Volvo Penta 5.0 Engine Problems

[The Big Chipper]

I just bought a 2000 Glastron GS229 with a 5.0L volvo penta. Original engine with ~245 hours.

We took it out and it ran for the first time this season. The previous owner ran it last season. After purchasing and running it, it did fantastic for 3 hours. Every once in awhile throttling up, we would feel a hesitation no more than a second or two.

Boat was taken to mechanic to inspect engine and fluids. They recommended a tune up so they changed out distributor cap, cables and plugs.

We got the boat back after tune up, launch it, start up and engine felt like it was running a bit wobbly/shaky. When throttling up in gear, at 1800 rpms it would start backfiring. Immediately took boat back to mechanic and they throttled it up in neutral constantly (unsure rpms but revved up) to diagnose thinking it was potentially the fuel/carburetor/plugs and eventually found out it was a fouled spark plug (one of the new ones). They replaced the plug and ran long throttled periods again (in neutral) to see if anymore backfiring sounded good and no wobbling. We departed dock and when reaching end of no wake and went to throttle back up, but there was no more power than when cruising no-wake speed, even at full throttle. I would put it in neutral and throttled up no problems and sounded like a normal revved up engine. But we couldn’t even get it out of water and on plane. Knew something was wrong and frustrated at that point unloaded everything and took it back to mechanic.

About 30 minutes later two of the mechanics took it out and said they were able to get it to plane after making adjustments. BUT now there was “knocking” coming from the engine and said they immediately turned around because they were concerned of blowing a rod, leaving them stranded.

To sum it up, my options now are to rebuild or get a remanned engine as per their recommendations. They suggest reman. We are a little skeptical and wondering if the mechanics doings are the cause for the engine issues that are now going on.

Any advice on the matter welcomed.

 

[alldodge]

Howdy
Sorry to hear about your troubles, but anyone that would rev a boat in neutral and expect find a fault is only a mechanic in name only. They have no business working on a motor.

You have not said what model or serial number the motor is.

 

[The Big Chipper]

It is a V8, 5.0GLPEFS; serial 4012018197

 

[alldodge]

Thanks for the SN

My guess is everything would have been OK if it was determined that there was a lean fuel issue at first.

What I think happened is carb was clogged up and needed cleaning, fuel pump replaced or other fuel system components. So the motor was run in a lean condition and burned a hole in a piston and/or tuliped a valve. The motor was not getting enough fuel and leaned out then detonation stated and it takes less then a minute to destroy a motor

Your motor could be rebuilt with less cost then another motor, but I would not let your current Mech's touch it. If you pull the motor and take it to a machine shop and reinstall, maybe less then 1500

Could get a reman from MM for $2400
https://www.michiganmotorz.com/vorte...ent-p-186.html

 

[The Big Chipper]

Wow! Thank you for the info! A crazy turn of events to say the least. Do you know anything of Jasper remanned engines? That is what their recommendation was, to get a 5.7L as replacement. Haven't seen much out there regarding their marine remans.

 

[alldodge]

Wow! Thank you for the info! A crazy turn of events to say the least. Do you know anything of Jasper remanned engines? That is what their recommendation was, to get a 5.7L as replacement. Haven't seen much out there regarding their marine remans.

My nephew use to work for them and they do a average job, but "again" I would not use their recommendation. Have already proven they cannot be relied upon.

If you change from 5.0 to 5.7 would be a good move and next to no additional cost, so all good. The initial issue of the failure has not been found. Going to a larger motor does need more fuel, not that much but still needs more. Use your same folks to do the new motor can cause the same end result

If you go with Jasper "YOU" call them and ask what the price is and warranty

 

[Augoose]

If it were my boat, I'd run a compression test on each cylinder to help determine whether there is significant damage to any cylinder. If compression checks out ok, then I'd then look at gas delivery and spark. If the fuel was from last year I'd pump it all out and start with fresh. I'd also clean and rebuild the carb. Ensure all battery wiring connections and connections behind the dash are clean and solid.

 

[72fj40]

It makes you wonder if they got the firing order right when they replaced the cap and wires. I agree, more diagnosis should be done.

 

[The Big Chipper]

All great ideas and options. If the solution isn’t due to Issues with the engines internal parts, those are nice cheaper options to start/test and would and definitely would be nice.

Im sure the carb does needs a good cleaning/rebuild. Ive honestly never dealt with any vehicle to have a lot of water in the fuel tank/system to have it experience issues.

 

[The Big Chipper]

Engine is out and parts taken off to see the block.