Hi all, new to the community here and was hoping for some help/advice please.

I have a 2008 focus zetec mk2.5 1.8tdci and about a week ago I noticed I had a diesel leak.

After a quick look under bonnet I noticed that the leak off pipe on the 4th injector had popped off and was leaking diesel everywhere. I purchased a new set of leak off pipes from ford parts as well as 4 new clips and fitted the parts.

Everything seemed fine for the next few days until yesterday when I noticed a different one had popped off this time (injector 1)

The clips seem to be holding fine, so I was wondering if its possible that there could be a blockage in the system somewhere? such as in the main leak off pipe that carries the diesel back to the tank? I'm thinking that if there is a blockage somewhere then the pressure could be building up until one of the pipes pops off.

Anybody have any experience with this? I've been told via another source that this is quite a common problem on the 1.8tdci

Any help or advice would be very greatly appreciated.

Just to add, I've also ordered some of the BG244 diesel treatment to clean out the fuel system hoping that if there is a blockage somewhere that this would clear it, just waiting for the diesel treatment to arrive.

Thanks

Andy

Hi Andy,

Its been brought up on here before, admittedly im not sure if it was the 1.8tdci or what the outcome was.

hopefully someone will be able to help you

cheers

stef

Thanks for the reply stef.

I have had a quick search on the forum using terms such as leak off pipes and diesel leak etc but cant find anything related to this problem, so hopefullly somebody will have had experience with this problem in the past.

I'm starting to think that it'll be a blockage somewhere causing a build up of pressure, seems the most logical explanation so I'm hoping that by using the BG244 diesel treatment that I'm waiting for and by switching back to using shell V-power that it will correct the problem.

Fingers crossed.

Andy

Just a quick update.

The leak off pipes haven't popped off for 2 days now *fingers crossed*

BUT, on the last couple of mornings I've noticed a small patch of diesel on floor under engine bay, as well as a small trail when I set off for the 1st 30 yards or so.

I'm guessing this is one of two possibilities.

1. The possible blocked pipe may now have split, although the fuel consumption seems fine

2. It's just some excess diesel from the leak residing on the drip tray/floor of car under engine bay.

I'm going to get hold of some torx keys to remove the under tray and clean it.

I've also added a can of BG244 this morning along with a full tank of shell v-power so will see how things go.

Andy

On ‎16‎/‎08‎/‎2011 at 3:37 PM, arobinson1984 said:

Just a quick update.

The leak off pipes haven't popped off for 2 days now *fingers crossed*

BUT, on the last couple of mornings I've noticed a small patch of diesel on floor under engine bay, as well as a small trail when I set off for the 1st 30 yards or so.

I'm guessing this is one of two possibilities.

1. The possible blocked pipe may now have split, although the fuel consumption seems fine

2. It's just some excess diesel from the leak residing on the drip tray/floor of car under engine bay.

I'm going to get hold of some torx keys to remove the under tray and clean it.

I've also added a can of BG244 this morning along with a full tank of shell v-power so will see how things go.

Andy

Andy, I m have the same problem, return pipe keeps coming off, all clips and pipes replaced, into a diesel specialist and nothing found but pipe keeps coming off, did you get  fix for your issue?

11 hours ago, martina said:

I m have the same problem, return pipe keeps coming off, all clips and pipes replaced, into a diesel specialist and nothing found but pipe keeps coming off,

Andy last visited in Feb 2012, he may not be around to answer. It would be good to get that feedback, though!

It almost has to be either a blockage in the return to the tank as Andy surmised, or a blocked vent from the tank. The return system will push back fuel under quite a bit of pressure if obstructed. The tank vent valve is, I believe, on top of the tank and rather hard to get to. Probably needs tank removal.

A whooshing noise when removing the filler cap might be a clue. Try removing the cap after a decent run with the tank nearly full.

Connect 2013,

had all return pipe o rings replaced at least twice, still keeps leaking. Has anyone had the same problem and has a solution

Hi all, just to chip in on this as I’m having similar issues with a 2.2 transit.

After I did a leak off test I reconnected the return lines & ran it. This caused all 4 black plastic inserts to be blown out throwing diesel everywhere. 
 

I’m led to believe that there should only be minimal fuel being returned to the tank? If this is the case then surely they shouldn’t have thrown out around a litre of fuel? My leak off measures varied, between 75ml & 85 ml. 
 

Therefore if the leak off test shows excessive fuel & the return lines keep blowing out I can only assume that the fuel pump is providing way too much pressure, the return pipes are of narrower diameter than the feed causing excess pressure and blowing them out?

Does anyone else think this could be the cause?

Initial reason for leak of test was due to misfire on cyl 4 and excessive smoke from the exhaust.

The return pipes weren’t leaking or blowing off before I carried out a leak off test & I’m quite certain the green seals are ok and seated correctly.

Any thoughts or comments appreciated 👍

cheers Jon

On 1/24/2021 at 11:02 PM, Jonathan Sutton said:

the fuel pump is providing way too much pressure,

The high pressure output from the fuel pump is probably 200 or more times greater than any plastic tube can take. If it went too high, it would trigger DTCs, then it would damage something major, probably the pump.

But there is another output from the pump, it has a return connection. It always draws in enough fuel to cope with maximum demand, even with the accelerator fully released. The excess is returned to the tank before the wanted fuel is raised to the very high pressure (up to 1500bar). This connection joins up with the injector "leak off" pipes, so any restriction in the return pipework to the tank has to carry this pump flow, which is much greater than the little leak-off flow.

It seems more likely that there is a blockage in the return pipework than excess flow. Problems with the pump or injectors big enough to cause that sort of flow would raise DTCs and give major starting or running problems.

If your test was 3 minutes, mainly at idle, then 75-85 ml does sound a bit big, but it is hard to find authoritative data.

As a side note, Leak-off is a bad term for this test, a certain flow is essential for the operation of the injectors, they use fuel pressure to open the main valve inside them, the solenoid or piezo part of the injector only opens a tiny pilot valve. So too low a leak-off would be as wrong as too high, not a hallmark of a really good injector!.

Hi all. I am a bit late for the party. I own a Ford Focus 2007 Diesel 2.0 TDCi 136 hp with diesel particle filter. I will be putting a video on youtube in a few days from now with my findings. On the Ford that I have, it has a fuel return pipe that takes excess fuel from the the pump and the injectors back to the tank. The pipe on my car has a junction that has what I believe to be an electrically operated inline valve. This valve stops the fuel from leaking out of the injector or air leaking in when the car is switched off. I had the problem that when the car accelerated just slightly the engine would sound pingy and metally. Today I changed this pipe and the engine sounds totally different. I believe that this valve was not opening and that there was excess pressure on the injectors. In fact some injectors were leaking fuel from the body seals. After I had removed the pipe I tried a redneck test on it using a 12 volt source and a pressure pump and it did not seem to operate. The symptoms I have had are the following:

1 : Ping noise when accelerating.

2: Some black smoke when accelerating.

3: Blocking of the DPF

4: Bad fuel economy.

5: Bad starting.

I am still testing the fix, but I hope that it is good news as this has been a 2 year journey for me. 

Hi all. I am a bit late for the party. I own a Ford Focus 2007 Diesel 2.0 TDCi 136 hp with diesel particle filter. I will be putting a video on youtube in a few days from now with my findings. On the Ford that I have, it has a fuel return pipe that takes excess fuel from the the pump and the injectors back to the tank. The pipe on my car has a junction that has what I believe to be a device for measuring the fuel temperature. At this point there the small pipe is not letting and pressure through. I had the problem that when the car accelerated just slightly the engine would sound pingy and metally. Today I changed this pipe and the engine sounds totally different. I believe that this valve was not opening and that there was excess pressure on the injectors. In fact some injectors were leaking fuel from the body seals. After I had removed the pipe I tried a pressure pump on the small connector and it held the pressure which it should not do. This could mean that it is blocked or there is a one way valve inside. Needs further investigation The symptoms I have had are the following:

1 : Ping noise when accelerating.

2: Some black smoke when accelerating.

3: Blocking of the DPF

4: Bad fuel economy.

5: Bad starting.

I am still testing the fix, but I hope that it is good news as this has been a 2 year journey for me. 

OK; just a quick update. The junction in the fuel return pipe consists of a one way valve and a Temperature sensor. I have fitted a new one, but put the old one in the sonic bath and now it opens at half a Bar. 

On 8/14/2011 at 5:10 PM, arobinson1984 said:

Hi all, new to the community here and was hoping for some help/advice please.

I have a 2008 focus zetec mk2.5 1.8tdci and about a week ago I noticed I had a diesel leak.

After a quick look under bonnet I noticed that the leak off pipe on the 4th injector had popped off and was leaking diesel everywhere. I purchased a new set of leak off pipes from ford parts as well as 4 new clips and fitted the parts.

Everything seemed fine for the next few days until yesterday when I noticed a different one had popped off this time (injector 1)

The clips seem to be holding fine, so I was wondering if its possible that there could be a blockage in the system somewhere? such as in the main leak off pipe that carries the diesel back to the tank? I'm thinking that if there is a blockage somewhere then the pressure could be building up until one of the pipes pops off.

Anybody have any experience with this? I've been told via another source that this is quite a common problem on the 1.8tdci

Any help or advice would be very greatly appreciated.

Just to add, I've also ordered some of the BG244 diesel treatment to clean out the fuel system hoping that if there is a blockage somewhere that this would clear it, just waiting for the diesel treatment to arrive.

Thanks

Andy

Hello.I have a seat Leon 1.6 tdi 2011.I have the same problem,my return leak pippe is popping. For the first time, the 4th part was replaced, now the car started losing power. All the mechanics say different things and they can't find the cause. Have you figured it out? what was the reason for pushing this part out and flooding it with fuel inside?thank you Aneta

On 11/6/2024 at 7:30 AM, Aneta said:

what was the reason for pushing this part out and flooding it with fuel inside?

It is unlikely to be a faulty pipe or connector to the injector. Much more likely is a blockage in the return system, as in the post 3 up from here.

As this thread started with the 1.8TDCI, I would add a bit more info here. The round metal thing in the return pipe just before the pipe goes over the top of the cambelt housing, is not a non-return valve as it is often said, it is a fine gauze filter. This is presumably to stop dirt being drawn back into the pump during certain types of fuel line bleeding operation, particular where a vacuum is used on the inlet side of the pump to remove all air. Dirt in the HP pump often leads to very expensive repair bills!

A blocked filter, or any other blockage, in the return line would force any plastic tube off. The return system has to carry quite a lot of fuel back to the tank.

 

Is it possible to clean this? And also is there a name or part number. I take it your on about the silver UFO shaped thing 😆 

On 11/13/2024 at 11:04 AM, Tdci-Peter said:

 

 

I have searched for this part and can't find it! Used Google image search.  Typed every possible related word into Google.... Nothing. And am not trying UFO fuel filter lmao! Had quick bash on 7zap but the part number shown in 7zap don't bring anything up. But I think there generic numbers like all the bolts are same number. 

 

Unidentified Fuelling Object?

The number on the image is just the catalogue number.  If you click on it, it should show you the Finis part number on the right hand side.  But it will be asterisked out since 7zap became chargeable.   You can click on that to get the full Finis number.

(Or just use Ford - Catcar.info insitead)

Similar being discussed here:
https://www.fordownersclub.com/forums/topic/62431-diesel-fuel-return-pipes-disconnecting/

 

2 hours ago, TomsFocus said:

Unidentified Fuelling Object?

The number on the image is just the catalogue number.  If you click on it, it should show you the Finis part number on the right hand side.  But it will be asterisked out since 7zap became chargeable.   You can click on that to get the full Finis number.

(Or just use Ford - Catcar.info insitead)

Cheers Tom, your one of the good ones. Always help me out.

Anyway for a bit of a conclusion for anyone coming across this at at later date. I unclipped the one side that you can unclip before the UFO mysterious part and had a go at blowing down it. You can hear the fuel gauge out the pump when you disconnect it. But blowing down it towards the UFO was virtually impossible so was thinking blocked. Couldn't suck on it either. So coupled a pipe onto the other bit where I detached it from (glugging fuel sound) and figured out other end into a bottle see if it runs and how much fuel it would fill in the bottle on the other end... Should of known it would just stall after 10 seconds or so as it wouldn't be primed so I attached my one way priming bulb tried sucking fuel from leak off just while trying to turn the engine over few times and the one way prime bulb that I kept pumping would keep up the negative pressure (suck pressure) from the injectors and leak off pipe. This probably didn't do anything but just incase it did I thought I'd mention it. I decided to give the UFO another blow before putting it back together. I don't know how easy or hard it's meant to be but I blew as hard as I could till I turned purple and nearly passed out but finally heard bubbling from the main fuel tank. So maybe could of unblocked it.. so puts all back together and primed it up and gave it another go. To start with I thought I'd done it cos idle running never blew off a leak off nozzle. Unlike before. So I gave it a few revs and checked again. It had popped off.. but this time didn't seem like it was leaking as much fuel. So am thinking maybe clips are weak or maybe aftermarket leak off pipe (£23 from Amazon) could be just poor quality. So I wrapped a tie wrap round the injector and round the nozzle on the leak off pipe and gave it another go. Expecting pressure to build up and blow that or another off. But it didn't. Left it running a while gave it sets of upto 4k revs and various few second holds at different rev counts. Checked the leak offs and no popping off or leaks. So cleared up my tools and went round the block.. to my suprise no leaks.. but also lost power. But I think that's cos I pulled an injector to get out a broken bit of nozzle from the old leak off pipe. The injector was filthy black gritty carbon gunk. I cleaned it and the port hole best I could but am guessing that's the power loss. Iv not cleaned it good enough. So that's another job! Besides I'd like to pull them all 1 by 1 clean port, replace copper washer and use one them injector cleaning kits with aerosol to check and clean injectors.

Sorry for rambling on but I believe more details is better than not enough.

Anyway ordered new clips for leak off pipes cos they were old ones. Also ordered o rings even though they came on the leak off pipe but just incase they not as good quality.

Conclusion : more than likely need to clean or replace the mysterious UFO part. Maybe I unblocked something with the negative pressure (not likely) . Aftermarket Leak off pipe is poor quality which in fairness it was bit crappy cos the stiffness of the pipe was pulling it away from last injector (right side furthest away from UFO ) couple of centimetres more pipe before the 90 degree bend would of solved this. Or even the nozzles on the aftermarket could be slightly smaller causing clip not to hold as strong. Or more than likely a mixture of it all cos if the UFO is slightly blocked or completely blocked the other factors ain't going to help.

So tie wraps are temporarily doing the job but ideally it needs sorting. So am still on the UFO hunt lol still replacing clips and o rings and on top of that gonna have to clean them or least that injector. Especially if I want to take over a tractor! 

Hope this helps someone cos I was cursing and stressing for the whole bank holiday weekend and it's one them frustrating nightmare jobs.

ALSO A TIP

When moving the clips get an old cloth and use a screw driver to poke a bit under and around the injector and place the rest of the cloth over the rest of the engine where the clip may fall. And to help use some magnets (wife's fridge magnets lol) to keep it in place and a magnet underneath close to where it would fall. Cos loosing them clips is nightmare to find!

I'll update as and when.

Thanks in advance 

3 hours ago, TomsFocus said:

Unidentified Fuelling Object?

The number on the image is just the catalogue number.  If you click on it, it should show you the Finis part number on the right hand side.  But it will be asterisked out since 7zap became chargeable.   You can click on that to get the full Finis number.

(Or just use Ford - Catcar.info insitead)

Can't seem to locate it on there either but... Love the new link thank you 

Did a forscan! No DTCs just some bad earth connection on self test to do with battery and alternator (will get round to finding but not really caused any problems that I've noticed) 

So ran some live test cos can't seem to register forscan without an invite or something. Didn't exactly know what to select but I figured these may give an idea.

Or at least I hope it does. If numbers are right (flywheel) to left (belts) number 2 is injector I pulled and should of cleaned better..(will do when some more carb cleaner comes) and injector 1 has fuel leak where you can see it bubbling up from injector port. This has become more noticeable since I held on the leak off pipes with tie wraps. 

Is this the cause of my excess fuel from the injectors or could I still have a blockage?

I don't follow the rest of the thread but from immediately above, Cylinder 4 balance, if it means what I think it does, would be the concern but  perhaps unrelated to anything else?
In fact, is No.2 performing the best?

Cyl 4 is welling up with fuel. Like copper washer needs replacing and 2 is the one I need to remove and clean properly. But is it fuel pressure that's caused copper washers to leak? If so. Then surely problem lies with pump/pressure reg or pressure sensor. As don't seem to have blockage after leak off.

Engine compression and loosening clamps cause the copper washers to leak.  The seats get damaged if they've been leaking for a while, so you'll need to recut the seat perfectly flat before fitting a new copper washer.  Copper washers can't be reused because they go hard over time.  (Technically they can be annealed, but for the sake of a few pence, just buy new lol).

14 hours ago, TomsFocus said:

Engine compression and loosening clamps cause the copper washers to leak.  The seats get damaged if they've been leaking for a while, so you'll need to recut the seat perfectly flat before fitting a new copper washer.  Copper washers can't be reused because they go hard over time.  (Technically they can be annealed, but for the sake of a few pence, just buy new lol).

Thanks. So you reckon if I clean em both injector and port re seat them with new copper washers it will hold? That's my next course of action anyway. Besides new o rings and clips on the new aftermarket leak off pipe. Gonna spray some carb cleaner through the UFO shaped fuel return filter. Which btw found the part number. Or think it is but still only couple results on internet and 1 don't have a picture .So it could be wrong.