"Misfire" on a diesel - possible cause?
Discussion
Our trusty Fiat Ducato (2003 2.3 JTD) has developed an occasional "misfire". As it's a diesel it's probably not the right word, but what it does is like a misfire in a petrol engine - it "staggers" under acceleration.
It's only done it 3 times - twice on Thursday evening, and once today. Otherwise it's running and driving fine. It is regularly serviced. I changed the fuel filter yesterday (advice from the garage), but it is still doing it.
I'm worried it could be something potentially expensive like the timing belt. It was last changed 4 years (and about 80,000 km) ago, so based on the km it should only be about half way.
Can a timing belt slip and cause these symptoms? Ot is it something else?
Unfortunately the garage I normally use is closed all this coming week (otherwise I'd be there first thing tomorrow morning) and the only other Fiat garage in the area doesn't have a very good name. We bought the van from them, but it has since changed owners and has even lost the Fiat distributorship.
I know if I go there and mention the timing belt it will definitely need changing. If it needs changing - no problem - it's cheaper than a new engine - but I don't trust them.
I would also prefer to spend the money at the other garage (it's the son of one of our customers). I'm not however going to wait a week if there's the risk of serious damage.
Grateful for any advice/suggestions.
It's only done it 3 times - twice on Thursday evening, and once today. Otherwise it's running and driving fine. It is regularly serviced. I changed the fuel filter yesterday (advice from the garage), but it is still doing it.
I'm worried it could be something potentially expensive like the timing belt. It was last changed 4 years (and about 80,000 km) ago, so based on the km it should only be about half way.
Can a timing belt slip and cause these symptoms? Ot is it something else?
Unfortunately the garage I normally use is closed all this coming week (otherwise I'd be there first thing tomorrow morning) and the only other Fiat garage in the area doesn't have a very good name. We bought the van from them, but it has since changed owners and has even lost the Fiat distributorship.
I know if I go there and mention the timing belt it will definitely need changing. If it needs changing - no problem - it's cheaper than a new engine - but I don't trust them.
I would also prefer to spend the money at the other garage (it's the son of one of our customers). I'm not however going to wait a week if there's the risk of serious damage.
Grateful for any advice/suggestions.
could be a heater plug (they are in constant use on modern engines)
Could be an injector.
There is very little you can check on a Common Rail system yourself/
You could remove the spill off pipes from each injector and attach a piece of clear pipe to each.
You have to remove the IMV connector from the pump and run the engine.
If one injector has excessive spill off you have found you faulty injector.
It can't just be replaced without a diagnostic machine to re enter the C2I codes.
Could be an injector.
There is very little you can check on a Common Rail system yourself/
You could remove the spill off pipes from each injector and attach a piece of clear pipe to each.
You have to remove the IMV connector from the pump and run the engine.
If one injector has excessive spill off you have found you faulty injector.
It can't just be replaced without a diagnostic machine to re enter the C2I codes.
I had exactly this on my Mk4 VW Golf GT TDi (ARL engine) its a PD injection system where there are extra cam lobes which drive the individual injection pumps (at mega high pressure) the lobes started to break down giving the effect of a misfire.
Its a well know problem with this engine and VW nows about it, i know it doesnt help you but if you have a similar injection system where the individual pumps are driven by the camshaft then its worth checking. VW gave me a "goodwill" fix and paid 80% of the cost as i had full history with them.
Its a well know problem with this engine and VW nows about it, i know it doesnt help you but if you have a similar injection system where the individual pumps are driven by the camshaft then its worth checking. VW gave me a "goodwill" fix and paid 80% of the cost as i had full history with them.
It could be lots of different things although the things which spring immediately to mind are too much EGR (EGR valve stuck open) or a faulty injector?
If you had an OBD reader (scantool) you could see if any fault codes have popped up? Even if the MIL (light on dash has not come on) most of these faults require 2 instrances in consecutive drive cyclces before the MIL comes on. Plug an OBD reader and see if you have any "pending" faults.
Hope that helps!
If you had an OBD reader (scantool) you could see if any fault codes have popped up? Even if the MIL (light on dash has not come on) most of these faults require 2 instrances in consecutive drive cyclces before the MIL comes on. Plug an OBD reader and see if you have any "pending" faults.
Hope that helps!
Thanks for the replies so far!
Unfortunately my technical knowledge runs out at changing filters/oil/brakes bits etc.
For the guys who replied so far, I guess I need to know whether the faults you are suggesting can wait a week until my trusted garage is open again, or whether they could cause more expensive problems, in which case I'll bite the bullet and go to the other garage.
P.S. Not overly worried about just breaking down - we've paid for breakdown cover for the van since the Fiat cover ran out, and never used it, plus it's mostly used locally and we could probably recover it ourselves if necessary (Disco + car trailer).
Unfortunately my technical knowledge runs out at changing filters/oil/brakes bits etc.
For the guys who replied so far, I guess I need to know whether the faults you are suggesting can wait a week until my trusted garage is open again, or whether they could cause more expensive problems, in which case I'll bite the bullet and go to the other garage.
P.S. Not overly worried about just breaking down - we've paid for breakdown cover for the van since the Fiat cover ran out, and never used it, plus it's mostly used locally and we could probably recover it ourselves if necessary (Disco + car trailer).
I had a random misfire on the Mondeo (no longer own the car)
It used to misfire totally at random, sometimes 10 miles between misfires, sometimes 2000 miles. Bizarre.
Unfortunately it never logged a fault code, or appeared to clear it when I turned the engine off.
No garage could find a fault, but I never took it to an actual diesel specialist - which is your best bet for the modern common rail engines to be honest.
The injectors are vvery expensive to replace if it is a faulty injector - sometimes they can be reconditioned though.
Get someone with a fault code reader to see if your computer has logged anything first - normally the injectors and common rail system has more sensors than a NASA probe...
It used to misfire totally at random, sometimes 10 miles between misfires, sometimes 2000 miles. Bizarre.
Unfortunately it never logged a fault code, or appeared to clear it when I turned the engine off.
No garage could find a fault, but I never took it to an actual diesel specialist - which is your best bet for the modern common rail engines to be honest.
The injectors are vvery expensive to replace if it is a faulty injector - sometimes they can be reconditioned though.
Get someone with a fault code reader to see if your computer has logged anything first - normally the injectors and common rail system has more sensors than a NASA probe...
t - its unlikely that it will be slipping. It's only happening occasionally. On Thursday it did it twice, then ran faultlessly for more than 200km.
Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
sunbeam_alpine said:
It's only happening occasionally. On Thursday it did it twice, then ran faultlessly for more than 200km.
Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
If you have a sticking injector, worse case scenario is that the high pressure fuel will cut a hole in your piston.Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
An occasional misfire is unlikely to cause that though.
odyssey2200 said:
sunbeam_alpine said:
It's only happening occasionally. On Thursday it did it twice, then ran faultlessly for more than 200km.
Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
If you have a sticking injector, worse case scenario is that the high pressure fuel will cut a hole in your piston.Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
An occasional misfire is unlikely to cause that though.
If a timing belt had slipped, it would be running shiute the hole time not just on occassions, Its properly the injector pump playing around, or a dodgy injector, if it misfires real bad i would leave it, if it only does it at certain revs or for only a couple of seconds then id stay short and local, if its done it 3 times for 2 seconds each time i would carry on and get it booked in with your friends garage, If you go to a garage you dont know and tell them you think its a cambelt, no doubt they will have your bloody pants down!
Hth a little, Garry
Without seeing the van i cant be held liable if it breaks, just an opinon from someone whos over eaten and stuck in his computer chair. (haha)
Hth a little, Garry
Without seeing the van i cant be held liable if it breaks, just an opinon from someone whos over eaten and stuck in his computer chair. (haha)
sunbeam_alpine said:
odyssey2200 said:
sunbeam_alpine said:
It's only happening occasionally. On Thursday it did it twice, then ran faultlessly for more than 200km.
Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
If you have a sticking injector, worse case scenario is that the high pressure fuel will cut a hole in your piston.Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
An occasional misfire is unlikely to cause that though.
odyssey2200 said:
sunbeam_alpine said:
odyssey2200 said:
sunbeam_alpine said:
It's only happening occasionally. On Thursday it did it twice, then ran faultlessly for more than 200km.
Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
If you have a sticking injector, worse case scenario is that the high pressure fuel will cut a hole in your piston.Having changed the fuel filter, the engine seems to be running a bit smoother, but it has done the "misfire" since I changed the filter.
As I said, the most important question for me is to know whether I can wait until my usual garage is open next week, or whether I should be going to another garage tomorrow i.e. can it be something which will cause more damage?
An occasional misfire is unlikely to cause that though.
Quick Update:
Went to the garage this morning. They connected up the computer, and it reported a problem with a crank case sensor (rev sensor). The guy said that it should be replaced, but that I could carry on driving, as they didn't have the part in stock.
Broke down 500 yards after leaving the garage!
Went to the garage this morning. They connected up the computer, and it reported a problem with a crank case sensor (rev sensor). The guy said that it should be replaced, but that I could carry on driving, as they didn't have the part in stock.
Broke down 500 yards after leaving the garage!
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