Water and Rust specs in cylinder 1983 140 merc

[duster22]

I was out on the water and my water pump failed. The engine overheated to about 240 f. Imediatetly i turned off the engine, and got towed in. Replaced the water pump and it started right up. it was running a little rough but i thought it was just the normal shake of that motor. Later i pulled the plugs out, and come to find one is not firing. Changed the plugs, wires distributer and still it doesnt fire. But the engine runs and drives fine on 3 cylinders. after i let the engine warm up to about 160 for about 20 mins i shut it off. the next morning i took the plug out that was not firing. I find it is FULL with water and rust specs in the cylinder!! Please could someone give me some advice to what to do from this point?

 

[Bondo]

Re: Water and Rust specs in cylinder 1983 140 merc

Ayuh,... Which cylinder,..??

Pull the manifold,+ look for water tracks,....
Pull the head,+ have it checked,+/ or rebuilt...

 

[duster22]

Re: Water and Rust specs in cylinder 1983 140 merc

the second one from the front its the one without the plug on the picture.

 

[P 0 P E Y E]

Re: Water and Rust specs in cylinder 1983 140 merc

Sir Bond-O is right.

You over heated the engine. You Have water in No. 2 Combustion Chamber These are the facts.

Here are the most probable fail modes:

Cracked Head: You over heated the engine and may have caused the head to crack. Perform a compression test. Don't take the head off till you check the exhaust manifold.

Bad head Gasket, old engine, high heat and higher pressures due to steam, may have blown the gasket.

Since the water is only in no.2 cylinder it probably is not the exhaust manifold. But still could be. The manifold is easiest to inspect and needs to come off to get to the head gasket.

Drain the block, remove the exhaust manifold. Visually inspect the exhaust port for no. 2. Take the manifold and block it up in your back yard in the position it would normally be on the engine. adapt and connect a garden hose to the water inlet and turn on the hose to see if water shows up in the exhaust port of no. 2.

If no water shows, it is time to pull the head. Make sure you put some CRC or marvel mystery oil in the watery cylinder to stop rust while you do the math.

Good luck, have patience and be careful.

 

[duster22]

Re: Water and Rust specs in cylinder 1983 140 merc

Ok, Well here is some more info. I took the plug out and cranked the engine over about 5 turns and all the water came out. BUT filled right back up aprox 5 cms then stops. ( i could hear the water droping). Maybe intake gasket?

 

[Lancer23]

Re: Water and Rust specs in cylinder 1983 140 merc

Could be a leak in the exhaust manifold, but I doubt it. Would be a huge coincidence to lose the water pump and the exhaust manifold at the same time.
My money is on a warped head due to overheat. Do a compression test and I suspect you'll find that cylinder won't give you any good numbers. Should be within 15-20 psi of the others.
You may think ALL of the water came out, but it didn't. You've got water down in the rings. The rust starts almost immediately on the cylinder walls and the piston rings/grooves. Even if the pistons move freely now, the rings will soon stick in their grooves and you'll have an oil burner. Putting oil in the cylinder doesn't get down to the rings because it will float on top of the water.
My recommendation (FWIW)
1. Compression test. Confirm cylinder is low
2. Pull the head and bring it to a good machine shop.
3. If the warp isn't too bad, you can surface the head. Otherwise, its time for a new head.
4. As soon as you get the head off, dry the cylinder out completely with a heat gun and then oil it well and cover it to avoid corrosion.

 

[duster22]

Re: Water and Rust specs in cylinder 1983 140 merc

Compression test results-

From the front to the drive is - 90,30,115,135

also some pictures of the manifold off.

 

[duster22]

Re: Water and Rust specs in cylinder 1983 140 merc

FOUND IT! there is a crack in the head. Does anyone know where to find one? cheapest place? 1983 140 merc

 

[duster22]

Re: Water and Rust specs in cylinder 1983 140 merc

Casting number - 2776954

 

[Bondo]

Re: Water and Rust specs in cylinder 1983 140 merc

Ayuh,....

Basically,... Any head off a 3.0l, or a 2.5l Boat motor will bolt on,+ Run,... just Fine...