View Full Version : valvetrain noise
Every once in a while, I hear what sounds like a drivetrain noise. It's a '95 TBI with 650 hrs. Can oil level have an effect on this? I recently did an oil change, allowing it to drain for 2 hrs, and added 5 quarts. The dipstick reads about 1 mark above high though (supposed to take 5.5qts). Can the high oil level contribute to such noises? Should I drain that amount of excess out?
If the boat is level and it reads high, I would remove enough to get back to full. If you hear clicking, it may be the injectors. Remove the flame arrestor and listen to it. Otherwise. wit the motor running, remove one or both of the oil filler caps(if it has 2) and look in to see that there is oil running along the lowest part of the head, below the valve springs. Do you have any blue smoke on start-up after the boat sits for more than a few hours?
08-29-2004, 12:37 AM
My boat makes that sound and like JimN said it was diagnosed by my mechanic buddy on the water.. He said the TBI will make a clatter type of noise when idling sometimes.....
Is it accurate to level the boat on the trailer, and check the oil level cold? I know the manual says to check it hot, but I've always checked car engines (except dry sump systems) cold. I don't notice any blue smoke after start up or after sitting, but I guess it would have to be out of water to do so.
As for the noise, I put a screwdriver to my ear and to the valve covers and water pump, and couldn't find the noise, so it very well could be the tbi. I'll check it next weekend when I run it. It only happens at idle. You can rev it and the ticking follows some, but I've never heard it at speed. Is this just a characteristic of tbi?
As long as the boat is relatively level you can check the oil and not need to worry about whether it's accurate . If the bow is up and it shows overfull, you should really get it to the proper level.
You generally won't hear noise from the injectors above idle because of the other sounds masking it. They're mechanical, but triggered electrically.
Thanks everyone. I'll listen at the injectors when I hear it again, and I'll get the oil to the correct level.
08-30-2004, 08:32 AM
DWE, my '95 did this when I would run it at WOT and then back it down. Turned out to be the valve train. Loosened every arm until they made noise, tightened it until the noise went away, and give it another quarter turn. I took it out this weekend and it ran perfectly.
I don't think I've heard of the valvetrain bolts actually loosening before, but that will give me another thing to look at. Hopefully it will be a simpler problem. But if not, I'll pull the valve cover gaskets and torque everything to spec.
08-31-2004, 08:29 AM
Mine has 937 hours and with that many hours you are bound to have a couple lifters go out of spec.