Tore engine apart and this is what I found

[The Wagprocrastinator]

I pulled my engine apart and this is what I found.
1) When the heads are on I can only turn engine over 3/4 the way. When the heads are off I turns over fine and can hear compression. What causes engine to only go 3/4 turn with heads on?

2) I took the heads off and cylinders #2 and #5 the plugs were corroded on the tip very bad. #5 was completely filled on the end. What causes this.

3) Cylinder #7 had 1/8" to 1/4" of build up on top of the piston. What causes this? All of the other pistons looked to be about eqaul. Not too much build up. Also one of the big holes on the head was filled up with green sludge, what is this.

All of the lifters look to be working the same and engine turns freely with heads off. The inside of the cylinders and crank look okay with no build up. I can't pull timing chain due to no balancer puller. Will borrow one tommorrow. :confused:

[beloth]

green sludge would probably be coolant mixing with oil ....just a guess....only thing in a engine area that is green is the coolant though.

[Damage, Inc.]

I think you're a bit confused here, or I am. You wouldn't hear compression when the heads are off. As for turning over 3/4 of the way, I'm not really sure and can't even imagine why it'd do that.

The buildup on top of the pistons is carbon. Every engine with lots of miles has it. No way around it.

Green sludge? Big hole on head? Not sure what you're talking about there.

[Wesdog]

Can't compress a liquid or solid. My guess is the stuff you found in #7 was interferring with the #7 piston to head clearance and stopping the piston before TDC.

[Stuka]

sounds like piston slap.. The building up on the cylinder got bad enough to stop the engine. Take that head off, and then it will turn fine. Although I dont see how you can hear compression with the heads off, whats compressing?

[The Wagprocrastinator]

What I hear sounds like air. I took off the head and it turns over fine. What causes the carbon on the head?

Originally posted by Damage, Inc.:
I think you're a bit confused here, or I am. You wouldn't hear compression when the heads are off. As for turning over 3/4 of the way, I'm not really sure and can't even imagine why it'd do that.

The buildup on top of the pistons is carbon. Every engine with lots of miles has it. No way around it.

Green sludge? Big hole on head? Not sure what you're talking about there.

[The Wagprocrastinator]

Green sludge? Big hole on head? Not sure what you're talking about there.[/QB]let me look again to explain better.

[ June 22, 2003, 06:06 PM: Message edited by: 86Buckeyewag ]

[The Wagprocrastinator]

On the odd side (firing order) last rectangular hole on the intake manifold side. It was filled with sludge colored green. Maybe antifreeze got on it when pulling intake.

[Stuka]

The buildup is either caussed by oil getting into the cylinder, or it running rich for long periods of time, which doesnt happen on the back 2 cylinders, those generally run lean like most V8's. Some carbon buildup is acceptable over time. But if it has a thick layer, then that will cause probs (as you have found out). Was the other head still on? as you can hear compression from that side.

[The Wagprocrastinator]

No both heads are off. I'll go turn it again to be sure.

[ June 22, 2003, 06:43 PM: Message edited by: 86Buckeyewag ]

[The Wagprocrastinator]

Okay my bad! It sounds more like the pistons going up and down. It turns freely. Not hard or anything like that. Does it sound like a head problem? What are the symptoms of burnt valves?

[Stuka]

Could be a leaking valve stem seal. Inspect the seal for that cylinder to see if its cracked or missing.

[wy_white_wolf]

When you were trying to turn the engine over with the heads on were the spark plugs still in?

If so than the engine was propably coming up on a compression stroke and gets very hard to turn over.

Since there's more build up oin the 7 hole it may have a bad valve guide or seal on that intake valve. Pull the valve and look at the topside of it. If there's any buildup there than the guide or at least seal is bad.

How long were the spark plugs in? What color is the build up on them? Black? Brown? Tan? White? Grey? Oily, wet or dry?

The green sludge is propably just buildup in one of the cooling passages. Can't really say without seeing. When was the cooling system last flushed?

[The Wagprocrastinator]

This jeep has been sitting for about two years. It ran when parked but not good. They had it checked and said it needed rebuilt. They were kinda brown to tan color. 2 and 5 were real bad build up. 7 plug looked okay.