big1000

so i just got a 1996 4runner with the 3rz-fe. The 5 speed is really fun.

It has a ticking sound coming from the engine. It could almost be related to an arcing spark plug wire, however I am sure that isn't whats happening. It only happens when the truck is under load, accelerating. Nothing when idling, and if I drove like a grandma I may rarely hear it. Some on here say it could be a loud injector, so I will try to listen with a mechanics stethoscope next week. I did the dollar bill trick on the exhaust and I am getting some suction...

So.. I'm hoping that with 160k on the truck, the valves just need an adjustment and I don't have a burnt valve. I'm doing a compression test in a couple of days to zone in on what cylinder(s), and then checking the valve clearances. Thank you to the guys who posted info on this site about adjusting the valves on the 3rz.

I'm also doing a smog test this weekend, and if it passes that will be a good thing.

My questions:

1. Is it possible that i haven't burnt a valve yet and some of the exhaust valves may be way out? the truck runs strong and doesn't miss...

2. Where in the flying phyladelphia ?!*% do I get valve shims for this truck? I am looking for a deal of course, but no luck with ebay or rock auto. If someone knows a good place to get good quality shims besides the set they sell at the dealer please speak up.

Cheers

big1000

Update:

The truck just passed CA smog. This supports my theory that I don't have a burnt valve, but valves may be out of spec.

Note: I am running a rich mixture of lucas oil injector lube and I think the ticking may have quieted some, but it is still there for sure.

also note: can you pass a smog test while running injector cleaner? YES

big1000

another update: the injector cleaner isn't doing ˟˟˟˟.

I took the heat guard off of the header to see if there are any cracks and nothing. No signs of an exhaust leak anywhere…

Also I was servicing the truck today and I noticed that if I take the valve cap off while the truck is running it blows air out like an exhaust pipe, not as strong, but still noticeable. Is this a problem? i've searched the forum for this but nothing.

I'm hoping i just need to adjust the valves. the truck runs fine.

big1000

Did a compression check today. I got the 20$ (15 with coupon!) compression tester from harbor freight, which I was pretty impressed with. Numbers are as follows:

Cyl 1: 130
Cyl 2: 129
Cyl 3: 122
Cyl 4: 135

So I'm thinking cyl 3 has exhaust valves that are out of spec, or possibly all of them. From what I've read as long as the numbers are fairly consistent you're good.

Wow this is a really hot thread!

big1000

I did notice recently that my cat rattles when the engine is starting from a dead stop but then the sound seems to disappear. I got under the truck and knocked it with my hand a few times and it seems to rattle from the inside, i.e. its not the little metal heat cover rattling. could this be causing the ticking I discussed in the 1st post? Is there an easy way to test this since the rattling is coming from the inside of the cat?

BigHoss_27

Broken baffle in cat blocking flow maybe mine rattles too but dissent run like urs is

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big1000

I think you might be onto something. Originally, since the sound ticked so fast and was relatively quiet I thought it couldn't be the cat. It also doesn't sound like its coming from the tailpipe, but now I am sure that I do have something that rattles from inside the cat.

Is there a cheap fix for the baffle thing? The truck just passed smog and California catalytic converters are super expensive. I don't really want to spend 300+$ for a ticking sound if ya know what I mean...

BigHoss_27

Rock auto was pretty cheap and mine rattles inside also and it runs fine but when I get to about 2500rpm it feels like its lugging like maybe not letting enough exhaust out building up back pressure

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scuba

Your compression numbers look decent. A little low but pretty consistent.
Yes, it's possible to have valves pretty out of spec without burning them. I had 1 or two that were close to .002 and my junk runs fine (after the adjustment at 150k and again at 200. I'm at 217 now).
Pony up and get the shims from your local dealer. Remind the parts guy that they should only be around $8 or $9 each.

If you passed smog, don't touch the cat for now.
If you need to rattle test it, pull it off completely and give it a shake.
You can try aftermarket cats (50 state cats are fine to run and will be cheaper than a CARB approved unit. Just have to have a family member or friend ship one in state.) but I don't recommend them. Start saving now for an OEM unit.
I ended up gutting mine and running an 02 Sim from urd. I highly doubt it will pass smog though.


That's my 2 cents. Sorry if I rambled. The thread jumped around a few times before I got in here to answer.

tantacoma

Have you ruled out the fan coming into contact with the shroud?

Riverman

Those 3rzs commonly have the donut gaskets between the exhaust and the y-pipe come loose and get sucked into the cat. This could explain both your ticking (exhaust leak at that junction) and your cat rattle.

I've had those donuts come off on both of the 3rz trucks that I've owned.

BigHoss_27

So just take it off and fish it out?

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big1000

since this sound only occurs when the truck is under load I'm thinking that it is unlikely. but then again if the engine position shifts slightly then this could happen I suppose

big1000

crazy! good to know! I'm gonna double check that its not the heat shield on the top of the cat, although I'm pretty sure it isn't.

and to scuba- I agree not to mess with the cat… I have a friend who is selling a tacoma with the 3rz soon so I might buy that and let the next guy do the valve check on this runner. I will keep you guys posted

Riverman

I've never pulled them out - I just deal with the cat rattle. If it ever throws a cat code, I suppose I will have to deal with it in order to pass inspection. On my last truck, it sucked 3 of them down there before I finally gave up on fixing the exhaust leak. I ran it like that for another 75,000 miles before it was wrecked at 250k+.

My current truck had the same problem when I got it this summer. I pulled off the manifold and replaced it with the mini header, and haven't yet had a problem with the donuts coming off that.

BigHoss_27

Mines got around 267k and I just did head and timing chain the truck had never been done before but it did throw a o2 sensor code

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