2010 4.3 TKS slight knock sometimes at idle

[mnfarmer93]

I have a 2010 4.3TKS in a crownline boat that has developed a slight knock at idle sometimes not always. What happen was I was going down the lake at about 3/4 throttle and the tether cord accidently got pulled and the motor got shut down. I restarted it right away, probably should have waited but didn't and noticed no oil pressure. Shut it down and waited a few minutes and started again except this time I had oil pressure but a little lower than normal and a small knock in the motor. I went down the lake a couple of miles half throttle and didn't hear the knock but when I slowed down to dock it appeared. I waited a few hours and started it again and all was good took off down the lake about 20 miles to the trailer and never knocked. Now tonight I take the kids out tubing and I was running good at first now when I shut it off and start it back up sometimes it knocks and sometimes it doesn't. When it is knocking the oil pressure at idle is lower that normal and it fluctuates at 3/4 throttle. I would say the if you start it and it starts to knock the oil pressure is probably around 10 psi and if it isn't knocking about 20. When you are going down the lake at about 3000 to 3300 rpm and the engine was knocking at idle the oil pressure will go up to 40 and fluctuate down to about 35 but if you start it and it isn't knocking at idle it goes up to 40 and stays there. This boat has about 30 hrs on it and the oil looks good but I am going to change it before I take it out again. So did I screw something up in the motor or is it something else?

 

[alldodge]

Re: 2010 4.3 TKS slight knock sometimes at idle

Having the motor shut off by the kill switch will not cause any problem. It's no more a problem then turning it off with the key. The knock your hearing is a coincidental factor only. As for the knock and lack of oil pressure let's start with, the gauge on your dash is not that accurate. If you have a bad connection, poor ground or a few other issues can cause the gauge to move around. As for the actual knock this needs to be looked in to. What weight and type oil are you using, and what type of oil filter?

 

[Bondo]

Re: 2010 4.3 TKS slight knock sometimes at idle

I have a 2010 4.3TKS in a crownline boat that has developed a slight knock at idle sometimes not always. What happen was I was going down the lake at about 3/4 throttle and the tether cord accidently got pulled and the motor got shut down. I restarted it right away, probably should have waited but didn't and noticed no oil pressure. Shut it down and waited a few minutes and started again except this time I had oil pressure but a little lower than normal and a small knock in the motor. I went down the lake a couple of miles half throttle and didn't hear the knock but when I slowed down to dock it appeared. I waited a few hours and started it again and all was good took off down the lake about 20 miles to the trailer and never knocked. Now tonight I take the kids out tubing and I was running good at first now when I shut it off and start it back up sometimes it knocks and sometimes it doesn't. When it is knocking the oil pressure at idle is lower that normal and it fluctuates at 3/4 throttle. I would say the if you start it and it starts to knock the oil pressure is probably around 10 psi and if it isn't knocking about 20. When you are going down the lake at about 3000 to 3300 rpm and the engine was knocking at idle the oil pressure will go up to 40 and fluctuate down to about 35 but if you start it and it isn't knocking at idle it goes up to 40 and stays there. This boat has about 30 hrs on it and the oil looks good but I am going to change it before I take it out again. So did I screw something up in the motor or is it something else?

Ayuh,.... Welcome Aboard,.... Right when ya restarted it,....

Did it turn over briskly, or did the starter Labor,..??

Btw,... a paragraph or three would make yer posts Alot more readable by Us ole farts,...

Don't worry 'bout the wasted web space,.... iboats is quite tolerant,...

 

[mnfarmer93]

Re: 2010 4.3 TKS slight knock sometimes at idle

Sorry about the no paragraphs English and writing is not my strong suit.
The filter is a mercury and as far as I know it has mercury 25w-40 oil in it.
I bought the boat late enough last year that I could not test run it but it was cheap enough I figured I could chance it. It had about 20 hrs on the tach when I bought it,the oil looked like new and I have 40hrs on it now. I should have changed it but I didn't my bad. I had it out 3 times before this and it ran like a top until I accidently killed it. When it died and I started it back up it started normal but it had no oil pressure. Also I think it is only at idle when it knocks or ticks and not when I speed it up but I am a little hard of hearing so I might not be able to hear it beyond idle. But I do know it is intermediate at idle which I feel is quite odd. At first I thought that I messed up a valve but wouldn't it do it all of the time?

 

[alldodge]

Re: 2010 4.3 TKS slight knock sometimes at idle

With so few hours on the motor the trouble could be because it sat so long. Machines can give you fits if they don't get used. You might be hearing a tick from a calapsing lifte, but as before it's difficult turning sounds into words. If it is a knock from a rod bearing it should get much louder as the speed increases. If you can get a hold of a hand held mechanical oil pressure gauge put it in the place where your electrical one is. If not suggest you change the oil and filter so you have a baseline. The engine may just needs some more time on it to free up, but it is unknown right now.