4.3 with a bad cam and distributor - What next?

[Lommerse33]

I've got a 4.3 V6 in a Rinker 186 Captiva that quit on me in September. I'm not exactly a DIY, but I try to stay informed and have qualified people do the work I need done. I took it to the local boat shop. They pulled the distributor and the gearing was tore up badly. I agreed with the service mgr that it was reasonable to assume the cam was shot too. Here were the options presented:

1: Pull the motor then replace the cam and distributor after flushing out any metal that might be lurking around in there. Pricetag: about $1000

2: Go the conservative route and put a new motor in it, taking care of any doubt about metal fragments and what lead to the failure in the first place.

I agree that replacing everything is the way to go. I don't want to simply replace the cam and be faced with the same fate not so far down the road. The problem is the pricetag: about $4K. This 1990 Rinker, although I love it, just isn't worth it. i.e.: My wife would kill me - and she'd probably be right to do so.

I've found an individual who's made a business out of rebuilding automotive 4.3 long blocks with marinized components and installing for about $1500, depending on the setup required. He stands by these motors for 1 year and has been doing business with another nearby shop for over a year and the shop says his work is good and that they haven't heard of a bad experience yet from their/his customers. So in the "Fix It" category, this is my most affordable option.

I'm also considering selling to someone who wants to fix it someone or boat shop who wants it for the Alpha 1 outdrive and whatever other components are salvagable (exhaust, alternator, power steering pump, etc). I think it's worth $3000 in good running condition, so I'd want to get at least $1500 for it as is. Is that realistic?

Any help/guidance/suggestions would be appreciated. What do the experts here think about automotive blocks being used for marine applications? What's the major difference between an automotive and marine set up? And also, how should I go about dumping the boat if going the $1500 route I outlined above isn't a good plan? Even here in Michigan, I can replace the boat for probably $3000 without too much trouble.

Thanks

 

[Don S]

Re: 4.3 with a bad cam and distributor - What next?

I've got a 4.3 V6 in a Rinker 186 Captiva

Does this thing have a year?

so I'd want to get at least $1500 for it as is. Is that realistic?

No, not realistic at all. $1500 for a non running boat without knowing year, model of engine etc? To many boats out there in this economy to spend 1500 bucks on one with a dead engine.

 

[JustJason]

Re: 4.3 with a bad cam and distributor - What next?

You should be able to see the cam gear with a flashlight. Have a look at it and spin the motor over so you can see all of it.
If it looks okay i'd just fix the distro and run the motor. The bigger metal chunks will pretty much sit in the oil pan, the smaller ones should get caught by the filter. The boats a 1990, I wouldn't sink to much money into it.

 

[Lommerse33]

Re: 4.3 with a bad cam and distributor - What next?

Don: The year of the boat is 1990, but it's had several owners and been repowered at least once. I'm told that the current motor was installed in 2007, shortly before I bought it. I enjoyed almost 3 good seasons before it crapped on me in Sept 2009. But based on your opinion of it's current value, I'm probably best served to fix it and enjoy it a while longer.

Jason: Assuming the gearing at the cam appears Ok, wouldn't I still be dealing with a great deal of unknowns? If the gearing on the distributor was failing, the timing would be affected and wouldn't there be good possibility of damage to the valves?

 

[TilliamWe]

Re: 4.3 with a bad cam and distributor - What next?

Jason: Assuming the gearing at the cam appears Ok, wouldn't I still be dealing with a great deal of unknowns? If the gearing on the distributor was failing, the timing would be affected and wouldn't there be good possibility of damage to the valves?

Did you run it very long when it was running badly? If not, then no, there is not a good chance that the valves are damaged. And a set of reconditioned Vortec heads should be around $400 at your local machine shop, if yours are damaged.

The most logical solution is NOT to replace the entire engine, if the entire engine is not damaged.

 

[fishrdan]

Re: 4.3 with a bad cam and distributor - What next?

I'm told that the current motor was installed in 2007, shortly before I bought it. I enjoyed almost 3 good seasons before it crapped on me in Sept 2009. But based on your opinion of it's current value, I'm probably best served to fix it and enjoy it a while longer.

2-3 Year old engine and the dist gear (and possibly cam dist drive gear) is worn out??? Was this a factory marine engine or a rebuilt engine? I would be looking at the oil pump and make sure a high volume/high pressure oil pump was not installed. If in doubt, replace the oil pump with a stock oil pump while the engine is out. Since they will all ready have the pan off to clean it/check for debris, the oil pump swap will take all of 10 minutes, + the oil pump ($25-50).

BTW, a high volume or high pressure oil pump can cause an excessive load on the cam/dist gears, too much pressure and not enough lubrication = crapped out gears.

 

[JustJason]

Re: 4.3 with a bad cam and distributor - What next?

I agreed with the service mgr that it was reasonable to assume the cam was shot too

Not necessarily. Those gears are usually either composite(plastic) or brass/bronze. The entire camshaft, including the gear, is hardened, and very strong. That's why I said, all ya can do is look at it. And you don't have to pull the camshaft to see it, unless of course the design of the boat doesn't allow you to stick your head over the hole and look. In which case a good boroscope should do the job.

If your looking for advice, it's up to you. If you boat 20 miles offshore, a new engine(or high quality re-manufactured) is the way to probably go if you wanna spend the big bucks for the best piece of mind. Or you could yank the motor, pull the oil pan and dump it. If your inland, and you have a radio on the boat and not too worried about getting a tow I would do the following.

1. change the oil and filter
2. plumb in an oil pressure gauge
3. use a priming tool, and spin the oil pump. I'd spin it for probably a good ten minutes while watching the gauge. You need to make sure the pump is not binding or sticking(which could have caused the gear failure) and also capable of making pressure. (wear and tear can kill that gear to, and becaue they are realatively cheap, stock gears aren't always of the highest quality.)
4. if it all looks good i'd just reset the motor, install the distro with a new gear, start it, and time it.
5. I'd probably change the oil and filter 1 more time, just incase.
6. Then go boating.

Should be about 2 to 3 hours worth of work.
Wether it's plastic or bronze, the big pieces will just sit in the pan for the rest of the engines life. The smaller ones will get sucked out by the oil change and the real small ones will get chewed through the oil pump and trapped in the oil filter.

There is a big difference between a remanufactored engine, and a dime a dozen rebuild, you'll have to do some googleing.

If the gearing on the distributor was failing, the timing would be affected and wouldn't there be good possibility of damage to the valves?

Nahh. Not if the gear broke. It more than likely held proper ignition time just fine until the gear failed. When the gear failed the rotor stopped spinning and the engine no longer runs. You usually burn the valves up by lugging the motor, if the timing was to far advanced you'd get some mean detonation and spark knock, and eat the pistons up first.

 

[dan t.]

Re: 4.3 with a bad cam and distributor - What next?

check the dist. shaft for loosness, worn dist. bushings can cause gear falure.if so you may need a replacement distributor. like JJ said check the cam gear, if its not worn change the oil, repair the dist., set the timing and go boating

 

[mla2ofus]

Re: 4.3 with a bad cam and distributor - What next?

Broken dist. gear will not affect valves. If the cam drive gear or chain, whichever the case , breaks ,then there is a chance of bent/broken valves.
I also would check the dist gear on the cam for broken teeth. If it looks OK As already said I'd check the oil pump operation, install new dist., change oil and filter and see how she does.
I think the oil pump drive shaft would twist off before the dist gear suffered damage if there is a pump problem.
Mike

 

[havasuboatman]

Re: 4.3 with a bad cam and distributor - What next?

Dude, those 4.3 distributer gears are the weak link. You said this boat has had a couple rebuilds put in it. Most likely they were long blocks and all of the other engine components were reused.
I suggest that you take Just Jasons advice. It is sound and reasonable.

 

[bonzoscott]

Re: 4.3 with a bad cam and distributor - What next?

It's not clear as to what caused the "Dist & Cam" to go. So often the mechanic recommends replacing the components that are not working without describing exactly what happened. Boat owner is not a "DIY" so the mechanic takes the best route and recommends what would not be a return on his part. In my opinion, valve seals have rotted, gotten into the pan, picked up by the pump, and locked the pump, shearing the roll pin on the distributor. Pull the distributor, replace the roll pin, flush the hell outta the motor with kerosene, install the distributor and try it out. If it appears to work, replace valve seals. Not an agenda for DIYer.

 

[mla2ofus]

Re: 4.3 with a bad cam and distributor - What next?

I don't see how a peice of seal small enough to pass the pump pickup screen could lock it up. Don't know myself, but Havasu said the dist gear in this engine is a weak link.
Mike

 

[zbnutcase]

Re: 4.3 with a bad cam and distributor - What next?

NOTHING wrong with using automotive castings; they are the same as marine. Where they differ is in gasket and bearing material, (M-400)brass core plugs, and cam profile. 'nutcase

 

[mla2ofus]

Re: 4.3 with a bad cam and distributor - What next?

Well, I wonder if he fixed it or sent it down the road??
Mike

 

[Fordiesel69]

Re: 4.3 with a bad cam and distributor - What next?

The 4.3L distributor gears are a well known failure in the automotive world, and I guess it wouldn't be any different in the marine world. Anyways the gear is very soft, whereas the cam is not, so failure of the cam is not likely. We would buy a reman distrubutor and replace it with no ill effects. I know these vehicles had made it at least another 30k if not longer before I quit that job.

In any case, it is safe to assume a new distributor will solve your problem and allow many more years of enjoyment. And if it goes again, then make a descision as to what to do. I guess you could also replace just your gear, but make damn sure the shaft has no play, as that could be why it failed.

 

[HT32BSX115]

Re: 4.3 with a bad cam and distributor - What next?

Howdy,


The internet is full of articles on replacing a distributor gear. Once it's out it's and you determine there's nothing else wrong with it replacing the gear is actually quite easy.

http://www.carcraft.com/techarticles/distributor_gears/index.html

damage to the valves?

Probably not applicable here.....

You're thinking about interference engines. Common in newer, over head cam, small engines. Small diesels are interference engines usually.


If you're not willing or able to do all the work yourself, You're sort of stuck with someone else doing it. As mentioned above, they're going to want to do it in such a way that it's done quickly reliably so it doesn't "come back".

Labor rates are so expensive these days that most people just want to quickly replace parts so they can get on to the next project!


Cheers,


Rick

 

[Lommerse33]

Re: 4.3 with a bad cam and distributor - What next?

Well, I wonder if he fixed it or sent it down the road??
Mike

I've been busy with work and the holidays, but I've been watching the responses coming in and I'm very encouraged. By-the-hour mechanics can scare the crap out of a person... I've got a "car guy" who does everything from brakes to engine replacement out of his home workshop and I've already talked to him about checking the cam gear as best he can without a tear down and replacing the distributor.

Thanks to everyone for their input. I love this forum!

Jason

 

[mla2ofus]

Re: 4.3 with a bad cam and distributor - What next?

Glad to hear that. I think you're gonna come out smellin' like a rose on this. I hope I'm not wrong.
Good Luck,
Mike

 

[Lommerse33]

Re: 4.3 with a bad cam and distributor - What next?

So, it's spring in SE Michigan and hopefully this weekend I'll get this thing out of storage. The thing is, I've been calling around and I can't find a gear for what I believe this distributor is, and I believe it's a 1990 Prestolite that it looks like Merc was using when this Rinker was new. Any thoughts on where to get one or an equivolent? Am I going about this all wrong?

Recommendations on a remanufactured dizzy for a 4.3?

Thanks for any help offered,
Jason

 

[Lommerse33]

Re: 4.3 with a bad cam and distributor - Update

Re: 4.3 with a bad cam and distributor - Update

So the weather in SE Michigan this spring has been down-right lowsy. I finally got together with my free help on this problem this past weekend. I got a new distributor from Mercury for what I thought was a really reasonable price ($326) since the old one was a bit spent in addition to missing teeth on its gear.

I installed the battery, changed the oil and we put the new distributor in after finding TDC on #1. Took a bit to get it started but that was mostly from sitting since Sept I'd guess. Once running, it was smooth as could be at idle. I need to dial in the timing to get it going under some throttle, but I think I'll be good to go here in the next few days.

Thanks to everyone who posted such encouraging and educational responses to my question.

Jason