the_supernerd

I have an '88 22R pickup that is ticking near the #4 cylinder. It sounds like it is coming from the head and does not change with load. It is really noticable around 2000-2500 RPMs. The valves are adjusted. It was slightly ticking when I got it, but it got louder when I revved the motor kind of high. I am assuming it was around redline. I posted this question before but no one seemed to know. Does anyone have a suggestion or possibly a guess at what it could be? Would a bad cam bearing tick?

sdoolin

Check for an exhaust leak. Both of my 4Runner had exhaust leaks when I purchased them. Easy to fix....

the_supernerd

I figured that is what it was, but I installed a brand new manifold and a remflex gasket and it did not change the noise at all.

Matt16

That a couple feet of any kind of hose and put one end to your ear. Put the other near where the sound is coming from. You will hear a very distinct "beating" sound if there is an exhaust leak. It is odd that the sound doesn't change under load, my exhaust leak wasn't noticeable under there was load on the engine.

Replacing the exhaust gasket (if you do find a leak) is a peice of cake- two hours tops as you will have to remove the manifold at the head end and the down-pipe end (just removed the down-pipe myself last night). You will need a deep 14mm socket and a foot-long socket wrench extension and the down-pipe/ manifold connection is easiest accessed from underneath the truck.

the_supernerd

I doubt it is an exhaust leak because I just put a brand new manifold, Remflex gasket and all of the emissions gaskets near the manifold. That did not fix the noise. It did not even change the tone a little. I have an exhaust leak in my other truck where the manifold meets the collector pipe and it sounds a lot different. It makes more of a ticking/puffing noise that gets louder under load.

The noise in this truck definitely seems to be coming from the valve train. The valves are adjusted and the rocker arms do not seem to be loose. The only other things I can think of are a loose valve rattling in the guide or possibly a bad cam bearing. Would either of those things cause a tick like I described above?

93Toyota PU

If it is a exhaust manifold leak, you might be able to see some exhaust fog on a cool/cold morning. Or feel the leak with your hand. Be careful of hot parts and do not crawl underneath a running vehicle unless you have it firmly and safely blocked so it cannot move (especially if it is manual transmission).
Also, I've had sticky injectors make a very distinct and sometimes loud ticking noise. Try to isolate the noise using the hose trick mentioned above or by buying a cheap mechanics stethoscope.

the_supernerd

I have a mechanic's stethescope. It is loud on the valve cover, especially the bolts, and the block is quiet. The noise is loudest at the #4 cylinder. It is carbureted, so I know that it is not the fuel injectors. I have crawled under it, and I can hear the noise echoing in the catalytic converter, but it is definitely not the source of the noise.

bigarms23

adjust your valves and check the exhaust manifold

skife

i'm 100% sure its not cam bearings....

your motor doesn't have them

93Toyota PU

Carbureted..my bad..should have seen that on your signature...

I'm not very familar with the Toyota engines internally...I'm just an old hack who reads and trys. But it sounds like it could be a lifter or rocker if so equipped.

the_supernerd

What I meant by cam bearings is basically where the cam rests in the head or the cap that bolts over it to hold it in place.

the_supernerd

I kind of suspected something like that. I tried to wiggle the rocker arms against the shaft and they seemed to be tight, but I did see a little oil bubble squeeze out when I did it. Because of the way the ticking sounds, it seems like one rocker arm would be a lot more loose than the rest. I will take another look at them, maybe I missed something. Do you know of a good way to check them other than the taking the rocker shafts apart?

the_supernerd

I thought of the rocker arms, but forgot about the shaft. I will check that out tomorrow. Thanks!

Matt16

On second thought, it sounds like your valve cover is over-tightened. I can't seem to get the right tightness myself, so if someone would jump in and give instructions, that would be brilliant.

Flash319

Timing chain tensioner is no good. Change it before your chain breaks.

the_supernerd

I thought it could have been the valve cover, but I had it overtightened before and it made two different kinds of ticks. One being the current tick, and the other being more of a quieter, deeper sounding tick.

I just put a new timing chain, tensioner, guides, etc, on it, so I doubt that it was it is, plus the noise is coming from the rear of the engine.

the_supernerd

I just went and looked at it again. I checked the rocker shafts and I found some noticable wear marks where the springs meet the rocker arms. There is one that almost looks like a crack near where the noise is coming from, so I think that might have something to do with it. I also probed around with a mechanic's stethescope and found that the noise is the loudest on the intake side valve cover bolts, but can not really be heard when probing the side of the head. I am really thinking that this is related to the rocker arms/shafts.

Thanks for all of your help!