Please help. Random power loss

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Just to update
I did as above and undid a injector at a time and found the knock disapeared when I undid the rear piston injector feed.

New injector (good make) and put back together and it still knocks and i think misfires
Rev very slowly it's fine until about 2500 then knocks until I leave if for about 30 seconds and it disperses
Knocks straight away if I blip the accelerator.

Fuel is all clean and oil is fresh and good.

Thanks for the advice anyway
Regards
Adam

Video uploading
 
I'd get a compression test done, rules out a few things for little effort. I had simlair probs with a salvage 2.5nad I tried to get running right, turned out to be a slightly bent rod on number 4.
When I pulled the head I could see the piston was a tad lower than the rest.
Wonder if injector line is obstructed ?
Does sound like mine when the rod was bent.
 
Whats it like when loaded does the knock start at lower revs?
Sounds pretty bad to me I would drop the sump and have a look at the rear cylinder lower skirt by removing big end bolts with the piston at its low point then push it up to view lower bore.
If nothing seen there then it will need head pulling off to examine further.
 
Ok
I took the head off today and found all 4 inlet rods where bent by a bit
Plus halve the valves are stuck open.

Going to do timing chain at same time.

Thank for the advise guys I will keep you informed as I go.

Many thanks
Adam
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Hi Adam.

I guess you are well underway with your repairs now, but I thought I would share my experience with my 2.25 diesel. I had a knock which I ended up tracing to piston slap. At some point the rear piston / bore must have overheated which trapped the bottom ring and held the piston over to one side. This caused it to slap on the power stroke. The main symptom for me was that it didn't knock on overrun - e.g. when going down a hill under engine braking, but did the rest of the time.

I'm not smart enough to tell if this is what is happening in your case, but I overhauled the head, replaced all the cam followers, pushrods, injectors and pump before I found the cause. So I thought I'd mention it as you may have the head off and you can split the big ends pretty easily to take a look.

Photo below just to prove I'm not making it up :), the other 3 were fine...

Regards, Ric

 
Hi Adam.

I guess you are well underway with your repairs now, but I thought I would share my experience with my 2.25 diesel. I had a knock which I ended up tracing to piston slap. At some point the rear piston / bore must have overheated which trapped the bottom ring and held the piston over to one side. This caused it to slap on the power stroke. The main symptom for me was that it didn't knock on overrun - e.g. when going down a hill under engine braking, but did the rest of the time.

I'm not smart enough to tell if this is what is happening in your case, but I overhauled the head, replaced all the cam followers, pushrods, injectors and pump before I found the cause. So I thought I'd mention it as you may have the head off and you can split the big ends pretty easily to take a look.

Photo below just to prove I'm not making it up :), the other 3 were fine...

Regards, Ric

Hi there
Thanks for the advise
I haven't started yet as I'm waiting for parts to arrive.
Was there marks on the bore so that i can check without taking the bottom end off.
Also how hard was it to change over to a new piston and bearings ect
Thanks for the reply as I didn't think about piston slap.
 
Not that i remember, my guess being that the piston material is softer than the block. However i have a suspicion that the bore is slightly oval as i've had an intermittent miss since i fitted the new piston which i put down to poor compression.

Splitting the big end isn't a big job, just follow the manual. The only check you may be able to do with the piston still in place is to get a set of verniers and see if the bore is oval. I got an new piston and rings from turner engineering along with a set of big end shells and nuts, it wasn't crazy expensive and the little end is just held by a circlip so no major work required.

Hope this helps. Ric
 
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