Help! Help! Help!

[hotrodmoline]

hey guys new to forum. 2000 exp 5.4 . engine started running rough out of town, took to mechanic shop, they put smoke to engine and found intake gaskets leaking they advised me that it would be ok to travel the 8 hrs back home with this problem parked exp for weekend and went to start 2 days later to leave. it cranked over 2 cylinders and then did a dead stop. i proceeded to think that intake gaskets had leaked water into a cylinder. i pulled all plugs and cranked over a couple dozen times to clean out cylinders. nothing blew out of cylinders. put all plugs back in and started and it then knocked. we loaded exp on trailer and pulled home. i have engine pulled and heads off every thing in heads apears to be good all valves move freely rods are all tight caps all tight cylinder walls all look great all factory hash marks still there one timing chain was loose the other was tight and when removed cam gear jumped back 5 degrees anybody got any ideas

 

[toms89]

Siezed while cranking... piston to valve contact?

 

[toms89]

Are the timing chain guides and tensioners in good shape? If not it maybe its possible the valve timing could have fluctuated enough to make contact?!

 

[hotrodmoline]

there was no contact between pistons and valves tensioners im not sure but the guides look great 1 of the tensioners was not exstended the same distance as the other i am thinking that was the problem from start but unsure. do you know if these motors are interferance motors?

 

[hotrodmoline]

I dont think it seized. like i stated i cranked engine for about a second and it did a dead stop. we pushed exp in heated shop and pulled plugs replaced and started and it knocked. it was about 5 degrees outside.

 

[toms89]

there was no contact between pistons and valves tensioners im not sure but the guides look great 1 of the tensioners was not exstended the same distance as the other i am thinking that was the problem from start but unsure. do you know if these motors are interferance motors?

Yes. There will be piston to valve contact if correct valve timing is not maintained.

Sounds like you checked the other areas of the motor. Unless maybe its an accessory, broken flexplate, starter or tranny issue.

 

[hotrodmoline]

ok have you ever pulled motor and trans out at same time that sucked. motor is tore down to short block and all i can find is the chain tensioner. im still alittle baffled the cylinder walls still look perfect. all the factory hash marks are still in the walls. 220,000 on this thing.

 

[toms89]

ok have you ever pulled motor and trans out at same time that sucked. motor is tore down to short block and all i can find is the chain tensioner. im still alittle baffled the cylinder walls still look perfect. all the factory hash marks are still in the walls. 220,000 on this thing.

I dont think its possible for the motor to be removed with the tranny still attached. Not enough room. Half the motor sits under the firewall as it is. Now you can remove the body if you have a lift and have complete access.

I was just shooting in the dark about the possibility that the timing chain if loose was allowing the valve timing to fluctuate enough to make contact. Doubt there would be much damage visible if it happens while cranking?!

 

[hotrodmoline]

just for information the motor and transmission can come out together they were almost straight vertical but it came out. im just struggling with putting back together with new gaskets and just replacing chain tensioners and putting back in car to find that i did not fix anything.

 

[toms89]

just for information the motor and transmission can come out together they were almost straight vertical but it came out. im just struggling with putting back together with new gaskets and just replacing chain tensioners and putting back in car to find that i did not fix anything.

I would not put it back in until I was sure what the issue was.

You must have one hell of a engine lift!! I barely could get mine high enough to clear the front without the tranny hanging vertical on it.

 

[toms89]

You did mention one of the tensioners was not tight. Did you replace it? I would replace both while you are there if you had issue with one.

 

[hotrodmoline]

it did hang vertical. it was great while it was vertical it drained into a drain pan made a very minimal mess and i had the front wheels of and it was sitting on short jack stands on the a arms all in an 8 foot ceiling with a leveler. any way any ideas.

 

[toms89]

I would double, triple check timing chain tensioners and guides. If you had an issue with one tensioner not maintaining tension chances are the guide may have broken. I would replace both tensioners at minimum but while your there why not replace guides as well.

AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - Symptoms of Bad Timing Chain, Ford V8 Engines

 

[hotrodmoline]

alright if this is an interferance motor and this motor ran and knocked after i removed the plugs then why am i only finding a tensioner problem? and are the chains suppose to stay tight with out tensioners on? when i tore engine down the driver bank chain had 3/4 slack on bottom side, the top was snug against guide. the pass bank was tight top and bottom.

 

[toms89]

alright if this is an interferance motor and this motor ran and knocked after i removed the plugs then why am i only finding a tensioner problem? and are the chains suppose to stay tight with out tensioners on? when i tore engine down the driver bank chain had 3/4 slack on bottom side, the top was snug against guide. the pass bank was tight top and bottom.

You should have no slack on timing chain once the tensioner builds up pressure for the first time.

By interference fit motor I assume you a speaking in reference to piston to valve clearance. Some older motors you could rotate the crank regardless of valve timing and nothing would hit. Not so with these modular overhead cam motors there would be piston to valve contact should the valve timing be off.

Don't really know the degree it would have to be off, advanced or retarded to begin to make contact.

It sounds to me like one of your hydraulic tensioners has failed or you have a broken guide!

Photo below should be as it appears. No slack!

 

[hotrodmoline]

thanks for the info im going to put gaskets and chain and tensioners in it and put it back in the hole.