fixing a failed injector seat and bolt

[E270 Owner]

I have just had a snapped bolt removed from my engine, it looks like whoever worked on it previously re-used the bolts. I have been told that new bolts need to be tightened down to 8 nm, then 2 x 180 degree turns, can anyone confirm this please.

NO

sorry should have said which bolt I meant.................der!
One of the injector clamp retaining bolts.

New bolts and grease from MB

Stage 1. 7 nm
Stage 2. 90'
Stage 3. 90'



Good Luck.

 

[barrygoodchild]

Thanks for that info, finally got all injectors out tonight, now for the big clean up and put back together.

 

[gsc1ugs]

got some great advice, normal bolt with spring washer if you have to tap to m8

 

[Mercious]

I had two of mine done last month.

2000 E320 CDI

No 6 injector popped out and I had it recut and a tensile oversized bolt fitted with the clamp drilled out to accommodate the tensile bolt.

Torqued to Nm 14 and later, when hot Nm18.

Don't mess with the 85mm 8M bolts. 55mm of thread and useless once they're taken out.

And useless is the hole they've been taken out of.

Read my sorry tale on here.

No 1 Injector nearly going through the bonnet and ripping out the electrics and diesel drain off line. That line is over £100.00 alone.

So I've had two done so far at £96.00 apiece.

And, if I could afford it, I'd have all six done.

Which I probably will do anyway.

My car's done 126000 miles and I barely drive 30 miles a week so the engine hardly gets hot and the bolts can't hold the injector.

The guy at Bedford M B tells me people turn up with dints in their bonnets not realising what has happened.

It's a worry.

I used a guy from Wavendon Bedfordshire.

He makes the tensile bolts and he comes to you but not at home. he comes to your chosen garage if they'll let him, because he needs an air line.

The MB standard bolts torque to Nm 7 and 2x90 degrees (but that's what I say)

The garage owner torqued the bolt on No 1 injector to Nm14 and it spun.

He wanted me off his forecourt so said very little.

I fired her up and the injector put a nice dint in the bonnet. And the guy from Wavendon had just left. It took about four days to get him to come back because he was so busy.

Tomorrow I've got the joy of taking the car out and getting the engine hot so I can re-torque the tensile bolts to Nm18.

I can't see it will work and I expect problems and about another grand in garage bills -and the man from Wavendon.

 

[Danny DeVito]

Thanks for all that. Would timesert not work for you in this case or do you think the bolts are better or just cheaper option ? And what about overall expected spend versus replace the head ? I presume when a head goes for repairs they could do bolt hole repairs too could they ?

 

[gsc1ugs]

Well ive just put a socket button m8 holding the injector, I started the van and drove it, however, still leaking slightly, better than before so I guess, even though I was told on some forum don't cut the seat, I think mine needs cutting, I can see down the hole with a mirror and torch it is pitted, what size is the socket that cuts the seat? and if this has down before cut that is, will they injector rub on the side eventually not sitting properly when clamped? those my only concerns at this stage.

 

[gsc1ugs]

does this look like it requires cutting? sorry about pic, just see black lines, not flat

 

[gsc1ugs]

 

[bob6600]

No 1 Injector nearly going through the bonnet and ripping out the electrics and diesel drain off line. That line is over £100.00 alone.

Just incase it helps anyone, I bought mine on ebay and it's a perfect fit for 1/4 of the cost! And the connectors are metal and not plastic like my original

Mercedes 6 Cylinder Cdi Leak off Overflow Line 6480700832 OEQ C E S Class | eBay

 

[bob6600]

does this look like it requires cutting? sorry about pic, just see black lines, not flat

Cannot see clearly in the pic but from what I can see, it does seem to need the seat recut

 

[gsc1ugs]

What size is the cutter please? Kits have 7pcs in

 

[gsc1ugs]

Mune is vito (obv) 109

 

[StevenN]

Some have used emerycloth stuck to the bottom of wooden dowel the same diameter as the injector. Not the best solution but its been used in the past.
You don't want to remove too much metal it just needs to be a good mating face.
Also "Special" Mercedes grease should be used to bed the injector and the washer to the head.
If you google the cutter kit there are some sites that hire them out

 

[gsc1ugs]

I have the cutter, whats this special""" grease?

 

[bob6600]

Ceramic grease

HIGH TEMP CERAMIC GREASE BY FEBI FOR MERCEDES ENGINES | eBay

 

[StMarks]

Some have used emerycloth stuck to the bottom of wooden dowel the same diameter as the injector. Not the best solution but its been used in the past.
You don't want to remove too much metal it just needs to be a good mating face.
Also "Special" Mercedes grease should be used to bed the injector and the washer to the head.
If you google the cutter kit there are some sites that hire them out

I thought that the ceramic grease was ONLY to lubricate the sides of the injector, and that it MUST NOT be used on the washer & mating surfaces.??

 

[gsc1ugs]

anyone confirm where grease is used?

 

[gsc1ugs]

says that its to stop seizing - can some bonding agent be used for the seat and the copper washer to improve the seal??

 

[bob6600]

says that its to stop seizing - can some bonding agent be used for the seat and the copper washer to improve the seal??

You can use what you like but my advice is to only use the copper washer. I have seen silicone type sealant used and it is not good. Remember the whole point of cutting the seat and cleaning it all is to ensure the seal is good and that there is no debris to contaminate the injector hole.

If the bonding agent ends up down the injector hole you will kick yourself so my advise is no.

I know the temptation, but I did my friend's (which was bodged previously) and apart from the temporary bolt (M10) that is in there, I cleaned the silicone type stuff off and removed a SECOND washer that had been shoved down there (Two is definitely not better than One in this case!). The double washer caused incorrect injector spray and it ran rough, esp at idle. After taking all the sealant off and spending plenty of time cleaning, all it well.

 

[gsc1ugs]

Thxs for advice, I have cutting kit and it says angled reamer for merc at 17mm can you confirm if I use the flat reamer or the angle?