2.3L OMC Engine Question

[Mark22]

I've got a question reguarding the timing belt on an 2.3L OMC Cobra engine. I took my boat to the lake today and after running it wide open for a while, I noticed that the engine had a clicking noise coming from the cylinder head or under the valve cover. It seems like the engine is running fine; it accelerates smooth and it only has a slight miss at WOT (I'm pretty sure that's a fuel filter issue). The clicking noise only seems to show up after the engine has been run and warmed up. I believe the culprit is the timing belt. I think that as the engine warms up, the belt is stretching and the valve timing is slightly off, resulting in a clicking noise. I was wondering if anyone had any experience with this kind of issue. If anyone knows where I could get a new timing belt, that would be helpful too.

1988 OMC Cobra 2.3L SOHC
Model # 232AMFTC
`88 Bayliner Capri 1750

 

[xtreme995]

Re: 2.3L OMC Engine Question

it also sound like you might could have a rocker working its way out of adjustment. simple things first i would pull the valve cover and check to make sure all of your rockers are set and your valves are not loose. if you want to take of your timing belt cover off you can check to see if your timing belt is worn by visual inspection of course and you can also pull on it if its real loose then it probably needs to be replaced i don't know exactly how much play the belt is supposed to have in it i wouldn't think very much though. but it is way easier to pull the valve cover than the timing belt cover so i would start there. hope this helps

 

[Don S]

Re: 2.3L OMC Engine Question

Just an FYI, You have an 87 engine, not an 88.

I think that as the engine warms up, the belt is stretching and the valve timing is slightly off, resulting in a clicking noise.

I doubt the belt is streatching, they just don't do that. You might have a faulty tensioner, but I still doubt the timing is causing the rocker arms to click. Probably just needs a valve adjust.

 

[xtreme995]

Re: 2.3L OMC Engine Question

thats what i'm thinking i haven't ever heard a timing belt make much of a noise on anything but dons is right the tensioner could be going bad. i would still check the valves for the clicking noise problem

 

[Mark22]

Re: 2.3L OMC Engine Question

Pulling the valve cover might be a good place to start. The thing that makes me wonder is why is the clicking getting worse after the engine has warmed up and been run wide open? I'm not sure exactly where it is coming from, but it sounds like its coming from the number 1 or number 2 valves. The noise isn't spark nock... It doesn't have the right sound for that. Could it have something to do with the ignition timing? I believe I set the timing last summer at 12degrees BTDC. I know the stock timing is 10 but it seemed to run better at 12. Also, I have got rid of the breaker point and installed a Pertronix ignitor ignition. Hypethetically, if the number 1 rocker arms were loose, would that cause the engine to loose power on acceleration or miss at high speeds?

Also, Don S, I know its a `87 model engine and drive. I just realized that I posted it wrong. Oops! It one of those `87 engines that got put into a `88 boat... I went round and round with the shift cable and gearset already. Thanks though!

 

[Don S]

Re: 2.3L OMC Engine Question

When things get warm or hot, they expand, tolerances change. Just do the valve adjust and see if things were a little over or on the edge of the tolerance for loosenes. After 20 years, things tend to be a little more worn and worse for the wear. I know I am.