Anyone experience Yanmar whistling?

[n7zpx]

I have a '96 Yanmar 4JH2-TE (62 hp turbo with 1400 hrs) that started whistling after a momentary full throttle. The noise is a pure tone that increases intensity with RPM (can easily hear it above the normal engine noise while in the cockpit). Oil pressure and temperature are normal, and engine performance has not changed. The whistling is present whether in gear or in neutral, and only goes away at the very lowest RPMs. Suspect something with the Turbo - but hoping someone else has experienced the same problem and can help provide some insight!

[Hudson Force]

I was lead to suspect the turbo while reading your post before seeing your same suspicion,- afterall it's built like a big whistle and movin a lot of air at high speed!

[DRS]

Check all the clamps on the pressure side of the turbo. It sounds like you have a leak in a clamp or hose.

[n7zpx]

DRS - thanks for the tip. That would be nice if that's the cause - I'll try that first as soon as I get back to the boat! (May 7)

[shakey doug]

Gday,
Either glamps as suggested by DRS or leaking inlet Manifold try soapy water as a indicator.

[Irish rambler]

There's a leak from the pressure outlet from the turbo to the manifold.
Hope this helps.

[n7zpx]

Thanks everyone for the tips. Tightening the clamps on the high pressure side of the turbo seemed to help a little, but the whistle is still there starting at about 1700 RPM, and then increasing in intensity. My max RPM is about 2700-2800, and then I start getting some black smoke - another indication of turbo problem? The manual says the max RPM should be 3400-3600 RPM.

I checked the other end of the turbo hose (which seems to be made out of some sort light weight metal) and it seemed to be securely bolted onto the intake manifold. I haven't yet checked the intake manifold with soapy water as was suggested - which I will try next.

I appreciate all the advice, and still hopeful I will find the problem before investing in a turbo re-build or something worse. The engine performs well (up to 2700 RPM) if I don't mind the whistling!

[MARINE ENGINNER]

Originally Posted by n7zpx

Thanks everyone for the tips. Tightening the clamps on the high pressure side of the turbo seemed to help a little, but the whistle is still there starting at about 1700 RPM, and then increasing in intensity. My max RPM is about 2700-2800, and then I start getting some black smoke - another indication of turbo problem? The manual says the max RPM should be 3400-3600 RPM.

I checked the other end of the turbo hose (which seems to be made out of some sort light weight metal) and it seemed to be securely bolted onto the intake manifold. I haven't yet checked the intake manifold with soapy water as was suggested - which I will try next.

I appreciate all the advice, and still hopeful I will find the problem before investing in a turbo re-build or something worse. The engine performs well (up to 2700 RPM) if I don't mind the whistling!

before 2 weeks i overhauled a yanmar turbo on a 4jh3-hte and the problem was a special circlip-seal that is on the exhaust side.yanmar recommends replacing this every 4000hrs your engine has only 1400hrs
so check your lubrication , type of lubricant , temperature of lubricant , oil filter , loose parts in turbo, inlet and outlet oil pipe to the turbo and carbon on the exhaust manifold-mixing elbow.be careful it is a fragile part running thousands of rpm

[n7zpx]

Originally Posted by MARINE ENGINNER

before 2 weeks i overhauled a yanmar turbo on a 4jh3-hte and the problem was a special circlip-seal that is on the exhaust side.yanmar recommends replacing this every 4000hrs your engine has only 1400hrs
so check your lubrication , type of lubricant , temperature of lubricant , oil filter , loose parts in turbo, inlet and outlet oil pipe to the turbo and carbon on the exhaust manifold-mixing elbow.be careful it is a fragile part running thousands of rpm

Marine Enginner - Thank you for sharing your experience and knowledge - I haven't solved the whistling yet, so I'll definitely take a look at the oil system components you suggested. With my lack of experience, I don't think I'll try to take the turbo apart, but if the external checks don't fix it, I'll probably remove it and take it in for a rebuild right after our trip to Catalina in July. Is the oil entering the turbo supposed to be at a lower temp than the engine? How do you recommend measuring it?

[MARINE ENGINNER]

Originally Posted by n7zpx

Marine Enginner - Thank you for sharing your experience and knowledge - I haven't solved the whistling yet, so I'll definitely take a look at the oil system components you suggested. With my lack of experience, I don't think I'll try to take the turbo apart, but if the external checks don't fix it, I'll probably remove it and take it in for a rebuild right after our trip to Catalina in July. Is the oil entering the turbo supposed to be at a lower temp than the engine? How do you recommend measuring it?

the first parts that enters the oil if oil pressure regulator valve and turbo
you can measure it with an infrared thermometer
1) oil temperature after the oil cooler before the inlet of turbo
2) oil outlet of the turbo (return pipe to oil sump-crankcase)
3) inlet and oulet of cooling water of the oil cooler - is it with engine coolant or sea water?
4)do you have any oil consumption ?if yes how much?
5)measure temperature on the casing of the turbo where the oil inlets and outlets , there are the 2 floating bearings
6) measure temperature on the oil filter and compare it with the inlet to the turbo

if these are ok take out the air intake manifold rotate the air side with your fingers be careful of worn blades so you dont get hurt and rotate it slow and try to feel if there is something worn
it will be like rotating something and suddenly you feel a "scratch" , this will lead to bearings and circlips
maybe there is carbon on the exhaust side on the blades and this leads to misaligned movement of turbo.soot is devil for turbos and sometimes the exhaust manifold is full of soot but not the turbo causing turbulence of the exhaust gas causing uneven operation-rotation

all these i tell you is what i can understand from your posts.in low rpms you don;t hear it because the revs of the turbo are low and the full throttle you described maybe is the reason damaging a blade or high temperature of oil sudden high rpm with low lubrication viscosity causing bearing "scratch"
one more thing take a long screwdriver start the engine rev up until you barely hear the whistle place the tip of the scredriver on the turbo casing and the plastic handle on your one ear close with your finger the other and hear the turbo , if the noise is more in your ear then is definitely turbo

[n7zpx]

M. E. - I have an infared thermometer, so I'll check all these points when I get back to the boat on July 2nd. I did have the air intake manifold off last time, and manually turned the wheel - it didn't seem to spin as freely as I would have thought. Also, there was a good layer of "dirt" on the inside of the turbo's intake coupling section. I was able to easily scrape off dirt with my finger, but didn't try to clean it all off fearing that the loose dirt would get into the turbo and cause more problems ! I'm new owner on this boat, and I don't have any records indicating if the turbo has ever been cleaned or re-built - so, it may be it is just caked with soot and probably the exhaust is fouled with carbon. Thanks again for sharing : )

[MARINE ENGINNER]

http://www.yanmarmarine.co.uk/pdfs/s...al/EPB5545.pdf here is the service manual if you like to have a look :-)

[Irish rambler]

It's a common problem on boat leisure boat engines fitted with a turbo. Firstly many boats don't have air intake filters as fine as their land based engine brethren so use a more suitable air filter (on my Perkins 4236 I use a forklift air filter) you will be amazed how much particulate matter it stops, incidentally giving less engine wear. that's the dust you were able to move with your finger on the intake vanes. Secondly many boat engines chug in and out of harbour then up go the sheets and the engines shut down, or are just used for charging batteries and never get working hard for long so the carbon in the exhaust never gets burnt off. Once your air leak(whistling) is sorted take the boat out and get it up to working temperature and then give it near full throttle for half an hour, you'll see the black smoke and gunge out of the exhaust as it cleans itself. Very important points to remember with a turbo engine is that when you start it do it gently @800 rpm, let the oil get pumped around the engine (the turbo spins at up to 30,000 rpm so you need oil to lubricate the shaft). warm it up under light load then it will work hard all day. When shutting down allow it to idle for around 3/4 minutes to allow thermal radiation around the cylinder head area. We have hard working trucks still with original turbo's nearing a million miles.

[n7zpx]

Originally Posted by Irish rambler

It's a common problem on boat leisure boat engines fitted with a turbo. Firstly many boats don't have air intake filters as fine as their land based engine brethren so use a more suitable air filter (on my Perkins 4236 I use a forklift air filter) you will be amazed how much particulate matter it stops, incidentally giving less engine wear. that's the dust you were able to move with your finger on the intake vanes. Secondly many boat engines chug in and out of harbour then up go the sheets and the engines shut down, or are just used for charging batteries and never get working hard for long so the carbon in the exhaust never gets burnt off. Once your air leak(whistling) is sorted take the boat out and get it up to working temperature and then give it near full throttle for half an hour, you'll see the black smoke and gunge out of the exhaust as it cleans itself. Very important points to remember with a turbo engine is that when you start it do it gently @800 rpm, let the oil get pumped around the engine (the turbo spins at up to 30,000 rpm so you need oil to lubricate the shaft). warm it up under light load then it will work hard all day. When shutting down allow it to idle for around 3/4 minutes to allow thermal radiation around the cylinder head area. We have hard working trucks still with original turbo's nearing a million miles.

Irish Rambler - thanks for your informative input - the use of a better air filter sounds like a good idea. The first time I had the air intake off, I was surprised that there was no filter element inside, just the huge holes on the cannister itself, which would be lucky enough to filter out small bugs and flys ! In fact, the service manual calls it an "air intake silencer", not an air filter.

[bstreep]

Your turbo should spin freely. As noted, they suffer from our low-rpm use. I can pull our turbo out in about 2 hours. Putting it back in takes a contortionist, but about the same to put it back in. A good cleaning is probably in order. Do NOT spin it with compressed air - it needs lubrication.