JacobPierce

i need help. my truck has done this since i have had it. it only does it on startup and a certain rpm. i have been thinking its the valves need to be adjusted but don't know.

Sensei

Loose valves will present a ticking noise. Light, quick tick tick tick. Knocking noises are usually associate with your reciprocating assembly ( crank, rods, pistons ). Pull the valve cover and rotate the engine until #1 cylinder is near TDC on it's compression stroke ( check your FSM or Haynes/Chilton manual. they all describe how to adjust valves ). Check you valve lash. Chances are they are loose. Adjust all your valves per the manuals.

abecedarian

Check your timing chain.
Pull the valve cover gasket and check for wear on the exhaust side of the chain. Look for grooves ....

JacobPierce

i am pulling the valve cover off this weekend and checking all the valves

93YotaGuy

If it is the valves do yourself a favor and adjust them by hand. In the past I have adjusted mine with the recommended adjustment but always had a tick. I have since adjusted both of my trucks by hand and have little to no tick at all. Going on 20k miles on my 4x4 with no problems.

abecedarian

Slack in the timing chain will change timing, both valve and ignition, possibly even a few degrees variation in ignition timing. Slack in the chain will cause the cam to move a little slower than the crank, then speed up to catch up to the crank and this will cause "jitter" and fluctuation in timing. Over time, this wears the chain even more.

Factory spec is to replace the chain at approximate 80K mile intervals. Beyond that, the chain will experience accelerated wear which will retard both cam and ignition timing. Eventually, the cam tensioner will run out of room to take up the slack and the chain will begin slapping against the long guide (exhaust side of the engine) and break that guide. Once the guide is broke, the chain will continue to wear (stretch) and wear through the timing cover.

19864runnerHawaii

Yes just as long as you follow recomended specs on torque you should be fine doing them yourself

Nailit69

I found that if I went down on the gap a tiny bit it quieted mine down but i'm talking like .001 .

Also discovered that a knock I thought was coming from my motor turned out to be my tranny so there could be other culprits. Check everything!

bobby_duce

the first time i adjusted my valves i did it when its warm and it didnt seem to help to much but then i did a cold adjustment and it seemed to help alittle.

int. ex.
hot .008 .012
cold .006 .010

Nailit69

I found the same thing worked when I did mine... cold was better.

JacobPierce

okay ii did it with it cold but did it to the hot specs and didnt help a lot so i am going to try it with the cold

Nailit69

next time you listen to sensei, grasshopper. Yea doing it cold to the hot spec probably made it even sloppier once it was warm.

Sensei

There's a reason mechanical engineers get paid a ton of money designing engines. There's a reason why engines fail when somebody thinks they no more than the manufacturer.

xxxtreme22r

Last time I had these types of symptoms, start up knock, knock at mid to high rpm and while clutch in shifting, it was a bad rod bearing. It went on like that for about a year or so before spinning the bearing completely.

I originally thought timing chain as well. Changed that when I first bought the truck. Didn't help. My guide rails were still good. Typically a stretched timing chain won't make noise till it takes out that guide rail and starts hitting the cover.

Snortin Nortin

Kool learning soo much here love this site!!!