Leaking cool fuel in Mercruiser 496 (2006)

djungeljim

New Member
Jun 20, 2016
27
Sweden
Boat Info
2006 280DA
Engines
496 MAG
After starting the engine the first time for the summer (started and ran with no problem) I noticed gas smell from the engine compartment. I belive I found the cause of the leak coming from top of the cool fuel unit (gen III).. Fuel seems to be seeping from the base of the fuel pressure regulator?? Has anyone heard of that problem?

I figured I should try replacing the o-rings to see if that fixes the leak; is it as simple as removing the two screws around the regulator and pull the regulator to remove it?

Looking at this picture I think the o-rings should be replace:able
https://weberpower.com/parts-weber-fuel-pressure-regulator-o-ring-kit.html
 
Last edited:
After starting the engine the first time for the summer (started and ran with no problem) I noticed gas smell from the engine compartment. I belive I found the cause of the leak coming from top of the cool fuel unit (gen III).. Fuel seems to be seeping from the base of the fuel pressure regulator?? Has anyone heard of that problem?

I figured I should try replacing the o-rings to see if that fixes the leak; is it as simple as removing the two screws around the regulator and pull the regulator to remove it?

Looking at this picture I think the o-rings should be replace:able
https://weberpower.com/parts-weber-fuel-pressure-regulator-o-ring-kit.html
You probably aren’t going to like how this experience plays out.

See my thread at http://clubsearay.com/index.php?threads/cf3-fuel-regulator-leak.92646/

There are others. Including a current one that chronicles my other engine. Cool Fuel paint delamination in the fuel cooler module cap is the root problem. Downstream issues include contaminated fuel rail and fouled injectors.
 
Ouch, yes that looks exactly like the leakage on mine. Thanks for your insight and your post!

Did you end up sand blasting the top cover?
On the engine detailed in that post, I replaced the entire CF3 unit because it was original to the boat. The initial CF3 design had problematic raw water connections that were prone to leaking so I needed to update the lower housing anyhow (paint delam was only in the cap in my case).

On my starboard engine, I replaced only the cap as the lower housing had already been updated at some point by the previous owner. This was much more economical at less than $200. The new cap is anodized—not painted. Unfortunately, on this engine paint made it downstream to my rail and injectors.

There’s a more recent thread of mine that details that remediation: http://www.clubsearay.com/index.php...l-rail-injector-removal-and-inspection.97847/
 
Blasting the cover works. Anodizing is overkill, it only comes in contact with fuel so it's no different than an aluminum gas tank.
 
Mercury may still be offering complimentary replacement of modules, injectors, fuel rails. I just had mine replaced and mercury supplied all parts and I paid labor. There should be topics on here about it.
 
Blasting the cover works. Anodizing is overkill, it only comes in contact with fuel so it's no different than an aluminum gas tank.
I don't disagree that blasting will work. I just didn't have convenient access to a local shop that could do it for me. Also, the replacement cap is a kit that includes the rubber cap o-ring, fuel regulator and quad-seal o-ring for the outbound fuel line. Part # is 8m0130861.

I will eventually have my old caps blasted and retain them for spares.
 
Last edited:
Mercury may still be offering complimentary replacement of modules, injectors, fuel rails. I just had mine replaced and mercury supplied all parts and I paid labor. There should be topics on here about it.
This is a good route to pursue, especially if you have a reliable/trustworthy local Mercury dealer.

For me, I need to keep the "professionals" at the local MMax as far from my ER as possible based on prior experience.
 
This is a good route to pursue, especially if you have a reliable/trustworthy local Mercury dealer.

For me, I need to keep the "professionals" at the local MMax as far from my ER as possible based on prior experience.
Luckily for me, my mechanic did the work through a dealer in the area that he knew. JP
 
Mercury may still be offering complimentary replacement of modules, injectors, fuel rails. I just had mine replaced and mercury supplied all parts and I paid labor. There should be topics on here about it.
I called my service center asking about this yesterday but they hadn't heard of this paint issue and asked me to send them the engine serial number to check for service bulletins. After searching information on this issue it seems the paint problem is not present in any service bulletins so I'm a bit concerned I won't get this help.
I'll try pushing some more but since I live in Sweden and not in the US I'm not so certain it will work here :/
 
On the engine detailed in that post, I replaced the entire CF3 unit because it was original to the boat. The initial CF3 design had problematic raw water connections that were prone to leaking so I needed to update the lower housing anyhow (paint delam was only in the cap in my case).

On my starboard engine, I replaced only the cap as the lower housing had already been updated at some point by the previous owner. This was much more economical at less than $200. The new cap is anodized—not painted. Unfortunately, on this engine paint made it downstream to my rail and injectors.

There’s a more recent thread of mine that details that remediation: http://www.clubsearay.com/index.php...l-rail-injector-removal-and-inspection.97847/
If I can't get replacement parts for free from mercruiser I'm considering removing the paint from my old lid.. although when searching for information on this problem I read that the screws for the lid are very prone to break because the holes aren't tapped!? That scares me from doing this myself
 
The screws come right out. What you read was in reference to the new replacement unit
 

Forum statistics

Threads
112,942
Messages
1,422,701
Members
60,927
Latest member
Jaguar65
Back
Top