Advice Sought. Engine Seized after installing Injection pump

[double u]

valvestems are pretty rugged thingsn our Renault 4cyl. the camshaft stopped & more than half of the valves got slammed shut by the pistons. Valves all ok, but the pushrods looked like flowers in a wind...

[jimbunyard]

You may have trouble removing the valve with it compressed.

Given the information we've heard so far, I'm not sure of the reason for the pessimism.

Get a ladysfoot, a small prybar or a big screwdriver and lever the valve back up. Squirt it with your unstickem juice of choice before you start.

After you get it up, tap it lightly with a hammer to see if it loosens up. If it does, maybe 'no harm, no foul'.

As for the reasons? That's best left for those with hands on experience with the actual engine.

[Compass790]

The reason for the pessimism in my case was not the stuck v/v it was the pic earlier in thread of the corrosion in the intakes. Sure he may be able to free the valve but I was thinking of the probable water damage in the bore. Suspect hone & re -ring in order here but he may be lucky

[RaymondR]

I have joined the "Take the head off and have a look before you do some real damage" group.

[Jack C]

Originally Posted by Compass790

The reason for the pessimism in my case was not the stuck v/v it was the pic earlier in thread of the corrosion in the intakes. Sure he may be able to free the valve but I was thinking of the probable water damage in the bore. Suspect hone & re -ring in order here but he may be lucky

I think that the light corrosion in the intakes is due to the salt laden moist air here reacting with a cast iron intake area fed from the air filter.

The same moist air goes into the cylinder which is coated with oil.

As I see no oil in the water and water in the oil and no drop in water level that leaves water rising in the exhaust. I checked the muffler, no water buildup there.

So piston seizing is probably due to carbon buildup on rings.

[Compass790]

Originally Posted by Jack C

I think that the light corrosion in the intakes is due to the salt laden moist air here reacting with a cast iron intake area fed from the air filter.

The same moist air goes into the cylinder which is coated with oil.

As I see no oil in the water and water in the oil and no drop in water level that leaves water rising in the exhaust. I checked the muffler, no water buildup there.

So piston seizing is probably due to carbon buildup on rings.

Maate our boat lives in salt water & has cast iron intake & it doesnt look like yours does. If you get water in the combustion chamber via the intake only whilst it's running it [B]may[B] not show up in the oil but it's your choice for sure as to wether to remove the head.
Normally the oil mist from the crankcase breather should stop yr intake from rusting.
I hope you are lucky & free it up without wrecking the bores.

[Jack C]

Originally Posted by jimbunyard

You may have trouble removing the valve with it compressed.

Given the information we've heard so far, I'm not sure of the reason for the pessimism.

Get a ladysfoot, a small prybar or a big screwdriver and lever the valve back up. Squirt it with your unstickem juice of choice before you start.

After you get it up, tap it lightly with a hammer to see if it loosens up. If it does, maybe 'no harm, no foul'.

As for the reasons? That's best left for those with hands on experience with the actual engine.

Jim, terrific advice. Yesterday I was chatting with Gabi, the guy who looks after the large trawler that is moored alongside my 48' Mayflower.

It turns out that he was a mechanic in the Israeli Navy.

He suggested spraying unstick juice, then tapping the valves with a plastic hammer.

I used a block of wood and a light hammer and tapped the valves. The stuck exhaust valve freed up after a few taps and after a few more taps came all the way up.

I then tapped all the valves, the all make the same sound now and I compared their heights, all the same!

I think that the previous owners followed the conventional thought of not taxing the engine. This probably has caused carbon buildup.

Next was trying to rotate the crankshaft forward and backward. It's still stuck but the tools I had with me gave limited leverage so I sprayed unstick into the cylinders and will try to rotate with a long bar.

So I have not joined the "Take off the head" group. Taking off the head requires a new head gasket. It will give me a view of the pistons, will probably confirm lots of carbon and possibly stuck rings. I could then pound the pistons to free them up.

As I am in no rush and I am now sure that the valves are not interfering with the pistons, I'll try the Nigel Calder approach, a large lever and gentle force.

I'll keep you all posted.

[RaymondR]

Originally Posted by Jack C

I think that the light corrosion in the intakes is due to the salt laden moist air here reacting with a cast iron intake area fed from the air filter.

The same moist air goes into the cylinder which is coated with oil.

As I see no oil in the water and water in the oil and no drop in water level that leaves water rising in the exhaust. I checked the muffler, no water buildup there.

So piston seizing is probably due to carbon buildup on rings.

The GM series have a conduit from the tappet cover into the air intake so the oily fumes from the crank case and head get put back into the intake and should keep it all oil coated. However if the engine is back flooded with raw water from the exhaust it can flow back through the inlet and exhaust valves into the intake manifold.

[Jack C]

Originally Posted by RaymondR

The GM series have a conduit from the tappet cover into the air intake so the oily fumes from the crank case and head get put back into the intake and should keep it all oil coated. However if the engine is back flooded with raw water from the exhaust it can flow back through the inlet and exhaust valves into the intake manifold.

Yes, there is typically a pipe from the crankcase breather or the rocker cover to the air cleaner so that oil mist goes into the intake. It reduces the smell from the engine. On the 3ym30 there is no pipe, its incorporated into the rocker cover to which the air cleaner is attached.

But I digress. The reason that there is the rust buildup is that the engine has now not run for over a year. So as oil misting depends on oil flow, there has been no misting.

If water had back flooded then I would have seen water when I removed the injectors?

Thanks for the suggestions.

[Compass790]

If you have a compression tester I'd be interested to hear what the compression numbers are after you free it up.'
Can't say i've seen carbon cause seizure like you have but there's a lot I havent seen. Suspect it's far more likely that the rings & bore are rusted.
Can understand your reasoning if you can get it to run & dont want to strip the engine to re-ring & hone it.
Good luck, following with interest.