Bue smoke after Injectors replacements / Turbo

[wpoynter]

Hello all,

I have a Yanmar 4HJ3-TE that was smoking bluish/gray with the smell of diesel fuel and putting out a small sheen of fuel into the water. I am pretty confident its not oil burning. Engine has 2,200 hours. We did a compression test and it was a little low on all cylinders, by maybe 10%.

A suggestion from a dock neighbor was that its possible that my new turbo isn't spinning and thus not burning all the fuel.

Question is, could a turbo that isn't spinning cause fuel to not burn and produce smoke? The engine doesn't sound normal, but runs and start fine. I am leaning that the turbo isn't spinning because of the lack of noise from it.

Thanks for any advice.

Wayne

[Cheechako]

If not the turbo, I'd talk with a Yanmar repair shop and ask if an injector is faulty. Sure seems like one is streaming not spraying.... Is it possible one cylinder isn't even firing well? I know my Perkins had one cylinder not firing from an escaped pushrod off a rocker arm, but it seemed to run smooth and start readily. It was pushing oil into the water also... and some into the crankcase!

While it runs, crack off each injector nut, one at a time. If cracking one doesn't change engine rpm or sound that's your problem injector/cylinder. You could put an old injector back on that cylinder and see if it's solved. If it is, that's a bad new injector.

I have no idea if a turbo would do that or not. But not sure it would at low rpm...?

[Lepke]

Remove air tubing as necessary and expose turbo vanes. Try to spin by hand. Turbo should spin freely. If it does spin, do Cheechako's test of the injectors.


Without the turbo, the engine runs rich, so expect some unburnt fuel in the exhaust.

[skipperpete]

Originally Posted by wpoynter

Hello all,

I have a Yanmar 4HJ3-TE that was smoking bluish/gray with the smell of diesel fuel and putting out a small sheen of fuel into the water. I am pretty confident its not oil burning. Engine has 2,200 hours. We did a compression test and it was a little low on all cylinders, by maybe 10%.

A suggestion from a dock neighbor was that its possible that my new turbo isn't spinning and thus not burning all the fuel.

Question is, could a turbo that isn't spinning cause fuel to not burn and produce smoke? The engine doesn't sound normal, but runs and start fine. I am leaning that the turbo isn't spinning because of the lack of noise from it.

Thanks for any advice.

Wayne

G’day Wayne and welcome to the forum. It’s easier to take off the turbo intake screen and, with the engine shut down and cool, spin the compressor wheel with your index finger to determine whether or not the turbo is locked.
The answer to your question is YES regarding smoke but only as the load increases…. And it will be black , …..at idle and mid rpm its likely there’ll be no smoke at all with a seized turbo but as the turbo blocks up with soot you’ll eventually reach the point where quite possibly the engine won’t even start.
Whats the story with the “new injectors”? Genuine Yanmar? Cheapies from Ebay? New nozzles only?
What sound is the engine making that “ doesn’t sound normal”, squeaking? Grinding? Clatter? Knocking?

[leecea]

You said the turbo was new too. Did you do new turbo and new injectors at the same time?

[wpoynter]

New injectors (not just nozzles) and heat shields for all cylinders and genuine Yanmar $$$$. Install by Yanmar.

I spoke to Yanmar dealer and he too recommended taking off the intake on the turbo and spinning it. They want me to run the engine under load in the bay for 20 - 30 minutes and see if this helps, getting it up to temperature.

The sound I am noticing is more of a "clatter", the whirl I used to hear, from what I think was the turbo, is not heard. Also, the Yanmar dealer said if the turbo wasn't spinning, the smoke would be black, not bluish / gray.

I will do the recommendations with the injector as well.

[skipperpete]

There are a lot of obscure reasons your Yanmar 4JH3-TE might smoke at low idle, the list is long but what is worrying though is the unusual noise, have you tried dropping out one injector at a time by loosening the fuel line at the injector to see/ hear if the noise either changes or goes away?, do it in neutral first, and then if the boat is well secured to the dock, try it in gear with a light load. From memory , your engine has a Bosch rotary VE injector pump with only one pumping element but unique in having a delivery valve on each outlet, there’s an infinitesimally small chance that one of those delivery valves has a broken spring or damaged valve, far more likely is the possibility that the injectors are wrong, the 4JH3 TE is a bit of an odd duck , I don’t even have a workshop manual for those 3 turbo models, only for the non turbo versions.

[SailingHarmonie]

If you see evidence of unburned fuel at idle speed, that is NOT the result of a bad turbo. You might have a bad turbo, but it would not impact performance at idle.

Are your injectors NEW or were they rebuilt? If rebuilt, who did it? the local mechanic? Or an injector/injection pump specialist? Who did the install of the new injectors? Did they fuss with the injection pump and possibly mess up the timing? That would account for the change in sound.

It sure sounds like at least one of the injectors is bad. That would be extremely unlikely if new, or from a rebuild at a specialist shop. On the other hand--the best injectors can be screwed up by a sloppy install when joe-blow grungy mechanic gets dirt in the fuel gallery.

This is an important fix. Unburned fuel running down a cylinder wall can wash off lubricating oil, and the cylinder and rings then suffer rapidly.

[wpoynter]

Gentlemen, first thanks for the great responses...here are some answers and clarifying information.

New turbo and injectors (new from Yanmar) at the same time, yes. Injectors installed by Yanmar, but I don't have confidence in the tech. Going to have some new folks look at it and also going to run in under load around San Diego bay this weekend.

New Question: If it was the oil ring or or compression ring, would the color of the smoke look like the attached? Folks around here at the various shops seem to want to rip out and re-power. I am not convinced.

SEE ATTACHED PHOTO....this is at idle. Revving the engine smokes out the area....

Wayne

[GreenWave]

You sure it isn’t oil being burned? How long does the sheen stick around? Is there oily residue around the exhaust port?

[SailingHarmonie]

Collect a bucket full of exhaust water. If the sheen is diesel fuel, the smell of unburned fuel will be diagnostic.

If it is fuel, it’s most likely easily fixable once the cause is identified.

If it is oil, and this did not happen before the turbo was replaced, my bet is a bad oil seal on the turbo. This can get very exciting if it leaks enough oil into the intake air the engine can run away.

No surprise the Yanmar dealer would prefer to sell a new engine. But if this problem started right after they worked on it, that is highly unlikely to be a coincidence.

[skipperpete]

The heavy white smoke at higher rpm is usually indicative of un atomised fuel entering the cylinder and often caused by a cracked or eroded injector nozzle but with some 4JH engines there’s another reason. I’ve only seen heavy white smoke like that on a 4JH 5, specifically with the MP2 injector pump and not related to the injectors at all.
There was a post a while back from a guy who had heavy white exhaust smoke from a 4JH, he fixed it but his explanation was fairly hard to unravel at first reading and basically he said he had a kinked fuel tank breather hose, as soon as he corrected that, the smoke cleared and the problem was solved. I’d seen the same 4JH white smoke problem previously on a very low hours engine but in this case it was caused by a blocked secondary filter….. new filter…. Instant fix but l was never able to explain precisely WHY until I did some work on one of the Yanmar MP2 injector pumps and found that this particular injection pump is weird in a lot of ways but primarily it is highly intolerant to low fuel supply pressure caused by suction line restriction or secondary fuel filter blockage. I won’t try and explain in detail why this affects the pump ( it has to do with the method of using spill cutoff to advance injection timing) but here’s a suggestion ……. Change the fuel filters, both or all of em and check the supply/suction side of the fuel system for negative pressure., it might cure the problem. I still have no real explanation for how this particular “ white smoke” event physically occurs other than I’ve seen it and fixed it. For those interested, look at the operation of an MP2 injector pump on a 4JH5 yanmar…. Yes, I know the OP’s engine has a Bosch VE pump but maybe , just maybe , it reacts in a similar way to fuel restriction.
If an engine is burning lube oil to the point where the exhaust smoke is blue, I can assure you of 2 things,1. The engine will have a lot of crankcase pressure and 2. The engine will be using a LOT of lube oil. Though there are times when a turbo is leaking oil into the boost side with no blowby but the engine uses lots of oil…. Since this is a new turbo I dismissed the whole “ burning lube oil” smoke idea completely and since this is often raised in exhaust smoke threads I’d suggest that valve guides and stem seals don’t really play much of a role in oil consumption on diesel engines …unlike gasoline engines with intake manifold vacuum where there’s a fairly solid suction to pull oil down the valve stems and into the cylinders

[sinnerman]

If the mechanic who installed the injectors over-torqued them, they could bind / not fire correctly.

Just a thought. (Not all mechanics actually read the engine manuals or know what they are doing. Even authorized service reps...)

Maybe remove the inectors, inspect and retorque. (You will need to install new seal rings if you do this..)

FYI, I installed brand new, Kubota-japanese injectors in my M-25 Westerbeke/Universal

Before installing them, I actually took these new injectors to a shop to verify that they were spraying correctly and all were firing at the correct pressures.

Overkill maybe, but sometimes you receive new parts that have manufacturing defects. Then you spend hours trying to troubleshoot the problem..

My two cents.

cheers

[Shaneesprit]

Firstly consider why the parts were changed, was it like this in the first place ?
Maybe originally the diagnosis was wrong.
Not only should the turbo be freely spinning it also should be clean - I have seen oil films on Turbo blades. Also there should be no leaks between the Turbo outlet and the inlet manifold. (certainly seen that before under load the exhaust will be glowing)

Smoke is always.
White = Air
Blue = Oil
Black = Fuel
Grey is a little more complicated, then you have to consider water.

You can securely tie to a dock and run the engine against that, just remember securely, means lines and anchor points on both the boat and the dock will be under tension.
Open water is better for an engine test but you have to consider what happens if an issue becomes a failure.

Not sounding right like the diesel knock (firing is wrong)
Is the engine running smoothly, or rough vibrating more than usual. - rough would point to a single cylinder issue.

Generally noisy knock - this could be timing was the fuel injection pump touched at all?

[Shaneesprit]

Originally Posted by sinnerman

If the mechanic who installed the injectors over-torqued them, they could bind / not fire correctly.

Just a thought. (Not all mechanics actually read the engine manuals or know what they are doing. Even authorized service reps...)

Maybe remove the inectors, inspect and retorque. (You will need to install new seal rings if you do this..)

FYI, I installed brand new, Kubota-japanese injectors in my M-25 Westerbeke/Universal

Before installing them, I actually took these new injectors to a shop to verify that they were spraying correctly and all were firing at the correct pressures.

Overkill maybe, but sometimes you receive new parts that have manufacturing defects. Then you spend hours trying to troubleshoot the problem..

My two cents.

cheers

Very true - (one of their Diesel engine ranges in cars) the GM factory here in the UK would not assist the GM dealers unless they had changed the injector seals 3 times 😂