Turbos- '' TROUBLE'' ..THE ANAGRAM IS THERE .NEED I SAY MORE

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george unthank

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I have had three turbos , thus far in my boat- with 200 hrs on clock
They cost € 2K a pop, and when you ring the - manufacturers they give you the same old same old,, they just go .''. do you want a new one .?''

The last one was fitted June 2011 , and guarantee of 1 yr notwithstanding they said my warranty had expired. I pointed out that I had done about 15 hrs with it. No! It was expired ..- by 1 month (less I think ) and nonchalantly , with a yawn they ask me if I want a new one at €2k a pop.. This is Dublin .. UK dealers are rarely so abrupt - but these guys have the corner of the market in Ireland .

This then will be my 4 th Turbo in 200 hrs !
Why do they pack in so easily
O observe all the instructions apropos oil temp, and pressure heading out and returning ( Heating up and cooling down )

They tell me there a few basic probs with turbos in boats
1.
Insufficient driving at high speed to prevent 'soot' build up
2
Dirty fuel or oil - But these go through filters ?
3
Waste gate
dont understand anything about this

4.
Intercooler
Equally - nada
5
wrong prop- putting too much pressure on blades to allow engine to attain revs required for turbo to click in. But she is designed to carry 5 adults and I have got 30 +knots with full load. I have goot 37 knots/hr on my own , so with just me in boat there couldn't be too much problems attaining sufficiently high revs to enable turbo to click in , even iif the prop was slightly 'heavy' in its bite -could there ?

If anyone knows a dealer in UK who supplies or reconditions for under 2k please pass address on
I contacted a cowboy type who deals in car parts who told me he supplied turbos for ships, but when I sent him along all the numbers and a picture of my turbo he hasn't been back to me . Cowboy ? or am I being unfair ?

There's another dealer here ( I live in Ireland - W.coast -Galway Bay) - He has just started up, and is dealing with my current turbo..lets see how it goes with him
I am told my Mercruiser Alpha 1.4 D stern drive is the same engine as the ISUZU van/ car .or a Volks wagon Golf ?? . but a 1.4 engine have a turbo.. and would a car turbo be suitable for a boat.

My insurance does not cover turbos unless you've had a collision and can verify you had one ! - They regard it as fair wear and tare
..
If ANYONE knows ANYTHING about turbos , please pass on SOMETHING of your wisdom.

I'd like to understand more about turbos, just for my own sake so if anyone had sketches or exploded views showing how they work these would be deeply appreciated .
Anyone out there ?
Come in
Please !
George
 
Turbos in road vehicles can outlast the engine, so with only 15 hours on the clock, there's something badly wrong somewhere to cause such early failure

When you say they 'go' - what actually has failed? Although they are very precisely engineered, they are very simple units and there is not a lot to break.

Carbon build up can interfere with function, but not in 15 hours running, and unless it is totally choked, a 20 minute 'blast' at high high speed will clear it; this is why you will often see offshore angling boats heading home at full chat: they are not just running for the pub, they are clearing their turbos and exhausts after a day of slow running at trolling speeds.

The normal cause of premature failure on cars in my (limited) experience is failure of the bearing and oil seals due to oil starvation. One of the most common causes of failure is the bearing oil feed line gets clogged. As the bearing depends on the pressurised oil supply to function, any shortcoming here cause rapid breakdown of the bearing surface and oil seal. When the seals fail one of two things may happen: If it fails on the inlet manifold side, oil gets drawn into the engine causing smoke, and in bad cases on a diesel the engine starts running on its own oil - usually to destruction. If the seal fails on the exhaust side, exhaust pressure can reach the crankcase causing excess crankcase pressure. This can result in the lube oil being forced out of the breather, which if it feeds into the inlet manifold as is often the case, again the engine runs away on its own oil. I have had both these faults occur on diesel road vehicles. Depending on the degree of damage, rebuild may be an option.

But failure after 15 hours suggests some other problem, such as failing lube supply, or water getting in from the exhaust and destroying the turbo somehow.

Theres a nice animation showing how it all works, and why it goes wrong here:
http://www.youtube.com/watch?v=Xp-EVOPBhIo
 
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Definitely needs investigating.

Bad fuel is NOT going to kill your turbo's.
As said, biggest killer of Turbo's is high speed running and then quickly stopping the engine. This cuts oil circulation to the turbo whilst it's still spinning at high speed (hence bearing failure)

There could be an oil feed / return issue on the Turbo. Easily checked by removing the hoses and looking for gunge/blockages.

Even abused turbo's on diesel cars rarely fail before 80k miles so even with neglect and lack of use, 15 hours indicates something seriously needs looking at.

Turbo's on boats are also extremely simple compared to their road-going counterparts. Much of the complicated malarkey is removed before marinisation.
 
As above turbos on cars have a long life, but looking after the turbo is important. Dont go running the turbo too hard from cold let it warm up. When you finish let the engine run at idle for several minutes to allow the turbo to cool rather than just cutting the power which can/will fry the bearings.

The lubrication system is another possible area at fault, is enough oil getting to the bearings?

Finally turbos can be refurbished, take the unit to an established specialist turbo engineer who will strip it down and can advise exactly what has caused the problem, so you can diagnose exactly what is causing your problems.
 
Is it the bearings that are the problem. if they are sitting for extended periods without use, you say 15 Hrs. in a year! The bearings can "Brinell" if left in the one position. Basicly that means they can get "Flat spots"
Turbo bearings rotate at very high speeds and any brinelling that may pass unnoticed in other applications will cause problems.
Have you tried an internet, or telephone directory search for someone who may be able to service the turbo?
However if the above is the cause you still need to find someway of turning the turbo on a regular basis. About once a week.
 
Brinelling (sp?) is a known phenomenon often connected with resonant/harmonic operation.

But if the bearings may be damaged sitting unused on the boat, what about months/years in a box on the supplier's shelf? Such items would need a 'use by' date, like fresh food.

Oil feed seems more likely.

Nick
 
To echo the replies so far, on cars its often the oil feed pipes that get restricted.

When you stop, the turbo is still bloody hot and this residual heat "cooks" the oil in the feed pipe thickening it so the pipe gets restricted. The local garage which specialises in high performance turbo cars has gone to the trouble of having flexible oil feed pipes specially made and wont refit the standard pipes. :)

Thats why its important to allow the turbos to cool after a "spirited" run. On cars some turbo timers will run for a few minutes after the ignition is switched off for just this reason
 
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george unthank said:
This then will be my 4 th Turbo in 200 hrs !
Why do they pack in so easily
Click to expand...

They don't normally; your experience isn't typical. Most boat turbos last for years without problems, assuming sensible use and regular oil changes. The turbo on my Volvo Penta engine has done 2200hrs and was thought to be in good condition when it was checked recently by a VP dealer. Incidentally, the turbo's never been touched in its life.

If you're experiencing regular turbo failure, there's an underlying problem which needs sorting before you buy another turbo. Suggest you get a decent marine engineer involved.
 
Alex_Blackwood said:
Is it the bearings that are the problem. if they are sitting for extended periods without use, you say 15 Hrs. in a year! The bearings can "Brinell" if left in the one position. Basicly that means they can get "Flat spots"
Turbo bearings rotate at very high speeds and any brinelling that may pass unnoticed in other applications will cause problems.
Have you tried an internet, or telephone directory search for someone who may be able to service the turbo?
However if the above is the cause you still need to find someway of turning the turbo on a regular basis. About once a week.
Click to expand...

What about over- wintering ? I dont see people taking out their turbos in foo season,-other than that and moving the bearings periodically I cant see how this Brinell effect can be avoided .
 
Alex_Blackwood said:
Is it the bearings that are the problem. if they are sitting for extended periods without use, you say 15 Hrs. in a year! The bearings can "Brinell" if left in the one position. Basicly that means they can get "Flat spots"
Turbo bearings rotate at very high speeds and any brinelling that may pass unnoticed in other applications will cause problems.
Have you tried an internet, or telephone directory search for someone who may be able to service the turbo?
However if the above is the cause you still need to find someway of turning the turbo on a regular basis. About once a week.
Click to expand...
most turbos run on plain bearings, the shfts float on the oil, therefore no brinelling. that only happens on very toughened steels used in making needle, roller or ball bearings.
Stu
 
Turbo Chargers

OP does not say what kind of engine it is fitted to. Not that it should matter very much.
A turbo has a turbine running in the exhaust gases close coupled to a centrifugal compressor to increase manifold inlet pressure. The turbine compressor runs at very high RPM. There is huge problem of the heat of the exhaust gases which can see the turbine very hot. This heat transmits to the bearings which are fed with engine oil under pressure. This oil does not cope well with the high temperatures involved. So you need a lot of flow. Some Turbos outer casing are water cooled which can help to manage temperatures a lot.
When I learned a bit about turbos some 20 years back Garret Airesearch were one of the primary suppliers (they also make gas turbine aircraft engines. However it seems at that time that all small turbos were regarded as throw away non repairable. I don't know what situation is like now.
The waste gate is a gate valve in the exhaust system which under (sometimes vacuum control) bypasses some of the exhaust gases past the turbo so limiting turbo speed hence limiting the outlet (boost) pressure.
This is especially important in petrol engines as over boost can cause detonation and engine damage. Which explains why turbos are good on diesel engines where detonation is the ignition function but not so popular on petrol engines. The OP will be able to tell if he has a waste gate by the plumbing of the exhaust line unless the waste gate is built into the turbo housing.
As said we need more detail of the failure mode of the OP's turbos. Guessing that it is bearing failure then as said it is most likely oil supply problems. As said a spirited run followed by rapid shut down of the engine can be a real problem as oil pressure stops and what oil is in the bearing can cook from heat soak. Hence a lot of diesel vehicles have a timer that keeps the engine idling for some minutes after you request shut down. An alternative option might be a separate electric oil pump again on a timer to operate after engine stop. I don't know if this is done in practice. If it is water cooled of course you would need a water pump as well. most people are simply fastidious about idling for a long time before shut down.
A classic example here is the Bell 47 helicopter. (MASH style) most of these have a turbo charged petrol engine. The engine runs at quite high power until it is finally on the ground. Pilots will usually leave the engine idle for 10 minutes to cool the engine and turbo before shut down. And another bit of useless info..
Many piston engined aircraft have turbo charging not so much to increase engine HP but to enable engine to maintain full HP at altitude where air is rare and engine performance falls off badly.
For the OP it is conceivable that better engine room ventilation especially around the turbo would help. This might explain why the same engine turbo combination is successful in other installations.
good luck olewill
 
if you have been running at high speed,leave your motors running to allow them turbos to cool naturally.
I could get the turbo on my old car glowing cherry red, so when its hot... its hot.
diesels shouldn't get to this temperature though.
Check out some of the modified car type companies who should be able to service it. theres enough of them about. Just because of the markings on the out side of your turbo, the compressor wheel and turbine may be different from any other application.
What markings are on it....
kkk
Garret
IHI Hitachi
 
turbo probs

turbo problems are easy to sort out,BUT need more info what is failing,bearing,compresser,exhoust wheel,
are bearings blue or worn on one side
is compresser wheel coming loose
exhoust wheel pitted or are the tips burnt
if you can post picks of parts
 
Hi George, I see you've double posted! I replied to The Lounge post:-

I worked for a turbo manufacture for 20 years. I mostly worked with passenger car and commercial vehicle applications. Turbos are designed and validated to be at least equal life with that of the engine. Turbo warranty (excluding the wonderful era of the Renault 5!) is very, very low and, in the main, issues are related to a specific problem. In other words, they simply don't just fail.

What is the mode of failure in your case? This should give an insight into the root cause?

A turbo is a fairly simple device and needs filtered air and a filtered oil supply to work. They are not serviceable items. Not necessary.

As most other posters have said, diesel engines like to be run. If the combustion is dirty (dirty air, dirty fuel, high soot fuel or incomplete combustion) it will start to build-up a deposit on the turbine wheel. It's easy to imagine this, over the course of time, leading to a problem.

Lack of lubrication is almost always a killer. A delay in getting oil to the bearings is bad news. This is generally an engine design issue. Poor oil filtration will also, eventually, score the bearings and the rest becomes history.

Hot shut down refers to stopping an engine from high load. This should also be designed-out by the engine maker as it was a problem 30 odd years ago. High quality oils, more tolerant of temperature extremes help, too. What happens is that once the oil stops circulating and the turbo bearing housing is very hot, the oil around internal surfaces can thermally degrade into coke. This again will ultimately lead to premature failure.

Foreign object damage, self explanatory, will immediately kill either the compressor or tubine wheel. A broken down airfilter is often a culprit here.

Wastegate. Flow characteristics through a turbine volute are a poor match to the flow requirements of a reciprocating piston engine, especially one with high speed range. At low engine speed, there isn't a great deal of energy to spin the turbine. Gas flows through a funnel (simplisticall) so a small one is needed make the tubine spin at the right speed to enable the compressor to generate boost. At high engine speeds there's an excess of energy so this small funnel would either become choked or would overspeed the turbine so some form of device is required to dump excess engery, viola the wastegate. An evolution of the wastegate is variable turbine geometry, but that's another story.

The wastgate is actuated by increasing compressor stage boost pressure acting on a spring over a diagraphm. This simply opens a poppet value located within the turbine volute upstream of the wheel. It vents excess gas to atmosphere. It's "wasteful" because it's not harnessing any energy out of the gas.

Most wastegate failures relate to sticking which generally can be tracked down to coke build up.

Intercooler, aftercooler, charge air cooler. The engine power is limited by air; it's easy to add more fuel, it's not so easy to add more air. The turbo compresses air and therefore increases density, viola, more air. The air post compression is hot and the adiabatic efficency of the stage is about 70%. Charge air cooling does exactly as it says on the tin, it reduces the air after compression, it's a heat exchanger. Reducing temperature also increases density, hence more air to burn for more power and better control of emissions.

Hope this hepls!
 
I'm going out on a limb here.....with an internet web forum diagnosis....something I rarely do....

Sticking out another limb and offering a 50p bet that this is an installation issue, load is too high, EGT is too high and its killing turbos.

Post this in the mobo section and attact attention from 'Latestarter'
 
the OP says he can get 37 knts so when the engine is working it seems to be OK so it appears that the issue is how the engine is shut down.

ANYWAY

All of the wise words in the posts above need looking into, but paying particular attention to letting the engine cool off before shutting down and slowly accelerating the engine from idle to max rpm, at 200 hrs the oil should be OK, IF its the correct type and its getting to the bearings in sufficient quantity.

Engine room ventilation is paramount with boat engines, more with a turbo in the mix, a MK1 hole is not enough you need a blower, the engine manufacturers will tell you how much air it should be able to move.

Was the engine born with the turbo or has it been fitted to make it go faster?

(I turbocharged a few ford truck engines for Ford in the 1960's to see how they would perform, Mr Ford wanted to go faster - we had our share of issues)
 
Marsupial said:
the OP says he can get 37 knts so when the engine is working it seems to be OK so it appears that the issue is how the engine is shut down.
Click to expand...

I would be amazed if a turbo only lasting 15 hours running, was purely down to shut down. How often do you really come to a halt on a boat from Wide Open Throttle to switch off immediately.

Simply the process of mooring takes the 'heat' off the engine and it's working less hard.

edit - Just to add, we're not talking modest premature turbo failure, we're talking almost 'bolt in then fail' situations.
 
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OP says
"This then will be my 4 th Turbo in 200 hrs !
Why do they pack in so easily
O observe all the instructions apropos oil temp, and pressure heading out and returning ( Heating up and cooling down )"


So its not very likely to be a shutdown overheat problem, particularly after such short service.

There's something else wrong that is causing this - not knowing what is actually failing in the turbo unit its difficult to guess, but I still put my money on oil supply problems to the bearings. I doubt he would make 37 kts if the engine was so badly overloaded to cause burnout. (Yes I know, massively overrated or overpropped engine for a small hull etc... I am assuming the power to weight ratio is about right for that sort of speed)

If OP has properly understood and is following his operating instructions, then that is unlikely to be the cause of his problems.

Come on George - tell us a bit more about it! What engine / boat do you have, in what way have the turbos failed? What happened when they went down, who says they are duff, etc etc. And why?

Is it a turbo problem at all? could it be a fuelling fault or other engine problem causing intermittent loss of power and nowt to do with the turbos?

Just tell us a bit more about what is happening. What do you see? Hear?, or is it just a gradual power loss over a period oftime? If so that's not likely to be turbos, and you are replacing the wrong bit!
 
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