Diesel injector seal

[MarkG14]

A couple of years ago, I had an injector seal fail on my C220CDI.

As the car had quite a high mileage, I asked for all seals to be replaced.

Unfortunately, while removing the no 2 injector, the bolt snapped and the dealer had to call in a specialist to remove the snapped off bolt.

All seals replaced, everything fine.

One year later (last year) the no 2 seal failed again. MB replaced this under warranty.

Today I discovered the no 2 seal has failed AGAIN.

I am awaiting MB response, but suspect an underlying problem for one seal to repeatedly fail.

Anyone had a similar problem and can throw any light on this please?

 

[DaveE320CDI]

A couple of years ago, I had an injector seal fail on my C220CDI.

As the car had quite a high mileage, I asked for all seals to be replaced.

Unfortunately, while removing the no 2 injector, the bolt snapped and the dealer had to call in a specialist to remove the snapped off bolt.

All seals replaced, everything fine.

One year later (last year) the no 2 seal failed again. MB replaced this under warranty.

Today I discovered the no 2 seal has failed AGAIN.

I am awaiting MB response, but suspect an underlying problem for one seal to repeatedly fail.

Anyone had a similar problem and can throw any light on this please?

Hi, Its possible that whoever repaired the seal in the past just removed the injector and put a new copper washer in! without using a seat cuttting tool to clean the injector seat in the cylinder head which always needs to be done before re-fitting new washer and injector, Dave

 

[MarkG14]

Hi, Its possible that whoever repaired the seal in the past just removed the injector and put a new copper seal in! without using a seat cuttting tool to clean the injector seat in the cylinder head which always needs to be done before re-fitting new seal and injector, Dave

Bit of a puzzle why no 2 is the only one leaking. Does the reseating need to be done only if the bolt snaps on removal? The injector was not replaced, just the seal.

 

[Trickythemerc]

The injector seat should be cleaned and if required recut before fitting new seals, the snapped bolt is a separate issue. The torque values on injector bolts are critical to ensure a good seal and very easy to to snap if over torqued.

 

[MarkG14]

The injector seat should be cleaned and if required recut before fitting new seals, the snapped bolt is a separate issue. The torque values on injector bolts are critical to ensure a good seal and very easy to to snap if over torqued.

The bolt snapped when removing the no 2 injector in order to replace the seal. The puzzle for me is that while all 4 seals were replaced, it is only the no 2 injector seal that is repeatedly failing.

 

[Trickythemerc]

Is the bolt in number 2 a genuine MB part ? They are not a standard bolt, they have a radius to allow the clamp to move when being tightened. This puts more clamp pressure on the injector and gives enough crush on the seal. Depending on how the broken bolt was done could it could be the reason for seal failure.

 

[MarkG14]

Is the bolt in number 2 a genuine MB part ? They are not a standard bolt, they have a radius to allow the clamp to move when being tightened. This puts more clamp pressure on the injector and gives enough crush on the seal. Depending on how the broken bolt was done could it could be the reason for seal failure.

I would hope the bolt is a genuine MB part, as the dealer is a franchised/authorised MB dealer (now Stratstone, formerly Jardine). Just spoken to the MB technician, who says the specialist who removed the broken bolt probably replaced the bolt with a helicoil (whatever that is). Could this helicoil be the problem?

 

[StMarks]

Anyone had a similar problem and can throw any light on this please?

Not really going to help in this instance I don't think MarkG14, but fwiw;
When I first purchased my little Vito, amongst it's many issues was that it had the infamous "black death" all over the top of the engine.
I cleared back & cleaned everything out, and having done so I identified that it was No2 & No3 injector seals that were leaking. Not badly, but it had obviously been a very long standing issue that had been ignored by the previous keeper/s.
I like to do all my maintenance myself, however having read up extensively I was concerned by the large number of horror stories where attempts to do this mundane task had ended in catastrophic damage.
So I visited my local MB commercial dealership & asked for a quote for them to do it. They did it (although they did charge me extra for a couple of components that they damaged).
Anyway, about 10 months later I noticed "that smell" again, had a look & discovered that No3 was chuffing again. I returned to them & they replaced that seal again FOC (and without breaking anything else this time).
It has been fine ever since (I think,,, tempting fate? ) and that was good few years ago now.
Hth.

 

[MarkG14]

Not really going to help in this instance I don't think MarkG14, but fwiw;
When I first purchased my little Vito, amongst it's many issues was that it had the infamous "black death" all over the top of the engine.
I cleared back & cleaned everything out, and having done so I identified that it was No2 & No3 injector seals that were leaking. Not badly, but it had obviously been a very long standing issue that had been ignored by the previous keeper/s.
I like to do all my maintenance myself, however having read up extensively I was concerned by the large number of horror stories where attempts to do this mundane task had ended in catastrophic damage.
So I visited my local MB commercial dealership & asked for a quote for them to do it. They did it (although they did charge me extra for a couple of components that they damaged).
Anyway, about 10 months later I noticed "that smell" again, had a look & discovered that No3 was chuffing again. I returned to them & they replaced that seal again FOC (and without breaking anything else this time).
It has been fine ever since (I think,,, tempting fate? ) and that was good few years ago now.
Hth.

As I said, this is the third time no 2 seal has failed. MB repaired the 2nd failure under warranty, and this seal has failed for the 3rd time - still under warranty from the 2nd replacement. Took the car to MB today, who confirmed the leaky seal and now booked in for yet another seal replacement on12th. My problem is that they will simply replace the seal without addressing the underlying cause of the continued failure. When I expressed my concern about this, the service team member informed me that the alternative was for me to pay for a new cylinder head costing thousands of pounds. They broke the bolt, they arranged the removal of the broken bolt, yet they expect me to pay for their (or their agents) failure!

 

[Trickythemerc]

What !!!!!!!!!!!!! A new head to fix a leaking injector seal Assuming the broken bolt was sorted with the helicoil and the thread size is back to stock and genuine parts used a simple seat recut should sort it out. Another possibilty is damage to the injector where it seats on the copper seal. Some people have cured this issue by using Honda injector seals which are slightly thicker and give a better crush under torque at MB torque values.

 

[DaveE320CDI]

What !!!!!!!!!!!!! A new head to fix a leaking injector seal Assuming the broken bolt was sorted with the helicoil and the thread size is back to stock and genuine parts used a simple seat recut should sort it out. Another possibilty is damage to the injector where it seats on the copper seal. Some people have cured this issue by using Honda injector seals which are slightly thicker and give a better crush under torque at MB torque values.

As above it seems to be that in previous attempts to repair they have taken the short cut and just replaced the copper washer without re-cutting the seat, the trouble is that after there as been blowby the aluminium seat in the head gets damaged and needs refacing to achieve a gas tight seal when a new copper washer is fitted,

 

[MarkG14]

Thanks for all the advice guys, much appreciated.

I’m considering just going to a injector specialist to get a new seal fitted/recut rather than bang my head on the wall with MB.

Telling me I need to buy a new cylinder head was the last straw.

 

[StMarks]

Thanks for all the advice guys, much appreciated.

I’m considering just going to a injector specialist to get a new seal fitted/recut rather than bang my head on the wall with MB.

Telling me I need to buy a new cylinder head was the last straw.

Again, I don't know if it applies MarkG14, however after I had my injector seals replaced by MB I was "told off" by a friend of mine who works in the motor industry. His experienced advice was that I should have taken it to our local Mercedes Independent Specialist, as "they do them all the time & have if off pat".

 

[Gemmao]

A couple of years ago, I had an injector seal fail on my C220CDI.

As the car had quite a high mileage, I asked for all seals to be replaced.

Unfortunately, while removing the no 2 injector, the bolt snapped and the dealer had to call in a specialist to remove the snapped off bolt.

All seals replaced, everything fine.

One year later (last year) the no 2 seal failed again. MB replaced this under warranty.

Today I discovered the no 2 seal has failed AGAIN.

I am awaiting MB response, but suspect an underlying problem for one seal to repeatedly fail.

Anyone had a similar problem and can throw any light on this please?

How much did it cost to get all seals replaced?