TD5 Injectors removed for inspection.

Evening all,
I have removed the injectors for inspection as part of my efforts
to cure my smoky TD5 110. They are partly covered in crispy black ****e, and although I didn't expect them to come out gleaming I'm not sure if what I've got is normal or terminal.
Anyone out there with experience of these?
Thanks,
Mike.

If the engine was running at its optimum you would usually expect to find an even coating of dry black carbon around the entirety of the nozzle, almost like a matt effect powder coated finish. In your case however it appears that the engine has been burning excess fuel or oil or suffering from low compression on all five cylinders. When you removed the injectors, was there any diesel present on the injector body above the copper washer? It is unlikely that all five injectors would be over fuelling or showing signs of seat leakage, so I would suspect the thick wet looking black deposits in your case to be oil which has uniformly found its way into each cylinder via the air intake. That said, the deposit build up around the holes in the nozzle tip would suggest that the seats may have been leaking slightly but you would usually only have one or perhaps two injectors doing this. Have you checked the air intake for oil and have you performed a compression or cylinder leakage test? It might be worth removing and cleaning your intercooler too. The only way that oil can find its way into the air intake is through the engine breather system, which vents into the air intake, usually after the air filter or via the turbo oil seals. I am not sure how the EGR system works on the TD5, so I can not comment as to whether or not any oil ways pass near or through it etc. but it may be worth investigating.

This is what a nozzle should look like with good cylinder conditions (no over fuelling, good compression, no oil consumption):



This is what the nozzle looked like on one of my cylinders which had not sealed correctly. The diesel was sprayed into the cylinder but compression on the compression stroke escaped past the copper sealing washer (even though it could not be heard) which meant that the diesel was only partially burned in that cylinder (hence the dampness). The partially burned diesel is thrown down the exhaust as white smoke (clag) and the engine ran rough.



-Tom

Thanks for the response Tom,
I have been chasing the cause of smoky-ness
for a few weeks now. Originally I thought turbo oil seals were the cause as the intercooler hoses were wet inside. Having changed the turbo and flushed out the intercooler and pipe work the smoke was reduced but not eliminated.
Hence the injector inspection. Pic of turbo attached.
Also had it plugged into test book at the local indie and no faults found, advice was to get injectors checked.
Cheers,
Mike.

Looking at the picture of your turbo, the compressor housing is scored is it not? This would suggest that the compressor wheel has had a lot of play which would naturally be caused by excess wear of the carbon bushes / main shaft through the turbo which would leak oil. Assuming that the replacement turbo is in good condition then this is irrelevant. If you have a set of replacement copper washers, you could try cleaning up the nozzles with a wire brush and then re-fitting them to see how things run. They are quite hard wearing things, so scrubbing away the crusty carbon deposits wont do any harm - just don't go silly on them. The build up will certainly be creating an external interruption to the spray pattern. As for having them tested, it depends on how your local diesel injection engineer is feeling. TD5 injectors are unit injectors which require a little more equipment to test properly than just your average pop tester unfortunately. A common rail or constant diesel feed (low pressure in this case) will be required as well as some form of equipment to actuate the injector plunger and build up the necessary internal pressure for the pop pressure to be overcome. Mind bogglingly brilliant stuff

-Tom

Hi Tom,
The compressor housing wasn't scored what you can see are the tracks of oil/air mixture which I guess cannot stick to the housing where the velocity is high. The local turbo guy said the old turbo bearings had worn (77,000 miles) and were out of spec. Have checked the new turbo since fitting and all looks ok. No crankcase pressurisation apparent. Electronics all seem to be in good order etc.
I've got some Mr muscle oven cleaner to gently clean off the injectors, seems to work well without abrasives. Got new copper washers and o rings to fit tomorrow. No conclusive evidence of leaking on them though.
Cheers,
Mike.

mikegsxr said:

Hi Tom,
The compressor housing wasn't scored what you can see are the tracks of oil/air mixture which I guess cannot stick to the housing where the velocity is high. The local turbo guy said the old turbo bearings had worn (77,000 miles) and were out of spec. Have checked the new turbo since fitting and all looks ok. No crankcase pressurisation apparent. Electronics all seem to be in good order etc.
I've got some Mr muscle oven cleaner to gently clean off the injectors, seems to work well without abrasives. Got new copper washers and o rings to fit tomorrow. No conclusive evidence of leaking on them though.
Cheers,
Mike.

Click to expand...

I can see where you are coming from now, although it did look a bit like a score mark at first glance though .

Have you considered the EGR valve? It is possible that it is sticking open, allowing an excess amount of exhaust fumes to be re-cycled back into the air intake, creating a horrible mix of fuel soaked carbon particles. As the engine runs, the cycle would only get worse as more amalgamated soot and unburned or partially burned fuel is recycled back through the EGR valve into the cylinder only to be met by another fuel injection cycle. You could try blanking the EGR system off and see if that makes any difference.

If the glitch is injector related, the problem appears to be uniform across all five cylinders. This might suggest that the engine is over fuelling which is much more likely than all five injectors failing simultaneously. From what I understand of the TD5 fuelling system, the low pressure pump in your fuel tank provides the constant stream of fuel to the fuel rail internal to the cylinder head, which is in turn stabilised by a regulator at either the entry point or the fuel return. The injectors are driven by the cam shaft which pushes down a plunger mechanism, creating high pressure within the injector its self. The wire to the injector is essentially a solenoid which permits the fuel flow through the injector to the nozzle, or something to that effect. I would imagine that the timing of the cam shaft and the point that the solenoid on each injector is actuated, is controlled by the ECU through a means of a signal from the cam shaft position sensor if the TD5 has such a thing. It could be that this is playing up? Another much more obvious thing to consider would be the air flow to the engine. If the air / fuel balance is out (MAF sensor issue, collapsed air hose or blocked air filter) each cylinder will be bogged down with too high a fuel to air ratio.

Other than that, I'm out of ideas really!
-Tom

You guys have far more engine knowledge than me but...

I also own a TD5 and had a bit of smoke pouring out. Aside fron the obvious MAF and MAS sensor clean and check. I fitted an EGR replacement kit.

This seemed to do the trick and i have no more smoking issues. My TD5 is a 99 model on 89'000 miles i think.(its been a long time since ive seen it, i cant remember! )

Anyway, the advice i was given was as soon as its out of warranty get the EGR valve disconnected and blanked off.

Kits are available everywhere.

Hope that helps.

Thanks Guys,
EGR was removed a few years ago. Its got a new L/R air filter, I have bench tested the MAF and no problems. Also had it Test Booked and no sensor faults were apparent on the test drive. The Fuel Pressure Regulator was leaking, this has now been changed but made no difference. Also renewed the fuel filter and pressure tested the lift pump and was getting 5 Bar. It smokes only at idle or when pulling away and seems clear when driving along, although the smoke may just be being dispersed in the turbulent air following Solihulls least aerodynamic creation
Its a fair point though that it is unlikely to be an injector fault on all five so I should be looking for something common. I had discounted a collapsing hose as boost pressure looks normal. Opened the ECU and no sign of oil contamination, I had replaced the injector loom a few years ago as a precaution. I'll see what i can do to eliminate a collapsing hose, between the airbox and turbo i'd guess?
Cheers,
Mike.

Well a huge thanks to you all,
Put the now mostly clean injectors back in.
Mr muscle did a good job on the injector sides and sealing faces but I left the tips as they were, didn't want to monkey about near the busness end. New washers and O rings and paid much attention cleaning the head before refitting. Primed the fuel system and turned the engine over by hand (couldn't get the fan off so had to jack up a wheel and in 5th quite an easy job to turn the engine over) to check for fuel leaking into a cylinder or head. All looked good started up and still smoky for 30 secs then clear. Took for a test thrash and all looking good. So conclusion is copper seals, pics attached.
Sound or look familiar to anyone?
Thanks again for all the advice,
Mike.