Ticking noise in engine only under certain conditions

[randy cain]

I have 132,000 miles on my 2001 Limited and it has started making a "ticking" noise somewhere around the left manifold area in the engine. It does not do it on cold start up and not consistently. Most of the time I hear it is after I driven the truck and let it sit for 15-30 minutes. It usually goes away in less than a minute. It sounds like an exhaust leak but one would think that it would make the sound more consistently and especially on cold start-ups. Talked to one Toyota dealer and was told that they have had to do some exhaust manifold replacements due to cracking. He also said that 2000 and early 2001 had some problems with "piston shirtail slapping" and that Toyota did not think it was a problem but corrected in later models. Anyone have any ideas what might be happening?

Moderators Note: Thread moved to the Engine & Drivetrain Forum for better exposure and replies. PM was sent to thread starter of its relocation. --- Possum

[Stooge]

Have you checked the valve clearances and changed the timing belt yet? I would start here. Doubt if the manifold "developed" the crack after 100K - the manifolds usually come "cracked" from the factory from an over zealous air wrench.

[Dude Boy]

the manifolds usually come "cracked" from the factory from an over zealous air wrench.

I doubt it. A more likely cause is p$ss poor welding and/or design.

[randy cain]

Did timing belt just past the 100,000 mark...keep truck well maintained due to the high mileage I drive it...but have not had valve clearences checked unless they were at timing belt install.

[rckstr]

my 2001 only has 33000 miles and make that ticking noise when i start it in the morning.

[BNR32]

RandyCain,

I've also got a 2001 Tundra, mine is a Ltd 4X4 w/ 50k on the odometer but I have the same symptoms on my truck. Every so often I'll here a ticking sound that seems to come from the driver's side ex. manifold. The other day when I was changing my oil I had the hood open and tugged the throttle open a bit and it didn't sound like an exhaust leak at that point.

I uncertain if the noise has anything to do with valve clearances, if my valves are that far out of adjustment I'm going to be looking for some even more serious problems in the head.

Does anyone know if the manifolds are cast iron or if they are welded tublular peices? I didn't even think to look when I was uunder the hood.

Sean

[Jimbo88]

I have 89K on my 2000, and i have been noticing some ticking while driving. I have no idea where it is coming from, other than "under the hood somewhere"..
It's common when cold, and internittently under load, hot or cold.

I also see a big puff of smoke in the rear view when I hammer down on the pedal, but again, it doesn't happen every time...


I hate intermittent problems; it is really difficult to narrow down the exact conditions under which problems actually manifest, let alone determine the true cause(s) of the problem...

Anyone have any sceintific(or qusi-scientific) tests I could perform to get a better idea what is going on here?

I plan to have my dealer do a compression test at next service..should I be due for a new timing belt yet?

[Dude Boy]

With the truck cold, have someone start it up and put it in gear while holding the brake. Have them apply a bit of throttle while you listen at each side of the engine. I used a piece of small diameter hose and put it through the wheel well right up into the manifold area. Hold the other end of the hose to your ear. It's common for the noise to almost go away when the engine is warm. The manifolds are welded up out of stainless tubing. See picture below.

[seqoia2001]

[quote=Dude Boy;105812]With the truck cold, have someone start it up and put it in gear while holding the brake. Have them apply a bit of throttle while you listen at each side of the engine. I used a piece of small diameter hose and put it through the wheel well right up into the manifold area. Hold the other end of the hose to your

[minomatchu]

My 2000 Tundra 4.7L w/ 59K does the exact same thing. It has been doing it for as long as I can remember. People tell me it sounds like an exhaust leak when they hear the truck. The ticking noise is especially noticeable when cold. I'd like to hear from someone that had the problem and solved it.

[mnarcticcat]

2001 Sequoia... 134,000 miles... I to have the ticking noise. The harder I step on the gas the ticking noise increases!