Official S65 Injector Failure Thread

Thumbie wrote

It probably wouldn't show anything IMO. Once the injector sticks open, things happen pretty fast.

Correct, S-shaped connecting rods happen almost instantly when they fail open. Yay physics 😩

Yeah, I'm sure stuff gets spicy in a hurry once an injector sticks open.

The question is, how are these injectors getting from within-spec to stuck in the first place? How often does that happen gradually and how often does it happen overnight?

I honestly don’t have any clue. I do know S85 owners have the same failures. I haven’t done my due diligence on their side to see what they recommend

I can say (about when it happened to me back in 2021) it took a significant time to have the hydro lock happened.
I mean:
At first, crude gas smell with limp mode and rough engine running.
At second, excessive engine starts with that exact symptoms above.
At third, hydrolock happened and therefore no more engine starts (engine locked).

Didn't have a s-shaped rod, but a fatigued one. Followed by a (two) hole in the block.

Important: not a single scratch on the cylinder walls.

IamFODI wrote

The question is, how are these injectors getting from within-spec to stuck in the first place?

A piece of dirt that got forced through a clogged "lifetime" fuel filter and wedges itself into the injector nozzle, preventing it from closing.

Edit: This is my opinion but everything I've read points to this as the likely culprit. Injectors don't just stick open on their own very often

126k on my E90 M3 with original injectors... just stumbled across this. Got me worried now! Not exactly the cheapest replacement but seems pretty straight forward DIY. Hmmm anyone know where to get a set at the best price?

Thumbie wrote

A piece of dirt that got forced through a clogged "lifetime" fuel filter and wedges itself into the injector nozzle, preventing it from closing.

Edit: This is my opinion but everything I've read points to this as the likely culprit. Injectors don't just stick open on their own very often

I think this failure is extremely unlikely, many people seem to think that tank filters are nearly unique to the M3, they aren't, they've been in widespread use for about 20 years. I haven't heard of widespread problems with these filters or injectors across all makes, have you?
Online I've heard of our S65 injectors failing, S85s and some Porsches (I forget which), in my job as a mechanic since '95 (indie upto 2013 then at Suzuki, bar 1 year at BMW). I've never come across one that's jammed open in my job personally (not saying it doesn't happen though!).

Also, I recently came across 2 cases which I documented in my 'blown motors' thread here (these 2 cases didn't blow the engines btw) where 1 of them had a single injector failure the other case 2 failed and they only replaced the failed injectors.
The single injector failure occurred in 8/2017 @125k miles, he replaced only the one and the car has done "many, many track days" and is still good now @140k miles! (It's a track dedicated car).
The double injector failure case @82k miles (only 2 replaced), carried on for another 2k miles before the rod bearings failed.
Even with the 2nd case it's extremely unlikely to have done another 2k miles if dirt had been getting though to the injectors, and we can certainly absolutely rule out the filter for the first case.
(PS jvictormp you replied to his case nearly 7 years ago ).

Additionally I have been recording which injector failed (where the info was available, or asked via PM/DM), and which one(s) failed is random, which would not be the case consistently if it was down to the filter failing. As in, the injectors nearest the fuel inlet (6 & 7 IIRC) would be the most common ones to fail if the filter had torn.

All that said, I can't be 100% sure, so I figured what the hell, a fuel filter isn't expensive, so I'll just add one in just in case lol (whether the tank filter &/or pump fail in the future). I thought it'd be easy enough, well it wasn't (at first look) because the fuel pipe is stainless steel! And I want to add the fuel filter in underneath the car where the diesels have them.
Anyway, I will be adding a filter there, I was reminded about compression fittings so that I can then add a hosetail fitting to the end of the pipes (you shouldn't just push and clip a hose on to a plain end of a pipe). Flaring a stainless steel pipe requires a special (& expensive!) flaring tool.

Btw, I replaced my injectors a couple of weeks ago.

Assimilator1 given your other posts on this forum I have read, I trust your experience a lot more than my personal opinion. And thank you for maintaining that list of failures.

Reading through non-bearing failures, injectors stuck open seems to occur more randomly than I previously thought, with a slight trend toward cylinder 6 and 7 but not a strong trend (BTW failure #88 on that list is a close friend of mine, if you had any follow up questions)

Either way, I am going to treat in-tank filter/pump and fuel injectors as just a 100k mile maintenance item, at least for me and my S65. Maybe unnecessary cost, but I didn't buy an M3 to be economical :drink:

Thumbie wrote

A piece of dirt that got forced through a clogged "lifetime" fuel filter and wedges itself into the injector nozzle, preventing it from closing.

Edit: This is my opinion but everything I've read points to this as the likely culprit. Injectors don't just stick open on their own very often

It could also be the thimble filter on the injector itself deteriorating.
One of the reasons BMW had so many iterations of fuel injectors on the piezo n54 style is because the thimble filter would disintegrate I think with temperature over time.

There was a post on the S85 forums talking about the thimble in the injector disintegrated.

https://www.m5board.com/threads/s85-bosch-fuel-injector-dissection-ev14.618248/

Anyway. I still have a stuck open injector that needs someone able to take it apart to understand how it failed open. Also have the accompanied 7 other injectors of the motor.

Thumbie wrote

Assimilator1 given your other posts on this forum I have read, I trust your experience a lot more than my personal opinion. And thank you for maintaining that list of failures.

Reading through non-bearing failures, injectors stuck open seems to occur more randomly than I previously thought, with a slight trend toward cylinder 6 and 7 but not a strong trend (BTW failure #88 on that list is a close friend of mine, if you had any follow up questions)

Either way, I am going to treat in-tank filter/pump and fuel injectors as just a 100k mile maintenance item, at least for me and my S65. Maybe unnecessary cost, but I didn't buy an M3 to be economical :drink:

Thank you.
Re #88 (their are 2, different lists), do you mean Jackson Rapaich?
If so, yes please! I PM'd him, but haven't had a reply yet. Would like to know the mileage when the injector failed, what year the car was and which cylinder was bore washed by the injector.

Re trend of which injectors failing, I haven't tallied the ones at m3post yet (need to find which cyls have failed for some [edit, just added a few, will update others later]), have you tallied them?
IIRC the ones I've tallied at m3cutters don't really show a trend, but it's low numbers.

RocketyMan
Interesting post about the S85 injector.
Are they the same part as the S65 ones?

Re your injectors, afraid I've dropped the ball on that after the injector shop messing me around, they asked for a long number off the injectors, I asked if they meant the part no or serial number, they just said the long number:confused2. Also they were talking about refurbishment when all I asked for was diagnosis, they then stopped replying to my emails!
Then with work on my car and a pet illness I completely forgot about it!
Maybe I should nudge them again....

Do you guys know if there have been any incidents of supercharged S65’s with failed open injectors? They obviously use different injectors but some of the kits still use Bosch, just in a different model.

Assimilator1 wrote

Thank you.
Re #88 (their are 2, different lists), do you mean Jackson Rapaich?
If so, yes please! I PM'd him, but haven't had a reply yet. Would like to know the mileage when the injector failed, what year the car was and which cylinder was bore washed by the injector.

Re trend of which injectors failing, I haven't tallied the ones at m3post yet (need to find which cyls have failed for some [edit, just added a few, will update others later]), have you tallied them?
IIRC the ones I've tallied at m3cutters don't really show a trend, but it's low numbers.

RocketyMan
Interesting post about the S85 injector.
Are they the same part as the S65 ones?

Re your injectors, afraid I've dropped the ball on that, after the injector shop messing me around, they asked for a long number off the injectors, I asked if they meant the part no or serial number, they just said the long number:confused2. Also they were talking about refurbishment when all I asked for was diagnosis, they then stopped replying to my emails!
Then with work on my car and a pet illness I completely forgot about it!
Maybe I should nudge them again....

The S85 injectors look to be a 4 hole design while the S65 look to be a 6 hole design. I would imagine this plays a part in atomization efficiency, otherwise don't see how this would matter too much between the two.
https://www.fcpeuro.com/products/bmw-injection-valve-genuine-bmw-13647839098

This characteristics of the S85 being [at 3 bar]:

Jetronic port extended 4 hole nozzle.

Flow Rates:
25.5 lb per hour
193 g per min (N-Heptane)
268.4cc per min

Resistance:
12.00 Ohm


I would expect the S65 to be similar.
It looks like a member here on the forum got them flow test and wound up with roughly 260 cc/min. Which would be compatible using them in the S85 in terms of flowrate.



S85 "long number" here:




Then the S65 "long number" here:

Could you post links to photos (probably best not show the photos here otherwise it'll be a massive scroll fest! lol) of your injectors showing there numbers?
Then I could just forward the links to the injector shop.

Thumbie wrote

Assimilator1 given your other posts on this forum I have read, I trust your experience a lot more than my personal opinion. And thank you for maintaining that list of failures.

Reading through non-bearing failures, injectors stuck open seems to occur more randomly than I previously thought, with a slight trend toward cylinder 6 and 7 but not a strong trend (BTW failure #88 on that list is a close friend of mine, if you had any follow up questions)

Either way, I am going to treat in-tank filter/pump and fuel injectors as just a 100k mile maintenance item, at least for me and my S65. Maybe unnecessary cost, but I didn't buy an M3 to be economical :drink:

Have now tallied the list of which injectors have failed (for the ones available), managed to add a few cyl numbers.

30 injector failures (of which 5 did not cause engine failures, see blown engine lists). Not all people noted cyl number.
Cyl No - quantity
1 - 2
2 - 3
3 - 1
4 - 1
5 - 2
6 - 4
7 - 6
8 - 4

There is indeed a bit of weighting towards cyls 6,7 & 8.
The fuel inlet is between 6 & 7.

I pulled my injectors at 49K miles and one of them had some carbon buildup.. All working perfectly but for peace of mind changed them out. Not sure if the carbon would have eventually caused it to get stuck open but probably not

rosemont83 wrote

I pulled my injectors at 49K miles and one of them had some carbon buildup.. All working perfectly but for peace of mind changed them out. Not sure if the carbon would have eventually caused it to get stuck open but probably not

No it wouldn't have, jammed injectors occur internally.
Although carbon build up on the tip will affect the spray pattern*, so power and economy. Anyway, you know your injectors will be good for sometime now .

[edit]*If it's near to the nozzles.

Assimilator1 wrote

No it wouldn't have, jammed injectors occur internally.
Although carbon build up on the tip will affect the spray pattern, so power and economy. Anyway, you know you know your injectors will be good for sometime now .

Yeah didn't think so.. photos for reference of the 49k mile injectors

The other numbers on the injector is the date code.

Notice on this last post from rosemont has "11" as the last digits. Therefore, 2011 was when they were made.

Nozzles seem clean, curious that just one of the injectors had a little carbon around the outside edge.

Year: 2010
Miles: 122,600

Injector Failure symptoms: sudden cylinder shut off, codes for misfires on 5/6/7/8

Duration driven with symptoms: 40-50 yards (I was thankfully at my friends complex navigating to his apartment when symptoms presented suddenly.)

I hurried to get into a parking spot and shut it off, I was going downhill when the cel came on and didn't immediately notice the cylinder shut off/misfires. Once I parked I pulled the oil fill and was met with raw fuel smell as I immediately suspected injectors.
With plenum off and holding ITBs open cylinder 6 stood out with a raw fuel smell.
As I used to be an n54 guy back in the day, this isn't my first rodeo. I pulled the rails with the injectors connected, cylinder 5 smelled of gas but no wetness besides some oil residue. I then primed the fuel pump with clean shop towels under all injectors to look for one hanging open, nothing, dry.
Regardless I ordered a new set of injectors and oil from FCP, popped them in and all seems well! Oil was very cloudy with about 80 miles since the last change (doh!)

Secondary failure: 25 miles driven since swap, no problems yet.

Injector failure cause or theory: injectors looked very gunked up.

BrokeBarney wrote

Year: 2010
Miles: 122,600

Injector Failure symptoms: sudden cylinder shut off, codes for misfires on 5/6/7/8

Duration driven with symptoms: 40-50 yards (I was thankfully at my friends complex navigating to his apartment when symptoms presented suddenly.)

I hurried to get into a parking spot and shut it off, I was going downhill when the cel came on and didn't immediately notice the cylinder shut off/misfires. Once I parked I pulled the oil fill and was met with raw fuel smell as I immediately suspected injectors.
With plenum off and holding ITBs open cylinder 6 stood out with a raw fuel smell.
As I used to be an n54 guy back in the day, this isn't my first rodeo. I pulled the rails with the injectors connected, cylinder 5 smelled of gas but no wetness besides some oil residue. I then primed the fuel pump with clean shop towels under all injectors to look for one hanging open, nothing, dry.
Regardless I ordered a new set of injectors and oil from FCP, popped them in and all seems well! Oil was very cloudy with about 80 miles since the last change (doh!)

Secondary failure: 25 miles driven since swap, no problems yet.

Injector failure cause or theory: injectors looked very gunked up.

Glad you stopped the car as up! May have saved its life.

PapaMurph wrote

126k on my E90 M3 with original injectors... just stumbled across this. Got me worried now! Not exactly the cheapest replacement but seems pretty straight forward DIY. Hmmm anyone know where to get a set at the best price?

The S65 injectors are very cheap to replace. Imagine you had to replace injectors on a N54... https://www.fcpeuro.com/products/bmw-fuel-injector-kit-13538616079kt