*Gen 3 Cool Fuel Module Issue*

73zeak said:
Well got the call from Marinemac yesterday. They say it is the fuel cool issue and it will be $900 to repair. That’s on top of the $500 already spent. Does this sound like the ballpark price for this repair?
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What exactly is wrong with it ? There's 2 pumps and a housing.
 
So I have the Gen 3 units on my 2007, 496 motors. Changed the filters last year no signs of paint chips.
I don’t recall seeing any paint on the inside of the bowl. Going to change the filters again before splash. Is it not advisable to remove the paint by soaking in solvent, ultrasonic bath or soda blasting?
Just so I am clear, Mercruiser will or will not cover the parts if engines are out of warranty?
 
Mike sandor said:
So I have the Gen 3 units on my 2007, 496 motors. Changed the filters last year no signs of paint chips.
I don’t recall seeing any paint on the inside of the bowl. Going to change the filters again before splash. Is it not advisable to remove the paint by soaking in solvent, ultrasonic bath or soda blasting?
Just so I am clear, Mercruiser will or will not cover the parts if engines are out of warranty?
Click to expand...

You DO NOT see the paint in the filter housing and the problem IS NOT with the paint on the housing itself - the problem IS with the cover that goes over the actual pumps (the pumps are AFTER the filters). The fuel pressure regulator is also mounted to this cover (the one on the rail is a dummy and does nothing). If you pull the regulator on the cover, you can often see if you have an issue - It is also extremely easy to use a gauge on the fuel rail to see if your pressure has jumped way up - IIRC your looking for 39-43lbs NOT 50+ like some show when the regulator is clogged with paint.......Yes, if you do have a problem, one solution is removing the cover and taking all the paint of with solvent or by some other means - then check the rails and have the injectors cleaned if necessary
 
I have a 2003 5.0 OM 625356 does this concern me do I have one of these modules on my engines?
 
I had the cool fuel module issue taken care of by Marine Max two years ago on my 330 DA. This past weekend my starboard engine had a water leak and it turned out one of the plastic threaded drain plugs that Mercruiser uses on the engines, in this case one of them on the cool fuel module, had cracked. The mechanic told me that the plastic they use becomes brittle from contact with anti freeze, and that will cause it to fail over time. We both agreed parts like this should be made of brass. The water pump housing on my 225 WE has brass threaded plugs, so I’m not seeing why these plastic plugs can’t be brass, although maybe there is some legitimate reason for it. Anyone else have this problem? Assuming these plugs can’t be changed to brass ones, it seems like at least these plastic plugs should be replaced on a regular basis.
 
lawndoctor said:
I had the cool fuel module issue taken care of by Marine Max two years ago on my 330 DA. This past weekend my starboard engine had a water leak and it turned out one of the plastic threaded drain plugs that Mercruiser uses on the engines, in this case one of them on the cool fuel module, had cracked. The mechanic told me that the plastic they use becomes brittle from contact with anti freeze, and that will cause it to fail over time. We both agreed parts like this should be made of brass. The water pump housing on my 225 WE has brass threaded plugs, so I’m not seeing why these plastic plugs can’t be brass, although maybe there is some legitimate reason for it. Anyone else have this problem? Assuming these plugs can’t be changed to brass ones, it seems like at least these plastic plugs should be replaced on a regular basis.
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That's a BS answer, raw water travels through those lines. It's a NPT thread so of course you could use brass, but could cause corrosion to the aluminum housing.
 
I assumed he meant the antifreeze from winterization. I also read somewhere that at some point they changed the material to a type of resin that was more durable.
 
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lawndoctor said:
I had the cool fuel module issue taken care of by Marine Max two years ago on my 330 DA. This past weekend my starboard engine had a water leak and it turned out one of the plastic threaded drain plugs that Mercruiser uses on the engines, in this case one of them on the cool fuel module, had cracked. The mechanic told me that the plastic they use becomes brittle from contact with anti freeze, and that will cause it to fail over time.
Click to expand...
I had this problem 2 years ago, I tried removing the blue plastic that was left, but was unable to get it out. The blue plastic was seemingly fused to the fuel pump. I plugged it with some silicone rescue tape, and it held for a season. Last year, the fuel pump had to be removed when replacing the water pump and all the pulleys, so with the pump on the bench, the mechanic was able to get the remnants of the blue plug out, and installed a new one. I think I should remove and reinstall the plug at least once a year and put some type of lubricant on the threads to keep them from locking up. The boat has never been winterized, just think it was an age issue.
 
Just spent the past week dealing with this issue. Thanks to all the comments on here I was able to diagnose my issue quickly. Port engine shut off on me abruptly. I could not get her to start. Got back on one engine to the marina and did some research.

Tested the unit and it was not getting any power, checked the relays and one was burnt. Replaced and still no go. Changed the CF III module and it fixed the problem. Looks like the CF III burnt my relay, while failing itself.

I will be replacing the other this weekend. Not worth getting stranded when you know there is likely to be a problem at some point
 
First thing I did when I bought this boat was change out both CF3s. They were working fine but not worth the headache that was likely imminent.
 
SMuleMD said:
Just spent the past week dealing with this issue. Thanks to all the comments on here I was able to diagnose my issue quickly. Port engine shut off on me abruptly. I could not get her to start. Got back on one engine to the marina and did some research.

Tested the unit and it was not getting any power, checked the relays and one was burnt. Replaced and still no go. Changed the CF III module and it fixed the problem. Looks like the CF III burnt my relay, while failing itself.

I will be replacing the other this weekend. Not worth getting stranded when you know there is likely to be a problem at some point
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That's a failed fuel pump, not a CF3 issue. The CF3 issue was about flaking paint and the bogus way the cooling lines attached. Fuel pumps wear out regardless of what the app is
 
scoflaw said:
That's a failed fuel pump, not a CF3 issue. The CF3 issue was about flaking paint and the bogus way the cooling lines attached. Fuel pumps wear out regardless of what the app is
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I agree that could be just a failed pump. I will let you know once I open the pump side to say if its a CF III issue...
 
I just recieved 2 of the updated housings.
8M0047216
As well as new pump covers and gasket.

The bolt holes for the 6 pump cover screws were not tapped/threaded.
WHATS UP WITH THAT?
Most of my old bolts are broken in the old housings. The ones that i did get out have threads that look fine but are messed up.
Ive tried some hardware store bolts that are m6×1 and thread in smoothly.
My guess is that the original bolts are streched? Why does Mercruser want $28 per bolt?

Ive been following several threads on the subject and have not herd any of this. I emailed the place I bought them from and hope to have some response soon.

Any thoughts?
Thanks
 
Not sure what your issue is. You say the holes weren't tapped , so you did the tapping ?
 
Sorry for the confusion.
The new housings have holes but no threads.

My original housings are the early style. Significant corrosion on the water side. Possibly salvageable but most of the bolts holding the cover broke. I spent hours over the course of days heating and cooling penatrant. Took them to a machine shop that broke most of them and wanted $40 each to drill them out. I punted and bought new housings and covers.
I saw someone who may have found the cause that the torque value in the service manual may be too high for the bolt size.
The bolts also seem excessivly long for holding the cover on. Im wondering if the bolts were streched when installed at the factory. Now im wondering if they are self drilling fastners. "One time use" engineered to fail! What makes them $28?
 
William Miller said:
I just recieved 2 of the updated housings.
8M0047216
As well as new pump covers and gasket.

The bolt holes for the 6 pump cover screws were not tapped/threaded.
WHATS UP WITH THAT?
Most of my old bolts are broken in the old housings. The ones that i did get out have threads that look fine but are messed up.
Ive tried some hardware store bolts that are m6×1 and thread in smoothly.
My guess is that the original bolts are streched? Why does Mercruser want $28 per bolt?

Ive been following several threads on the subject and have not herd any of this. I emailed the place I bought them from and hope to have some response soon.

Any thoughts?
Thanks
Click to expand...

The replacement I ordered came with everything, including the filter, and all cover holes were threaded already. Granted, it sounds like you purchased the housing only but I have to imagine the bolt holes should still be threaded. For the cost, I'd be returning them as defective rather than messing around tapping/threading the holes.
 
William Miller said:
Sorry for the confusion.
Now im wondering if they are self drilling fastners. "One time use" engineered to fail! What makes them $28?
Click to expand...

Based on the ones on the CF3 I removed, they are not "one-time use". Seems like the housings missed final inspection from the manufacturer. Never heard of them needing to be threaded by the installer.
 
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