Diesel injectors and replacement

[chunkolini]

I got rid of my ancient Doblo a few weeks ago 180k miles, lived in limp mode and falling to bits.
replaced it with a lowish mileage (38k) renault grand Scenic. Been driven round town by an old lady ferrying her disabled son around. Average speed showing was 18mph
Precautionary cam belt change was a laugh. my mechanic neighbour came in laughing and waving it at me; it had split half way through.
A few weeks ago it went into limp mode, AA call out and one of the injectors had died. How much!! The mechanic said one had already been done. Had the duff one replaced
Drove happily for a while then yesterday Limp Mode again and a injector fault showed on the diagnostic thingy.
It came back to life and seems fine again.
So do I replace the last two injectors?
not happy doing this sort of thing myself, do I buy cheapo ones off fleabay? price varies a lot, or reconditioned ones? or what do you guys reccomend?
At the moment I am solvent and would like it sorted so i can forget about it

 

[cheb]

Has it had a really good long hot high revving run? Batter it down a motorway as close to 70mph as you dare for a good wee whiley. My diesels are always better after a gentle pootle through the highlands on the way south

 

[chunkolini]

It's had plenty of that.
It did feel better after being driven for a couple of weeks.
Fine today.
Is this a coincidence?
It went into limp mode as I flipped through the computer modes, just as I clicked the button it went

 

[tom2207]

i normally throw a shot of good two stroke in , then run a tank through before doing anything rash , but you will probably put on all sorts of lights , so if you have even a cheap obd reader that can clear the lights , give it a go and after that time for a think.

 

[Morrisman]

Has it had a really good long hot high revving run? Batter it down a motorway as close to 70mph as you dare for a good wee whiley. My diesels are always better after a gentle pootle through the highlands on the way south

My dads diesel Citroen Picasso C3 automatic went to the scrap yard a month or two ago, with several dead electronic modules... or so the garage told him. He doesn't do many miles, and for the whole of lockdown he would simply move it up and down the drive a couple of times a week 'to keep it in shape'.....

The gearshift started playing up, and I told him he is doing damage by never getting it up to temperature or getting the charging system topped up properly.
Eventually the gear shift died altogether, random selections etc, and he took it to some back street mechanic who diagnosed it as module failure due to repeated low battery level. No idea if that was correct or not.

I told my dad repeatedly to let me take it out for an Italian tune up....but it never happened.

 

[Munkul]

Apparently this happens with loads of cars inc VW (maybe especially VW)

Get one bad injector - replace it - get problems with another. Repeat.

My cousin in the trade repaces all 4 each time now. It comes off his profit margin, but ensures it doesn't come back.

As an engineer I can't understand WHY though

 

[chunkolini]

Maybe an Italian tune up?
Just thinking it's a lazy flexible motor and I rarely rev it hard.
But is it going to be replace them anyway as Munkul says, do they die collectively like old couples?

 

[Morrisman]

Apparently this happens with loads of cars inc VW (maybe especially VW)

Get one bad injector - replace it - get problems with another. Repeat.

My cousin in the trade repaces all 4 each time now. It comes off his profit margin, but ensures it doesn't come back.

As an engineer I can't understand WHY though

I had issues with my diseasel Mondeo dropping into limp home mode occasionally, under acceleration, but it would clear if I simply turned the ignition off, then back on again. I did that a couple of times on the M6 early one morning....

Eventually I got it diagnosed... fuel pressure issue.

I suggested to the 'mechanic' we would start with fuel filter change, basic engine service..... to which he 'warned' me it might be the rear pump breaking up and bits of metal destroying all four injectors.... very expensive... and maybe I should think about trading the car in..... lots of sucking air across teeth and growing....very 1970's garage style....

It was fuel filter.

Harsh words were exchanged when the 'filters and oil service' took over 8 hours, and somehow turned into a £240 'full annual service and wash and valet'....

I don't use that garage any more.

 

[mike os]

Make sure the error code is cleared

 

[Morrisman]

Make sure the error code is cleared

I did ask about that, but never followed it up as communications had broken down by the time I left with the car. If I sold the car on a prospective buyer might check, but its 12 years old and I'll probably keep it until it fails terminal from something or other.

 

[hotponyshoes]

Injectors are a precision part.
In theory they should all be exactly the same and all doing exactly the same amount of work so it's not unbelievable that they would all fail at the same time.

If it's an hours paid labour to get access, 5min job to change and hour + coding to put back together then you may as well swap all 4 if they are cheap enough.

It's a job I would have a go at myself so I would just replace one at a time as needed.

 

[octo0072000]

long run 30/40 mins keep revs up to 3000 run in 3rd gear then see how it goes with injectors change them all you need to go to a diesel place not a garage

my avensis does 50mph at 3000 in 3rd gear never get out of 4th gear round local no wonder diesels have problems

 

[armalites]

Apparently this happens with loads of cars inc VW (maybe especially VW)

Get one bad injector - replace it - get problems with another. Repeat.

My cousin in the trade repaces all 4 each time now. It comes off his profit margin, but ensures it doesn't come back.

As an engineer I can't understand WHY though

With modern engine management the injectors compensate for cylinder balancing to smooth the running so if you cylinder is down/up then another cylinder will adjust to keep the smooth running. Once that injector gets to the point it's too far out of tolerance with the others a error will be logged. That injector gets replaced, engine management relearns and then you'll find another cylinder is trying to compensate for a new injector, that may well then pull that injector past accepted tolerance and it will flag and error. I guess you've already worked out the rest of the story.

What can also happen is the injector logging the error isn't the one with the issue it's trying to compensate for another one so the one with the error gets replaced and amazingly another fails.

This may be different on a low mileage engine where and injector has actually failed.

 

[Morrisman]

long run 30/40 mins keep revs up to 3000 run in 3rd gear then see how it goes with injectors change them all you need to go to a diesel place not a garage

my avensis does 50mph at 3000 in 3rd gear never get out of 4th gear round local no wonder diesels have problems

Most of my driving is 3 mile runs to town, then back again. On the way home, occasionally, once it is all warmed up, I’ll floor the throttle in 3rd and get the turbo spooled up in a burst of tyre smoke and screaming, tortured rubber......

Well, it actually just accelerates a bit faster than a bicycle, but the 1.6 diesel gets a workout dragging the heavy old car up to 60mph and the fuel system flows hard.

Oddly enough, my 1500kg car gets the same mpg as my 250kg 1.1 litre motorcycle.

 

[octo0072000]

Most of my driving is 3 mile runs to town, then back again. On the way home, occasionally, once it is all warmed up, I’ll floor the throttle in 3rd and get the turbo spooled up in a burst of tyre smoke and screaming, tortured rubber......

Well, it actually just accelerates a bit faster than a bicycle, but the 1.6 diesel gets a workout dragging the heavy old car up to 60mph and the fuel system flows hard.

tried mine in 6th at 30mph = tickover
mine had it's tune up run yesterday for 30 mins

 

[Munkul]

With modern engine management the injectors compensate for cylinder balancing to smooth the running so if you cylinder is down/up then another cylinder will adjust to keep the smooth running. Once that injector gets to the point it's too far out of tolerance with the others a error will be logged. That injector gets replaced, engine management relearns and then you'll find another cylinder is trying to compensate for a new injector, that may well then pull that injector past accepted tolerance and it will flag and error. I guess you've already worked out the rest of the story.

What can also happen is the injector logging the error isn't the one with the issue it's trying to compensate for another one so the one with the error gets replaced and amazingly another fails.

This may be different on a low mileage engine where and injector has actually failed.

This makes perfect sense

 

[tom2207]

With modern engine management the injectors compensate for cylinder balancing to smooth the running so if you cylinder is down/up then another cylinder will adjust to keep the smooth running. Once that injector gets to the point it's too far out of tolerance with the others a error will be logged. That injector gets replaced, engine management relearns and then you'll find another cylinder is trying to compensate for a new injector, that may well then pull that injector past accepted tolerance and it will flag and error. I guess you've already worked out the rest of the story.

What can also happen is the injector logging the error isn't the one with the issue it's trying to compensate for another one so the one with the error gets replaced and amazingly another fails.

This may be different on a low mileage engine where and injector has actually failed.

or if its been some sort of contamination , water dirt or in this part of the world laundered diesel , the same think that killed the first has pretty much done the same to the rest , its just that they are not bad enough to log a fault code , but they soon will be .
Long gone are the days of servicing then on the bench and if diesel setting the break pressures and the odd nozzle and your away again , injectors are hi tec and expensive.

 

[500e]

Tune mine almost every day harder to tune the 190hp Yettie though

 

[chunkolini]

Fault codes have been cleared, let's see how it goes but I think replace them while I'm solvent is probably sensible