2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

[cliffblue]

Just got my 2001 4.3L Alpha 1 Tracker Party Deck out of the shop. For my $2600 they pulled the engine and replaced the rotten transom, replaced the lower unit with a used one that was serviced because they could not get the bent prop shaft out of mine, oil and filter change, new fuel filter and a new thermostat that had just been changed last spring. On the first run, the boat has a vibration in gear under 2000 rpm. They said check the stainless prop. The prop shop said it was worn but ok. It leaked 4 or 5 gal. of water when I pulled the plug. They checked that and found a loose hose clamp. Next time out, not a drop! Like that! I cruised at 3000 rpm for 10-15 min. then went full throttle. Rpms were around 200 less than before it went in the shop and after 5 min. or so the rpm's fell off so I throttled back right away, the water temp had went up maybe 5 degrees. from 160 to 165. Checked the engine and found the left exhaust manifold was barely warm and you couldn't hold your hand on the right one. I replaced the shutters last spring and had no trouble. They did have to pull the manifolds before they could pull the engine. Did not wfo again, but cruised another 2 hours at 3000 -3200 with no problem except that vibration 2000 rpm and under. Could the u-joints be out of time? What should I look for or question them about the hot manifold? Thanks,Cliff

 

[Technorunner]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

sounds like shifted sparkplugwires. or bad plugs, that would explain both the vibration and EM not being warm. Does it sound like it should on idle??

 

[Fishermark]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

Could the u-joints be out of time?

Maybe bad u-joints, but they don't go out of time. With the new rebuilt transom etc, it is possible the engine alignment is off - perhaps they either did not do an alignment or it was not done correctly. They should at least check it.

What should I look for or question them about the hot manifold? Thanks,Cliff

Perhaps you simply have a bad / clogged manifold.

By the way - I would say you got a great deal on the price with all the work that was done. Providing they did a good job of course.

 

[Fordiesel69]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

How does a 2001 have a rotten transom? Just curious.......

If an ex flapper gets stuck, not only will it cause it to run funny, but also one or both manifolds could overheat. Also don't forget the check balls in the tstat housing.

 

[MarkSee]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

Checked the engine and found the left exhaust manifold was barely warm and you couldn't hold your hand on the right one.

Is it the exhaust MANIFOLD that is suppose to be only warm to the touch or exhaust ELBOW?

Mark

 

[cliffblue]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

This engine doesn't have the balls in the thermostat housing. I just put in new flappers last spring. I would hope the shop could reinstall the manifolds with the shutters in correctly. I have the one piece manifolds, no elbow. The engine idles smooth. This boat is pretty difficult to get around the engine. I'm a pretty good mechanic, but this 52 year old fat man was not about to try to pull the engine. I promise that the guy or guys that squeezed down and around to unbolt this motor, earned every penny. I think they were so sick of it that they did not do a through check out before I picked it up. I could barely pull the exhaust manifolds when I acetone checked them and replaced the shutters. A previous shop I went to about the leak said the engine is not original. Their solution for the leak was to smear silicone over all the bolts that penetrated the transom. Hence, different shop. I suspect whoever changed the engine did a crappy job of sealing it and the leak rotted the transom. The boat is all aluminum with a 1" thick board where the drive attaches to the motor. They did overlay the board with rosin to seal it. That all looks good.

 

[cliffblue]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

The shop owner will meet me at the lake 1 afternoon next week to see for himself the problems I have. We'll see how it goes.

 

[achris]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

.... I have the one piece manifolds, no elbow.....

Get rid of them before they kill that engine... These were one of Mercury's great ideas, that failed spectacularly... (Along with single point drain cooling system drains, TKS carbs and the 470...:facepalm

Chris......

 

[Bondo]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

Get rid of them before they kill that engine... These were one of Mercury's great ideas, that failed spectacularly... (Along with single point drain cooling system drains, TKS carbs and the 470...:facepalm

Chris......

Ayuh,.... Ditto that,... Those batwing manifolds are a blown motor/Anchor, just waitin' to happen....

Do a conversion to better manifolds...

As for the precieved Problem,...

from 160 to 165. Checked the engine and found the left exhaust manifold was barely warm and you couldn't hold your hand on the right one.

Water takes the path of least resistance, 'n 1 manifold is gonna carry away more water than the other,...
How long can You hold yer hand on 165? iron,..??? I find it instantly, Uncomfortable....

I'd still replace those manifolds, ASAP.... They could be a $2,000.00 long block, next trip out....

If the prop Looks "Worn",... I'd start there for the vibrations....

 

[90stingray]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

Ayuh,.... Ditto that,... Those batwing manifolds are a blown motor/Anchor, just waitin' to happen....

Do a conversion to better manifolds...

Not to highjack... but what's the deal with these manifolds? I would have steered away from my boat if i had known they are so bad.


I have been following this thread, curious as to what the vibration is. Or what the solution is. Glad to hear shop manager is going to do a ride along... and not just blow you off.

 

[Bondo]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

Not to highjack... but what's the deal with these manifolds? I would have steered away from my boat if i had known they are so bad.

Ayuh,.... Somethin' known as core shiftin' is the problem....

When their cast, the inner lost core isn't Exactly where it's Supposed to be....

The result is thin, 'n thick spots in the castings, 'n No way to tell....

The thin spots Fail, dumpin' water into yer motor.... in All the Wrong places.....

 

[90stingray]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

Ayuh,.... Somethin' known as core shiftin' is the problem....

When their cast, the inner lost core isn't Exactly where it's Supposed to be....

The result is thin, 'n thick spots in the castings, 'n No way to tell....

The thin spots Fail, dumpin' water into yer motor.... in All the Wrong places.....

WOW! I will be looking for a conversion set in the very near future. Thank you.

 

[achris]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

WOW! I will be looking for a conversion set in the very near future. Thank you.

Go for the dry-joint system... WAAAAY better than the old system... If you need part numbers, PM me.

 

[90stingray]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

PM sent. Thanks.

 

[achris]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

PM sent. Thanks.

PM received. Give me a little time and I'll answer... thanks.

 

[cliffblue]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

When the shop owner and I went to the lake to check things out, the vibrations could only be felt from 1100 through 1500-1600 rpm's. The intensity of them varied. He offered to loan me a prop to see if it made a difference. Fair enough. He also said the right exhaust manifold that I could not hold my hand on was normal and the left manifold that was barely warm was the odd one. I get your meaning Bond-o. As long as the temp diff is not a problem indicator, I'll let it go. What do y'all think? I'll post the prop test results when I can get it and try it out. He also saw that I tended to leave the outdrive up in the position that performed best at speed. He suggested I trim down most of the time for better hole shots and less stress on the drive line. Opinions? I am getting quotes on exhaust manifold upgrades. Thanks, Cliff

 

[cliffblue]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear.

This difference in exhaust manifold temps is really bugging me. Popped off the t-stat housing and blew through the water lines to each manifold with 100 psi air. I could not tell any difference between the two. After reassembly I started it on the muffs and with me standing behind the boat, the left/cooler side started putting out water in seconds while the right/hotter side took 3-4 times as long. the water on the left stayed cool while the water on the right got hot! What is pushing more water through the left side??? I guess I will have to pull the manifolds to see if the shutters are in correctly. What else could it be? When the water leaves the t-stat, has it already been through the engine. Shouldn't it be 165 degrees no matter how much or which manifold it leaves through? I wonder if the right shutter has fell into the Y-pipe and exhaust back pressure is causing this.

 

[cliffblue]

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear. (Answers)

Re: 2001 4.3L Alpha 1 - one exhaust manifold is hot and she shakes in gear. (Answers)

Ok, the manifold temp difference appears to have been caused by the right hose from the stat housing to the manifold having more bends than the left one and it being too long at the stat housing end causing it to crimp slightly in the first bend. I trimmed an inch or so off it and now the right manifold is still warmer than the left, but only slightly. The shutters still look new. The prop hub gave it up on the lake and it's replacement is a lot smoother. I have an off-idle shake and stumble that I'm 90% sure is engine. I will start another thread for it if I can't find the cause. Thanks to everyone. Cliff