to know, I have sent the company an email and will wait for a reply, next week at this stage. Otherwise I might take them off and tighten them - the no.1 is the easiest to get out just so I will probably remove it and tighten to see if it fixes the issue - then maybe Ill just go through each one myself and tighten them - my biggest problem at the moment is not having a bench mounted vice - gonna make the tightening a lot harder to gauge...

MikeFl4 said:

What is the best course of action here? I'm assuming the company will take them back and fix them but what's to say they do it right the next time? (for reference, none of them were leaking before hand, I just heard it was part of good maintenance to have them refurbed every 60k miles - since mines got 230k I figured it was about TIME they got refreshed!)

Click to expand...

Mine have been in there 170k miles with no issues. I took them out the other day and they look pretty good to be fair. I was going to have them refurbed but I think I've just changed my mind!

Take it you used new sealing washers or annealed the old ones?

MikeFl4 said:

Good to know, I have sent the company an email and will wait for a reply, next week at this stage. Otherwise I might take them off and tighten them - the no.1 is the easiest to get out just so I will probably remove it and tighten to see if it fixes the issue - then maybe Ill just go through each one myself and tighten them - my biggest problem at the moment is not having a bench mounted vice - gonna make the tightening a lot harder to gauge...

Click to expand...

The issue is if you try to tighten them and they don't seal, you could leave spanner marks or worse and the company might say you've opened them and the leak is your fault. As our Keith says, send them back.

Probably a stupid question but they were tightened up using a 27mm socket?

Grrrrrr said:

Mine have been in there 170k miles with no issues. I took them out the other day and they look pretty good to be fair. I was going to have them refurbed but I think I've just changed my mind!

Take it you used new sealing washers or annealed the old ones?

Click to expand...

Yes, I would have left them if I wasn't in this pursuit of having an excellent running M51, the engine is 95% but there are still times where the idle hops around and engine shakes (its very minimal but it should not be happening) - Its better with the new injectors but with the little testing I could do knowing about the leaks - it still suffers from the same idle issues (when engine is being revved its perfectly smooth and plenty of power, starts half turn of the key hot or cold, but 5% of the time if you rev the engine up then let off the throttle - once it reaches idle again it can be slightly lumpy - like its maybe missing on one cylinder, very minor, BUT I know it can be better! - it then usually clears once you give it a rev again and it runs smooth) - also to add to this, its pretty much only when at the idle 800rpm it does this, if you have it around the 1k rpm its perfect - and everything above this it never misses. I also don't know if this is because I haven't gotten to break in the new injectors but even after letting it warm up - giving the engine a solid rev still lets out a decent cloud of black smoke... looks like I'm going to have to look into some kind of induction leak, possibly it only leaks under pressure.

Went I sent off the injectors I had the company supply me with new washers - I can safely say that they are sealing to the head fine as I see no leaks coming from the combustion chamber.

Mark Piercy said:

The issue is if you try to tighten them and they don't seal, you could leave spanner marks or worse and the company might say you've opened them and the leak is your fault. As our Keith says, send them back.

Click to expand...

Yes, I had a look last night and even with the correct 22mm spanner to tighten the top half, it would probably only do more harm than good - just a shame I have to undo all the work again as nothing else in the system is leaking! (this is the first time ive done an injector replacement on an engine, so very happy that its not leaking from anything I did - just the damn injectors!)

Grrrrrr said:

Probably a stupid question but they were tightened up using a 27mm socket?

Click to expand...

Yes, I've got a 27mm deep socket with the window as well for the no.4 - I'm 99% confident that the injectors are correctly tightened to the head - and that the fuel pipes are tightened correctly (not leaking) to the injectors.

They all do a little shudder at idle as the aircon clutch cuts in and out. Idle should really be 750 rpm, increasing the idle speed is usually done to cover a fault.
There definitely should be no black smoke hot or cold.
It really needs to go on diagnostics after you get the injector leaks sorted.

Datatek said:

They all do a little shudder at idle as the aircon clutch cuts in and out. Idle should really be 750 rpm, increasing the idle speed is usually done to cover a fault.
There definitely should be no black smoke hot or cold.
It really needs to go on diagnostics after you get the injector leaks sorted.

Click to expand...

HAH, I wish it was the AC! Some one of the previous owners along the line took out the compressor and lines - just left the ports into the cabin open to the elements for who knows how long. My parts P38 has got an intact AC system so in time I will swap it over.

The idle is probably around 750rpm - like when I say 800 im just basing it roughly off what the tachometer is saying - so like one line down from the 1k rpm.

One of the next purchases will have to be a Nanocom at this stage, im too far invested in saving this P38.....

I wish I had a proper specialist garage I could trust but nobody wants to work on 20+ year old cars, the last garage I took it too for suspension bushes ended up shearing off the top of one of the rear shock mounts (Long story here, I now have a hole cut into my rear floor in order to access it from the top and will figure out a repair from there - otherwise it would have been body off chassis!)

Bit by bit its getting better, just a constant struggle with time and money as always! Really enjoying when stuff gets fixed though, just a shame I have to do most jobs 2-3 times over before they are right.