1997 4.3lx GEN+ mercruiser not starting

[Ron9228]

Hello all, this is my first post but I come here often for troubleshooting I love this forum. Anyways, I was recently on the water(salt water) and the engine shut off, luckily we were done and at the dock. I tried starting it and got nothing but a few clicks, replaced battery and it did the same thing, I also jumped starter solenoid and got the same thing, but I replaced the solenoid anyways. Next I figured it had to be the starter so I replaced the starter, and still just clicks. Finally after reading on the forums I pulled the spark plugs and 3 of the 6 spark plugs had rust and few drops of water came out of the cylinders on the ones that had rust on the plugs. The oil looks good I don't think any water managed to get in it. Now I am trying to manually turn the engine but I don't know where I need to turn it.

 

[Fun Times]

Re: 1997 4.3lx GEN+ mercruiser not starting

I pulled the spark plugs and 3 of the 6 spark plugs had rust and few drops of water came out of the cylinders on the ones that had rust on the plugs. Now I am trying to manually turn the engine but I don't know where I need to turn it.

Hi there, What cylinders had the water? Was it all one side or both?

As a starting point, With all the spark plugs removed and the stern drive lowered down, you should be able to hopefully crank the engine over using the engine starter now to help monitor how much water sprays out of the cylinders and what ones.

 

[Ron9228]

Re: 1997 4.3lx GEN+ mercruiser not starting

Hi there, What cylinders had the water? Was it all one side or both?

As a starting point, With all the spark plugs removed and the stern drive lowered down, you should be able to hopefully crank the engine over using the engine starter now to help monitor how much water sprays out of the cylinders and what ones.

I am not sure the cylinder numbers but they are the cylinders on the left side. Right side plugs were dry and looked normal.

I did not think to lower the drive, I will try that.

 

[achris]

Re: 1997 4.3lx GEN+ mercruiser not starting

Hi Ron,

Water in one side usually indicates an exhaust manifold failure. What style manifolds do you have? 2 piece or 'batwing'?

Chris......

 

[Ron9228]

Re: 1997 4.3lx GEN+ mercruiser not starting

Hi Ron,

Water in one side usually indicates an exhaust manifold failure. What style manifolds do you have? 2 piece or 'batwing'?

Chris......

It's a 2 piece.

I just went to lower the drive and the trim motor just clicks, up, down, and trailer. I'm guessing it's a ground issue not solenoid since the starter is also clicking. Any suggestions on where to start checking besides the battery connections. I have a voltmeter.

Thanks for the help

 

[Ron9228]

Re: 1997 4.3lx GEN+ mercruiser not starting

Thanks I love you guys, starter was able to turn it and some water came out but not a lot.

 

[Fun Times]

Now the investigation of why begins!

Now the investigation of why begins!

Starter was able to turn it and some water came out but not a lot.

You'll want to see if that side continues to make water plus find out why.

While this is more on the rare side of things, Just bear in mind that hopefully you didn't damage any internal engine parts or crack the engine block where the starter bolts screw into due to trying to start the engine while hydrolocked with water.

Good luck.

 

[tpenfield]

Re: 1997 4.3lx GEN+ mercruiser not starting

I had a 7.4 L hydro-lock on me . . . similar symptoms to your situation regarding the battery & starter.

From your description, it sounds like it hydro-locked while idling at the dock. So, as mentioned exhaust manifold/elbow joint would be suspect.

You should probably do the following things if not done already. . .

Check oil level (I had the oil level up 1 quart, but not milky since it had just happened)
Change oil (based on what you find for the oil level, etc)
Fog the engine to inhibit rust internally
Run a compression test
Run a cylinder leak test

See where that leads to . . .

Since you are in salt water, damage to the valves and valve seats is more probable.

 

[180shabah]

Re: 1997 4.3lx GEN+ mercruiser not starting

Sounds like two separate issues...
Exhaust is beyond it's serviceable life and bad electrical connections (clean ALL of them)....

 

[fen-isl]

Re: 1997 4.3lx GEN+ mercruiser not starting

One more thing to check. I have the same engine and once had a problem with water in the oil. The dip stick looked clean but the crankcase was a milk shake. Pull your oil cap and extension tube off valve cover then take your finger and swipe under the valve cover. If it comes out milky I would changed the oil and filter asap. As u boat in salt water

. If it clean then check your exhaust manifolds and risers and exhaust flaps.

If its a milk shake u need to pressure test cooling system to find leak or crack.

Good luck

 

[Ron9228]

Re: 1997 4.3lx GEN+ mercruiser not starting

Yes it locked at idle when we returned to the dock.

I checked the oil and it looks normal and is at full line.

I was able to run the engine in the driveway, now it dies at idle but seems normal with giving it some throttle. After letting it run at 1/4 throttle for 10 min, it still dies at idle. Also turning it over sounds rough, as if it wants to lock again.

Finally after starting it the first time, rusty looking water came out the exhaust from the out drive.

 

[Fun Times]

Re: 1997 4.3lx GEN+ mercruiser not starting

I was able to run the engine in the driveway, now it dies at idle but seems normal with giving it some throttle. After letting it run at 1/4 throttle for 10 min, it still dies at idle. Also turning it over sounds rough, as if it wants to lock again.

Sounds like you're still making water in the cylinders, It is not safe to continue running it if so.

You'll want to pull and inspect and test the exhaust manifolds, exhaust risers, elbows and gaskets.

 

[fen-isl]

Re: 1997 4.3lx GEN+ mercruiser not starting

Definitely check the oil the dip stick on that engine only shows level. It never enters the crankcase/oil pan and can give you a false reading of quality of the oil. The dip stick goes down the outside of oil pan then does a 90 degree into bottom of pan but the actual dipstick never enters that part so the oil looks brand new when in fact it may not be (learned that the hard way)

 

[Ron9228]

Re: 1997 4.3lx GEN+ mercruiser not starting

Thanks all, sometime this week I will drain the oil, fog the cylinders, check out the exhaust manifolds and risers, and hopefully check out the compression if all else is good

 

[998cc]

Re: 1997 4.3lx GEN+ mercruiser not starting

Thanks all, sometime this week I will drain the oil, fog the cylinders, check out the exhaust manifolds and risers, and hopefully check out the compression if all else is good

The sooner, the better--especially since it is salt water.

 

[floater212]

Re: 1997 4.3lx GEN+ mercruiser not starting

had that happen to our '96 4.3 it turned out to be bad exhaust flappers. it happened after I did a quick stop and killed the motor, then as the wake came up from behind.... no more starting just a click and the dreaded tow to the dock. I pulled the plugs back at the house and water came out of the one side cylinders. cranked for a while until the water stopped, squirted some wd40 in and cranked some more no more water. replaced plugs and fired it up. fine for now and now it's time to take it in for service... replaced both flappers the bad side broke in 3 pieces and they said I was lucky, the smaller service man was able to reach his arm down the exhaust and remove all the pieces other wise it turns into a 5hr job.

 

[Ron9228]

Re: 1997 4.3lx GEN+ mercruiser not starting

had that happen to our '96 4.3 it turned out to be bad exhaust flappers. it happened after I did a quick stop and killed the motor, then as the wake came up from behind.... no more starting just a click and the dreaded tow to the dock. I pulled the plugs back at the house and water came out of the one side cylinders. cranked for a while until the water stopped, squirted some wd40 in and cranked some more no more water. replaced plugs and fired it up. fine for now and now it's time to take it in for service... replaced both flappers the bad side broke in 3 pieces and they said I was lucky, the smaller service man was able to reach his arm down the exhaust and remove all the pieces other wise it turns into a 5hr job.

I know the exhaust manifold is past it's expectancy and needs to be replaced. But I was also thinking about checking the flappers. Thanks guys I'll keep you posted on when I get it running in good order.

 

[Ron9228]

Re: 1997 4.3lx GEN+ mercruiser not starting

I finally fixed it about 2 weeks ago. I replaced the manifold, riser, and elbow. I had to use new riser bolts since the old ones would not budge. While installing the new bolts I broke one bolt in the manifold without knowing.

I took her out the next day to see how she ran and sucked up so much water that it was coming out the valve cover exhaust hoses.

I ended up retreading the manifold. Reinstalling the new bolts. Draining the oil and running a lot of seafoam and oil through the engine. I think I changed the oil 3 times. Checked the spark plugs, no water was found. Now I have taken her out about 6 times since than and no issues. Except one which I'll share next. Thanks all

 

[Ron9228]

Re: 1997 4.3lx GEN+ mercruiser not starting

I go free diving a lot off my boat. The other day I jumped in and asked a buddy that was on the boat if he could raise the trim. He had no idea how to do it. So I told him to press the black button on the side. Well I wasn't thinking that he'd press the throttle only button, which he did and it got stuck and never disengaged.

I had no idea and when it was time to move the boat it would not go in gear. I ended up removing the panel where my throttle control screws in and took the back cover off the throttle box. Everything looked fine, so I just grabbed a screwdriver and pushed on the spring that controls the throttle only button, and it worked. Hopefully this helps someone later on. Again thanks guys

 

[Ken Ellis]

Is this site still active? I see the latest post are from 2011 and 2013