I have a Volvo FH12 Version 1 that’s got the diesel diluting the engine oil problem.
So far I have replaced the low pressure feed pump on front of the engine, checked the bearings
in the shaft, all okay.
Have removed the diesel injectors and have them checked by two different companies, these have come
back with a clean bill of health. I then have replaced the Injector sleeves.
All this and the diesel is still getting into the engine oil. Between 1000 - 1200 miles I get about a quarter more oil when
checked on the dipstick.
I am wondering if anyone has got any suggestions before I take the head off to check the fuel gallery.
All suggestions gratefully received.
Have not checked the fuel pressure, but I can leave it standing for a week and it starts first turn
of the key, pulls like a train, doesn’t smoke. Very pleased with it to be honest, its just this
problem with the diesel in oil. Not sure if it helps but don’t get any oil in the diesel.
The fact that it’s holding prime leans towards the problem being in the head. If the leak was in the fuel system itself you would lose fuel pressure and it wouldn’t start on the button, so it looks like the head. It could also be bad rings, but then you’d get smoke and the oil would come up past the rings too, so you would balance out at best even with a lot of fuel going down into the crankcase, at worst you’d burn lots of oil, so again, it all points towards the head.
Unfortunately it looks like you’ve got a big job in front of you, it could be something small and easy to fix, that doesn’t often happen with a lorry, but keep your fingers crossed, just in case
I’ve never stripped a Volvo ohc engine, but is it possible a fuel pipe in the head under the rocker cover is leaking and the diesel draining thru to the sump?
did you fit a new low pressure pump or just inspect it they have a small pin hole in the bottem to let oil or derv out if the seals are gone if this is blocked then you get fuel in the oil when an fh is ticking over there is about 1 to 1.5 bar pressre inthe fuel system and the oil is about 3 bar plus so usually its the other way round the only place the derv is near the oil is the pump and the head take the rocker box cover of kink the return pipe over at the tank then lightly pressureize the feed pipe at the tank with a blow line it is either a cracked head or injector selanoid leaking but pressure is the only way you will find it a dripping injector will just lay in the piston crown its gota be from the selanoid or injector body some were ps did you fit new o rings when you replaced injectors
keith the thief:
did you fit a new low pressure pump or just inspect it they have a small pin hole in the bottem to let oil or derv out if the seals are gone if this is blocked then you get fuel in the oil when an fh is ticking over there is about 1 to 1.5 bar pressre inthe fuel system and the oil is about 3 bar plus so usually its the other way round the only place the derv is near the oil is the pump and the head take the rocker box cover of kink the return pipe over at the tank then lightly pressureize the feed pipe at the tank with a blow line it is either a cracked head or injector selanoid leaking but pressure is the only way you will find it a dripping injector will just lay in the piston crown its gota be from the selanoid or injector body some were ps did you fit new o rings when you replaced injectors
Not impossible to be rings even if oil isn’t going the other way if you can rule out the head - but wouldn’t expect any effect much more than the oil ponging of diesel.
Hi thanks for your help, yes new o rings when fitting injectors, on removing injectors on the second time, noticed soot deposit getting past sleeve injector, so will replace that one. With regards to the low pressure pump on the front, removed and checked again found nothing wrong, as it was a brand new pump three weeks ago. Will check return pipe back to tank, if all ok only thing left I believe is a cracked fuel gallery in the head ££££££ is it worth the expense lol? Thinking of swapping it for an 09 480. Have an 02 version 2, not too impressed with that, what do you think lads??..
round these parts (the peak district) the 13 litre engine have not gone down well with no end of local hauliers (large and small fleets) due to poor fuel consumption, injector sleve problems,water leaks,head gasket problems to name a few!
i understand if you are trunking up and down the motorway you may not have some of these issues but on bulk tipper and tank work running at max weight most of the time up hill and down dale where the truck has to work for a living the 13 litre engine has given far more problems than the 12 litre ever did
i have been a volvo man for years but i am not as keen on the 13 litre engine, i understand that you cant run old trucks for ever and with that in mind a lot of the locals have started voting with their wallets and started buying other makes!
Moose:
round these parts (the peak district) the 13 litre engine have not gone down well with no end of local hauliers (large and small fleets) due to poor fuel consumption, injector sleve problems,water leaks,head gasket problems to name a few!
i understand if you are trunking up and down the motorway you may not have some of these issues but on bulk tipper and tank work running at max weight most of the time up hill and down dale where the truck has to work for a living the 13 litre engine has given far more problems than the 12 litre ever did
i have been a volvo man for years but dont rate the 13 litre engine, i understand that you cant run old trucks for ever and with that in mind a lot of the locals have started voting with their wallets and started buying other makes!
As a matter of interest what are the operators now buying ? .
scania/renault seem popular at the moment, and also merc have gone to another well known tank/tipper firm, both the scania and renault are doing better than the volvo on fuel which is strange as volvo provide the engines for renault, local operators report that the renault engine mapping is better, how can this be?
daf have never realy been a big seller in this area, a local firm that runs both daf and man report that the daf is by far the better truck, and as for man lets just say they will be all gone asap!
the engine’s in the dafs are v poor a local well respected fitter tells me and he should know as he seems to be rebulding the things most weeks!
of the operators that have run dafs they say the feul returns can be v good, the cabs are v good and they are nice to drive but they dont like to much hard work, by hard work i dont mean high motorway miles as most trucks should do that it’s the bit between the motorway and the loading/tipping point that seems to age/wear out some trucks faster than others when running at maximum weight
Having had experience of this on several makes, my money will be on an injector solenoid leaking. The best way to find this is to run it off a gallon can of fuel laced with uv dye. Run it long enough to to use the whole gallon, lift off the rocker cover & using the proper uv lamp & glasses will reveal the culprit. I have had good results doing this but it is important to run it off a gallon can for a short period then the dye doesn’t get into the lube oil & therefore make it look like everything is leaking!!
Having had the injectors tested doesn’t always mean that all is ok, they can’t test them in a real world environment.
sound advise from wagger i did say check the selanoids 2nd hand heads aint that dear but be careful who fits it you need special tools to alight the head and pull it forward on to the from timing plate iv meet fitters who say i dont do it like that but if it aint aligned properly in 18 months the cam and timing gears will wear badly what years yours in1996 the injectors changed from lucas to bosch or vice verca they also fitted differend injector sleeves with very slightly different dimentions the teat at the end is a different size the puller and refit tool has 2 different ends that pull thru the sleeve to spread it in to the head talking to some of my mates at volvo inc the fore man who is ■■■■ hot he says he has changed heads before for this reason the head is the only place the derv and oil are together except the pump and you have changed that but pressurize them injectors or use the dye as wagger says block the return and pump the hand primer this may be enouth
they are £15 each after discount once youv got the rocker shaft off do the lot dont be a scratcher you can pull and fit the lot in 1 hour once the injectors are out then you have eliminated the problem make sure the the refitting tool has the right size bit on the end or you wont spread the tip properly
After all that, it was a cracked cylinder head never mind the old girls back on the road now, looks like I’ll keep her forever. Didn’t think much of the overpriced euro 5’s
If you seen the amount of version 1 Volvo’s on round timber forestry work in Ireland you’d know you have the next best truck ever made next to a 143. Modern stuff has too much stuff on them,it’s all about who build’s the best wiring loom now not the truck.
