What causes injectors to pop out?

[R4PID]

Hi,

Simple question really. I had all 5 x injectors replaced on my Jeep GC 2.7 CRD in March this year.

This week one of the leak off pipes came away and on further inspection it appears that one of the injectors has popped out.

From all I can tell an injector will only pop out when not securely fitted, is this correct?

I'm hoping to get it fixed under the 12 month warranty from the people who did the work but what to ensure that there would be no other reasons to explain the injector popping out.

Also, is it a case of just popping the injector back in an re-securing?

Cheers

[PhilTD5]

that will be the mercedes 2.7 cdi then. common problem with all cdi mercs is injectors failing or 'chuffing' Sometimes its an easy fix, sometimes its stripped the thread out of the cylinder head.

[R4PID]

Yeh, it's chuffing. I'm guessing its faulty then. Will try get the work done under the warranty for the original work.

[PhilTD5]

Its certainly worth a try, however its very rare that any warranty is given. They can be a pain to seal at the best of times, if it hasn't been 'chuffing' since march, then it must have been fitted correctly. The problem is the immense combustion pressures the injector is subject to, plus the heat expansion of the different metals involved. Alloy cylinder head, steel injector body and securing bolt is only 6mm.
There are actually companies out there that only deal with this problem!

[R4PID]

Yeh, true. The guys used specialise in diesel Black Death. The seating bolt looked original though. I believe they're stretch bolts and should be new when replacing injectors. Maybe that didn't help keeping it secure?

[J4CKO]

I think these use a stretch bolt to hold the injectors in, if they are replaced and the bolts arent they do have a tendency to pop out, sometimes through the plastic cover, if any Merc engined car smells of diesel it is usually down to the seals, so the seals get replaced and the stuff put back, ok for a while until the bolts fail.

[PhilTD5]

yeah we always used to use genuine mercedes bolts and copper washers. There was also a white grease from mercedes to coat the injector body in.
Fortunately the cars dont suffer from black death as the engine cover isnt a seal against the cam cover. Early Cdi sprinters however are a different animal! Ive took the cover off to find it looks like the covers still there, but its hard carbon that needs to be chiseled out without damaging the injectors, wiring or leak off pipes. Not a nice job!

[R4PID]

Will it 'pop' back in easily enough do you think? If I can get a new securing bolt could I do it myself?

Not using new stretch securing bolts in the first place seems like a reason for the garage who replaced the injectors to fix it.

[PhilTD5]

depends on the threads in the cylinder head, you could try to see if the bolt does screw in, but dont force it. Very easy to strip the threads out on these engines.

[R4PID]

My recovery provider is now somewhat better off, having paid extra to get them to take it the garage who did the replacement injector work in March. That garage fixed if for me FOC, which was nice. They got a bottle of whiskey by way of thanks. Seasons greetings.

[eltax91]

R4PID said:

My recovery provider is now somewhat better off, having paid extra to get them to take it the garage who did the replacement injector work in March. That garage fixed if for me FOC, which was nice. They got a bottle of whiskey by way of thanks. Seasons greetings.

Did they replace all the bolts this time?