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Diesel leak under pressure

Posted: 07 Apr 2024, 19:16
by therealchrisgray
1.9 diesel, non-turbo, of unknown origin, fitted decades ago, van was originally petrol.

No pool of liquid under the van when I got in it, but I started it up and was distracted by the sound of flowing liquid from the back. It turned out there was diesel dripping rapidly (possibly flowing, not gushing, yet) from the back of the engine.

I'm assuming there's a leak somewhere between the pressure pump (or in it) and the injectors. It's been an hour since I turned the engine off and no leakage since then, so I'm pretty confident it's the pressure system. Pump is on the crankcase, right?

I'm parked up on a beach in Tenerife, and the van is fully loaded with camping and other stuff, plus I have limited tools and no way to get parts delivered either. So I'm not going to do much more than half-empty it and take a quick look. I guess I have to go find a mechanic tomorrow.

Maps shows several mechanicos at one location within a 15-minute drive of here, so hopefully I'll find one that can deal with it in the next few days.

Any other suggestions or speculations?

I'm supposed to be getting on a ferry back to the mainland on Thursday morning. Not sure if that's going to happen, but the next one is Sunday and I'll be against the clock to make later commitments if I have to wait even that long. Plan C will be to just stay here indefinitely, I do like the weather!

And now I shall walk a mile down the beach to the Indian I had my sights on when this happened! Sun is setting, not a good time to be getting into the engine bay.

(Van has been under hot sunlight for over a week, but surely engine parts aren't going to be that sensitive to heat?)

Thanks for any suggestions, advice, or commiserations!

Re: Diesel leak under pressure

Posted: 07 Apr 2024, 19:48
by lefty67
Hopefully it will be something simple like the injector leak off pipes or the rubber blanking cap on 1st injector. I had a split blanking cap in Applecross, Scotland, diesel pee'd out of it when the engine was turning over.

Re: Diesel leak under pressure

Posted: 07 Apr 2024, 20:22
by davidoft1
I would say probably a leak off
Pipe, generally easy to trim and
Refit , pretty sure they won’t let you on the ferry with a fuel leak

Re: Diesel leak under pressure

Posted: 08 Apr 2024, 08:10
by therealchrisgray
Thanks guys, it's the injector.

Image

Is this something a knucklehead can fix in a dirt car park? I have spanners, sockets, screwdrivers, and a lovely hammer, but have never worked on a diesel before. I've done carb strip-down and clean in the past (20 years ago) but I suspect I'm better taking this to a pro.

On the plus side, I needed a day or two out of the sun anyway, and the Indian was delicious.

Re: Diesel leak under pressure

Posted: 08 Apr 2024, 09:15
by Oldiebut goodie
It's not the injector - it is the leak-off pipe as suggested above. It is leaking from the end cap - to fix, get another piece of hose same internal diameter and blank the open end with a bolt/plug of some sort and job's done.

Re: Diesel leak under pressure

Posted: 08 Apr 2024, 10:46
by therealchrisgray
Thanks for the advice. I guess today is the day I get to start learning about diesel engines, lesson one being leak off pipes.

Can someone sanity-check what I think I understand?

Fuel comes in to the injectors under pressure and any excess goes into the leak off system. Each injector has two outlets for this, used to link all four injectors in series. So the middle injectors use both ports, allowing excess fuel to flow along the engine. At the other end of the engine from my leak, the spare port is a take-off back to the pump.

And my leak is from a bit of hose that is just there to plug the last, unused outlet port? And this plug forces the excess fuel to flow to the other end of the engine where it's taken back to the pump?

So all I have to do is replace that hose and plug it?

The leak appears to be at the end of the pipe, around the plug. Is it possible the end has perished and I can just trim it back and replace the plug?



PS please tell me this online article is nonsense:
The Diesel Leak Off Pipe is a fuel system hose that is equipped on vehicles with carburetors. Its main function is to return extra fuel from the carburetor to the fuel pump, it also has other important purposes.

Re: Diesel leak under pressure

Posted: 08 Apr 2024, 10:52
by therealchrisgray
While I have your expert attention...

My van has always started first time, even after standing unused for 6 months or more, but recently it took several tries after standing for just 3 weeks.

One of the articles I read said that a hole in the leak off pipe can allow air in and cause the fuel system to lose pressure over time if left to its own devices.

Does this sound like the explanation for that issue?

Re: Diesel leak under pressure

Posted: 08 Apr 2024, 11:34
by davidoft1
therealchrisgray wrote: 08 Apr 2024, 10:52 While I have your expert attention...

My van has always started first time, even after standing unused for 6 months or more, but recently it took several tries after standing for just 3 weeks.

One of the articles I read said that a hole in the leak off pipe can allow air in and cause the fuel system to lose pressure over time if left to its own devices.

Does this sound like the explanation for that issue?

could well be a leak off issue, you can just cut the end off the leaking pipe and put a screw etc in the end 

Re: Diesel leak under pressure

Posted: 08 Apr 2024, 11:43
by lefty67

Re: Diesel leak under pressure

Posted: 08 Apr 2024, 11:44
by lefty67
lefty67 wrote: 08 Apr 2024, 11:43 It should have one of these on it

https://brickwerks.co.uk/product/blank- ... s-genuine/

They do perish and split over time. As OBG suggests a temporary fix is to get a peice of pipe and plug it with a bolt.

Re: Diesel leak under pressure

Posted: 08 Apr 2024, 16:38
by therealchrisgray
😆 Left it at a garage while I went and got breakfast and waited for you good chaps to educate me. They said it would cost 2-300 euro just for parts!

So I drove it half an hour to the local equivalent of BnQ and spent a tenner on tube and screws, which seems to have done the trick for now. Plus I have lots of tube and screws leftover! Next time someone tells me to just use a bit of tube, as if everyone in the world normally carries one in their van, I'll be ready.

Thanks for the pointers, good people of the world.

Re: Diesel leak under pressure

Posted: 08 Apr 2024, 17:00
by Oldiebut goodie
For a £5 part! That is really taking the P.
I would replace all the leak off pipes and cap as soon as you can get proper pipe and cap from Brickwerks. The rest of the pipes may well be on the way out if they are of the same age.

Re: Diesel leak under pressure

Posted: 09 Apr 2024, 07:36
by therealchrisgray
Yeah, they look pretty ratty and are obviously of differing origins. Will replace the lot with the proper thing.

Re: Diesel leak under pressure

Posted: 09 Apr 2024, 09:12
by clift_d
Make sure you buy hose that is 100% Ethanol compatible, like the stuff that Brickwerks sell, or something like Gates Barricade. If you buy generic SAE 30R9 or SAE 30R14 specification hose, that only ensures that it's rated for 5% (E5) ethanol content - the good manufacturers make their fuel hose so that it exceeds the requirements of R9 or R14.

Re: Diesel leak under pressure

Posted: 09 Apr 2024, 09:49
by Oldiebut goodie
I wouldn't worry about ethanol - it is bio diesel to be concerned about with a diesel.