engine knocking (researched)

[kouki_monstor]

hey everyone, i just finished my car's DOHC swap and the car runs like a dream, except for the fact that i get these knocking noises at around 3-4000 rpm im guessing, since i dont have a DOHC cluster installed i cant keep track of the RPMs. it only happens when i drive and rev, not at idle, but it sounds like metal clanking against metal. im pretty suspicious the tensioner, since when i was removing the timing chain guides i noticed that one of the bolts that hold the tensioner in, and i realized that the hole was stripped. i tried to tighten it as best as it could and didnt think much of it, but now im thinking it's coming back to haunt me. what do you guys suggest i do? is there any way i could re-tap the threads and reinstall the tensioner? the metal in that part of the engine seemed really brittle, so im just a bit unsure of re-tapping it.

another thing is that when i was turning the crank to put the engine at TDC, i noticed that the timing chain lost its tightness after i turned that crank. it was just sitting there loose. it was tight before i turned the crank so i thought that's how it's supposed to be, so i just left this alone. oh yea, i realized this after i found the stripped bolt on the tensioner.

so could somenoe please point me in the right direction? any comments and thoughts would greatly help. thanks!

[kouki_monstor]

bump ^

[frapjap]

...when i was removing the timing chain guides i noticed that one of the bolts that hold the tensioner in, and i realized that the hole was stripped. i tried to tighten it as best as it could and didnt think much of it, but now im thinking it's coming back to haunt me. what do you guys suggest i do? is there any way i could re-tap the threads and reinstall the tensioner? the metal in that part of the engine seemed really brittle, so im just a bit unsure of re-tapping it.

If you narrow down the sound to the front cover, theres a good chance it may be the lack of a bolt. Was there a bolt in the stripped hole when you tore it down? Try it without a bolt. It may just be clanking against the loose bolt. If all else fails, JB weld it!

...another thing is that when i was turning the crank to put the engine at TDC, i noticed that the timing chain lost its tightness after i turned that crank. it was just sitting there loose. it was tight before i turned the crank so i thought that's how it's supposed to be, so i just left this alone. oh yea, i realized this after i found the stripped bolt on the tensioner.

How loose are we talking? Its normal to have a little slack, as when you rev it, the tensioner should do its job and tighten up the chain. So long as its not drooping by a half inch or more. IMO Considering the car runs well and all it seems you're timed correctly, I woulnd't give much thought to it.

so could somenoe please point me in the right direction? any comments and thoughts would greatly help. thanks![/QUOTE]

[kouki_monstor]

hey thanks alot!! yea there was a bolt in there when i tore it down. theres only to bolts that hold down the tensioner, and one without the other would make the tensioner spin around, so i couldnt just leave it on one bolt. so i just kept twisting the bolt til it got just a little tight, but not too tight to the point where it would come loose again, cuz it's stripped. but yea thats a great idea, if all else fails ill just jb weld it! haha thanks.

oh and about the chain, it seemed pretty loose, say if u grab the chain and moved it all the way up then all the way down, that distance would about about an inch. im hoping that's just normal, but it may be slacking right now also because the tensioner isnt doing its job. but worse comes to worse i really hope it's the tensioner. well ill open it up and check it out soon. thanks for all the help!

[frapjap]

hey thanks alot!! yea there was a bolt in there when i tore it down. theres only to bolts that hold down the tensioner, and one without the other would make the tensioner spin around, so i couldnt just leave it on one bolt. so i just kept twisting the bolt til it got just a little tight, but not too tight to the point where it would come loose again, cuz it's stripped. but yea thats a great idea, if all else fails ill just jb weld it! haha thanks.

It works, I promise. I'm missing a bolt on the waterpump because its stripped. I JB welded the missing hole and the surrounding area and its doing well many many miles later. Just be sure to let it cure all 15 hours : )

oh and about the chain, it seemed pretty loose, say if u grab the chain and moved it all the way up then all the way down, that distance would about about an inch. im hoping that's just normal, but it may be slacking right now also because the tensioner isnt doing its job. but worse comes to worse i really hope it's the tensioner. well ill open it up and check it out soon. thanks for all the help!

Thats not far off normal. With my tensioner thats was operating properly I got about 1/4 to a 1/2 inch of play. I'm going to stand behind the belief that its normal and fixing the tensioner will solve any unnecessary slack.

Oh, no problem with help, thats why the forum is here. **Theres also a good sticky about dohc cam alignment with some very good pictures. Its in the KA section. Check it out and good luck!

[kouki_monstor]

hey thanks a whole bunch man!!

[kouki_monstor]

well wadda ya know.. i had a friend listen to it, and it turns out to be a knocking rod due to a bad bearing according to him. =(. looks like it's gonna be another engine swap for me sometime soon.