I am new to this forum but wanted to post this problem, repair steps, and ultimate repair story. I dealt with this problem for months and it drove me crazy. I went through the forums repeatedly but wasn’t able to find what ended up fixing it.
August 2015 – Purchased the boat with 185 hours on the Volvo 5.7 GI engine (2005 MY). The boat was meticulously maintained and had a recent fuel pump/cell.
September 2015 – Had 6 adults on the boat (most I had to date) on a choppy day. After 40 mins, I hit some chop at 3200rpm and the engine sputtered/cut out. All of the gauges went to zero and popped back up again. This happened a few times in rapid succession. As I went to shift to neutral, it cut out completely. It started back up fine. It did this a few more times and I decided to call it a day. I could not get above 2500 rpm without the engine cutting out.
At this time, I also noticed the gas gauge pinned on 7/8 full. It didn’t even wiggle. For an hour of use, it should have come off this measurement, or so I thought.
I brought the boat to the Cobalt dealership as they had done the fuel cell. I felt it could be related to that as the boat seemed to be choking under load. They found codes but no mechanical issues. They thought the codes might have been left over from when they did the fuel cell. They weren’t sure why but they cleared the codes and ran the boat in their tank for 45 mins – no issues.
October 2015 – I brought the boat out on a weekday evening to test it. The conditions were calm. It ran beautifully.
We went out the following weekend and the exact same issues occurred.
I went to the forums. I read about a large host of issues it could be. I checked all of the plugs around the throttle as some said they may be loose. I checked the connectors to the fuel cell as some said they might be loose, dirty, or corroded. I made sure the batteries were 100% charged (battery tender) and the connections were tight. I made sure the alternator connections were tight.
When I checked the fuel tank (hadn’t filled up since before the first issue occurred), the amount of pressure that released from the cap was scary. It sounded like I opened a bottle of soda. I began to focus on the fuel vent line as I read this very well could be the issue which causes the pressure to build and starve the engine for fuel. It made sense to me. I followed the line from the tank to the bow (not easy) and could not find any kinks. I checked the vent fixture on the exterior of the boat and noted the screens had been gunked up. I removed the o-rings and screens, soaked them in cleaner, then scrubbed with a small brush to remove the gunk, then reinstalled.
I also added marine fuel stabilizer to the tank and filled it up. During fill up, I had fuel shoot out of the vent port on the side of the boat pretty quickly. It took 10 more gallons after that, although I had to nurse those 10 gallons in. It took over 10 minutes to get those 10 gallons in.
I took the boat out again. Same issues.
November 2015 – I took the boat to a different dealership in town. My friend happens to sell boats there. He felt that his head mechanic could get it fixed. We went through everything and they ran some tests. They found codes again and also noticed that the plugs, cap, and rotor were in bad shape. They appeared to be original, or close to it. They replaced them, cleared the codes, and ran the engine in the tank for 45 mins – no issues.
I took the boat out 3 times before it started acting up again. The first two times were only for about 30 minutes. Again, the issues always presented themselves at around the 30-40 minute mark. I ran the boat with the gas cap undone, in case the pressure issue was the case. The issues still occurred.
January 2015 – I brought the boat back to the second dealership and went through the issue list. They decided to look deeper into the venting issue as well as the fuel gauge being pinned on full. They ended up finding a good amount of fuel filling the vent line. They blew out multiple ounces of fuel from that line. They said that this definitely played a role as the system could not breathe (cap closed tight, and vent line blocked solid by fuel). They ended up running a second vent line to the back of the boat. They felt this would fix that issue. They also tested the gauge.
I took the boat out and the gauge worked. It also seemed that the fuel tank was venting correctly.
After 40 minutes, yep, it happened again. The boat would cut out above 3k rpm when I hit chop. I decided to drop all but one passenger at the dock and figure this thing out. It was fairly calm out as it is still early in the season. Most of the lake was smooth. I was able to run on the lake at 5k rpm with smooth waters. As soon as I hit waves, it cut out. I felt I was getting somewhere here. I ran with the engine bay open and had them look for anything out of the ordinary when the engine cut out. No luck. I sat there in the middle of the lake and talked this out. I decided to check the gauge connections as I noticed the battery gauge bouncing around when driving. I thought this was odd. All the gauge connections were fine. When I was under the dash, I figured I would check the switches and circuits. All fine. The last thing to check under the dash was the ignition. There were 5 different connections on the ignition, each terminal connection was affixed with screws. I checked the first three which were all right. I got to the fourth and my face lit up. I got a full 2 turns of the screw by-hand. I got another ½ to ¾ with my knife (couldn’t get a long screw driver in there). With 2.5 turns undone, the connectors were loose on the terminal. As I hit the waves, they could jostle and briefly lose connection ultimately causing the engine to cut out. I finished tightening up the rest, closed everything up, and launched it. I ran nearly full throttle over waves for 10 minutes. I wanted to beat it up to make 100% certain this was it.
Guess what? It was. That fixed it.
I spent the next morning tightening every screw, bolt, and connection on the entire boat. This is probably good practice to do annually. Some of the panel screws were pretty loose. Fortunately, none of the mechanical or electric connections were loose – only that single screw on the ignition.
I called the dealership on Monday to let them know. I recommended that they check that in the future. Now, I know the cap, plugs, and rotor needed replacement. I saw them, they were rough. Also, the vent line was definitely an issue. I don’t feel too bad about getting those problems fixed.
I hope this account helps someone else out there. The boat ran beautifully since day 1. We knew it was a solid, well maintained boat. With only 185 hours, the engine was barely used for a 10-year old boat. I do a lot of my own auto repairs myself so this was very frustrating. I am very happy that I found this issue and fixed it. I learned a lot through this experience. Thanks for taking the time to read this.
August 2015 – Purchased the boat with 185 hours on the Volvo 5.7 GI engine (2005 MY). The boat was meticulously maintained and had a recent fuel pump/cell.
September 2015 – Had 6 adults on the boat (most I had to date) on a choppy day. After 40 mins, I hit some chop at 3200rpm and the engine sputtered/cut out. All of the gauges went to zero and popped back up again. This happened a few times in rapid succession. As I went to shift to neutral, it cut out completely. It started back up fine. It did this a few more times and I decided to call it a day. I could not get above 2500 rpm without the engine cutting out.
At this time, I also noticed the gas gauge pinned on 7/8 full. It didn’t even wiggle. For an hour of use, it should have come off this measurement, or so I thought.
I brought the boat to the Cobalt dealership as they had done the fuel cell. I felt it could be related to that as the boat seemed to be choking under load. They found codes but no mechanical issues. They thought the codes might have been left over from when they did the fuel cell. They weren’t sure why but they cleared the codes and ran the boat in their tank for 45 mins – no issues.
October 2015 – I brought the boat out on a weekday evening to test it. The conditions were calm. It ran beautifully.
We went out the following weekend and the exact same issues occurred.
I went to the forums. I read about a large host of issues it could be. I checked all of the plugs around the throttle as some said they may be loose. I checked the connectors to the fuel cell as some said they might be loose, dirty, or corroded. I made sure the batteries were 100% charged (battery tender) and the connections were tight. I made sure the alternator connections were tight.
When I checked the fuel tank (hadn’t filled up since before the first issue occurred), the amount of pressure that released from the cap was scary. It sounded like I opened a bottle of soda. I began to focus on the fuel vent line as I read this very well could be the issue which causes the pressure to build and starve the engine for fuel. It made sense to me. I followed the line from the tank to the bow (not easy) and could not find any kinks. I checked the vent fixture on the exterior of the boat and noted the screens had been gunked up. I removed the o-rings and screens, soaked them in cleaner, then scrubbed with a small brush to remove the gunk, then reinstalled.
I also added marine fuel stabilizer to the tank and filled it up. During fill up, I had fuel shoot out of the vent port on the side of the boat pretty quickly. It took 10 more gallons after that, although I had to nurse those 10 gallons in. It took over 10 minutes to get those 10 gallons in.
I took the boat out again. Same issues.
November 2015 – I took the boat to a different dealership in town. My friend happens to sell boats there. He felt that his head mechanic could get it fixed. We went through everything and they ran some tests. They found codes again and also noticed that the plugs, cap, and rotor were in bad shape. They appeared to be original, or close to it. They replaced them, cleared the codes, and ran the engine in the tank for 45 mins – no issues.
I took the boat out 3 times before it started acting up again. The first two times were only for about 30 minutes. Again, the issues always presented themselves at around the 30-40 minute mark. I ran the boat with the gas cap undone, in case the pressure issue was the case. The issues still occurred.
January 2015 – I brought the boat back to the second dealership and went through the issue list. They decided to look deeper into the venting issue as well as the fuel gauge being pinned on full. They ended up finding a good amount of fuel filling the vent line. They blew out multiple ounces of fuel from that line. They said that this definitely played a role as the system could not breathe (cap closed tight, and vent line blocked solid by fuel). They ended up running a second vent line to the back of the boat. They felt this would fix that issue. They also tested the gauge.
I took the boat out and the gauge worked. It also seemed that the fuel tank was venting correctly.
After 40 minutes, yep, it happened again. The boat would cut out above 3k rpm when I hit chop. I decided to drop all but one passenger at the dock and figure this thing out. It was fairly calm out as it is still early in the season. Most of the lake was smooth. I was able to run on the lake at 5k rpm with smooth waters. As soon as I hit waves, it cut out. I felt I was getting somewhere here. I ran with the engine bay open and had them look for anything out of the ordinary when the engine cut out. No luck. I sat there in the middle of the lake and talked this out. I decided to check the gauge connections as I noticed the battery gauge bouncing around when driving. I thought this was odd. All the gauge connections were fine. When I was under the dash, I figured I would check the switches and circuits. All fine. The last thing to check under the dash was the ignition. There were 5 different connections on the ignition, each terminal connection was affixed with screws. I checked the first three which were all right. I got to the fourth and my face lit up. I got a full 2 turns of the screw by-hand. I got another ½ to ¾ with my knife (couldn’t get a long screw driver in there). With 2.5 turns undone, the connectors were loose on the terminal. As I hit the waves, they could jostle and briefly lose connection ultimately causing the engine to cut out. I finished tightening up the rest, closed everything up, and launched it. I ran nearly full throttle over waves for 10 minutes. I wanted to beat it up to make 100% certain this was it.
Guess what? It was. That fixed it.
I spent the next morning tightening every screw, bolt, and connection on the entire boat. This is probably good practice to do annually. Some of the panel screws were pretty loose. Fortunately, none of the mechanical or electric connections were loose – only that single screw on the ignition.
I called the dealership on Monday to let them know. I recommended that they check that in the future. Now, I know the cap, plugs, and rotor needed replacement. I saw them, they were rough. Also, the vent line was definitely an issue. I don’t feel too bad about getting those problems fixed.
I hope this account helps someone else out there. The boat ran beautifully since day 1. We knew it was a solid, well maintained boat. With only 185 hours, the engine was barely used for a 10-year old boat. I do a lot of my own auto repairs myself so this was very frustrating. I am very happy that I found this issue and fixed it. I learned a lot through this experience. Thanks for taking the time to read this.
