1997 2RZFE (155k miles) Timing Chain

Hey all! First post on the forums.... just curious if you guys could offer some advice on my truck. I've only had it for about a month and have an issue.

My 2RZ has the 'cold everything's fine, warmed up it sounds like a Diesel at idle' problem that's become more pronounced since I bought it (and it seems especially after my oil change). It's most conspicuous at idle, but tapers off in intensity as the RPMs climbs and other noises shroud it. I never hear a peep of abnormality when cold.

When I first got the truck the first thing I did was check the valve clearances, all were spec except one exhaust valve that was the tight extreme. I've included a link below. However, I didn't think to look at the guides to check their condition when I had the valve cover off.

http://img256.imageshack.us/img256/6417/valvecheck12272010.jpg (My note on the tight exhaust valve says to check again in 15k... I didn't want to buy any special tools if I didn't have to)

Anyway, I'm curious if there's any obvious way to check for the bad timing chain/tensioner before I undertake the whole removal process? The stethoscope around the front of the motor seems to corroborate with my suspicions... other than that? Is it possible to replace just the tensioner guides without cam chain/head removal? The illustrations in the factory service manual seem to indicate this might be possible, but I only glanced through the procedure.

Also, anything non-timing chain related that I should replace while I'm in there other than accessory belts?

 

ive got a 98 that makes some noise only when warm also.. what concerns me is at just about 2100 rpm's it has a very pronounced noise, that im almost afraid to check out. not a knock though but its noisy and irritating like the chain rattleing or a single valve slappin hard.

 

It's hard to pinpoint my noise and it sounds to be different than yours. With the hood up just sounds like a motor for the most part, the peculiar portion of the noises is actually most noticeable in the cabin.... but the stethoscope doesn't say that there's anything noticeable near the trans/engine mating surface nor near the rods or bell housing, etc. etc.

If it is a valve for you, the valve check on this motor is really painless (at least for a clearance inspection)... Intake and valvecover off and that's all there is to it. There's one or two bolts that needs to be undone near the firewall that can be rather difficult to get to, but otherwise it's about 1/20th the effort to do a valve check on my 20 valve I4 motorcycle.

 

well turns out it was my exaust manifold heat shield. Cracked broken and missing a bolt.

 

usually don't need to touch the chain until after 200k. the exhaust manifold usually cracks by then. what you can do is either get an lce header or the oem one off a 2001-2004 4 banger tacoma from the dealer.

 

Mine has 190k+ and i just ordered a DT header so hopefully all my noise stops.

 

Are you referring to the header itself or the shrouding as Kingbrian mentioned? If it's on the header itself can you give me the location/union of where it's typical?

 

i believe its right around the 2-3 port right under the heat shield.

 

Thanks! I'll look into that. I have a theory that's probably pretty far out there if the header is the case... when I bought the truck I gave it a good seafoaming and proceeded to give it an 'italian tuneup' pretty much Daily. You can tell it really needed it since if you look at the exhaust tip when I got the truck VS now, there's HUGE amounts of soot that has been blown out. I may have exacerbated a present crack or perhaps caused it by the rough driving (heat) in combination with burning off any carbon that might have been plugging it.

 

Trifenix.... I owe you a beer.