4.3L V6 Mercruiser Hydrolocked

[1ruralmailman]

Re: 4.3L V6 Mercruiser Hydrolocked

another thought is you may have a small problem with the ring gear,all it takes is a small burr from it actually hydrolocking and it might stop it from rolling over.one other thing if you are still getting water in cylinders you may have a cracked or leaking intake manifold,as 4.3 were noted for that problem.

 

[joewithaboat]

Re: 4.3L V6 Mercruiser Hydrolocked

^^^The 4.3 distributor will drop in at any angle, not just 0 degrees or 180 degrees like most SBC engines, this may be an issue.

What ???

 

[joewithaboat]

Re: 4.3L V6 Mercruiser Hydrolocked

Based on how bad your manifolds look, id be pulling the intake to investigate what the water jackets look like in the heads. Then maybe the block. Do you boat in salt water?

 

[halfmoa]

Re: 4.3L V6 Mercruiser Hydrolocked

What ???

On most every engine I've ever worked on the distributor either goes in at zero degrees or 180 degrees. On the 4.3 I used to have the distributor would go in at about every position imaginable. Just one spline off and it'd do CRAZY things.

 

[joewithaboat]

Re: 4.3L V6 Mercruiser Hydrolocked

On most every engine I've ever worked on the distributor either goes in at zero degrees or 180 degrees. On the 4.3 I used to have the distributor would go in at about every position imaginable. Just one spline off and it'd do CRAZY things.

I'm sure there is an exception out there somewhere but in every engine i have worked on the distributor could care less were it goes in as long as the distributor wires go on correctly.

The architecture of the 4.3 and the 5.7 distributors are the same. On most the whole thing is the same accept the module, rotor and cap.

 

[Don S]

Re: 4.3L V6 Mercruiser Hydrolocked

First, your manifolds are junk, just like your risers.

On to the compression test.

You can do a compression test with the distributor removed from the engine. I has no bearing on the compression readings.

If the engine is locking up, on the cylinder you are trying to test the compression on, then either your battery is dead, or your battery cables are loose or corroded, or the starter is as bad as your manifolds and risers.

 

[makonnen]

Re: 4.3L V6 Mercruiser Hydrolocked

While that is true, you can plop the distributer anywhere on the camshaft and change where the spark plugs go. But here are a couple of things to consider...

- It looks unprofessioal - some wires will have tons of slack, others will be stretched

- Wire sets are designed to be specific lengths, so if the wires are not plugged into the "right" place ... again some will look stretched while others will have too much slack

As you mentioned there are exceptions ... I can't think of any in the boat world. But in the auto world, most Japanese engines have distributors that limit the advance and retard you can turn them. These distributors can only be installed in the "correct" location.

 

[joewithaboat]

Re: 4.3L V6 Mercruiser Hydrolocked

While that is true, you can plop the distributer anywhere on the camshaft and change where the spark plugs go. But here are a couple of things to consider...

- It looks unprofessioal - some wires will have tons of slack, others will be stretched

- Wire sets are designed to be specific lengths, so if the wires are not plugged into the "right" place ... again some will look stretched while others will have too much slack

As you mentioned there are exceptions ... I can't think of any in the boat world. But in the auto world, most Japanese engines have distributors that limit the advance and retard you can turn them. These distributors can only be installed in the "correct" location.

In the performance world, good wires are all the same length... you cut them to fit.

The only reason the distributor might have to go in a designated place is if something protruding off the distributor limits is location. I had a 2.3 turbo Ford that was this way.

Has nothing to do with how much "advance or retard you can turn them"
The distributor goes in a circle.. it has no idea where #1 is in relation to the outside world. Only that the wires be in the proper order.

If putting number 1 in a specific location makes you feel more professional then by all mean carry on!

 

[rodgeml1]

Re: 4.3L V6 Mercruiser Hydrolocked

Thank you all so much for the suggestions. Anything you suggest or ask is music to a desperate man's ears (it is fishing season after all....and I'm stuck on the sidelines. I'll do my best to answer all of your questions or give feedback for all of your suggestions but please forgive me if I miss one.

Its "not likely" that a head is cracked.

I sure hope you?re right.

4.3's "rarely" suffer from head gasket failures. Again iront block, head and manifolds means similar expansion rates when the engine heats up. Think of the history of engines that have pattern gasket problems (manifold, head, oil pan), they are all aluminum head / manifold, iron block combinations.

I certainly understand CTE effects, so this makes sense. I hadn?t thought about it but it?s a good point.

- What does the oil look like?

It looks clean. I checked it on Saturday right after I was able to get it running after starting to have this problem and had run it for about 10 minutes. Not a hint of water or milky consistency.

- Catch the fluid coming out of the exhaust ports with a tissue paper. Is it water or fuel? I doubt its that much fuel coming out.

This is definitely going to be my next step. I tried to smell it yesterday but had so much oil and fuel on my hands I couldn?t tell the difference. I?m going to get a clean start on it today and check to see if it?s fuel or water. I?ll let y?all know what I find.

- I assume this is coolant cooled engine?

Nope?.this is an open loop (raw water) cooling system.

- Make it happen again, when the starter gives you the big THUNK, put a socked and a ratchet on the crank pulley bolt head and turn the engine by hand, is it hard to turn?

I meant to do this last night but ran out of time. I?ll give her a turn today and see what I can find.

- Could the engine / valve timing / ignition timing be WAY WAY off. In my youth, I've messed up valve / timing chain / ignition timing so bad that the starter would do some really weird things.

When I was able to get it started this weekend, she ran smooth and even, so I?m thinking it?s probably not a timing issue. But I?m not experienced enough to know for sure.

 

[rodgeml1]

Re: 4.3L V6 Mercruiser Hydrolocked

Also, automotive 4.3s from the mid 90s are notorious for leaking coolant on the front left side from the area between the intake and head.

How notorious? Would this be evident with a leakdown test?

 

[rodgeml1]

Re: 4.3L V6 Mercruiser Hydrolocked

Based on how bad your manifolds look, id be pulling the intake to investigate what the water jackets look like in the heads. Then maybe the block. Do you boat in salt water?

Unfortunately I haven't boated much at all with this one as I just bought it as a turn-key purchase. :facepalm:
Based on the condition of the risers and manifolds, I think it's safe to say it was used in salt water. Would I have to pull the engine in order to get to the intake manifolds?

 

[rodgeml1]

Re: 4.3L V6 Mercruiser Hydrolocked

Thanks for the response Don. I was curious as to what your inputs would be.

First, your manifolds are junk, just like your risers.

Roger that....I have two new replacements of each on the way.

If the engine is locking up, on the cylinder you are trying to test the compression on, then either your battery is dead, or your battery cables are loose or corroded, or the starter is as bad as your manifolds and risers.

I keep charging the batter so I'm hoping it's good. I'll chase down all the wiring and make sure it's good, along with all the connection and make sure the wing nuts are tight (just kidding on the wing nuts....I know that's one of your no-nos). I'll start troubleshooting the starter as well to figure out if it's failing on me.

I have to admit y'all, it's a huge relief to even have a few more ideas to continue to troubleshoot. I can't think you enough.

 

[joewithaboat]

Re: 4.3L V6 Mercruiser Hydrolocked

How notorious? Would this be evident with a leakdown test?

The "notorious" leak is on vehicle engines that came factory with Dex-cool antifreeze. It had a reaction to and degraded the plastic in the gaskets. If i remember there was a lawsuit concerning it. I dont think that would apply here.

Not to say that the front water cross over might not be leaking. Judging from the condition of your water jackets in general leaks anywhere is defiantly on the table.

 

[rodgeml1]

Re: 4.3L V6 Mercruiser Hydrolocked

If the engine is locking up, on the cylinder you are trying to test the compression on, then either your battery is dead, or your battery cables are loose or corroded, or the starter is as bad as your manifolds and risers.

I pulled the starter today to test it out. Below is a video of it being actuated using normal boat power. I measured 14V at the starter. I'm thinking this probably isn't my problem.

http://www.youtube.com/watch?v=FtQaxP4okKc&feature=youtu.be

 

[halfmoa]

Re: 4.3L V6 Mercruiser Hydrolocked

The "notorious" leak is on vehicle engines that came factory with Dex-cool antifreeze.

Very, very good point!

 

[littlebookworm]

Re: 4.3L V6 Mercruiser Hydrolocked

Try to turn the crankshaft with a rachet and socket on the flywheel bolt. Without the plugs in, you should be able to turn it fully with little problem. If that's OK, move on to the next step. Pull the valve covers and check the rockers and pushrods. I don't think you'll find a problem, but you check things in sequence. If all's OK, move on. Put the starter back in and try the compression test. See what the numbers are. If all's OK, do a leakdown test. After all this, you should have an idea of the condition of the engine. If the engine locks up on you while you are doing this set of tests, there's one more thing you should do before you pull the engine apart. Pull the outdrive off. You may have a bad universal which is locking up occasionally, causing the engine to lock. Pulling the outdrive is relatively simple and eliminates or identifies the drive as the cause of your problem. You should also download manuals for your engine and drive to help you understand how things work. There are a few sites which allow free downloads, including 4shared.com. Good luck and let us know what you find. Hy

 

[makonnen]

Re: 4.3L V6 Mercruiser Hydrolocked

"Also, automotive 4.3s from the mid 90s are notorious for leaking coolant on the front left side from the area between the intake and head."

I would have to respectfully disagree with that. I am a licensed mechanic ... my entire career and apprenticeship was at a GM dealer starting in the 90's. I don't remember any probem like that on 4.3's.

First of all, 4.3's in the mid 90's were Vortec engines with one single large injector in the middle of the plastic air plenum that sat on top of the intake manifolds. Boats don't have this ... plus boat 4.3's have cast iron intakes. The 4.3's in the late 90's and 2000s have the same style but they have 6 sequentially located in a rectangular box in the middle of the air plenum with plastic lines leading to the intake manifolds (check valves at the end of the plastic lines).

These engines were famous for air plenum and fuel injector leaks / problems. Also the check valves at the end of the plastic tubes were so sensitive, they would simlpy not open below 55 PSI fuel pressure. I remember replacing a lot of plenums, plenum gaskets, fuel injectors and fuel pump. I remember very very few 4.3 mechanical problems.

 

[makonnen]

Re: 4.3L V6 Mercruiser Hydrolocked

littlebookworm makes some very good points.

Nothing wrong with that starter in the video. Would help to get us more videos like that.

 

[rodgeml1]

Re: 4.3L V6 Mercruiser Hydrolocked

Try to turn the crankshaft with a rachet and socket on the flywheel bolt. Without the plugs in, you should be able to turn it fully with little problem. If that's OK, move on to the next step. Pull the valve covers and check the rockers and pushrods. I don't think you'll find a problem, but you check things in sequence. If all's OK, move on. Put the starter back in and try the compression test. See what the numbers are. If all's OK, do a leakdown test. After all this, you should have an idea of the condition of the engine. If the engine locks up on you while you are doing this set of tests, there's one more thing you should do before you pull the engine apart. Pull the outdrive off. You may have a bad universal which is locking up occasionally, causing the engine to lock. Pulling the outdrive is relatively simple and eliminates or identifies the drive as the cause of your problem. You should also download manuals for your engine and drive to help you understand how things work. There are a few sites which allow free downloads, including 4shared.com. Good luck and let us know what you find. Hy

Thanks for the great suggestions! This is going to seem like a REALLY dumb question to most of you so please forgive my ignorance. :redface:But, how do I get to the flywheel bolt to turn the engine with the housing and engine coupler installed? Do I need to remove those to get to it?

 

[halfmoa]

Re: 4.3L V6 Mercruiser Hydrolocked

"Also, automotive 4.3s from the mid 90s are notorious for leaking coolant on the front left side from the area between the intake and head."

I would have to respectfully disagree with that. I am a licensed mechanic ... my entire career and apprenticeship was at a GM dealer starting in the 90's. I don't remember any probem like that on 4.3's.

While I respect your experience, I've fixed mine and 2 others. The problem seems to develop around 80K according to the massive amount of forums and Youtube videos dedicated to the subject. Maybe people can't afford to take a 16 year old vehicle to Mr Goodwrench? I was just trying to contribute....I'll leave now.