Just curious if anyones experianced a ticking/rattleing sound from there engine ONLY at a certain rpm which seems to be roughly around 2500rpm or so. i say that only cause i dont have a tach. Its waaay annoying. almost sounds like it could be in need of a valve adjustment but sounds a like somethings going around under the valve cover broken but ive listened and heard nothing from that area....just cant pinpoint it. ive checked the exhaust manifold and that little EGR tube or what ever but nothing....no loss of performance or anything just getting tired of hearing it. my motor has 145k and was wondering if it was the timing chain or something. dont know if its been changed by previous owner...
its most likely your plastic timing guide on the exhaust side has ended up in your oil pan and the "ticking" sound you hear is the timing chain eating a hole through your cover they are called a "chain damper" in this pic the way to check is to pull your valve cover off and shine a flashlight down by the timing chain, you should see the guide there, if not.... if it is there tap it a lil bit with a long screw driver to see if it will move, it shouldn't. typically the guides/single last for 70-150kmi depending on how hard you drive. there are a few metal guides available for the 83+ 22r so you can get 200k+ out of em b4 the chain starts to stretch. there is also the possibility that some of your valves are WAY out of adjustment and are striking the valve cover, this is easy to diagnose as there will be fresh marks in your valve cover.
Another cause for the problem could very well be a worn rod bearing... Easy way to check is a "snap" test. Rev the motor quickly to about 3k RPM and let off the gas quick, if you hear the rattle during the decel of RPM most likely you will have the rod bearing issue.
It will also make a rattle if your valve cover is too tight which will cause the rocker arm to hit it. Did you recently replace a valve cover? James
i havent done anything to the engine since i purchase it. so i guess im hoping its just a timing chain. ive had a rod knock before in one of my chevy trucks in the past and it definetly doesnt sound like that unless it sounds different in a 4 banger....
SHONUFF called it. took the valve cover off and i dont even know how my truck is still driving seeing how theres a nice big groove in my cover and the chain is waaay loose! guess ill be changin that since i cant afford a swap yet...
your timing cover is prolly still good, it takes about a half inch before it gets to the coolant passage. if you know somebody that can weld aluminum, have em lay a bead down the grooves so the next time your guide goes you'll still have a lil "cushion" instead of the chain starting where it left off do you have a oil leak next to the #1 cylinder on the intake side @ the headgasket? its not a big deal if you do, but its a pretty common leak area. i think its a hell of alot easier to do the T chain if you remove the head instead of the oil pan, and a new head gasket and head studs will solve that leak. the whole 2 birds one stone thing....
SHONUFF,thanks for the help and advice. had i read this a little sooner, i would of kept my old cover. i already bought a new one and the truck is actually at a buddies shop since my job takes me away from how and i have no time to fix at the moment. ill mention what you had said and see what they do/ say. thanks a lot!
