HELP! Bayliner 1988 OMC 5.7L I/O engine V8

[Manipulator]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Hmmmm. Do you have a vacuum gauge? You can tell a lot from an engine with a vacuum gauge. Does the engine idle well despite the noise? When you rev the engine does the noise get louder? Back of the engine you are talking the intermediate housing. I'm no OMC mechanic. I would have to say you have a problem in the intermediate housing. I really do not think you have a engine problem.

 

[bruceb58]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

No intermediate housing on a Cobra which is what you have. <br /><br />With the drive removed, the only thing hanging on the crankshaft is the coupler.<br /><br />Sure sounds like bad main bearings to me but could possibly be the starter pinion gear not pulling completely away from flywheel due to corrosion.

 

[Wotknot]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Sound comes from back of the engine. Any guesses?

2 things come to mind.......a blown coupler or the u-joints

 

[KaGee]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Did you or did you not pull the drive? Your post is unclear. Pulling the drive elliminates it as a source. It has to come off anyway if you pull the motor.

 

[rizy1976]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Thanks guys for so much help. Its really motivating. I did not hear the engine while drive removed but the marina ppl told me they did remove the drive and the sound still existed. They did not dig deep into it as they started contemplating a remanufactured engine for $5500. <br />I started it engine afterwards the I brought it back from marina with drive back on. The is exactly when I heard. Engine did not idle good. I had to keep pulling the throtle hard to keep it running, engine made grinding noise from the rear end. There was some smoke around prop area. My friend removed the belts from front and sound was still there. My frined who is a car mechanic told me that he was sure that its not a bad motor sound as it was not knocking instead grinding. He suspected that there is something grinding at the rear end of the motor between motor and the drive. Also the engine did they stay started by itself without throtling may be cause of bad gas which might have been in the tank for years. My frined and I plan to take the engine out on weekend and then would try to trouble shoot. Any ideas what things we need to look for in the situtation.<br />Thanks for so much help.

 

[JoJoBetsy]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

The important question to ask is, "How much did you buy the boat for?" Unless you're into a project boat kind of mood, your breaking point will become fairly clear on whether to keep it or cut your losses. This is especially so since we are in the season, when the boat should be floating and not taking up your precious boating moments.<br /><br />And new boats versus old boats is the debate of the century. It's like the synthetic versus dino oil debate that really comes down to...again...that financial vs. floating break point. I prefer used boats myself and I admire your sense of adventure by having the guts to pull a motor on this ol'gal. There are some things that just need a professional and each of us will tell you differently what those "things" are. <br /><br />I always say owning a boat is like having a cash investment that only pays dividens in headaches and pleasure. That juxtaposition is the recreational boater's mentality. <br /><br />jb

 

[KaGee]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Good morning Rox!<br /><br />There is nothing in the drive line that would make a grinding noise once the stern drive is pulled. <br /><br />Wild random thoughts here... exhaust shutter making noise that is being interpreted as your grind.... something in the bellhousing riding against the flywheel... how about the starter bendix not totally disengaging... distributor bushings?????<br /><br />Your buddy may be right... at least I hope he is for your sake... I tend to think something internal "grinding" would have tied up by now.<br /><br />Once you pull that motor, you will need an alignment tool to properly reinstall the stern drive. Hopefully by now you have a manual coming to you.

 

[spartanpele]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

It might sound stupid, but I would get out the hammer, start up the engine on muffs, and then tap on the starter after the engine is running. If the starter is stuck, tapping on it might allow the engagement rod to swing back. <br /><br />Just be careful that you're not around any of the moving parts!! <br /><br />If it works, then take apart the starter or simply replace it.<br /><br />But I think the biggest thing you need to do is to determine where the noise is coming from. <br /><br />Is it the engine or the outdrive? If its the engine, what part (front, back, which side), and determine if its an internal or external noise? Have someone keep an eye on the oil pressure gauge to make sure it isn't peaking or extremely low, then listen closely to where the noise is from.<br /><br />Grinding noises are a result of something spinning and rubbing up against something else. So if you excelerate the rmps, the grinding would speed up or slow down accordingly. <br /><br />Pounding noises could be pistons, rods, even the wrong spark plug that the piston head is hitting.<br /><br />But you really need to determine where the noise coming from first before even considering a major engine overhaul. btw: pull each of your plugs and see what kind of wear they show... and get out a compression tester to test each of the cylinders too.<br /><br />But find the noise....

 

[rizy1976]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

That is great bit of advice... Thats surely is the way to go... Ill do some investigation coming weekend.. <br />thanks

 

[rizy1976]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Please give me some advice how to run the engine with drive take off... is it okey to run engine without anything hooked to it.... Where do I put the water hose when the drive is take off.... also is there a way to bypass the gas inflow from tank from a container that has fresh clean gas in it.<br />I checked the oil from the dip stick n seemed to be good with no level drop.<br />Any ideas on this....

 

[KaGee]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Look Here <br /><br />Follow hose #37 up to the thermostat housing. Remove the hose from the t-housing and rig up your garden hose there. Turn up the water pressure high enough to keep the engine temp normal. It does not take a lot.<br /><br />Follow the fuel line from the carb back to the fuel pump. Follow the fuel pump inlet line to hopefully a water seperation filter. Remove the line on the inlet side of the filter, and rig your external tank there. (Obviously, replace that filter cartridge first)

 

[Cptkid570]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

I don't know OMC, but I keep thinking u-joint, gimble bearing, or exhaust shutter (although that wouldn't grind). A good idea would be to remove the drive and run the engine without the drive. That would help eliminate a lot of stuff at the rear of the motor.<br /><br />The funny thing about Rox's original post is about the previous owner passing away. Funny how many broken boats are abandoned because the owner passed away. Leads me to think that the grinding noise led to the prior owners death! haha Just kidding.

 

[rizy1976]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Can anyone please explain me a lil bit, how to take the drive off the engine. Do I need to completely take it off the boat from rear. Would I need to crane to bring it down? What steps do I need to take for running the engine without drive hooked to it. Is it safe to run engine that way?<br />Please advice me on this as I plan to work on the boat tommorow. Thanks

 

[whywhyzed]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Originally posted by David 1995:<br /> JUST MAKE SURE YOU GET A "MARINE" BLOCK AND PARTS. Some people use auto-blocks, but they dont have the proper stainless parts, and not designed to run at high-rpm's constantly like a marine engine.

hmmm... where's that horse with the X's on it's eyes icon...<br />Stainless?<br /><br />brass core plugs, and marine camshaft all you need to worry about on the long block

 

[Darkhorse1201]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Taking off the out drive is fairly easy. First you will need to lower it all the way down. Disconnect the 2 trim cylinders. At this point you will either need a engine hoist, an over head crane, or at the least something to sit the outdrive on for stability. There are plenty of threads on here on how to build a quick stand for the outdrive. Do a search and you will see what I mean. Next you would remove the 6 bolts holding the outdrive to the transom mounting. The outdrive should then be pulled away from the gimbal housing via the engine hoist or rolled/ dragged back on the stand you have made. I wouldn't try to do it manually unles you have a couple of guys with you as the outdrive is fairly heavy and you wouldn't want to drop it. Hope this helps and welcome to iboats!

 

[rizy1976]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Thanks. I'm really impressed to be part of iboats. Never thought that ppl could be so much help in forums. Im glad found a good place so random. <br />Well, please also give me an advice if its okey to run the engine for diagnostics without the outdrive hooked up. I would try to eliminate possible causes of grinding sound one by one and would try to run the engine to see if the sound goes away. Any specific order that I shall follow after taking off outdrive?<br />Thanks

 

[ross_larter]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Sounds like the starter not dis engaging to me, take off the starter and see if the return spring is slipped off, you will be able to tell as the teeth will be half stripped as well.<br />ril

 

[KaGee]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Originally posted by Rox:<br /> ...Well, please also give me an advice if its okey to run the engine for diagnostics without the outdrive hooked up. I would try to eliminate possible causes of grinding sound one by one and would try to run the engine to see if the sound goes away...

YES you can run the engine without the drive on.<br />I gave you some advise above^^.<br /><br />Noises can travel, so finding the source is a matter of searching for it and listening.<br /><br />As I said earlier above ^^, once the drive is removed, there is nothing left to make noise in the drive line. The gimbal bearing remains motionless without the driveshaft through it.<br /><br />Any noise you hear after the drive is removed will be centered somewhere in the engine, bellhousing or exhaust.

 

[spartanpele]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

I don't remember reading it in the thread or not, but it also would be extremely helpful if you had a couple "boat savy" people come and look it over and listen to it before taking things apart. I don't mean mechanics at the local marina...I'm talking any family/friends/coworkers who know boat engines. It also wouldn't hurt to record the sounds and download them to the pc and then attach it here so people on the forum could give a listen. I know I wouldn't want to take things off until I exhausted all simple solutions first, (starter, pulleys, etc.), and its possible its something simple that another person might notice right off.

 

[rizy1976]

Re: HELP! Bayliner 1988 OMC 5.7L I/O engine V8

Hi folks, I did do some work on the boat.... took the drive off.. took the belts off from the front.. ran the engine... heard grinding noise.. tried to search for it.. it was quite noisy overall around the motor but it was obvious that it was comin from the rear end of the motor. My mechanic frined is very sure its coming out from the flywheel. He things the bushing on the flywheel or the wheel itself has prob. He wants to pull the motor out, open up the rear side of it and work on the flywheel area. He says the inner part of motor is good.<br />Does it makes any sense to you guys? Should I let him pull the motor out? Seems like thats the only option I have... what do u gurus think about this..<br />thanks