Turbo failure - Yanmar 4JHTE

[NormanB]

Would you recommend blanking off a failed turbo on a Yanmar 4JHTE and continuing to run the engine without the turbo, as a long term and enduring solution.

The turbo shaft between turbine and compressor snapped chewing up the ‘blades‘ up at each end.

The engine apparently appears to have plenty of power (without the turbo) to shift the boat at 6+ knots without apparent issue.

All described on a short you tube video:

I am asking your view(s) as conflicting advice has been given in the comments to the video

 

[Beneteau381]

Would you recommend blanking off a failed turbo on a Yanmar 4JHTE and continuing to run the engine without the turbo, as a long term and enduring solution.

The turbo shaft between turbine and compressor snapped chewing up the ‘blades‘ up at each end.

The engine apparently appears to have plenty of power (without the turbo) to shift the boat at 6+ knots without apparent issue.

All described on a short you tube video:

I am asking your view(s) as conflicting advice has been given in the comments to the video

It will be overfueled and black smoke will be on your trail! It will probably be a bog std Garrett, take the bits to a wagon turbo repairer, a lot cheaper!

 

[NormanB]

Beneteau381 Did you look at the vid and the comments?

 

[lynallbel]

I would hazard a guess, no turbo boost = no extra fuel = no black smoke.

Was quite common at one time with land rover converisons to remove the turbo and run its as natually aspirated, same inj pump and injectors.

 

[lynallbel]

Ps some of the comments were great, especially the one from the 40yrs a marine engineer!

 

[anoccasionalyachtsman]

I would hazard a guess, no turbo boost = no extra fuel = no black smoke.

Was quite common at one time with land rover converisons to remove the turbo and run its as natually aspirated, same inj pump and injectors.

Yes, the op had a small flexible pipe connected to the turbo which led to the governor on the injector pump. As the pressure in the inlet side rose it signalled the governor to send more fuel because the turbo was doing its thing. Without that pressure the governor won't send the extra fuel.

I know this for a fact because that small pipe broke on my car leading to a woeful lack of turbo effect. And yes, it was a Land Rover.

 

[Skylark]

Would you recommend blanking off a failed turbo on a Yanmar 4JHTE and continuing to run the engine without the turbo, as a long term and enduring solution.

No, not as was done in the video.

The turbo version of the engine is probably around 25% more powerful than its naturally aspirated brother. So the fuel pump will be supplying more fuel than can be burned efficiently by the available oxygen (assuming a very basic, uncontrolled, fuel injection system). The resulting combustion will create a lot of carbon and this will quickly build up deposits in the combustion chamber and exhaust system.

There may be other deign differences between an NA and a turbo derivative of the same basic engine. One could be that the turbo engine has a lower compression ratio; this would further reduce efficiency when run without the turbo.

Of course, the owner and his mechanic is free to do as he chooses. I’d call it a bodge.

It does however raise an interesting point. The price of a replacement turbo quoted by Yanmar is absolutely outrageous.

The unit in question is not a Garrett product. Garrett supplies few products to Yanmar. I think that their main supplier is IHI. MHI supply, too, iirc. Garrett supplied more heat exchanger product to Yanmar than turbo.

The video shows a pretty basic turbo albeit it has a cast, water-cooled turbine housing which is expensive to produce. I’d estimate that the manufacture sells it to Yanmar for around £250. They probably get a 5% premium when selling to the Afternarket division if it’s a current production offering. When it’s no longer current production, they would probably get a 25% uplift. Yanmar is unquestionably screwing the user with that price.

 

[caiman]

As regards oil dilution due to excess fuel,perhaps sending the oil off for analysis would be a good indicator regarding long term prognosis?
Apologies if this has already been suggested.

A mate just had his defender 'fully serviced'When the transfer box started to die he had his oils examined.Engine and gearbox oil new,transfer box and diff oils original,

Cheers.

 

[rotrax]

Yanmar is unquestionably screwing the user with that price.

Yanmar screw ALL customers in Europe with their prices. US prices are around 40% less.

Due to no or poor servicing before my ownership I have had to replace a valve in my 4JH4-HTE Yanmar engine. The valve was 60 quid, the head gasket 250 quid. Plus VAT!

That is really a pisstake.

I can buy a high performance motorcycle valve for a tenner. A complete OE quality top end gasket set for a four cylinder car is fifty quid.

The engine is a low pressure turbo with a vacuum control for fueling when the turbo is working hard. Both rotor blades are tiny - not as big as the turbo from a Kawasaki motorcycle!

Your fears re overfuelling and carbon deposits are probably groundless.

A good specialist turbo repair shop would be the way to go - if it is beyond repair, that is another question.

Simple to remove the shaft and blades and seal the shaft holes with washers and bolts. Then the engine would work, but as you say, not so efficiently.

 

[Beneteau381]

I would hazard a guess, no turbo boost = no extra fuel = no black smoke.

Was quite common at one time with land rover converisons to remove the turbo and run its as natually aspirated, same inj pump and injectors.

Sigh!

 

[Skylark]

The engine is a low pressure turbo with a vacuum control for fueling when the turbo is working hard.

Where does the vacuum come from?

 

[Beneteau381]

Yes, the op had a small flexible pipe connected to the turbo which led to the governor on the injector pump. As the pressure in the inlet side rose it signalled the governor to send more fuel because the turbo was doing its thing. Without that pressure the governor won't send the extra fuel.

I know this for a fact because that small pipe broke on my car leading to a woeful lack of turbo effect. And yes, it was a Land Rover.

So a land rover engine does something so all engines do do the same something? I used to work on CATS, went to sort out one, a D7, same thing, they had taken the turbo off, it worked, just about, but black smoke like you had never seen and diesel in the sump. So not all engines are the same, phsically a turbo one and an NA model based on the same engine look the same BUT they aint! My NA MD22 has a compression ratio of 17.5-1 but the turbo version is 17-1 The pistons are different, they also have under piston oil sprayers to cool the pistons. The injectors are quite different too. Blanking off the turbo is a good get you home trick but for long term? Nah!

 

[anoccasionalyachtsman]

So a land rover engine does something so all engines do do the same something? I used to work on CATS, went to sort out one, a D7, same thing, they had taken the turbo off, it worked, just about, but black smoke like you had never seen and diesel in the sump. So not all engines are the same, phsically a turbo one and an NA model based on the same engine look the same BUT they aint! My NA MD22 has a compression ratio of 17.5-1 but the turbo version is 17-1 The pistons are different, they also have under piston oil sprayers to cool the pistons. The injectors are quite different too. Blanking off the turbo is a good get you home trick but for long term? Nah!

You're quite right. I found this https://www.yanmar.nl/theme/yanmarp...odels/Operation-Manuals/JH2-OP-Manual-ENG.pdf earler, showing the detailed specs. The turbo version comp ratio is 16.2, the n/a 17.8. Interestingly it also shows that the pump timing is retarded by 5 degrees on the n/a, so the OP could do that for a longer term fix. The turbo is also identified as an IHI RHB52, and a search shows it being in common use on some fairly cheap cars, along with some sensibly-priced spares.

 

[NormanB]

You're quite right. I found this https://www.yanmar.nl/theme/yanmarp...odels/Operation-Manuals/JH2-OP-Manual-ENG.pdf earler, showing the detailed specs. The turbo version comp ratio is 16.2, the n/a 17.8. Interestingly it also shows that the pump timing is retarded by 5 degrees on the n/a, so the OP could do that for a longer term fix. The turbo is also identified as an IHI RHB52, and a search shows it being in common use on some fairly cheap cars, along with some sensibly-priced spares.

Would an IHI RHB52 use the same materials for road and marine use?

 

[Skylark]

Would an IHI RHB52 use the same materials for road and marine use?

I suspect that RHB52 is a generic model number. It will give some information about the product but not enough to define it specifically. It’s part number will be it’s unique identifier.

It probably defines what I know as the frame size. This defines the wheel diameters and their journal bearings. It may also define it as having a water cooled turbine housing but not its precise spec.

The compressor housing shown in the video was a pressure die cast. The tooling for this is very expensive and gravity die casting is much more common. That suggests to me that it is common to several applications.

To give the right flow characteristics the compressor wheel is said to have a trim. This is a relationship between the diameter of its inducer as a ratio to its exducer diameter. This is generally engine and rating specific so you would need to know it to find a like for like automotive application.

Compressor wheels can be made from a number of high grade aluminium alloys and may have a form of heat treatment, known as hipping, depending upon results of low cycle fatigue testing.

The turbine wheel could be made from one of several materials, generally related to exhaust temperature. It also is machined to a trim, same principle. Turbine wheels can suffer high cycle fatigue so a specific application may have additional machining on the wheel to change its exducer natural frequency to move it out of trouble.

The turbine housing is very specific to marine as the engine bay has to have a maximum touch temperature for safety, hence the water jacket. This could be made in a lower grade cast iron as its temperature will be quite low but it needs very high resistance to thermal cracking. In general turbine housings are produced specifically to meet an exhaust manifold and exhaust system interface. There are very many potential variants of mechanical installation, material/temperature, gas flow and gas flow bypass.

In summary, some parts will be common, others very specific to the engine.

Also worth keeping in mind that at full engine power it will be rotating at something like 150,000 rpm. If your mate Fred down the road knows a bit about turbos doesn’t balance it correctly ( it’s normal to balance the two wheels separately and then again as a rotating assembly) it has the potential to shake itself to destruction in seconds.

Hope this is helpful and informative.

 

[rotrax]

Where does the vacuum come from?

Perhaps I should have said a pressure control as little vacuum exists within a diesel manifold.

 

[Norman_E]

You're quite right. I found this https://www.yanmar.nl/theme/yanmarp...odels/Operation-Manuals/JH2-OP-Manual-ENG.pdf earler, showing the detailed specs. The turbo version comp ratio is 16.2, the n/a 17.8. Interestingly it also shows that the pump timing is retarded by 5 degrees on the n/a, so the OP could do that for a longer term fix. The turbo is also identified as an IHI RHB52, and a search shows it being in common use on some fairly cheap cars, along with some sensibly-priced spares.

I tried to find the same information for my 4JH DTE, but get 403 Access Denied. Do you have a link to the manual for my engine. I have had turbo problems, as mine siezed up, and the engine made clouds of black smoke. The Yanmar agent in Marmaris repaired it but it would be interesting to find out which turbo I have and how much it would cost to replace if it fails again.

 

[Beneteau381]

I tried to find the same information for my 4JH DTE, but get 403 Access Denied. Do you have a link to the manual for my engine. I have had turbo problems, as mine siezed up, and the engine made clouds of black smoke. The Yanmar agent in Marmaris repaired it but it would be interesting to find out which turbo I have and how much it would cost to replace if it fails again.

A mate of mine with the turbo MD22 suffered a seized turbo, it was actually clogged with solid carbon on the exhaust side, his wife carefully picked out as much carbon as she could off the blades etc, it got it going again, I told him to give it a good italian tune up, he did, it worked for quite a few years afterwards until he sold it. It would have been interesting to see what the dealer did, perhaps a similar thing?

 

[Norman_E]

On my boat the dealer stripped off the turbo and the heat exchanger which also needed looking at. They cleaned out and rebuilt the heat exchanger and they took the turbo to a specialist who cleaned it out and replaced the bearings. They also replaced the exhaust elbow as they said my stainless one was causing galvanic corrosion of the aluminium turbo casing.

 

[Skylark]

I have had turbo problems, as mine siezed up, and the engine made clouds of black smoke.

Although they do happen, turbo failures are pretty rare. Their failure is usually as a consequence of something else, often related to the duty cycle.

What exactly seized up, do you know?

Rather than prepare yourself to buy a spare, I’d recommend establishing the root cause of the seizure and fix the problem.

Turbo endurance is designed to give the same life expectancy as the base engine.