Troubleshooting help needed- /6 engine rebuild won't turn, DAMMIT!!!!! Found the problem Options

[tornik550]

Argh- I rebuilt a 2.7l this winter. Everything went very well with no obvious problems. I installed my engine, hooked up all the hoses, filled with oil and hooked up the starter. I had problems with the starter wiring however I finally got them resolved. I was getting 12.6v at the starter. I cranked the starter and the engine turned a couple of times then stopped. When I would crank the starter again, it would just sound like a starter with too low of voltage- the solenoid would shoot out but the starter wouldn't turn. I checked voltage and it was 12.5v. If I look at the fan blade when I crank the starter, I do not see it move even slightly.

What are my options of what could be wrong? I see it as a starter problem or the engine is somehow seized. I do not have the axels hooked up so I cannot see if the engine turns by pushing the car in gear. I have a small window cut in the firewall so I wiggled a 19mm box wrench onto the timing pulley nut. I tried to see if I could turn the engine even slightly and I could not. I couldn't put much force into it however I would have thought it would have moved to some extent.

I think I will remove the starter and see if it cranks off of the car. If it functions properly, how can I check to see if the engine is seized without installing the axles. Is there anything common that could cause this issue? I would really prefer not to remove the engine. I am getting somewhat sick of working on it.

Any ideas?

[mepstein]

Pull the spark plugs and try turning the fan by hand. If it doesn't turn easily, pull the engine and get help.

[Cairo94507]

Mark nailed it first reply.

[Maltese Falcon]

Is there a chance that some of your fasteners in your clutch/pressure plate/flywheel might be standing off and interfering somewhat ; not allowing free movement. Any metallic , or clicking noises while it turns over?
If it is just a weak battery, try putting a fully charged jump-box on the battery while cranking.
This happened to me with a g50 installation, some of the bolt heads were a bit too tall (in the clutch assy.)and whipped against the pressure plate. There was some noise and it was not cranking at speed. I slipped the trans from the engine, removed the clutch assembly, fixed the problem with shorter profile bolts, and that solved it.
If your 2.7 turned freely with a wrench on the stand, it should still turn freely with a starter. (IMG:style_emoticons/default/idea.gif)
Marty

[zambezi]

How about the classic ground strap at the tranny problem? That will make for a slow cranking.

[tornik550]

I checked several things and didn't have any luck. I removed the starter to see if I could turn the engine without it installed- didn't work. I checked the wiring again and all was ok. Removed spark plugs and no change. Of coarse the transmission is ini neutral.

It is strange cause the engine will not turn at all- even slightly either direction. When I first turned on the starter, it cranked 1-2 revolutions.

I did a partial rebuild. I did everything from the cylinders/pistons out. I did not have any binding issues at all during the rebuild. I could easily turn it by hand.

One of the last things that I did that moved the crank was when I mounted the flywheel. I everything turned without difficulty. After than I mounted the clutch, pressure plate then the transmission. I didn't try to see if it turned ok once the transmission was installed.

So unless there is something that I am not thinking of, there has to be something wrong around the flywheel. Another thing that I thought of was what if bolt or something fell into one of the intakes? First, I looked into the bores with a borescope and didn't see anything. Also, if something were stuck in a cylinder, the engine just shouldn't turn one direction. I should be able to back it up without difficulty.

Has anyone else had an issue with something binding around the flywheel? I saw Marty's post which may possibly be my problem.

[PanelBilly]

Yes pull the plugs and report back

[tornik550]

Plugs are pulled. Previous tests were all done without plugs. Engine still won't move.

[brant]

sorry about this...

pull the trans and see if the motor is free
then pull the motor and start tearing it down until you find the offensive part.

[ThePaintedMan]

sorry about this...

pull the trans and see if the motor is free
then pull the motor and start tearing it down until you find the offensive part.

(IMG:style_emoticons/default/agree.gif)


Process of elimination. Likely you have a flywheel interference issue, cause you said the motor turned over fine after the rebuild.

[tornik550]

sorry about this...

pull the trans and see if the motor is free
then pull the motor and start tearing it down until you find the offensive part.

(IMG:style_emoticons/default/agree.gif)


Process of elimination. Likely you have a flywheel interference issue, cause you said the motor turned over fine after the rebuild.

I think I just needed someone else to tell me that. Looks like the tranny is coming out tonight.

[tornik550]

I went out and removed the transmission only from eh car. The transmission turned without difficulty. I tried to turn the engine and it still would not turn so I removed the pressure plate and clutch. Still the engine wouldn't turn. I decided to remove the flywheel. I figured a flywheel lock wasn't needed since the engine wouldn't turn. I put some muscle into removing the flywheel bolts. Before the first one started to turn, it felt like something broke free and now the engine turns like it previously did.

Now what? Was it bound to something that broke free? Something related to the flywheel that I can't see? Did something break (didn't sound like it)? Where should I go from here?

[mskala]

...
Now what? Was it bound to something that broke free? Something related to the flywheel that I can't see? Did something break (didn't sound like it)? Where should I go from here?

Check cams are still rotating and in time?

[tornik550]

...
Now what? Was it bound to something that broke free? Something related to the flywheel that I can't see? Did something break (didn't sound like it)? Where should I go from here?

Check cams are still rotating and in time?

I just checked and cams are moving normally however once I completely turned about one revolution- it got jammed again. I was able to unlodge it if I turned the engine the other way. Clearly I am hanging up on something.

[tornik550]

ARGH- I found my problem. 13mm nut in cylinder 5.

I had previously checked each cylinder with a borescope however this time I saw a slight glimmer. I was able to twist the borescope and see a nut close to the exhaust valve on cylinder 5.

I do not know how the nut got in there. My kids were playing around my engine one day. It may have occurred then or at some other unknown time.

I haven't been able to fish it out yet however I think I can get it out. I can clearly see the Pistons head which looks ok except a slight indent in the valve pocket. I can see the cylinder bore which also looks good. I cannot see the valves or combustion chamber. I assume there is a big indent in the compression chamber cause I can see that there is damage to the nut. I do not know the condition of the valve.

What would you do?

Get the nut out, bolt up the transmission, compression test and if the number are ok then run it? (I plan on re-rebuilding the engine next winter)

Or

Tear the engine down and assess the damage.

[boxsterfan]

What would you do?

Get the nut out, bolt up the transmission, compression test and if the number are ok then run it? (I plan on re-rebuilding the engine next winter)

Get out the nut, bolt her up and proceed.

[brant]

Ouch. Get it out and run a leak down.

Hopefully ....
Or rebuild one head if necessary

[Dr Evil]

Wow, man. That is some shit luck. Never force a stuck engine. I hope nothing got broken.

[mepstein]

ARGH- I found my problem. 13mm nut in cylinder 5.

I had previously checked each cylinder with a borescope however this time I saw a slight glimmer. I was able to twist the borescope and see a nut close to the exhaust valve on cylinder 5.

I do not know how the nut got in there. My kids were playing around my engine one day. It may have occurred then or at some other unknown time.

I haven't been able to fish it out yet however I think I can get it out. I can clearly see the Pistons head which looks ok except a slight indent in the valve pocket. I can see the cylinder bore which also looks good. I cannot see the valves or combustion chamber. I assume there is a big indent in the compression chamber cause I can see that there is damage to the nut. I do not know the condition of the valve.

What would you do?

Get the nut out, bolt up the transmission, compression test and if the number are ok then run it? (I plan on re-rebuilding the engine next winter)

Or

Tear the engine down and assess the damage.

I would pull the head. Better to fix something while the cars in your garage than see smoke out the back of your car when your far from home. Just the piece of mind would be worth it to me.

[tornik550]

I was planning on rebuilding the engine again this next winter so if smoke comes out the back, I wouldn't mind too much.

What is the purpose of doing a leak down test vs. a compression test in this situation? I have both tools so it doesn't matter, just curious. If I had a bent valve, then it seems like I wouldn't get any compression from the valve not sealing on the seat? I can clearly see the cylinder wall and piston crown and they generally look fine. I am sure that if there is damage, it would be a valve or the compression chamber.