the47guy

Well, this my first post(I think), been using this forum for a long time just never posted anything. I have searched for this but just am still not sure which thread suits my problem.

I currently have an 88 4runner with the 22re. I just replaced plugs, wires, oil, oil filter, fuel filter, piston rings, rod end bearings, head gasket, timing chain, sprockets, tensioner, guides(plastic), alternator, water pump, air cleaner box, all gaskets, and various vacuum lines.

I noticed that when I put my time chain on it was tight but felt it could be tighter. Seemed like it went on to easy. Very easy. Truck ran fine before so I figured it should be fine. Adjusted valves to .08 and .012 and have rechecked it After everything was together I timed it with the diagnostics jumped to 5BTDC. Took jumper out when straight to 20BTDC. She idles almost perfect. Now to my question.

When I am driving and I apply the slightest bit of throttle I get a slight metal grinding sound. Doesn't do it at idle or when you apply medium to heavy throttle. Just very light throttle. If you can hold it in that sweet spot it will keep doing it. Besides that she runs strong. Good throttle response and power. It also does it right when you let off the throttle. I can't get it to do it unless I'm actually driving so it is hard to figure out where the noise is coming from.

Any help would greatly appreciated. Thanks.

xxxtreme22r

Timing chain too loose (maybe even a tooth off) and hitting guides, or you could have a rod bearing shot.

When you rebuilt the engine did you have everything checked by machine shop or did you just throw new parts in it without checking the rod ends and crank for roundness? Did you lube those bearings when you put them in? How did you breakin the engine?

Why did you do the rebuild? Never did say if this noise was there before the rebuild.

the47guy

I didnt have a machine shop check it. I'm a helo mechanic and used the tools I had already to check the crank, rod ends, cylinder walls for roundness. Probably should of had a machine shop double check. Everything checked out fine per the FSM. I've double checked the timing marks and they are lined up. Top is at 11:55. Dark link is where it should be. I figured that wasn't it because it runs great, just that noise. Used assembly lube for everything I measured from the crank to the cam as well but I don't have the measurement with me at the moment. I'm wondering if the T chain is just a little too loose. Would a thicker head gasket fix that or would I be messing too much with compression at that point?

the47guy

Bump*

xxxtreme22r

Make sure it's not related to a bearing of a belt driven accessory. Like the Alternator, power steering pump, power steering idler. etc etc.

the47guy

Will do thanks.

yotaman85

this.. i rebuilt a motor once because it had a knock, put it together, still knocking. turned out to be the harmonic balencer.

the47guy

Turns out it is coming from around my rockers. Any ideas?

xxxtreme22r

Front or back? Maybe the valve cover is on too tight.

the47guy

The back

xxxtreme22r

Try backing off the valve cover nuts. You might have it too tight. Your only supposed to tighten those things lust past figure tight bearly squishing the grommets. If it's that though, you might not even hear the tapping from inside the cab.