JCB 3CX excessive smoke and loss of power

[SimosSoldatos]

Hi everyone, i have a 1990 jcb 3cx with a perkins a4.236 turbo diesel engine.The issue i have is that it puts out a lot of white/greyish smoke(it might be burning oil because of the smell although it doesent seem to be blue).That happens when it's not under heavy load although it doesen't really go away under load. Under load it puts out black smoke and it sounds like it is struggling for air. At first i found out that the intake tube that goes from the air filter to the turbo was getting squished together blocking anough air from going into the turbo. I changed it for a new one that seems less flexible and that doesen't happen anymore but the smoke and loss of power is still there allthough it's a bit better. I then took the outer air filter out(it has 2 an inner and an outer one) and once i did that the power was back and the black smoke was gone completelly same with the white smoke almost, it pretty much smokes very little which i consider normal for an old engine. I have ordered new air filters too which should be here in a few days. I'm not sure this will fix the problem completelly but i would like to know your opinions. Could it be something else?Could this possibly happen because the engine needs a rebuild (new rings, bearings etc). Lastly i will upload a video soon so you can listen to the sound of the engine (seems ok to me) and also see the smoke if the new air filters don't solve the issue. Thanks for any help in advance!!!

[Jeremy Rowland]

Hi and welcome to the site all being well it sounds like you have cracked the problem, check your machine once the new filters are fitted, the first place to look is always the filters and luckily the cheapest repair, I doubt it would need rings and liners, if this was the case then it would be using lots of oil and be pressurising the crankcase.
While you are changing the air filters, you should also really change the fuel filters too.

Jeremy

[Slooby]

The white/grey smoke could be your turbo oil seal in the core on its way out, as that is a fairly typical symptom, especially if it clears a little bit after running for a while. Easy way to check is pop the inlet pipe off the front of the turbo, and the exhaust off the back, after it's been stood overnight and look for oil sitting in either scroll. If there is any then chances are the oil seal is shot and the turbo needs either a rebuild or new core (aka CHRA), excessive end float or any lateral moment of the shaft when there is oilin the bearings is also a bad thing pointing to the turbo needing attention (the core replacing)

[essexpete]

Do what Jeremy and Slooby suggest and if all OK treat to new oil and filter as well.

[SimosSoldatos]

Thank you guys a lot for your answers the new filters are in and it's much better, initially it puts out some white/grey smoke that goes away after a while like Slooby said (i have attached a picture of the turbo, it looks pretty oily on the cold side so i'm sure it needs attention) and i'm pretty sure at some point in the future i will have to service it or even replace it if needed but as of now i rarely use the machine and i don't really think it's worth the 500 euros or more it will take to fix it, if it's not going to cause any damage which i'm pretty sure it won't(correct me if i'm wrong). After the smoke from the turbo went way i started putting load on it and no black smoke was pressent, there was only an unnoticable amount of that white smoke. After using it for a while the white smoke started being a little more noticable under load but i think it's because of the turbo so maybe it's ok(here's a link to a video of it working ,the second half of the video is more important were you can see how much smoke there is: https://www.youtube.com/watch?v=LAOeaFjStc0 ). It's definitelly 100 times better and now the power is also back. In the video you can also listen to the engine, it sounds ok to me but another opinion would be great. Lastly i posted a picture of the fuel filter, i think it has been replaced recently but i'm not sure if the glass part on the bottom is supposed to be full. Do these filters separate water? Should i open the screw at the bottom and drain it or is that fuel? Again thank you guys for the responses and sorry for the lenghty posts!!! Looking forward to your answers!!!

[Slooby]

Oil on the outside of the turbo is no real telltale of a leaking oil seal, on an old working engine like a JCB an oily engine is pretty normal. You need to pop the intake elbow off the turbo and take a look inside, usually after it's had overnight to cool off and any leaks have had a chance to weap. If any oil is pudling in the turbo below the impellor wheel then the seals in the core are failing. You should repeat the inspection on the exhaust side of the turbo too.

Having looked at your video though I wonder if you have a fueling issue, perhaps a sticky injector, because of the way the smoke pulses with rpm. I would suggest dropping some fuel system cleaner additive into your fuel to see if that helps clear things up, if not and the turbo is looking OK, then it may be time to give the injectors some love and maybe even the pump...

The glass bowl beneath the fuel filter is a drop out so you can see if there's any water in there needing bleeding off. There's another drop out filter on the left hand chassis leg, beneath the fuel tank, that also has a glass bowl to check for water and allow bleed it off there as well.

[SimosSoldatos]

Thank you Slooby, for the fuel filter should i just take the screw out from the bottom and drain it untill clean fuel comes out? Most importantly i'm i going to have to bleed the fuel lines (is air going to go in while draining the water?) or i just start it normally?

If it doesen't help and it still puts out the same amount of smoke as in the video can i use the machine? Or is that going to cause damage to any components?

[essexpete]

It does not look too bad to me for a +30 year old machine.

[Slooby]

For either the fuel filter, or the drop out filter on the chassis leg, check the glass bowl for signs of water. It should be obvious if there's any water in there as it will be at the bottom of the bowl, and there should be a drain plug to one side of the central bolt that holds the filter assembly together, if there isn't you might be able to drain any water off by cracking the central bolt.

If you do drain anything out of the filters you will have to bleed the fuel system and prime it, that really is a job that requires the service manual which you can find in the downloads section on here. But it involves starting with tge bleed screw on the chassis leg drop out filter, then the mechanical lift pump, followed by the fuel filter on the engine, two bleeds screws on the injector pump and finally each injector in turn starting at the one nearest the injector pump and working along to the one furtherest away.

Unless the engine is really struggling to run or using a lot of oil (keep checking the oil level) then you're very unlikely to damage it

[MrF]

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...