Smoky Perkins

[aidan]

I have a bit of a problem with a smoky Perkins 4.236t in a wheel loader.

The engine was completely rebuilt, 3 years ago, new block as old one was porus, new pistons, liners, head, turbo overhaul, 1000hrs done since. Its not been a great rebuild, its smoky under low load high revs from new and now its got a constant wisp of smoke even at engine idle, white smoke rather than black or blue, and it appears to be getting worse.

Its got that much smoke a casual observer would say, something wrong with that engine or else its a lot of work done. however plenty power and no problem starting, and sounds good, idle speed is fine too. Smoke qty doesn't change ever after a few hrs working.

I dont think bores are glazed, it gets a workout everyday climbing a hill for 5 mins travelling on the road.

The smoke is also getting worse, I think. We dont seem to be using oil or water. The air filter and fuel filters are clean.

The injector pump and nozzles were reconditioned at the time of the rebuild. Its possible there was a mistake made as the engine rebuilder and installer were different people and injector pressure or timing got mixed up with a regular 4.236.......

Regular 4.236 seems to be 22-24degrees timing and 17.1MPA https://pruefberichte.dlg.org/filestorage/Massey-Ferguson_375_Nr1085_1987-englisch.pdf

and 4.236t seems to be 16degrees and 23.1MPA. https://pruefberichte.dlg.org/filestorage/Massey-Ferguson-390T-Nr1256-1990-englisch.pdf

Anyone with experience of such a situation....... @ACEngineering maybe you have seen similar in your involvement with perkins and jcbs and manitous...........

 

[Farmer_Joe]

My first instinct would be timing surely worth trying as a first attempt

 

[Stock]

How much oil between services?..........................................................................

 

[Farmer_Joe]

White is unburned derv or water, if your not using any water than it’s un burned derv, Google 3.0 vag engine white smoke that’s from faulty injectors the smoke is unreal!

 

[Dave W]

Has it got a thermostart heater plug? They can fail and constantly leak fuel into inlet manifold. Had similar on a machine with faulty ignition switch. Wasn't returning properly and leaving heater energised allowing fuel in.
Engine ran perfectly but smoked like hell

 

[aidan]

Has it got a thermostart heater plug? They can fail and constantly leak fuel into inlet manifold. Had similar on a machine with faulty ignition switch. Wasn't returning properly and leaving heater energised allowing fuel in.
Engine ran perfectly but smoked like hell

She doesn't

 

[ACEngineering]

She doesn't

Are you sure cause thats the first thing i would be looking at, they are common to dribble fuel in while running.
Will be in the inlet manifold just above the turbo i suspect if its like other perkys.

 

[aidan]

Are you sure cause thats the first thing i would be looking at, they are common to dribble fuel in while running.
Will be in the inlet manifold just above the turbo i suspect if its like other perkys.

it had years ago but wasnt working so we took away the fuel pipe, the heater plug is still there so no big hole in intake manifold

 

[glasshouse]

White is unburned derv or water, if your not using any water than it’s un burned derv, Google 3.0 vag engine white smoke that’s from faulty injectors the smoke is unreal!

Derv?
That would make the owner ill, not the engine.

 

[startinghandle]

White smoke is unburnt fuel ,if you let it idle for a few minutes then rev it is there a lot of smoke if so injectors could need attention
My old matbro ran better with a small amount of red universal 2 stroke oil added something like a
200-1 ratio to make up for reduced sulphur

 

[Farmer_Joe]

White smoke is unburnt fuel ,if you let it idle for a few minutes then rev it is there a lot of smoke if so injectors could need attention
My old matbro ran better with a small amount of red universal 2 stroke oil added something like a
200-1 ratio to make up for reduced sulphur

What he said if not thermo thingy as you stated has to be injectors,( assuming there is no other way for un burned derv to get into cylinders) there cheap for old Perkins engines so won’t break the bank

 

[Oliveau]

Injection pump timing, or injector

 

[TripleSix]

Compression test first please.

 

[Oliveau]

Compression test first please.

But OP says it starts fine, which perhaps it wouldn’t do with low compression.

 

[TripleSix]

But OP says it starts fine, which perhaps it wouldn’t do with low compression.

If it's only poorly on one or 2 pots it will start ok but will smoke

 

[TripleSix]

This started ok but was a bit lumpy with white smoke, then a blue haze when warmed up. had plenty of power

 

[Teddy99]

Was it blowing much from the crankcase and rocker cover ?

 

[Vincent]

Seen a Perkins that had 2 injector washers fitted to an injector and it smoked bad. Is it smoking since overhaul or did it start doing it after.

 

[Cowabunga]

I had an Ursus with the A4.236 non turbo engine. Under light load and particularly on the over-run it had white smoke from new. It pulled like a train and started instantly and sounded perfect. I put it down to either a faulty valve in the DPA injector pump or a leaky thermostart in the manifold. Never could be bothered to find out precisely why it was overfuelling, but that was certainly the problem. Never used a drop of oil and you could smell the diesel in the air when it idled on a still day. It wasn’t an obnoxious smell like the normal exhaust of a tier3 common-rail Perkins.

 

[Bobthebuilder]

Thought it was a thread about a blues singer