Issues with Engine running????

[loudelectronics]

Ok I was out this afternoon surfing and the boat ran great. Came in for supper and then decided to go try the IBex out. Well the boat would not start. So I let is sit and boom,, started like nothing was wrong. Took it out and it ran fine. Came back in to get the board and took off again. The boat started dieing and then would not go over 5 or so mph. There was alot of white smoke coming from the exhaust. Anyways I get in the boat take off and boom,, runs fine like nothing was wrong. I then put perfect pass on and it died again. Not sure if this was just a coincidence. Started running fine again after. I pressed the taps button and it died. Then it started to run fine again. I noticed it was running a bit on the warm side well above the 190 that it normally runs at. I took the boat out and ran full throttle around the lake. Ran fine then as soon as the needle got to the 210 or so mark it died. Once it cooled down it ran fine again. After this last test at WOT it seems like it is running fine.

I am not sure if I have bad gas, plugged intake as I was in alot of muck a combo of the two or something seriously wrong here. It only billows white smoke when it is not running right, it is normal when running fine. But I drove it hard and long after all this and so far so good. Where are the fuel filters on the 24 V's? This might also be it. Coolant level is fine, oil level is fine.

Let me know what you guys think. I do not have a dealer any where close so don't tell me that. This is my vacation this week and need to use my boat.

Thanks for all the insite ahead of time.

[dogbert]

Do you have a closed cooling system?

You definitely have a cooling problem, your boat should not really run much above 175. That white smoke is probably steam from your engine overheating. Your engine is designed to go into protect mode.

I'd check you impeller and your raw water intake.

Under no circumstances do you want to run your engine above idle!

[chpthril]

White smoke is coolant/water in combustion chamber......not a good thing.

Bad impeller
Circulation pump
leaking intake manifold gasket
water in fuel
cracked head or block
leaking head gasket - when engine overheats, heads can bow and release tension on gasket.

Check oil for milky look.

[dogbert]

White smoke is coolant/water in combustion chamber......not a good thing.

Not always, I've had the symptoms he described after sucking up some debris into my impeller. As the impeller comes apart while towing someone, you'll see clouds of steam behind the boat that look like smoke (although, now that I have an FAE, I don't see that anymore).

But I'd check all the things chpthril said!

[laserfish]

If you are running that hot, I would think you would have alarms going off. I run 175 all the time. The only time it has been higher is when the impeller was coming apart and needed to be replaced.

[dogbert]

If you are running that hot, I would think you would have alarms going off. I run 175 all the time. The only time it has been higher is when the impeller was coming apart and needed to be replaced.

Not necessarily, if there's too much air in the engine, no alarms will go off. Surfdad had this issue and he blew his engine.

[zad0030]

Definately check the impeller!!!!

[laserfish]

All the more reason to change the impeller every year! Cheap insurance against overheating. Cost of impeller vs. Cost of engine.

[loudelectronics]

Ok, tell me more about this impellar?

My engine is the 6.0L Vortec with closed loop.

I have checked the oil and its good. The coolant level is variable however I have not added any since I have bought the boat. It seems to spit it out the overflow alot and makes a mess of my carpet.

The performance is sporadic. It will just decide to not start after it has been used for a while. Let it sit and cool and it is fine. It does seem to go into limp mode when it does get hot. As soon as it cools it is fine. Like I said after I ran it hard it seemed to be fine, I inspected the intake and there was some minimal debris in there so I think I got it flushed out. The thing that is getting me right now is why does it not start?

When the engine is running, it seems to run very smooth like nothing is wrong at all with it.

Just got update that it seems to be running fine tonight. I was not there to confirm.

[Jeffe]

The blinker fluid may need to be replaced & I would check out the Flux Capacitor while your at it.

[whitlock87]

I have a MP5.7 340hp and it runs at 140 f

[dogbert]

Ok, tell me more about this impellar?

My engine is the 6.0L Vortec with closed loop.

I have checked the oil and its good. The coolant level is variable however I have not added any since I have bought the boat. It seems to spit it out the overflow alot and makes a mess of my carpet.

The performance is sporadic. It will just decide to not start after it has been used for a while. Let it sit and cool and it is fine. It does seem to go into limp mode when it does get hot. As soon as it cools it is fine. Like I said after I ran it hard it seemed to be fine, I inspected the intake and there was some minimal debris in there so I think I got it flushed out. The thing that is getting me right now is why does it not start?

When the engine is running, it seems to run very smooth like nothing is wrong at all with it.

Just got update that it seems to be running fine tonight. I was not there to confirm.

If you had debris in your impeller, I'd have it replaced. Have you replaced it since you got the boat?

[loudelectronics]

The dealer told me they replaced it before I bought it. It has 70 hours. It will get some good use today and I will report back when I get some more seat time.

Thanks for the help so far.

Any body have this starting issue?

[zad0030]

If your impeler is damaged it makes perfect sense why the engine runs fine until it overheats. Becuase the impellers job is to pump water thoughout the engine to keep it cool. And until it heats up there will appear to be nothing wrong. When mine went out I noticed two things, small bits of white smoke out of the exhaust and the exhaust was louder, kinda like a speed boat or a nice muscle car.

[loudelectronics]

Well I think the system was just plugged. I ran some seafoam through it and 15 hours later it is running great. The starting problem only appeared once in the first tank of gas with seafoam and went away after a few cranks. I will have the impellar changed this winter.

Has anyone ever ran seafoam in there tank? I put it in one tank and at $4.60 a gallon I got 9.5 hours or 22 bucks an hour just teaching people how to surf and wakeboard with full factory ballast and 6 people in the boat. The tank after I only got 6 hours to a tank with out seafoam primarilly wakeboarding at 21 mph. Does this make sense? Ballast was the same but more people with seafoam. Second tank was less demanding as there were way less falls or stops and starts.