Possible damaged exhaust valves? on 258

[txjeeptx]

  GHSCE cars, not many who'd get that one.

[Tony and Nicki]

You can tell what valve is what by what manifold runner it lines up with. AMC inlines have exhausts at both ends, so they're EI IE EI IE EI IE.

Exhaust valves get hotter than the intake valves, so they can stick more easily, and are affected more when an engine is overworked, overrevved, or improperly fueled(too lean can heat em way up).

Mmmm OK thanks again. Well in that case they were both Intake Valve Push rods. I managed to get the Valve Cover off after I lowered the cross member but still left the cross member bolts in and it still wouldn't come off. Finally I unscrewed the plate that the wiper motor mounts to and was able to get it off but only because someone had biffed the metal back that juts out there. I was planning to do that myself but someone beat me to it.

Anyway I replaced the pushrods and also # 5's bridge which was broken on the intake valve side. Turned it over to see if the 5 and 6 valves were now working, which they were and did a cold, dry compression test on 5 and 6.

They read 120lbs on 5 and 90lbs on 6 so clearly all is still not well but a heck of a lot better than they were.

I haven't put the valve cover back and tried starting to see how it runs 'cos I ran outta time but sometime next week I'll be able to get to it. Then it will remain to be seen if the rods get bent again and how it runs.
I expect it will still smoke until all the oil in the combustion chamber is burnt up (if that's what it is) so I'm crossing my fingers that the rods don't bend and the smoke eventually clears up...

Thanks for all your help

cheers!
tony and nicki

[Eagleearl]

The pushrods would got your compression up but they are not likely to cause smoking. While you have your valve cover off check the valve seals to make sure they are there and not cracked. They are the rubber umbrellas under the valve springs. The oil rings could be stuck in the pistons  or worn out but may get better with some running. Also check that the drains for the oil back into the block are not plugged.

[Tony and Nicki]

The pushrods would got your compression up but they are not likely to cause smoking. While you have your valve cover off check the valve seals to make sure they are there and not cracked. They are the rubber umbrellas under the valve springs. The oil rings could be stuck in the pistons  or worn out but may get better with some running. Also check that the drains for the oil back into the block are not plugged.

Thanks for the advise. I'll put those jobs on my list for next week.

As regards the smoking I was thinking that when I tipped the engine upside down in the stand while full of oil, the oil would have gotten into the combustion chamber and is burning off when it get's hot. It doesn't smoke 'til it's been run for about 10 minutes.

cheers!
tony and nicki

[Tony and Nicki]

Just a quick update:

It's not smoking anymore!

Not sure why but took it for drive to autozone and was smoking as usual. Then drove round nieghbourhood and noticed it stop smoking. Brought it back to garage and lo and behold: NO SMOKE! Just to be sure I started her up today and sure enough NO SMOKE.

Also running smooth with 17 1/2" Hg @ 600rpms in D and steady as a rock

Thanks for all the help

tony and nicki

[Gil-SX4]

Check the oil

[jim]

Check the oil

That's a scary thought.  Hope it didn't quite smoking because there's no oil left to burn!

[Tony and Nicki]

Check the oil

Ok thanks,

It did need 1/2 qt but I topped it up before I started her up.

I don't think the smoke was caused by blow by 'cos I would have seen smoke when I saw the donor engine running in the  jeep it came from.

I'm guessing that the smoking was due to oil present in the combustion chamber from when I tipped the engine upside down in the stand while full of oil and was burning off. For some reason, maybe just a coincidence, it stopped smoking shortly after I replaced the bent push rods.

Cheers!
tony and nicki

[mudkicker715]

Check the oil

Ok thanks,

It did need 1/2 qt but I topped it up before I started her up.

I don't think the smoke was caused by blow by 'cos I would have seen smoke when I saw the donor engine running in the  jeep it came from.

I'm guessing that the smoking was due to oil present in the combustion chamber from when I tipped the engine upside down in the stand while full of oil and was burning off. For some reason, maybe just a coincidence, it stopped smoking shortly after I replaced the bent push rods.

Cheers!
tony and nicki

And a likely cause to your bent pushrods.

[Tony and Nicki]

You mean the oil spill could have caused the push rods to bend?

Mmmmm Hadn't thought of that. Why would that be?

Actually though I'm pretty sure the push rods were bent before I installed the engine. I know it sounds stupid but thinking back I remember seeing them. But out of ignorance/stupidity, not seeing what I didn't want to see and not paying attention I let it pass

I reckon the PO probably overevved the engine while off-roading in the jeep.

Anyway for whatever reason it's running nice now with no smoking so hopefully I can pass emissions next week or at least try.

cheers!
tony and nicki

[mudkicker715]

Just saying if you had fluid in the combustion chamber it can cause chaos.

[Tony and Nicki]

oh ok. Thanks for the heads up

[Jurjen]

A.k.a hydrolock

http://en.wikipedia.org/wiki/Hydrolock