Technical Crank pressure blow by normal on ducato 2.5 97mod motor

[Felix007]

Hi,I am new here and from Norway.
I bought a Ducato camper van with the 2.5 l diesel engine 1997model motor
The motor has new piston rings,injectors,valves bearings water pump timing belt and some other(overhauled after timing belt failure) things in 2020.not much used after.
the motor starts VERY easily and performs perfectly.It does not use oil.And the oil looks fine.But i noticed when i hit the gas pedal the exhaust is black under acceleration.So I open the oil cap to se if there was any pressure there.There is more than normal pressure i would say.the pressure will move the oil cap away if I lay it on top of the cap hole.
Is this normal on theese motors??
The motor seems to be in good condition in every other way.

 

[bugsymike]

There may be a certain amount of "blow by" on diesel engines when compared with petrol. However if you are not using oil that is good.
You say not used much since rebuild so maybe not "run in" yet.
I assume when engine rebuilt and new piston rings that the bores were "honed" and the new piston rings were correctly gapped and fitted with gaps away from each other. The "honing" greatly helps the new rings to bed in and make a good seal, I do it every time.
Sounds like you were lucky , I have found on those Sofim engines if the cambelt breaks and valves meet the pistons, it often bends a con rod by a few mm.
If the smoke is black as in excess fuel and not "blue" like burning oil, this usually means either not enough oxygen as in if a turbo engine an air leak on the pressure side, pipes , intercooler, turbo weak, etc. Or if too much fuel then worn injectors or maybe the injector pump is giving too much fuel due to wear or need of adjustment.

 

[Communicator]

A long time ago, I forgot to replace the oil filler cap on a Saab 99 (petrol). Lost the cap, and secured temporary plastic over open hole to keep muck out. Plastic soon burst, and had to make a temporary thick plywood cover for use until replacement purchaased. Found cap much later lodged on cross member under engine.

 

[Felix007]

Here is video of the motor

 

[bugsymike]

Here is video of the motor

Apart from the amusement factor of the waving hand, I am afraid that proves nothing, try it on most diesel engines.
A video of your exhaust smoke when revving engine hard for a few seconds may be more constructive.
Apologies if I seem rude, but I prefer it to BS as I am old school.

 

[Felix007]

There may be a certain amount of "blow by" on diesel engines when compared with petrol. However if you are not using oil that is good.
You say not used much since rebuild so maybe not "run in" yet.
I assume when engine rebuilt and new piston rings that the bores were "honed" and the new piston rings were correctly gapped and fitted with gaps away from each other. The "honing" greatly helps the new rings to bed in and make a good seal, I do it every time.
Sounds like you were lucky , I have found on those Sofim engines if the cambelt breaks and valves meet the pistons, it often bends a con rod by a few mm.
If the smoke is black as in excess fuel and not "blue" like burning oil, this usually means either not enough oxygen as in if a turbo engine an air leak on the pressure side, pipes , intercooler, turbo weak, etc. Or if too much fuel then worn injectors or maybe the injector pump is giving too much fuel due to wear or need of adjustment.

Thanks for answering.
I didnt do the overhaul,so I am not sure if cylinder was honed and if it was.was it done correct?.But the motor start easy and fast.never had any motor that start as fast as this one.its instant when you turn the key,so I guess compression must be good for that to happen.I posted av video.as you can see on the video there is no build up pressure and no exhaust gas from the oil cap

 

[Felix007]

Sorry,didnt see your post before typing

 

[bugsymike]

Thanks for answering.
I didnt do the overhaul,so I am not sure if cylinder was honed and if it was.was it done correct?.But the motor start easy and fast.never had any motor that start as fast as this one.its instant when you turn the key,so I guess compression must be good for that to happen.I posted av video.as you can see on the video there is no build up pressure and no exhaust gas from the oil cap

It sounds sweet enough, I have had several of these engines in Iveco Daily and Ducato and quite like them compared with the later versions.

 

[Felix007]

I will take a video of exhaust on high rpm tomorrow

 

[bugsymike]

I will take a video of exhaust on high rpm tomorrow

Just give it a full throttle blast for a few seconds when fully warmed up, whilst exhaust tailpipe is videoed.
I put a 2.8 version from a 1997 Ducato in a Coronet by Botved of Denmark cabin cruiser in place of a 150 Hp Volvo Penta petrol engine and by the time I had finished adjusting the turbo boost and the Bosch injector pump had almost the same top speed as the original 3.75 litre petrol engine but with less than half the fuel consumption.