ummm timing belt prolly easy question to answer

[5spd4life]

ok i started my beast after a year of sitting, and it ran fine quiet like woah, but i cranked it and started it and all of a sudden it started making a thudding noise cause the timing belt totally had slack in it for no reason, so i say "what the hell" and start pulling the timeing belt think i could pop a new tensioner in it, but i was turning the crankshaft pulley to line it up at TDC (top dead center of course u knew that) and i realize as i turned the crankshaft pulley my belt tensed up and i had very little play in it anymore, two questions...what the hell happened there, and should i replace the tensioner, and should there be any slack at all in the belt or should i be able to bounce a quarter off it? ok so that was three questions, so shoot me....

 

[GTM]

...
think i could pop a new tensioner in it, but i was turning the crankshaft pulley to line it up at TDC (top dead center of course u knew that) and i realize as i turned the crankshaft pulley my belt tensed up and i had very little play in it anymore, two questions...what the hell happened there, and should i replace the tensioner, and should there be any slack at all in the belt or should i be able to bounce a quarter off it? ok so that was three questions, so shoot me....

I don't want to know. If it's coming up hard then I suspect you may have bent some valves. Noises are subjective so I don't know what thumping means to you. Maybe it's just belt whip and slapping something. It's been sitting for a year presumabley the belt had taken a set. If you can't turn the engine pull the plugs inspect where the pistons are.

The safe thing to do if you can't turn the engine is to pop the cam followers at the hydraulic adjusters using a 14mm(?) open end wrench by levering up and to the side. Do this for every valve where the lobe is up. Now very carefully rotate the crank backwards and remove some more, now forward and see if it continues to lock, if so go backwards until they are all removed. Lay them out in the order of position. All the spring hats should be level, if not bent valves and the head must come off

TDC, cam pins up, and marks must align. You may find you are a tooth off, but you wont bump valves so set the cams again if needed. Going back together set all pistons so they are level and you can reinstall _all_ the cam followers without bumping anything. You will have to set the oil pump/balance shaft timing.

And now you can do a compression check.

Cheers,
GTM

 

[5spd4life]

ok belt is now all of a sudden fine...timing is perfect why the hell did the belt become loose? i may never know, but i hope it dosent happen again, i think im just gonna replace the belt and tensioner anyway

 

[Defiant]

http://www.dsmtuners.com/forums/showthread.php?t=126376
http://www.dsmtuners.com/forums/showthread.php?t=89121

 

[GTM]

ok belt is now all of a sudden fine...timing is perfect why the hell did the belt become loose? i may never know, but i hope it dosent happen again, i think im just gonna replace the belt and tensioner anyway

While dispensing professional advice it's best to err on the conservative side since we can't inspect or know the degree of _loose_ or _sounds_ which could be fatal to an engine. With the unknown conditions of this engine it most certainly warranted close inspection rather than dismissing the over-run potential as the cause until you had gathered enough information. Loose between the cams and loose on the slack side is relative but must be established as being within specifications.

I think you may have bought right so have some money to play with and going over the timing belt system probably would be the best insurance of preventing serious problems. It also might be prudent to go over the head bolt torque as another source of potential problems. If you plan on trying to extract more HP then swapping of bolts for studs and increasing the torque value could also give a measure of security. I have and others have reported being successful at changing 1 at a time on a cold engine when they have been experiencing minor coolant loss due to an early stage head gasket leak.

Keep us posted if something else unnerving comes up.

Cheers,
GTM