ironhead31

I bought a 93 truck with the 22RE and I am concerned about a knock or tapping noise at startup.In the morning when it is cold it will not do it or when it sits for awhile and the choke kicks in it won't because it revs up and the oil pressure rises fast I guess.It only does it after it warms completly up,shut off for about 20 minutes then started up.It is a tapping,knocking noise,about 4 or 5 times then stops.It runs great does not knock or smoke on idle or on the run only on startup.The dealer service dept. said it was the timing chain so we replaced it but guess what,it still does the same thing!This is my first toyota product so I know NOTHING about it.I have always been a chevy man I just always wanted one of these little toy.trucks.Is this normal for this truck to do this?Any ideas or help on this? Thanks

riverrat

Had drafted a message about timing chains until I actually read all the way through your post- DOH!!!

zedex

Sounds like a crank rod bearing. After you first fire it up there is no oil to take up the slack in the bearing. Once you get oil pressure it goes away. I would try running some heavier oil and see what happens.
Timing chain?

CrazyDiamond

As long as its not a real heavy knocking sound, it could just be the tapping of your rockers on the cam lobes until oil gets to teh top of the engine. Mine has always done it, and I have a friend's that does exactly the same thing. 22re rockers are noisy to begin with...they just make a bit more for that first few seconds until oil gets to the top.

Don't forget, 22re's have a non-hydraulic rocker setup, not nice self-adjusting hydraulic lifters like alot of domestic cars do. This means it's metal on metal with a tiny gap in between until oil gets up there.

Hope that helps.

skshepherd

A lot of the Tacoma guys are having the same problem and many have come to the conclusion it is something called piston slap, check out Tacoma Territory forum on delphi or search for New England Tacoma Territory, I think they have some links there. How I understand it is that there is just excessive play between piston and cylinder wall which is aggrevated by the cold temperatures, and it goes away once the engine starts to warm up and the metal expands.

However, I am wondering if it might have to do with poor oil circulation as in many of the camrys and other toyotas that are having oil sludge buildup issues.

Good luck.

Brendan

my truck does the same thing. i'm not too worried about it.

amusement

Leave it up to the Canadian's to write a great article about piston slap

http://www.canadiandriver.com/articles/jk/020320.htm

CrazyDiamond

Piston slap is a possibility, but the noise I'm talking about stops within 1-2 seconds, so I don't think that the pistons have time to expand that quickly. I still think that it's 1-2 seconds of dry cam lobes and rockers. It stops so suddenly, it's just as if someone flipped a switch.

Incidentally, could also be a loose timing chain tensioner, which tightens up as soon as oil pressure pushes it out and takes the slack out of the chain.

DreamToy

It dosent make any knocking at all when driving?
Mine did something similar......more than 1-2 seconds, ended up being a rodknock.

John

hex

We have a 83' pickup with a 22R at work and I bought my 87' pickup with a 22RE. My buddy asked our company mechanic how come they both made that sound when they started up and his reply was "because they're Toyotas". So I guess it's pretty common.

thisismyusername

Was the answer found? I am encountering the same issues on startup. Timing chain is good, guides are good, and I have a toyota oil filter, so its not messing with my oil pressure? maybe oil pump?