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Old 29 September 2014, 15:03   #1
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Turbo questions !!

Just a couple of quick questions before I buy a new one !! Would play in a turbo shaft bearing cause the turbo to not boost, and could my tappets being a little loose cause the turbo not to boost !! I've tried googling it and no answers so need a little help before I spend a small fortune on a new one ??
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Old 29 September 2014, 15:07   #2
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No and no.

If the turbo isn't spooling up, chances are that its seized.

What's this turbo attached to?
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Old 29 September 2014, 15:21   #3
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if there is enough play in the shaft, could the 'blades' not be touching the sides of the turbo thereby stopping it turning properly? also if the bearings are worn, could it be possible that there are other worn parts causing it not to boost. and no i dont reckon tappets would have any effect on what the turbo does.
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Old 29 September 2014, 15:26   #4
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if there is enough play in the shaft, could the 'blades' not be touching the sides of the turbo thereby stopping it turning properly? also if the bearings are worn, could it be possible that there are other worn parts causing it not to boost
Whateva, it's f'kd.
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Old 29 September 2014, 15:29   #5
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What engine is it fitted to would be a big help.
With the engine stopped & the air filter removed you should be able to spin the shaft with your fingers. There should be a little lift in the shaft
If it rattles up & down then it's knackered
The shaft should centralise once spinning as the shaft runs on the wedge of oil rather than the bearings
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Old 29 September 2014, 15:32   #6
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Take the air filter off and see if it's spinning when the engine is running. Have you a vacuum waste gate fittied
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Old 29 September 2014, 16:34   #7
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Sorry guys meant to say it's on a ford mermaid in my pacific, on idle I can hear to spin up, and if I run it on the trailer it throws out black smoke and sounds like it working but soon as I launch it and under load I have no turbo !! The shaft moves about 1-2mm side to side !!
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Old 29 September 2014, 16:43   #8
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Sounds like a seized waste gate, just like you get on the small 1.7 merc
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Old 29 September 2014, 16:44   #9
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It's a real basic set up and I'm sure there's no waste gate fitted !!
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Old 29 September 2014, 16:50   #10
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Sorry guys meant to say it's on a ford mermaid in my pacific, on idle I can hear to spin up, and if I run it on the trailer it throws out black smoke and sounds like it working but soon as I launch it and under load I have no turbo !! The shaft moves about 1-2mm side to side !!
that much lift isn't a problem sounds like you have a loss of turbo pressure elsewhere

is it wastegated? if so check that the wastegate isn't stuck open or the valve burnt away also check for air leaks in the system after the turbo.

exhaust elbows can corrode & restrict the gas flow out of the exhaust

what makes you say you have no turbo? is it smoking heavily as you try to accelerate? you mention smoking on the trailer but not when trying to get the boat planeing, doesn't the mermaid have an enrichment device on the pump which measures turbo pressure & adjusts the pump as required? can you get a guage to check the manifold pressure?
could it be something else restricting the engines performance?
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Old 29 September 2014, 16:54   #11
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I would have expected a waste gate to keep the boost pressure regulated and not allow it to over boost possibly damaging the engine and your symptom sounds like one that is stuck open, ie runs great but no power under load in the water
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Old 29 September 2014, 16:55   #12
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It doesn't smoke at all when on the water and for the last two months the boat was flying well for a pacific, it was jumping on to the plane and black smoke was pouring out when under load, I was getting 26knots but now only 17 !! Could a damage hose on the turbo cause this only because they aren't in the best of condition !!
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Old 29 September 2014, 17:03   #13
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It doesn't smoke at all when on the water and for the last two months the boat was flying well for a pacific, it was jumping on to the plane and black smoke was pouring out when under load, I was getting 26knots but now only 17 !! Could a damage hose on the turbo cause this only because they aren't in the best of condition !!
yes! I think there is a small hose from the manifold to the pump which measures turbo boost & tells the pump to shovel more coal on, if that's split then the pump will not supply enough fuel

if its an air leak between the turbo & manifold you would expect loads of black smoke

my first step would be to find a gauge & measure the turbo boost it doesn't need to be anything fancy any pressure guage that can read up to about 20psi will do

im not sure what pressure they run at but it shouldn't be too difficult to find out the boost pressure required
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Old 29 September 2014, 17:08   #14
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Thanks I will have another good look over her tomorrow and get some pics , I'm not sure where I would connect the pressure gauge to ??
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Old 29 September 2014, 17:14   #15
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anywhere in the manifold system after the turbo will do there is usually a gauge port somewhere or you may need to locate a suitable hose and make up a tee of some sort

sorry I cant be more specific but im not totally familiar with the mermaid

pics might help
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Old 29 September 2014, 18:09   #16
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Hi all


Could be bearings gone on the turbo.Worth putting it on computer.Just to make sure nothing electrical.
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Old 30 September 2014, 05:21   #17
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Hi all


Could be bearings gone on the turbo.Worth putting it on computer.Just to make sure nothing electrical.
No obd on an old mermaid.
No wastegate either iirc
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Old 30 September 2014, 07:05   #18
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Try running it on a different fuel source is out if can. Might just be restricted fuel flow
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Old 30 September 2014, 07:53   #19
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Hi all from what i gather of turbo's, if bearing failure the turbo will not reach peak revs.As you describe you have play in the turbo.check for air and oil leaks to.
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Old 30 September 2014, 11:12   #20
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Might try the fuel source tomorrow that's not a bad idea !! Also I spoke to a mermaid engineer today he said even with bearing play the turbo will still perform well and they are bullet proof, he seemed to think the only thing it could be is leaking manifold gasket so need to go and take a new look !!!
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