Ficher Panda 12 mini, Water Mixer failures - Hunter 49

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I have a Ficher Panda 12 Mini in my 2008 Hunter 49. The Ficher Panda Genset now approaches 2500 hrs continues to chew up exhaust water mixers at an alarming rate of about 1 every 600-800 hours.
I will attempt to attach pictures to this entry.
I am looking for anyone who has the same genset with or with or without these problems and would be really great if I could get another Hunter 49 owners experience in this area.

The following are some lines I have followed;

1. Firstly I thought just bad luck, faulty from manufacture etc, so replaced, the genset had done about 800 hours then.

2. Next time I spoke to Ficher Panda whom where very helpful, and they said it could be a potential difference ( electrically) between where the water gets injected into the exhaust and hits the side. This seemed reasonable as the whole was consistent with where the water would hit. I had already looked for any electrolysis type action caused by stray currents and could not find any sign, but I added and earth wire from the mixer to the main body genset earth.
3. Next time around I mistakenly took the very black lumpy appearance on the inside of the flange where it bolts onto the manifold for Carbon build up, and attributed this to possibly insufficient load for clean burning. To load a 12 kw genset is not so easy even on my boat, but I made a point of seeing that the unit ran with a load of at least 20-40%.
4. No the latest one I realize there is very little carbon but major erosion that is chewing through the cast alloy indiscriminately. This latest one has two holes and one is just before it gets to the mixing are or main exhaust flow. The erosion is occurring in both the mixing elbow and in the manifold most predominately within 2” of the flange. What is about to fail now is the manifold itself is suffering this problem around the flange and will soon collapse as well and this will be a very costly part Im sure.

I am now pondering if this is exhaust back pressure related because the problem seems to be only within the last 1 inch of the exhaust manifold and on through about 2” inches into the mixer. For example the far end of the mixer where it is thinnest from new and the exhaust hose is connected has never shown and problem, and also back up in the exhaust manifold, ie further inside, the manifold seems fine.

So all ideas thoughts are welcome.

 

[kloudie1]

Since the failures aren't in the same locations, I'd say that Panda is providing a substandard casting for that part. There are crazy things that happen at mixing sites like this in terms of erosion and erosion/corrosion.. I see three options.. one is to continue to fight with Panda and replace often.. two would be to coat the new part before installation.. There is a process called "Electro-less nickel plating" (ENP) that is usually commercially available around industrial locations. It might be possible to put that small part in a bath with another industrial batch and have it plated .. the manifold might be a candidate as well if it can be grit blasted clean in the corroded area.... third option might be to fabricate a new part out of a material that would not be so affected by corrosion.. some of the Monel (400) or Inconel (622 or 625) alloys would be great.. again they would be available around pipe or machine shops servicing chemical plants.. Seems like this would be expensive, but a good shop could probably fab one for about the same price you are having to pay to Panda. If you have a buddy who is a metallurgist, ya might want to consult with him as well.

 

[SEMPERAVANTI41]

I think I remember reading in the FP manual that they consider the Exhaust Mixer a "wear" item and recommend yearly(?) replacement. I am planning as a winter project to remove it and have a new exhaust mixer fabricated by Marine Manifold located in Farmingdale, NY near my home. I plan to have it made of cupro-nickle, unless someone has a better suggestion. I had gotten a very reasonable price from them, but they need an actual part to copy. Also they were not sure how to make the female threaded hole for the temperature sender, but I don't think that's a big deal as I can tap a metric thread myself. I expect cost to be around $100.00. Is anyone interested in also having one made? I plan to have at least two made.

 

[Rick486]

A friend and I also have 6kw minis. Our experience has been that the mixing elbow will last around 400 hrs on our machines. I have 850 hrs or so and am on my 3rd elbow. I don't recall the cost but it's substantial. The part should be stainless steel or bronze rather than an aluminum casting. On my elbow there are two thin spots cast into the elbow to permit access to the bolts that hold the elbow onto the exhaust manifold. The elbows fail at that thin spot. Not a good design. I am fond of saying that the Northern Lights is an industrial machine and the Panda is a science project.

 

[MitchM]

some folks who were disgusted with the cost of yan mar mixing elbows went to a custom motorcycle shop and had one fabricated in stainless that lasted a huge amount of time longer than yan mars...

 

[Rick486]

some folks who were disgusted with the cost of yan mar mixing elbows went to a custom motorcycle shop and had one fabricated in stainless that lasted a huge amount of time longer than yan mars...

My comments were on Fischer Panda. Not Yanmar. My Yanmar 4jh4e has about 900 hrs and the mixing elbow was removed last summer and inspected. Clean and no problems.

 

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Kloudie 1:Yes I am approaching FP whom have to date been very helpful, but it seems a new service manager is on the floor and my last communications I received the standard response which was no help.
I will look into Electro-less nickel Plating but I’m currently in the Philippines (Puerto Galleria) and finding some of these things here can be very challenging and frustrating.
Yes re-manufacturing was also my thought but I had not considered other alloys, I was headed towards Stainless. FP Germany had advised me this probably wouldn’t help, but I’m now out of options. The Mixer should not be so hard to make in Stainless but the manifold itself I suspect has got maybe 800 hours left in it at best.

Semperavanti41: I hope your memory is in error, I would be up to 8 by now and probably would not have this genset any more. I’m afraid my metallurgist knowledge is not that flash and I am also unsure how cupro-nickle will react with the manifold, but I guess at this point a $100.00US investment is certainly an option, so YES i would be interested. My thought being if you/we are to make one then probably best we make out of whatever has the best chance of lasting in that environment, and I am no expert in this area. I’m also assuming you have the identical Genset/mixer elbow.

Rick486: Does the mixing elbow look the same on you 6kw minis ? If you don’t mind what are you paying for your elbows or have you managed to talk FP in supplying a couple ? As to Northern Lights FP and all the others. I have only had two types of problems with my FP... 1) Every hose Stainless Hose clip has broken and there must be 30 of the buggers (not one on my Yanmar by the way) and this mixer elbow. Of the others I have seen all are bigger and nosier for the same power, but its been awhile since I looked at the latest offerings.

MitchM Rick486: Yes this is about Ficher Panda but just in passing my Yanmar 4JH4TE has just over 3000 hrs Never had elbow replaced, and the only problem I have with my Yanmar is the heat exchanger end caps. See my blog https://screensaver49.wordpress.com/2014/11/30/novemberthailand-ao-chalong-yacht-haven/
Right now my Yanmar is out of action for the second time due to the heart exchanger and my FP is out of action due to the elbow

 

[Velero49]

Screen Saver,
Did you take the exhaust manifold off to remove the mixing elbow? It has two blind nuts, the temp sensor and the water injection hose all behind the. If you have pictures of the removal I would greaatly appretiate it. Thank you

 

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Mixer Elbow removal procedure:
Apologies if I'm telling anyone things they already know. I don't have any useful pictures but this should help

1. Drain coolant. I still have not found a good way to do this but what I do is disconnect the hose (11) ie the front right hand one facing the manifold and drain it into a container.
   
   
2. Disconnect radiator hose (19)the small over flow one.
   
   
3. Disconnect the bigger hose on top (01) at the left hand end.
   
   
4. If you did not disconnected the small hose front outer (11) to drain the coolant then do it now.
   
   
5. Loosen the rubber exhaust hose and push the hose clip down.
   
   
6. Disconnect the plug that connects the exhaust temperature sensor
   
   
7. Undo the three outer upper allen key bolts (21)
   
   
8. Undo the three lower ones behind the manifold
   
   
9. This leaves one lower/rear blind manifold bolt. The actual manifold has a slot (not a round whole) for this. So there is not need to remove this nut.
   
   
10. If you have disconnected everything above only the one blind nut on the manifold and one more hose behind the exhaust hose should be holding the manifold.
    
    
11. You may be able to get the hose on the mixer that is behind the exhaust hose either through between the starter, or from the rear just under the alternator. If you can loosen that hose clamp do so. If not don’t worry.
    
    
12. In either event you should now be able to twist the manifold out at the front slightly and wriggle it from side to side. If you do this while pulling up it will eventually begin to move and release.
    
    
13. Once it has moved up about ½” the rear lower blind slotted manifold bolt should be clear and this will allow you tilt the exhaust manifold away from the engine and allow further access to the hose mentioned above in step 11 that is behind the exhaust mixer.

 

[Rick486]

Screen Saver,

Rick486: Does the mixing elbow look the same on you 6kw minis ? If you don’t mind what are you paying for your elbows or have you managed to talk FP in supplying a couple ? As to Northern Lights FP and all the others. I have only had two types of problems with my FP... 1) Every hose Stainless Hose clip has broken and there must be 30 of the buggers (not one on my Yanmar by the way) and this mixer elbow. Of the others I have seen all are bigger and nosier for the same power, but its been awhile since I looked at the latest offerings.

Not exactly. It has a curve in it. It does have the blind nuts but on my machine, they are reachable. I believe they cost around $250. And no, FP has not given me any. They regard it as a service item.

Thank you

 

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I had managed to talk FP into supplying them (via Germany) as essentially I have worked with them to try and find some explanation. However it seems a new Service Manager has started and he is far less co-operative and simply following the service rule book not what is best for the customer or the product or the name. So the last one I bought at yep around the $250US mark, then of course there is freight and duty etc on top to get it to me here http://www.driper.com/sattrack/0/screensaver2016-data.kml in Philippines
I had to have the one I had welded up, because a new one just couldn't arrive in time and the gods were against me, throwing main engines issues as well at my Yanmar, a Typhoon and no sun, with batteries at an age of replacement 8years. But I now have a my new FP elbow and I'm going to coat the inside with something that will withstand the high temperature and see how that goes.
I hope Christmas is kind to you all.

 

[Velero49]

Thank you and Marry Christmas to you too.........

That's what I was afraid off - removing the exhaust manifold.... arrrrghhh I will probably replace the exhaust manifold gasket too.

 

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Ah its not so bad, once you have done it a few times
I have never replaced the gasket between manifold and head its metal as I recall and if you treat carefully it seems to be fine. The one between mixer and manifold I have replaced a few times, but not every time. The first time I got a new mixer it did not come with a gasket as I expected, this last one did come with one.
If you have not replaced those hose clips at some stage, I would at the very least replace the hard to get to ones or any that are easier with what ever you take off to do anything, because they will break I promise you.