top end engine knock. ideas?

[ohioshodude]

hello all. well as some of you know my sho has been out of commission for oh about 2 years now. i've tried to start it every two weeks or so but as i'm busy, sometimes i forget about it. it has been about a month and a half since the last time i started it. over the last 4 times i've started it it's developed a knock in the top end. using the "poor mans stethescope" (screw driver) i've narrowed the sound down to the front, passanger, intake side of the valve cover. i also get the noise from the intake area on the rear valve cover but not nearly as loud. as it has nearly 180k miles and probably never had a 60k i'm sure its well over due, and possibly part of the problem. i guess i'm asking if this is serious or if its just normal from being out of spec. if nothing else i may tear it down in a few days. thanks!

 

[Ishodu]

Could it be a loose timing chain slapping against the valve cover?

 

[ohioshodude]

well i thought that might be what i hear but thats on the other side of the engine. and i get no weird noises over there.

 

[Ishodu]

Ya sorry I missed the part where you said passenger side.

 

[NotSoSlowSHO]

how long do you normally let it run when you start it up?

 

[ohioshodude]

for a good while. 20-40 mins. lets everything get up to normal operating tempature. but the noise doesn't go away.

 

[ohioshodude]

either i've stumped everyone or those who know what the problem might be are at the convention. hehe
TTT

 

[PROPHET]

Could it be carbon build up, sticky valves, or dirty injectors.

 

[ohioshodude]

yeah i guess it could be any of those tony. i guess the only way to know for sure it to tear it open. which i'm not looking forward to. i just don't want to damage anything, its not loud enough to sound like its destroying anything but it is noticably loud. i just wondered if anyone else had problems like this. hopefully someone will chime in.

 

[sho 'nuff]

I had a strange knocking coming from my engine, and it turned out to be the timing belt was loose and it would slap against the timing belt cover. I don't know if it is a common problem for the timing belt tensioner to stop working but that is what happened to mine, it stopped giving tension on the belt. I replaced it, the noise went away and I gained about 10 hp back.

 

[danny gorgo]

Im guessing it may be a way out of spec shim. When you're running that kind of mileage with no valve lash adj. its only a matter of time before your cam(s) start rapidly wearing and start making a loud ticking noise, such as you have described.

 

[Ferendon]

The shim was my guess, it could also be.... *DUN DUN DUN* a rod knock. : Let's hope it's the belt or a shim. I doubt it's a rod knock, but with that many miles and no 60... If you can, stick your finger in there and check the rod bearings...
LoL, much easier said than done. Where's AutoSHO or Scott?