Volvo Penta AD41 power issue

K-2

K-2

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Re: Volvo Penta AD41 power issue

booost.jpg Click on engine for larger picture. Number 11 . Not all 41's have it.
 
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Scarborough

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Re: Volvo Penta AD41 power issue

Thanks K-2, checked all the photos I got and I can't find one of that area so I will duck down tomorrow morning before dropping the kids off and check it :)
 
Scott Danforth

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Re: Volvo Penta AD41 power issue

they may not be wastegated. when you checked your boost pressure, was that at the turbo before the heat exchanger, or at the manifold after the heat exchanger.

have you made sure there is no obstruction in the air side of the heat exchangers?
 
alldodge

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Re: Volvo Penta AD41 power issue

Scarborough said:
Hi all,
Sorry for the late reply. I did have the Bosch specialist over last week. We sat down and went through all the tests done to date, in the end he told me we need to get the pumps in for a service :( He also mentioned that there have been issues with the VE pumps where the membrane pushing the spring loaded pin down when the turbo pressure increases gets stuck (see attached Bosch picture). I pulled both off just to have a look, I must say both was sliding up and down very easy plus had no rubbish around it once I pulled it out, in fact they both looked very clean (see attached photos).

View attachment 226492View attachment 226493View attachment 226494

A friend of mine keeps telling me it is the Turbos. The problem I have with that is that there is no smoke but then again if the smoke limiter in the IP is working there wouldn't be any smoke because the pressure on the membrane is not enough to allow more fuel in, aaarg....

Before I pull the pumps off I will take off the exhaust side of the turbo and check if I see anything that doesn't look ok. I have another question, since this setup is using legs and the exhaust is pushed through the legs, could there be a restriction there hindering the pressure to build up?

I was really hoping that having the Bosch guy out here he would test it tell me what is wrong with it happy to send it in but I am reluctant to spend more $$ on a hunch but at this stage it seems like my best option after I checked the turbos.

Will get there in the end, I hope :)
Click to expand...

Anything is possible but the probability of it happening to both engines at once is pushing the envelope. Wish you could find a good Volvo mechanic with the proper tools. They could check the output pressure of the pumps as it was running, but still keep going back to this is with both engines.
 
K-2

K-2

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Re: Volvo Penta AD41 power issue

What is your max RPM in neutral now?
Scarborough in post #33 you gave us some boost/rpm numbers. Were you in neutral or out running around under load when these readings were taken?

I hate to beat a dead horse but I keep going back to the controls. I'm not sure exactly what you have but before I switched to MMC controls I had Morse, all cable, so twin engines-2 stations that added up to 12 cables! Also 4 of these :
SeaStar Dual Station Transfer Unit - SeaStar Solutions 061371

Lots of monkey motion, works great until the cables stretch and get gunked up inside.
You have mentioned that backing off the throttle doesn't do anything for the first 50% of lever movement,,, sounds like there is a lot of slack in your systems. But you have checked this many times.
 
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Scarborough

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Re: Volvo Penta AD41 power issue

Hi Scott
The boost pressure was taken splitting the hose going from the intake manifold to the top of the injector pump under load. In neutral I did get some reading revving it up to 3500 of 1psi. When you ask if I have checked that there is no obstruction in the air side of the heat exchangers, that is the CAC just before the intake manifold, right? No I have not pulled these off ever, according to the workshop manual reconditioning charge air cooler (CAC) doesn't look that hard. Will pull them off, at this stage, why not :)
 
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Scarborough

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Re: Volvo Penta AD41 power issue

Hi K-2,
In regards to the cables, I would love to only have to replace the cables but we had the mechanic down in the engine room throttling the engines manually during a sea trial. The throttles do not use the SeaStar setup but the gears does.
 
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Scarborough

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Re: Volvo Penta AD41 power issue

AllDodge,
I agree and I don't understand why they are reluctant to do this? The local Volvo mechanic does have all the tools and is recommended by people I trust and respect, plus he is always happy to help so I will go back to him and ask for that check BEFORE I pull the IP off. The other tests I would like to see is pressure on the exhaust side of the turbo plus measuring the EGT's as Scott mentioned earlier.
 
Scott Danforth

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Re: Volvo Penta AD41 power issue

since you took your readings after the CAC just for giggles take a reading right after the turbos, prior to the CAC. if the readings only differ by about 1.5 psi, then it is not an obstruction in the CAC

did the Bosch mechanic check exhaust back pressure?
 
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Scarborough

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Re: Volvo Penta AD41 power issue

Hi Scott, will try that on the weekend and at the same time pull off the turbo exhaust cover just to see if the Turbos are ok.
 
Scott Danforth

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Re: Volvo Penta AD41 power issue

try to move the impeller shafts in the turbo housing. if it moves, you need to check it against spec. use a dial indicator and check both radial play and axial play of the impeller shaft on both ends.
 
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Scarborough

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Re: Volvo Penta AD41 power issue

Hi all,
Ok, I have just removed the Port CAC and there was no issues in there, at all, clean as a whistle. I can't say the same about the exhaust turbo though, please see attached photos. The gap between the blades and the turbo housing is around 2.5mm - 3.00mm, I tested it by using a drill piece and I managed to get the 2.5mm drill in there but 3.00mm is also very close, especially for the Port engine but not just there.
Port DSC00401.jpg
Port DSC00432.jpg
Stbd DSC00393.jpg
Stbd DSC00423.jpg

Can someone please tell me if these turbos are not right? To me they do not look right and would explain the low turbo boost at 2600 rpm?

Cheers,
Scarborough
 
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K-2

K-2

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Re: Volvo Penta AD41 power issue

I can't tell the end of the vane from the shadow accurately,,,probably just me;) .
Here is a few pics of a 41 turbo for sale on internet, rebuilt.41.jpg
turbine.jpg
580 hours seems very low to be having turbo problems on both engines,,,,there's that BOTH ENGINES thing again.
 
Scott Danforth

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Re: Volvo Penta AD41 power issue

2.5 to 3mm seams excessive. is there any radial or axial play?
 
alldodge

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Re: Volvo Penta AD41 power issue

I'm not sure you have a problem with the turbos. The first link is to Holset turbo manual and within the manual there are links to torque and clearance requirements.

http://www.myholsetturbo.com/manuals/HX30_32_35_38_40_GW.pdf
http://www.holset.co.uk/partsservice/service/HX_Service_Data_Sheet.pdf

There is no specification for clearance from housing to vanes, but there is specification for radial and Axial. Your vanes look good even through there is some soot, but no chips or scoring. In the manual there is a list of problems on page 28, which identifies issues which could cause lack of power
 
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Scarborough

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Re: Volvo Penta AD41 power issue

Hi Scott, AllDodge and K-2
Thanks for the pics K-2, looks better. There is no axial play at all and they spin very easy. Thanks AllDodge for the holset manuals, very good. I have had a turbo mechanic over here confirmed that they definitely needs replacing, guessed he would say that lol, but I did also get it confirmed by a college that has no financial gain either way. So next step would be to find either a reconditioned one or a new replacement as I have been told these will need resleeving etc etc.

There are many reconditioned on eBay varying from $800 to $1400US plus around $170US shipping it to Australia. I have two questions:
1 - I know the VP part number is 861260 but what is the original part number, K26, something, the plate that should have the details on it is missing? engine is a "AD41P-A 869033" from 1996(I am guessing)
2 - Any recommendations of reputable sellers?

Thanks all for all suggestions and help. I am feeling like this might actually fix it :) Will keep you all posted with any updates
 
Scott Danforth

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Re: Volvo Penta AD41 power issue

you should be able to just get a new center section
 
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Scarborough

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Re: Volvo Penta AD41 power issue

Thanks Scott, will check into that to see if anyone can do that locally.
 
K-2

K-2

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Re: Volvo Penta AD41 power issue

Yes they can be rebuilt, I called a turbo shop in Seattle last month and they quoted me $500 USD.
I will be shipping them one of mine in a few weeks .
Less than 600 hours and the turbos are shot? I wonder what is causing that ?
Good Luck !
 
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