Pajero Owners Club of South Africa

Happy New Year fellas! This Shogun has done only 65k miles and came to us with the head off and timing chain snapped. Pistons and valves all unmarked. We have re-assembled everything with new gaskets and the engine starts well and runs fine and pulls well with clean emissions. However, after one hour of sitting ticking over, its puts 2 to 3 litres of diesel fuel into the sump. We checked for visible leaks on the injector and return system, and have renewed the front seal on the diesel pump. Still putting diesel into the sump. Anyone got any experience of this problem, or where to go with it next? Cheers.

Hello, May I ask how you checked the injectors? there are a number of tests that should be performed on them and all require an injector pop tetser.

Hi Wilddog,

Thanks for the reply. The injectors were just visually checked, running the engine with the cam cover removed, nothing more. We haven't done any 'pop' tests but might have access to a pop tester. The engine appears to run fine and shows clean correct emissions on an MOT test. Could you kindly expand on the various tests and I'll do them or get them done. But there was no visible sign of a diesel leak at the top end when running it with the cover off for just a few minutes...

I had the same problem.
I investigated all possibilities, including a leak in the return rail etc.

The volume of diesel finding its way into the sump, pointed to a rather serious leak somewhere.

It was eventually fixed when the pump shaft seal was replaced.
(it is a Vexel VP44 pump, so the seal should be available for a few R at any diesel specialist)
Don't delay, the consequences can be very expensive, because the sump oil is degraded.

Thanks for that 4ePajero. Yes, this was a big suspicion as you say so we took the pump to the local diesel pump specialists who replaced this seal. When we put it back on, it was still putting diesel into the sump at about the same rate. So, either this is not the problem, or, it is the problem and the new seal is leaking the same as the old one. And if it is, why? Strange one.... I understand this seal is on the 'low' pressure side of the pump so unless there is a build up of pressure behind it, I don't see why it should ever leak. Wierd...

if the actual shaft is damaged it will leak on every new seal.

Thanks Pikanini. Yes. Also if the bearings are excessively worn, this could damage a new seal too, but all 'looks' to be OK, shaft and bearing.

Hi Tuscan4.0s. I realize this post is very old but I am sitting with the exact same issue and have checked all that you have done. We have even replace the pump seal twice already.

Did you ever manage to sort this issue out? Was it the shaft or pump bearings or did you find the cause somewhere else in the engine?

My Paj currently adds about 1 to 2 litres of diesel into the sump for every 100kms driven.

Sump diesel dilution can basically come from 3 areas.
1. Injector pump front seal. (ruled out)
2. Injectors leaky or out of spec peeing diesel down the bores into the Sump.
3. Leak off rail under tappet cover leaking. Could be the crush washers not sealing proply, or the leak off rail has a crack in it leaking diesel into the Sump.
EDIT: or the injector union nut from the high pressure delivery pipe isn't sealing properly, but this would lead to performance issues and lumpy idling.

Have the Injectors pulled and checked for the two stage pop pressures and spray pattern asap. Also have new crush washers installed and the leak off fuel rail pressure tested for cracks. Any good diesel injector workshop should be able to do this for you in a day.

Don't mess around with oil dilution, it will bite you in the long run.

Nick

Sent from my SM-G920F using Tapatalk

Thanks for the quick response Nick.

My mechanic had the injectors out and tested them (what I can only suppose is like a pop test at think 18bar). They found a leak on the body of one injector and tightened it up to fix it, after which it did not leak anymore. He fitted new crush washers when he replaced the injectors as well. I suppose I would have to rather take them to a proper Diesel Repair shop in order to have them properly tested.

How much pressure is in the leak-off rail? We tested it in place by pumping air into it and squirting oil over all the fittings to check for leaks, but saw nothing leaking. We even idled the engine with the top cover off but this was not very helpful in trying to detect a leak .

I read on the UK forum that the pipes running from the diesel pump to the injectors can also be faulty (as you mentioned, where they connect to the injector). Apparently they were only designed to be removed up to 5 times before they start leaking .

Has anyone replaced these pipes before? Wonder what they would cost...