Leaky injectors

[andywhy]

Hi all,

I've asked this in my other topic but thought it might get seen here better.

Picking my HDi up tonight (woo!) but last night I noticed it had diesel around 3&4 injectors on the block. I cleaned it up and ran the engine but saw no leak.

What is the most likely cause of this? HP pipes not tight enough? Leak off pipes split/leaky? Or is it possible it's around the injector itself where it goes into the block?

The injectors look very new or well refurbed so it's possible some work has been done on the car recently, and that perhaps the mechanic didn't wipe up any spilt diesel when he finished.

What's your thoughts? And what's the worst case scenario I'm looking at?

Thanks

Andy

[Poodle]

Worse case scenario? Injectors need rebuilding, or maybe your fuel rail is cracked. Much more likely is that the high pressure unions need nipping up a bit or the leak-off pipes or o-rings are a bit perished. Definitely wait until the problem reappears before worrying over much, was it definitely diesel?

[andywhy]

Definitely derv yes, couldn't miss that smell. I'll go with the unisons first if it reappears and see how it goes. The injectors look brand spanking new so I doubt they're the problem.

Are the o-rings on the base of the injector or on the pipes?

[darrenjlobb]

When you get it home andy, wipe everything down nice and clean, degrease it / get it all shiny and like new, then drive it until the problem re appears....if it dosnt, then theres your answer, if it does, then first assess if its diesel or oil (as common for rocker cover gasket to weep and pool down by injectors). If its diesel, then id say most likely the leak off o rings / pipes them selves. Injectors seal against head with fire seals, but you wouldnt get raw diesel leaking here even if they were leaking, so that wont be your problem, its possible the injectors themselves leak if someone has had them apart at home and not rebuild them correctly.

Either way as poodle said, in a worst case you need some injectors, but i doubt that very much!

[Poodle]

Didn't mean to insult your intelligence fella, but would be daft to chance missing something obvious. O-rings are on your leak-off pipes.

[andywhy]

Cheers. Darren, as said last night it was definitely derv. It was light yellow not black and you couldn't miss the smell

No intelligence insulted! I didn't know where the O-rings were which is why I asked. It was clean last night so I'll drive it home and see if anything is there when I get back. If so, I'll tighten up the unisons and try again.

[callumcull]

When you get it home andy, wipe everything down nice and clean, degrease it / get it all shiny and like new, then drive it until the problem re appears....if it dosnt, then theres your answer, if it does, then first assess if its diesel or oil (as common for rocker cover gasket to weep and pool down by injectors). If its diesel, then id say most likely the leak off o rings / pipes them selves. Injectors seal against head with fire seals, but you wouldnt get raw diesel leaking here even if they were leaking, so that wont be your problem, its possible the injectors themselves leak if someone has had them apart at home and not rebuild them correctly.

Either way as poodle said, in a worst case you need some injectors, but i doubt that very much!

What Darren said, spot on!! I've had my fair share of problems with injectors!

[andywhy]

OK I've nipped up the HP pipes and checked the leak off pipes, they're not leaking. However there is still diesel coming from somewhere and after a clean up then drive, it looks like it's coming from where the injectors go into the head. Is that possible? Darren says above it's not, so where else could it be coming from? It's definitely not on a single injector either.

Beginning to think the 306 was a bad move

[Poodle]

He's right, it's not possible. Can we get pictures? Close and wide please.

[andywhy]

There's nothing to see except for diesel forming around the base of the injectors, and it only happens after a drive. It won't do it at idle or revving. From the top down it feels dry. I'll get some pics as soon as I can if you still want them.

---

[Poodle]

That's looking like it's spraying from the unions to me, i know you've tightened them a bit, but that's what it looks like. Try putting some talcum powder/chalk dust/etc on and around the injectors and going for a quick drive, should be able to see a bit better then.

[rd070707]

maybe if theres been work done on them before the unions could have been cross threaded? this happened on my 307, luckily slackened them off and retightened and it stopped it

[andywhy]

I can try loosening and re-tighening. Do I need to depressurise the rail first? If so how do I do that safely? I also don't have a 13mm spanner (gone missing) so will have to get one of those first. I tightened with a 14 which wasn't a good idea.

[Poodle]

You don't need to depressurise the fuel rail, fuel leaks back to the tank and pressure normalises within about a minute of turning the engine off.

[andywhy]

OK, loosened off completely and then tighened the HP pipes up as best I can with a 14mm spanner but I'm damaging them so I can't do much more without a 13mm. The leaks are now "less" but not perfect. After 13mi drive with half at motorway speeds they leaked only a tiny amount, enough to convince me I'm on the right track at least. Tomorrow I'll try and get a 13mm spanner to nip them up more.

How tight should these be? Should I be putting much force behind the spanner? I don't want to go too far and overtighten/rip the threads.

Thanks for the help so far everyone. I knew I could rely on you

[rd070707]

Iirc the high pressure unions are listed at 20nm

[andywhy]

My friend was kind enough to pop up an hour ago with a 13mm spanner... Turns out it's the wrong size! It's actually 1/2", which I had. I swear I tried it earlier. But anyhow, we nipped them up a bit more and the leak has pretty much stopped. Injector 4 is still weeping but it's tiny (barely a single drop after a 13mi drive). It's nothing I would honestly worry about. We did manage to widen the neck of the spanner so that's now knackered, but job's a done one. I'll grab hold of another 1/2" spanner soon and nip it up that last tiny bit. It's amazing how much of a difference that last little bit makes.

Thanks for your help everyone. Having never dealt with injectors before this was a new experience. Next up, new tyre, then she'll be fit for the road

[rd070707]

Nice one mate good to hear

[Poodle]

The injector union insert is 13mm, the pipe union is 17mm, your spanner splayed because it was the wrong size. Tighten the pipe union while counter-holding the injector insert, don't tighten the inserts.

[tigerstyle]

Plastic cam cover, wow?
Good advice Poodle on supporting the insert while nipping it up, are fractured lines a problem ever on the hdi?

[ginge191]

(as common for rocker cover gasket to weep and pool down by injectors).

Correct me if i'm wrong by i tried looking for an HDi rocker cover gasket and struggled.......
Do these even exist?!

[darrenjlobb]

(as common for rocker cover gasket to weep and pool down by injectors).

Correct me if i'm wrong by i tried looking for an HDi rocker cover gasket and struggled.......
Do these even exist?!

had no problems getting one for me 16v head... part of the head rebuilt / gasket kit....

[Poodle]

I've never come across fractured lines or rails on these engines, but that's not to say it'll never happen. By the same token i've never seen the rocker cover gasket leak on these, whereas i guess Darren has seen a fair few, so who knows lol.