Newbie here, have a noise ?

[Kmort]

Re: Newbie here, have a noise ?

Dipstick beeing pushed out is usually caused by pressure building up in the oil pan. This often happens when there is a ventilation problem and can cause all sorts of trouble if the pressure gets high enough. Usually the dipstick is pushed out before this happens. Check ventilation hoses going from valve covers to flame arrestor, some valve covers also have a screen underneath, where the hose is connected, check to see that this screen (4,3's usually don't have any screens) and the hoses are not clogged.

I have a 4.3 and I've checked those hoses and they are open. However, I've found them smoking a little near the arrestor and when I pull them out of the valve covers they have some oil around them. To add to all this "oily matter", I just noticed an oil leak at or around the oil sensor next to the oil filter. Hope to get to the bottom of this when I return to the lake this weekend, but if any further ideas.... I'd greatly appreciate. Thanks.

 

[180shabah]

Re: Newbie here, have a noise ?

...I've found them smoking a little near the arrestor and when I pull them out of the valve covers they have some oil around them...

Normal

...I just noticed an oil leak at or around the oil sensor next to the oil filter...

Not normal, but should be very simple fix.

 

[adeneo]

Re: Newbie here, have a noise ?

A little oil and smoke from the vents is normal, as stated above.
If the vents are clear, the only other explanation for pressure in the oil pan is worn piston rings/cylinder walls, causing blow by. This is air passing via the piston rings and pressurising the bottom end.
You need to have a compression test done.
Pressure can only come from the pistons and this will show you which one is causing the problems.

Be certain that the engine does not have too much oil in it, this can cause the same syptoms.

The rattling noise in thread starters engine is probably piston movement in the cylinder bores, gets worse when increasing rpm's, and will cause a slight loss of power, often goes away on lower rpm's. Gets worse really fast when it's already started, as the piston movement will wear out the rings and bores excessively.

If you are getting blue smoke and burning oil smell (not just on start-up but when engine has been running) from exhaust definately worn rings.
If there's air pressure in the hole where the dipstick is when engine is running on idle, also definately piston rings.

Stupidly enough a new (as in new not second hand) dipstick may cure the problem if the rubber seal on the old one has worn or gone hard but there should be negative pressure in the oil pan if the engine is healthy, so even if the new stick stays in the engine, it will still need a full rebuild, and probably needs to have the cylinders bored out 0,30. Sorry!!

It's a common problem to have leaks appear in the oiling system when there's air pressure in the engine pushing the oil out any place it has a chance of escaping.

 

[NYboater]

Re: Newbie here, have a noise ?

I may have found my problem, i checked the timing and it was ok. Had the issue with choke sticking so I adjusted the tension on the spring. When i was there I remembered when I 1st rebuilt the carb I had issue with the float pin sticking to the inside of the bowl and floading the motor, there are no keepers hold it in. I did encounter some rough seas the last time I used the boat so I got thinking maybe the pin went the other way and dropped out one side causing the float to bind and not work . I pulled the top of the carb off and it had dropped out, not shure if I did this when I took it off, But I was careful when I removed it so I could check. There was also fine particals in the fuel bowl, maybe one jet was pluged and causing it to go lean , I did remove the fuel filter in the carb at the rebuild because it had a inline before the fuel pump, there was hard crystalized gas in the old fuelpump and carb before I replaced, maybe this is particals left in the fuel line that feeds the carb seeing that was not replaced.I will test this out this afternoon I hope and let everyone know the outcome.

 

[180shabah]

Re: Newbie here, have a noise ?

Sounds like you could be on to something there.

Let us know how it goes.

 

[NYboater]

Re: Newbie here, have a noise ?

Well the noise is still there. now it bogs if i hammer it, if i ease into trottle it runs great and actually better than before on top end. The noise might be the shutters, how can you check these, do you have to remove the exhaust manifold?

 

[NYboater]

Re: Newbie here, have a noise ?

Not the shutters, I removed top of manifolds and checked them this am, I pulled the plugs and the only one's that have color are the center plugs,front and rears look clean. So I'm back to a carb issue I beleive. Just don't know where to start looking again. It's a 2 brl merc carb .