Cool fuel module ever leak water in to the gas?

Nick70

Nick70

Active Member
Apr 20, 2016
206
New England
Boat Info
2006 Searay 260 DA 496 mag
RAYMARINE stuff.
Engines
496 Magnum
Bravo III
2006 260 DA, 496 mag bravo III.
Serious internal engine problems. Water in oil. Low compression in two cylinders 38/75..it’s bad. Just checked the gas in the cool fuel module and both sides have water in the gas. The ‘out’ side also has a substantial amount of crap..sediment..in it. Sounds/looks like an internal leak in the cool fuel module itself. Is this a thing? Never heard of that happening. Only with the older units having paint wear off the top cover. This is not the case in my situation. I’ll call Mercury on Monday. But any info is appreciated.
I’d hate to put my fresh rebuild together (some time in the future) with the same culprit. Need to figure a way to test it for internal leak also.
 
bfernald0 said:
Absolutely it can. Check out this guy's youtube video. He's also more than happy to talk to you if you call him.

Click to expand...
He just rebuilt mine..I’m talking with him now.
Figuring out what’s happening.
Thanks
 
jmauld said:
How much is a rebuild?
Click to expand...
I’ll look for the receipt or on my bank statement but it was a few hundred. Well worth it though considering a new unit is around $1400. BUT, you can’t even get one now.
 
bfernald0 said:
Let me know what happens. I have not used him yet, but have spoken with him. Let me know if he screwed up.
Click to expand...
I spoke with Jack at length today. Whatever happened, I don’t think he screwed up and I’d continue to do business with him. I’ve called him a couple times and he always picks up and talked me through the symptoms. He’s very knowledgeable.
I’m tearing the engine down now. Got the heads and manifold off. Took off the module and checked the gas in it. Filter side had some water. Fuel pump/pressure regulator side had a little water, and some sediment in it. That’s when I called him. He asked how I checked the gas. I poured it in to a clean container. He said the way to do it, especially on the fuel pump side is with a turkey baster to suck it out, as by pouring it, no matter how much you may have cleaned the outer edge, the gasket material is grungy and will slop right off. So that’s possibly what I’m seeing in the gas. He advised I pull the pressure regulator and check that filter. I did..it was spotless. This supported his idea of gasket crap contamination. I could pull the whole pump assembly out but only if I’m ok with basically rebuilding it, as wires and stuff would be pulled apart in the process. As much as it would be awesome to definitely look and see the inside, I’m not there yet. My module had already been re fitted with the new non painted cap. His hypothesis is, the previous owner may have done that, but not had the injectors checked and cleaned. as they get clogged, the burn leans out..causing valve overlap..allowing for water to get sucked in from the exhaust manifolds. I have a lot of water in my oil. He advised I check the injectors. I did. My two low compression cylinders injectors were gross. I tapped them on wood and of course black flecks of what looked like could be old paint chips fell out. Seems like it could have been a creeping problem for a long time( got the boat with aprx 450 hrs, now has 627) which recently became very noticeable.
he even said with a 496, you won’t really notice if one cylinder isn’t firing.. well, I was down two and could definitely tell. I had done plugs, wires, coils..compression test finally. 6 were 155-175..#1 was 38psi, 8 was 70psi.
that’s when I knew I was in bad shape. I marvel mystery oiled it hard..what did I have to lose?..got #1 up to 60psi lol..
Bore scoped it..looked like a chocolate milk shake.
then started the tear down. I’ll have everything magna fluxed and checked out. New bearings, rings, etc..port polis the heads..valve job. Maybe some higher performance stuff..maybe not. I want reliability. I definitely don’t want the same thing happening again though. But he pressure tested it twice for 10 minutes each time. And the pressure regulator filter was spotless..which is co located with the pump in the same compartment were I poured the suspect gas from, which supports his theory. This is a learning experience for sure. I know this boat and engine a lot better. I’m kind of ok with it..it is what it is and I’m doing most everything myself.
I’m definitely grateful to have found Jack for sure. He’s professional, extremely knowledgeable and takes the time with people.
sorry for the lengthy response..
 
Valve overlap? Never heard that one before. Sounds like a blown head gasket and water in your fuel tank. JMO
 
Nick70 said:
I spoke with Jack at length today. Whatever happened, I don’t think he screwed up and I’d continue to do business with him. I’ve called him a couple times and he always picks up and talked me through the symptoms. He’s very knowledgeable.
I’m tearing the engine down now. Got the heads and manifold off. Took off the module and checked the gas in it. Filter side had some water. Fuel pump/pressure regulator side had a little water, and some sediment in it. That’s when I called him. He asked how I checked the gas. I poured it in to a clean container. He said the way to do it, especially on the fuel pump side is with a turkey baster to suck it out, as by pouring it, no matter how much you may have cleaned the outer edge, the gasket material is grungy and will slop right off. So that’s possibly what I’m seeing in the gas. He advised I pull the pressure regulator and check that filter. I did..it was spotless. This supported his idea of gasket crap contamination. I could pull the whole pump assembly out but only if I’m ok with basically rebuilding it, as wires and stuff would be pulled apart in the process. As much as it would be awesome to definitely look and see the inside, I’m not there yet. My module had already been re fitted with the new non painted cap. His hypothesis is, the previous owner may have done that, but not had the injectors checked and cleaned. as they get clogged, the burn leans out..causing valve overlap..allowing for water to get sucked in from the exhaust manifolds. I have a lot of water in my oil. He advised I check the injectors. I did. My two low compression cylinders injectors were gross. I tapped them on wood and of course black flecks of what looked like could be old paint chips fell out. Seems like it could have been a creeping problem for a long time( got the boat with aprx 450 hrs, now has 627) which recently became very noticeable.
he even said with a 496, you won’t really notice if one cylinder isn’t firing.. well, I was down two and could definitely tell. I had done plugs, wires, coils..compression test finally. 6 were 155-175..#1 was 38psi, 8 was 70psi.
that’s when I knew I was in bad shape. I marvel mystery oiled it hard..what did I have to lose?..got #1 up to 60psi lol..
Bore scoped it..looked like a chocolate milk shake.
then started the tear down. I’ll have everything magna fluxed and checked out. New bearings, rings, etc..port polis the heads..valve job. Maybe some higher performance stuff..maybe not. I want reliability. I definitely don’t want the same thing happening again though. But he pressure tested it twice for 10 minutes each time. And the pressure regulator filter was spotless..which is co located with the pump in the same compartment were I poured the suspect gas from, which supports his theory. This is a learning experience for sure. I know this boat and engine a lot better. I’m kind of ok with it..it is what it is and I’m doing most everything myself.
I’m definitely grateful to have found Jack for sure. He’s professional, extremely knowledgeable and takes the time with people.
sorry for the lengthy response..
Click to expand...
 
What a mess. Do you check the oil regularly? Seems odd that all of a sudden you'd have a bunch of water in it due to longterm water ingestion. How did the exhaust valves look? Corroded? How'd the manifolds look?

Cylinders 1 and 8 are an odd combo. Usually when you've got water ingestion going on, the valves toward the stern, on an i/o that would be 7 and 8 I believe, corrode first as the water runs downhill. That's where you tend to lose the compression.

If you're tearing the whole thing apart, I'd also check the oil cooler.
 
scoflaw said:
Valve overlap? Never heard that one before. Sounds like a blown head gasket and water in your fuel tank. JMO
Click to expand...
Big block v8s, depending upon how they are timed, can actually create brief periods of vacuum in the exhaust. In a boat that can be a real problem. This happens at idle. Never want to let them idle for long periods at the dock,. And before shutting them down, it's a good idea to run them up to blow any excess moisture out of the exhaust.

https://www.cpperformance.com/t-what_is_exhaust_reversion.aspx
 
bfernald0 said:
Big block v8s, depending upon how they are timed, can actually create brief periods of vacuum in the exhaust. In a boat that can be a real problem. This happens at idle. Never want to let them idle for long periods at the dock,. And before shutting them down, it's a good idea to run them up to blow any excess moisture out of the exhaust.

https://www.cpperformance.com/t-what_is_exhaust_reversion.aspx
Click to expand...

This one shows the phenomenon even better.

 
bfernald0 said:
Big block v8s, depending upon how they are timed, can actually create brief periods of vacuum in the exhaust. In a boat that can be a real problem. This happens at idle. Never want to let them idle for long periods at the dock,. And before shutting them down, it's a good idea to run them up to blow any excess moisture out of the exhaust.

https://www.cpperformance.com/t-what_is_exhaust_reversion.aspx
Click to expand...
He has a stock 8.1 motor with ecm controlled timing. With thousands of these motors in use this is virtually unheard of.
 
Cool fuel modules #8M0047215 are available again. I see them showing in stock at quite a few marine part sites and on ebay. I had seen them out of stock "indefinitely" for the past few weeks I have been looking. They are not cheap, $1600 delivered (incl tax and shipping). For my 2005 motor, the extra $$ is worth the peace of mind that I'm unlikely to have a fuel module issue in the near future.

I'm also considering installing an upstream (between tank and fuel module) standalone fuel filter/water separator to augment the filter in the CF3.

Thoughts?
 
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