Slowyoda

Howdy y’all, I have a 1991 pickup with the 22re. I recently bought it from a friend who replaced the timing chain and timing chain guards about 6,000 miles ago. I have been noticing an occasional rattle right after a hot start, generally last about 3-4 seconds. I have changed the oil recently and have an OEM yota filter in there. Seems like the tensioner could be the culprit but I would think if it was bad I would hear the rattle at every start or even while running. Any ideas?
Thanks

87-4runner

Possibly over torqued the tensioner bolts?

Slowyoda

Ok yeah, I’ve heard about this but I’m confused as to how over torqued bolts would affect the tensioner?

87-4runner

It probably puts the plunger in a bind...

snippits

Right before I put a timing kit in my 92 22RE, it would only do the chain rattle on cold starts, not hot starts, and then only lasted a few seconds at most. Guides were still intact when I tore it down.

Tensioner is spring loaded, and it works on oil pressure once the engine is cranked and running.

Slowyoda

Right. Yeah the hot start is what makes my situation weird. It’s also not on every hot start so I’m kinda wondering if it’s not the timing chain at all. I’ve heard folks say that the valves can make a knocking noise as well?

swampedout

Valves can be noisy.

Also, different type of oil filters will get oil onto the chain faster. Theres a couple threads where people have done a ton of research on this topic.

Kinda weird its a hot start issue...

Slowyoda

Yeah, I’m considering trying a different oil filter next time I change the oil. Although, I’m staring to think it’s not an oil pressure problem. I noticed the last time I changed the oil there was no knock on the first start even with no oil in the filter.

Joshuajayg

My truck will rattle just a tiny bit when I first start it until the oil starts pressurizing through all the orifices. May not be a problem at all.

Consider this... in a hot engine, everything has expanded. The lifters are further from the valves, the chain tensioner has more freedom of movement, the oil is less viscous. You shut down and some of the oil drains leaving air in its place in the normally pressurized lines. Now you start again. Everything is still expanded but there's not oil immediately. It takes a second for everything to pressurize. During that time, your more chain can slap a little more, your tensioner is more floppy, and your rockers rattle a bit. You get more noise. My newly rebuilt 22R-E does this as well as my V-6 2020 Tacoma. I'm not concerned and unless you experience this sound for five seconds, you shouldn't either.

Hope it's not issue at all.

Slowyoda

Ok, thanks for that explanation, makes a lot of sense. So your saying that this noise is somewhat “normal” operation? I’m thinking about checking the valves tomorrow to make sure everything is in spec but I’m not terrible worried about it. I suppose I’m just paranoid because I had a 92 Nissan truck that started out doing this then quickly progressed to rattling continuously.

snippits

When I did timing kit and head gasket, my 92 22RE had chain rattle on cold startup only for a few seconds plus a head gasket leak. On tear down, there were chain marks on the cylinder head and timing cover. Guides were still intact, and tensioner had normal wear. Chain could have been replaced tens of thousands of miles before I bought it, and that's what caused at least some of the chain marks...don't know. If it's indeed chain rattle, the chain is slapping metal. Pretty sure my chain slap was due to chain stretch.

I installed chain kit and head gasket kit 39 months ago, and I have not had one bit of chain rattle.

JJ'89

Appears this guy dealt with his rattle in time, and installed new stuff with what appears to be a metal guide, best I can tell anyway

87-4runner

I bet that was making some serious noise grinding on the head....

STERFRY333

Could be because the oil is thinner when it's warm so the chain compresses the tensioner easer before the pressure comes up

Joshuajayg

It wouldn't be hard to open the valve cover and see if something has come apart in there. Peace of mind.

Slowyoda

True indeed, I’ll will take the cover of this week and report back 👍

Slowyoda

So I popped the cover off and found the guides to be in good shape as I suspected. There is definitely a groove where the chain hit the timing cover before the chain was replaced. So if the sound is the chain I’m guessing it’s the sound of it hitting the guides?

snippits

That's a groove on the cylinder head.

Metal chain on metal does not sound like chain on plastic guides. Chain could possibly be rubbing timing cover. That's what mine was doing, but only on cold starts, and then it only lasted a second or two. Guides were still intact.

Only thing I can figure is chain stretch, or the tensioner is binding or bad. If the chain is rubbing timing cover, eventually it will make a hole deep enough that coolant will start getting in the oil. My timing cover had some grooves, so I replaced it with a new one.