Technical 1.3 Multijet Leak Off Test Results

[Eltezz]

Does anyone know if this looks about right for my engine? This kit is the standard one available on ebay and is not calibrated in any standard units but I have accurate measuring beakers and the 7 mark works out at 35ml. I ran the engine for 3 1/2 minutes on tickover so this works out at 10ml per minute. Does this sound about right?

Cylinders 1-4 left to right.

 

[bugsymike]

According to some tests this appears slightly on the high side, but not excessively so.
Some suggest 30ml. So not conclusive either way.
Ideally I would look for one reading much higher than the rest.
Where as yours is fairly even , has it done a few miles?
Was there a particular fault you are trying to locate?

"Good injectors should not leak more than 25ml in this test. Looking at my results from left to right the first one is an original factory fitted injector in this car and shows a good 20ml result."

 

[Eltezz]

Thank you for that info. Despite my searching, there doesn't seem to be any official time given for this test. In other words, how much leakage over how much time?

The car has done just over 83,000 miles. I have recently done a lot of work on it and have been left with the following issues:

1. Slightly worse starting, i.e. used to start instantly, now turns over 3-4 times before catching.
2. Engine idle is lumpy
3. Hesitation, slow pickup when smartly opening the throttle until 2000rpm ish. This is minor but noticable.
4. The worst problem, clouds of grey/blue smoke like you wouldn't believe. It stinks awful as well, doesn't smell of diesel or oil.

I think I might remove and examine the injectors next as I have done pretty much everything else.

 

[bugsymike]

Thank you for that info. Despite my searching, there doesn't seem to be any official time given for this test. In other words, how much leakage over how much time?

The car has done just over 83,000 miles. I have recently done a lot of work on it and have been left with the following issues:

1. Slightly worse starting, i.e. used to start instantly, now turns over 3-4 times before catching.
2. Engine idle is lumpy
3. Hesitation, slow pickup when smartly opening the throttle until 2000rpm ish. This is minor but noticable.
4. The worst problem, clouds of grey/blue smoke like you wouldn't believe. It stinks awful as well, doesn't smell of diesel or oil.

I think I might remove and examine the injectors next as I have done pretty much everything else.

If it's worse when starting from cold and you have ruled out heater plug side, then engine compression is worth testing when injectors out, though I wouldn't condemn injectors from what you have said so far.
Does it use engine oil , or the oil stays about right level , but smells of diesel as dripping injectors can cause that diluting the engine oil.
Also if yours has DPF and tries to do REGEN if only doing short journeys, it can dilute engine oil with diesel and also give pungent white smoke out of exhaust.
If the grey/blue smoke is mainly on start up from cold but largely goes away when engine warm that also points to piston/bore wear.
Where as DPF REGEN can try to happen hot or cold. I had a C3 Picasso 1.6 Diesel that from cold you couldn't breath the fumes, but after removing and cleaning the DPF then telling the ECU that it had been replaced it ran fine four 4 years before I had to fit a new DPF and top up the Eloys fluid they used.
When lumpy from cold, have you been able to detect which cylinder is not on full power. It was easier in the old days to undo injector pipes individually to locate a weak cylinder , however with modern Common Rail systems that doesn't work and if you try to unplug injectors one at a time electrically then it will throw up Error codes which will need deleting from ECU.

 

[Eltezz]

Mike, good info, thank you. I have been keeping a record of what I have been doing, to try and keep on top of events. It's a bit of a read, but I copy and paste it here if you want to have a look. Next step this weekend is injector removal and compression test.

My notes:

Initial faults - using oil (lots), clear leak around left front of engine. DPF still blocked after regen.
Slight hesitation around 1800 rpm.

First round of work:
Front of car removed to gain access. DPF removed and cleaned with Wynn's off car cleaner.
Oil cooler removed and cleaned, refitted with new gasket.Front of engine cleaned.
Fuel pump regulator removed and checked due to slight leak. Refitted with old gasket.
Throttle body removed and de-coked. End of EGR/inlet to inlet manifold also de-coked.
Turbo had oil in both sides and axial play of 1-2mm. Replaced with new Ridex turbo and new gaskets.
New AC condenser fitted. New coolant. New oil and filter. New air filter.

Car started first turn of key. Road test - within 1/4 mile DPF DTC, probably due to excess cleaning fluid
still inside. Limp mode and 1 mile later car cut out and died on side of road. DTC injector pressure support.

Second round:
Fuel pump removed and dissasembled. Nothing obvious so reassembled and replaced.
Car now started. Tried to move out of garage but halfway out, died again. Same DTC.
Pump removed again and rebuilt with seal repair kit. New gasket for regulator. Borrowed high pressure
test kit and pump is producing 380bar at 850rpm and 1250bar at 3000rpm. MES also confirms this.

Car now starts but not instantly as it used too. Feels lumpy at low rpm and hesitates slightly on
throttle up. Now blowing huge volumes of grey/blue smoke but not at start up. Very small amounts of smoke
at start and idle but once I rev it up a few times it begin throwing out the smoke even while idling.
Smoking occurs whether car is hot or cold.
After many starts and running whilst checking live parameters noticed oil level was rising - diesel in oil.
Removed MAP sensor and decoked, refitted. Should I try a forced regen? Still not left my garage.
Have noticed in MES that intake air quantity is lower that desired air quantity and also doesn't seem
to increase with RPM. Have found other mentions of this on the net so a bug is MES?

Drained and replaced oil and filter - oil like water so definite diesel in it.

Back to square one. Have pulled injector electrical connections one at a time while idling,
can't tell any difference from engine note. Carried out leak off test. Amounts look a little high but pretty
even across all injectors.

 

[bugsymike]

Mike, good info, thank you. I have been keeping a record of what I have been doing, to try and keep on top of events. It's a bit of a read, but I copy and paste it here if you want to have a look. Next step this weekend is injector removal and compression test.

My notes:

Initial faults - using oil (lots), clear leak around left front of engine. DPF still blocked after regen.
Slight hesitation around 1800 rpm.

First round of work:
Front of car removed to gain access. DPF removed and cleaned with Wynn's off car cleaner.
Oil cooler removed and cleaned, refitted with new gasket.Front of engine cleaned.
Fuel pump regulator removed and checked due to slight leak. Refitted with old gasket.
Throttle body removed and de-coked. End of EGR/inlet to inlet manifold also de-coked.
Turbo had oil in both sides and axial play of 1-2mm. Replaced with new Ridex turbo and new gaskets.
New AC condenser fitted. New coolant. New oil and filter. New air filter.

Car started first turn of key. Road test - within 1/4 mile DPF DTC, probably due to excess cleaning fluid
still inside. Limp mode and 1 mile later car cut out and died on side of road. DTC injector pressure support.

Second round:
Fuel pump removed and dissasembled. Nothing obvious so reassembled and replaced.
Car now started. Tried to move out of garage but halfway out, died again. Same DTC.
Pump removed again and rebuilt with seal repair kit. New gasket for regulator. Borrowed high pressure
test kit and pump is producing 380bar at 850rpm and 1250bar at 3000rpm. MES also confirms this.

Car now starts but not instantly as it used too. Feels lumpy at low rpm and hesitates slightly on
throttle up. Now blowing huge volumes of grey/blue smoke but not at start up. Very small amounts of smoke
at start and idle but once I rev it up a few times it begin throwing out the smoke even while idling.
Smoking occurs whether car is hot or cold.
After many starts and running whilst checking live parameters noticed oil level was rising - diesel in oil.
Removed MAP sensor and decoked, refitted. Should I try a forced regen? Still not left my garage.
Have noticed in MES that intake air quantity is lower that desired air quantity and also doesn't seem
to increase with RPM. Have found other mentions of this on the net so a bug is MES?

Drained and replaced oil and filter - oil like water so definite diesel in it.

Back to square one. Have pulled injector electrical connections one at a time while idling,
can't tell any difference from engine note. Carried out leak off test. Amounts look a little high but pretty
even across all injectors.

Great, plenty of information, from symptoms you describe my instincts would be towards DPF still blocked.
I don't know off hand how easy it is to remove on your vehicle.
On the Citroen with similar faults as you describe, I removed the DPF soaked it in a deep bucket for several days in Bookers commercial Oven cleaner and strong bleach , after which I blasted it with a commercial steam cleaner/pressure washer and got loads of brown muck out, I repeated this a couple of times including back flushing until I was happy water could flow through it easily , once drained I refitted, started vehicle up and took it to my friend garage where I used his Snap On Zeus Diagnostic tool to tell the ECU it had a new DPF, then confirmed the Eloys fluid used in this vehicle was sufficient, gave it a good road test with clean results, then flushed and refilled engine oil with new filter etc.
Note the vehicle had been used as a "minicab" and had over 200k miles on it.
I ran it for 4 years then with no issues apart from an alternator, around then it asked for a new DPF so I kindly gave it one and later sold it with 225K miles, so original purchase price of £300 for 2012 vehicle seemed a fair value for four years motoring
Incidentally if you decide to do a compression test I would look to 300-400 psi as a miniumum cranking pressure.
However I would look towards DPF first if it was me.
What pressure readings before and after DPF are you getting from sensors?
Another small point, one of my daughters recently bought a VW Golf 1.6 diesel, the previous owner mentioned he used to put DPF cleaner in the fuel every few tank fulls. Shortly after owning it the DPF light came on which annoyed me, however I put a full tin of DPF cleaner in the tank and gave it a 30 mile run in 4th gear at 3000rpm approx and light went out.
The other thing I noticed was the temp never went above 1/3rd even with hard driving, so with daughter only doing short low speed town driving it was not helping. So I fitted a new engine thermostat (which was a right pain in the arse to fit) now temp quickly reaches 90 degrees in centre of gauge which so far seems to been the main cause of the problem.
DPF cleaning automatically doesn't really work unless engine temp at normal and a decent run as mentioned to permit the operation to work.
In the old days a diesel was a good choice for economical town use, now it isn't due to modern emission requirements but salesmen rarely tell the new owners!!!

 

[Eltezz]

Mike,

After I purchased the car and this problem started happening, I began checking parameters in MES and found that the new DPF parameter had been reset about a 1000 miles earlier. Also, whilst removing the DPF I found missing nuts, swarf under the exhaust manifold trapped in oil and a helicoil in one of the turbo bolts so I am pretty sure a new DPF was fitted.

Once I removed the DPF I fully plugged all outlets and filled it with Wynn's DPF off car cleaner and left it for the maximum 8 hours. However, apart from sooty liquid, very little else came out of it. Once flushed with a pressure washer and refitted, MES reports a differential pressure of roughly 1psi at idle and 4 psi at 3000 rpm. I think this is on the high side.

Thinking about it, I reckon the following might have happened starting with previous owners:

Engine starts leaking oil from oil cooler
Small sump on this car leads to oil level dropping without them realising/checking.
Turbo begins to let go, excess oil blowby begins to start damaging DPF.
DPF gets changed but underlying fault is not rectified
I buy the car which is steadily damaging the new DPF as I drive it. Oil is still being lost (without me realising initially).

If this is the case then the DPF on the car is probably uncleanable and toast anyway. Now I have sorted the turbo and the leak, maybe I should try a new DPF?

 

[bugsymike]

Assuming your pressure sensor results accurate, then not far out.
As it says in this piece, was the DPF "reset as new? If not it may account for it possibly trying to frequently Regen.
Apart from all that, when you have injectors out it will be interesting if when tested they say any are dripping especially if oil diluted. I know older pre DPF 1.3 Multijets did have a history of that, even to the extent that some "ran on". I always frequently changed my daughters oil on her Grande Punto as it always felt watery to me.


"You would normally measure dpf pressure in mb. A good one at idle would be 10mb or less bring revs up to about 2500rpm and less than 100mb flat out under load and 300mb max. 300mb is about 4.5 psi. Ash content is a calculation and needs resetting on diagnostic tools after a dpf is replaced."

 

[Eltezz]

Ok, just been out and checked with MES -

850rpm - 46mbar
2500rpm - 248mbar
3000rpm - 330mbar

Note that these figures are in the garage with no load. Also I have been doing a lot of engine stop/start and idling while doing various tests so it probably needs a regen fairly badly.

One thing I noticed, there is a very small drip/leak of a watery black sooty liquid from where the wastegate arm exits the bottom of the turbo. This would seem to indicate a lot of fluid laden gas in the exhaust side of the turbo. The impeller still spins freely so I don't think the brand new turbo is at fault so must be coming from the cylinders? This can't be helping the DPF...

 

[bugsymike]

What mbar does it read if you put your foot down quickly then release, so a sudden surge that would build pressure quickly in DPF I am thinking if partially blocked this may show it..
Also if possible can you run engine outside till warm and hold around 2500rpm to see if it tries to Regen for it's self on a steady throttle.
Obviously better if it can go on a run doing the same.
Did you get an ash content reading?

 

[Eltezz]

I have started to remove the injector lines ready to take the injectors out so can't do that check at the moment.

MES shows clogging at 98% and clogging level as "normal". It was at 68% after I did the cleaning and refit. I will use MES and do a forced regen on the car and see what happens.

Will update once I have some progress...

 

[Eltezz]

Update:

Having purchased an injector removal tool, I was reluctant to use it as it is the kind that you have to remove the top of the injector in order to attach it. I know this destroys the calibration so decided to put a long 1/4" socket and extension on the fuel inlets and try working them side to side. The Sun must have been shining on me because all four started to move! I then worked them side to side while pulling upwards and all four came out no problem.

The compression kit I had bought proved to be of no use as it had no adapter for the Bosch injector, only fo screw in types. Considering how well the car had started in the past I decided that compression was probably not an issue so instead took the injectors into work for a cleaning session. Each one was dissasembled and put in individual containers and then into our ultrasonic tank for 20 minutes. I checked each injector nozzle under the microscope before cleaning and all had carbon build up and some spray holes blocked. After cleaning they were rinsed in acetone to stop flash rust. I checked the nozzle pattern and all were perfect so into some fresh diesel they went while I reassembled. Injector nozzles were re-torqued to 65nm.

Back in the garage I spent another couple of hours cleaning out the injector bores before refitting with new copper washers. I fully reassembled the car and started it up. Took a couple of tries but then started ok.

Unfortunately the smoke was back... So, decided to take @bugsymike advice and concentrate on the DPF. I let the engine warm for a bit and then started holding at 1500, 2000, and 3000rpm in the garage. Slowly the smoke began to thin out over a period of 8-10 minutes and the lumpy running dissapeared as well. I haven't moved the car for about 4-5 weeks so decided to risk backing it out and trying some more engine revving outside. The car behaved so I connected up MES to have a look. First thing I noticed was the injector corrections had gone from -1.5, -1.3, 1.4, 3.9 at idle to all -0.3 so the cleaning must have had an effect. I then looked at the DPF and clogging level was at 112%. The differential pressure was 70mbar at idle. I was pretty happy at this and resolved to take the car out for a short run the next day (today).

So, on to the test run, driving down our track to the road it was immediately obvious that the engine was running much smoother. Once on the road I decided to just barrel up and down a half mile each way just in case it played up. As I started to accelerate smartly through the gears the car began to throw out unbelievable volumes of smoke - couldn't see anything behind! I got to the first turnaround point and decided to just keep going and sure enough, giving it some beans it slowly started to clear. On the final two runs and trundling back up the track, not a bit of smoke anywhere.

Once back at base I plugged in MES which reported that a regen had just taken place and the clogging level was now 21% with the tickover differential pressure being 19mbar.

The car now pulls much harder with no hesitation anywhere in the rev range - lovely.

Thanks Mike, I don't think I would have got there without your pointers

 

[bugsymike]

Update:

Having purchased an injector removal tool, I was reluctant to use it as it is the kind that you have to remove the top of the injector in order to attach it. I know this destroys the calibration so decided to put a long 1/4" socket and extension on the fuel inlets and try working them side to side. The Sun must have been shining on me because all four started to move! I then worked them side to side while pulling upwards and all four came out no problem.

The compression kit I had bought proved to be of no use as it had no adapter for the Bosch injector, only fo screw in types. Considering how well the car had started in the past I decided that compression was probably not an issue so instead took the injectors into work for a cleaning session. Each one was dissasembled and put in individual containers and then into our ultrasonic tank for 20 minutes. I checked each injector nozzle under the microscope before cleaning and all had carbon build up and some spray holes blocked. After cleaning they were rinsed in acetone to stop flash rust. I checked the nozzle pattern and all were perfect so into some fresh diesel they went while I reassembled. Injector nozzles were re-torqued to 65nm.

Back in the garage I spent another couple of hours cleaning out the injector bores before refitting with new copper washers. I fully reassembled the car and started it up. Took a couple of tries but then started ok.

Unfortunately the smoke was back... So, decided to take @bugsymike advice and concentrate on the DPF. I let the engine warm for a bit and then started holding at 1500, 2000, and 3000rpm in the garage. Slowly the smoke began to thin out over a period of 8-10 minutes and the lumpy running dissapeared as well. I haven't moved the car for about 4-5 weeks so decided to risk backing it out and trying some more engine revving outside. The car behaved so I connected up MES to have a look. First thing I noticed was the injector corrections had gone from -1.5, -1.3, 1.4, 3.9 at idle to all -0.3 so the cleaning must have had an effect. I then looked at the DPF and clogging level was at 112%. The differential pressure was 70mbar at idle. I was pretty happy at this and resolved to take the car out for a short run the next day (today).

So, on to the test run, driving down our track to the road it was immediately obvious that the engine was running much smoother. Once on the road I decided to just barrel up and down a half mile each way just in case it played up. As I started to accelerate smartly through the gears the car began to throw out unbelievable volumes of smoke - couldn't see anything behind! I got to the first turnaround point and decided to just keep going and sure enough, giving it some beans it slowly started to clear. On the final two runs and trundling back up the track, not a bit of smoke anywhere.

Once back at base I plugged in MES which reported that a regen had just taken place and the clogging level was now 21% with the tickover differential pressure being 19mbar.

The car now pulls much harder with no hesitation anywhere in the rev range - lovely.

Thanks Mike, I don't think I would have got there without your pointers

Very pleased with your success and surprised with that percentage of 112% clogging that it allowed a Regen
Many people report that they can't even " force a Regen " with much lower % so a good result.
It may be worth using DPF cleaner additive on every other tank of fuel, also giving it that good run say once a month to allow it to Regen when it needs.
The other thing I may have mentioned is the problem of town use for modern diesels and checking if engine temp quickly reaches 90 degrees, centre of gauge as cold engines aggravate the issue.
Re the extractor tool, I had that issue with the first one I had to do some years ago and having to remove the top nut on injector dislodged a tiny ceramic ball valve, I know to watch for that these days, but it did cause a lot of work at the time.

 

[Eltezz]

Would you be able to recommend a brand? I have never used an additive and it seems a bit of a minefield...

I am also going to keep a close eye on dpf clogging in future as well.

 

[bugsymike]

Would you be able to recommend a brand? I have never used an additive and it seems a bit of a minefield...

I am also going to keep a close eye on dpf clogging in future as well.

Wynns or STP DPF cleaner fuel additive seems OK. Basically stick with a brand you recognise.
That and the other advice on vehicle use.

 

[DaveMcT]

I had 2 injectors stuck solid. The copper seal had been leaking, caused a carbon build up that jammed one solid and its partner pretty badly. I used a puller type extraction tool that screws to the injector top. And I’m glad I did because it needed serous force to get it out.

I stripped and cleaned all injectors and reassembled. The rebuilt engine ran fine afterwards. It did develop problems due to my rushing the valve lapping but that wasn’t an injector issue.