JCB 3CX excessive smoke and loss of power

[SimosSoldatos]

I used think "oh its a old engine, It'll be ok to just run it with a oily old turbo" on some vehicles, expecting it just to cause a bit of smoke now and again on affected engines, then one day my Land Rover 90 had its oily turbo go bad, and the engine ran away on the oil pumped into the intake when the turbo core bearings failed. I had to abandon it when the clutch wasn't strong enough to stall it out and watch from a safe distance while it ran at high rpm screaming and consumed all its sump oil as fuel. I coudl have tried to choke it with something up the intake or something but by that stage, I was expecting engine internals to come out when it was exploding so weighed up the cost of another engine vs waking up in hospital with pieces of conrod embedded in me or worse.

So now, I'm kind of wary about people blanket saying yes a turbos a bit oily but its not a big problem. While it sounds like your not at this stage yet, I'd be aware that this could happen in future...

Sounds like an awfull experience, i'll definitelly keep that in mind and i'll take a look at both sides of the turbo as suggested in previous posts to make sure no oil is sipping out of the seals.

[SimosSoldatos]

Alright, so after a while i found some time to check both sides of the turbo for oil. Looking inside wasn't relly possible but iused a plastic ziptie and i pushed it carefully through the turbine blades on both sides so see if it would pick up any oil. The ehxaust side seems fine but on the intake side there was a bit of oil on the ziptie so it's definitelly buirning some oil. Also i've noticed that after sitting for a while a drop of oil concentrates at the bottom or the cold side of the turbo on the outside propably passing through the seal.

I opened the oil fill cap while the engine was revved up to the rpm range i use it to work and no excessive amount of smoke or air preassure was coming out (when placing my hand on it i felt no preassure) so i'm thinking whatever smoke is coming out of the exhaust is most likely not because of worn piston rings but because of the turbo plus the oil level dosen't seem to drop quickly.

I have two options, one is buying a repair kit for 75 euros or so or buying an entire new chra (core) for around 140 euros. I think the best plan would be to remove the old core and inspect it to see if a repair kit is all that's needed. On the other hand just copletelly replacing it is the easier option which would make me feel a bit better as i haven't repaired a turbo before and i'm worried i won't do a good enough job.What do you think???

Lastly there seems to be an oil preassure or temperature sensor attached to the oil filter mount which slowly leaks engine oil(there's a picture below). I tried tightening it but it still leakes, plobably a broken o ring, i'm afraid i will overtighten it and strip the threads. Should i take it off completelly to inspect it or tighten it more???

Sorry if some of my questions seem a bit dumb but i don't really have experience with this stuff and i'm afraid of messing things up cause as a student it wouldn't be easy to justify spending money on repairs that could be avoided.

[Slooby]

I'd go with the replacement CHRA at that price, actually getting the core apart to rebuild it is a specialist job as the impellor and retaining bolts need rebalancing if you take them off the shaft, with a replacement CHRA all you keep are the housings from the old turbo.

[agrimax]

Hi Simos. The oil pressure sensor needs replacing really and they're not expensive.I'd also go with Slooby and replace the turbo core sooner rather than later as it's only going to get worse and if the seals do go completely and the engine runs away,you won't be able to stall it with a torque transmission. Looking at the fuel filter bowl,I'd say it's full of water and sludge which suggests the primary filter on the chassis will be even worse. If some of that water is finding its way to the cylinders,it can cause white smoke,but I'd say the turbo leakage is the main contributor.

[gecko.cx]

I have two options, one is buying a repair kit for 75 euros or so or buying an entire new chra (core) for around 140 euros.

Is that from some place reputable or straight out of china?
Given the tolerances and metallurgy required to make a reliable turbo, it's not something you want to go too cheap.

Lastly there seems to be an oil preassure or temperature sensor attached to the oil filter mount which slowly leaks engine oil(there's a picture below). I tried tightening it but it still leakes, plobably a broken o ring, i'm afraid i will overtighten it and strip the threads. Should i take it off completelly to inspect it or tighten it

Teflon tape is your friend.
Remove it, wrap a couple of layers of teflon tape as you would a plumbing fitting and reassemble.

[SimosSoldatos]

Thank you guys for the responses, the brand of the chra is JRONE and i've found it for sale from what seems to be a pretty reputable parts dealer in bulgaria. Here's the link, let me know what you think:( https://www.kolos-ms.net/en/item/465/tu ... 311879.htm )

I'm sure this is the right part since everything matches with the part numbers of my turbo.(here's the turbo i have: https://www.turbo-services.co.uk/produc ... schwitzer/ )

[FOWLER MAN]

All good advice here from Slooby and Agrimax Repairing the turbo core is definitely a specialist job.

Thoroughly clean the turbo and surrounding area before removing anything.
Be sure not to let anything drop into the turbo oil feed when fitting the new core.
I have seen the bearings run out in a new core almost immediately because the oil supply has been cut off by the smallest foreign body getting into the oil supply. Seal the open end of the oil feed till you are ready to connect it.

You should hold the stop out and turn the engine with the starter till you have oil at the turbo feed. Then run on tick over for a minuet or two to be sure the turbo is fully lubricated before revving the engine.
Good luck.
Fred

[FOWLER MAN]

Hi,
This may be of interest for future reference ?
Fault Diagnosis Chart from Perkins Engines.
This lists fourteen possible causes of blue / white exhaust.

[SimosSoldatos]

All good advice here from Slooby and Agrimax Repairing the turbo core is definitely a specialist job.

Thoroughly clean the turbo and surrounding area before removing anything.
Be sure not to let anything drop into the turbo oil feed when fitting the new core.
I have seen the bearings run out in a new core almost immediately because the oil supply has been cut off by the smallest foreign body getting into the oil supply. Seal the open end of the oil feed till you are ready to connect it.

You should hold the stop out and turn the engine with the starter till you have oil at the turbo feed. Then run on tick over for a minuet or two to be sure the turbo is fully lubricated before revving the engine.
Good luck.
Fred

Thank you for your answer, i've also seen that people pour some engine oil in the oil feed port at the top of the turbo before connecting the feed pipe, so i think i should do that too.

Also do you happen to know which one the stop out button is???Is it the one in the picture below???

[agrimax]

I'm nearly sure that is a test button for the dash warning lights. I think if you press it when the engine is going,it's just to show that the bulbs are working.
You would need to either remove a fuse or remove the wire from the fuel cut solenoid on the injector pump,to prevent the engine from starting whilst cranking,to prime the turbo with oil.