1987 4Runner 22RE
Okay ... here's what I've done ... and hopefully it's not fatal.
Replaced timing chain ... got her running (after discovering I had the distributer 180* off) fixed water leak (heater pipe gasket) and after letting it idle for awhile (5 min) I got this loud knocking noise from the top rear of the engine.
I let it cool down (3 hours)... restarted ... noise still there. I pulled each plug wire, one at a time of course, from the distributer (to try to isolate) but no difference ... noise still there.
Any suggestions?
Valve adjustment? If so ... what are the specs (hot/cold etc)?
It is a very loud tap/knock which increases in synch with rpm.
It did not make this noise either before timing chain replacement or on initial startup, just after checking for leaks (second start up).
Any thoughts (on the problem of course)?

 

Forgot to add that I also changed plugs just prior to ...

 

What's your oil pressure look like? Sounds like the engine might not be getting enough oil flow. Whatever you do, don't drive it like that.

Ed

 

Not too familiar with the 4 cyl. but mine and a couple others developed a bad knock at the top back of the motor. We were convinced it was valves, but it turned out to be a bad bearing on the crank. The guy who told me about it had a main bearing go out and mine was the #2 bearing. Hope this isn't the case, but keep it in mind when you have checked the valves and all is fine.

 

Oil pressure seemed fine ... if I can trust the gauges. If it were a rod bearing wouldnt the noise have stopped when I pulled the effected cylinder plug wire?
Going back at it this morning ... after I look at my wife's Caravan which is now refusing to start (fuel pump I think). GEES ... When it rains it pours!

 

I'm thinking about buying a horse and buggy. Anyone in Omish country have one for sale? Hey ... at least when they quit working you can shot 'em and eat 'em (the horse not the Omish)
!

 

Shoot .... not shot ... my typing matches my mechanical inabilities!

 

Update:
Noise still there, 4Runner down. Dodge fuel pump or Power Module broke. Hey, maybe there's an engine swap in the future.
Still waiting on the horse and buggy.

 

As long as the engine is spinning, it is causing stress on the rod and bearing, so It won't stop making the noise.

 

Okay ... but what about the horse and buggy idea?
I'm guessing it'll be a PITA to correct. I will search threads on the subject. So how is your truck after repacing bearings?

 

double and triple check your work....i used to be a service tech for an HVAC company and I found if it was working fine BEFORE i got there but then it stopped working after I was done doing what I needed to do it was something I did 99% of the time. I mean what are the chances of a bearing going bad the EXACT same time you performed all this work....of course stranger things have happened....Good luck with it

 

Always double check yourself before assuming something else is to blame, this has saved me a lot of headaches before!

Fink

 

Runs real quiet! In fact, too quiet... I haven't gotten the block back yet.

Can you get lockers for those? I would think one would be ok if you put on 33's with a 3" lift!!!

 

i don't know, i think it would be under powered with 33's, only 1 hhp (hoof horse power)

 

I bet if you stuck a turbo up its backside ya might get a little extra kick.

 

Hey ... my pessimistic (however it's spelled) nature is glaring through. Please see newest thread on the subject ....
HELP! Need Suggestions On Engine/Parts Venders?

 

I had this problem coming from the lower part of the engine with a loud tap that led to crank eventually. I thought it could have been this. If it was than are these all that needs to be replaced? Or has more damage been done now that it cranks?

 

Sounds like oil to me, but basically because if something were out of adjustment, it would have happened right away. When engines lose oil pressure for whatever the reason, it takes about 2-5 minutes of idling (way way less if you drive it) for things to dry out and start wearing very quickly. You could have very well eaten a rod bearing, though you're lucky it hasn't spun and seized the thing up yet.

Did you use any liquid gasket maker on there? If so did you actually wait the full 24 hours to let it cure before starting the motor? Or did you use too much? That stuff if not used properly can come loose in there, float into the oil passages, and clog them up. As it happens, the bearing channels are some of the smallest ones, and are naturally the #1 place where stuff gets stuck (blobs of gasket maker / silicone, metal, etc). Bad things go on inside your motor when that happens.

Best of luck bro, but it sounds like a total teardown to me. Hopefully you can just get by with some new bearings and bolts...

 

I am fairly confused about your question, but to answer something:

I am getting all new bearings and the crank needs to be turned and balanced (not all that professionally balanced, but at least somewhat balanced). The bad bearing caused stress on one rod and caused it to be untrue. Now I am replacing one rod. The cylinders are now out of round because of the uneven wear (this could be the 188,000 miles or it could have been expadited by the bad bearing). What this amounts to is 6 new 30 up pistons, a bored out engine by 30/1000, new rings, new bearings, turned crank, and of coarse the seals and such (which I got out of my rebuild kit).

 

Just not convinced its the crank or rod bearings ... it is definetly a top end noise ... and noticed that past idle rpm the noise dissappears
... still wondering