03 tacoma 3.4 engine knock HELP

[garyk1970]

good to join you guys...hopefully someone has seen this problem before and can give me some advice.03 taco crew cab 4x4 5vzfe 69,000 miles.has bottom end knock when warm.only at idle. in drive seems louder.used teth.scope and the loudest in center of oil pan.toyota dealer said they couldnt help(waranty help)only 9k miles out.they recommend to pull engine and tear down to furter diagnose.ive always known toyota for durability,changed oil every 3k.anyone seen this before , any help? thanks in advance, Gary

[corning_d3]

It sounds like that engine was a lemon, unless it was rode hard. It sounds like your describing either a rod or main bearing. What does your oil pressure show? Low pressure and a knock is a bad sign...

[Flash75]

"has bottom end knock when warm.only at idle. in drive seems louder"
Does it knock at any engine speed other than idle when in drive? Can you hear the noise when driving, if yes, under what conditions? You said it happens when the engine is warm, is it ok with a cold engine? Additional information may help give a better idea on the source of the knock.

Clifton

[garyk1970]

Originally Posted by Flash75

"has bottom end knock when warm.only at idle. in drive seems louder"
Does it knock at any engine speed other than idle when in drive? Can you hear the noise when driving, if yes, under what conditions? You said it happens when the engine is warm, is it ok with a cold engine? Additional information may help give a better idea on the source of the knock.

Clifton

truck driven and owned by my 62 year old mother in law,she doesnt even like to pass someone.only knocks in drive standing still, sometimes at idle.any other rpm or engine speed or load no knock.cold engine ok,no knock.sounds like middle main bearing to me,just cant believe that many miles with a major problem.i pulled cover tonite and checked flywheel,no cracks that i can see.she claims it had this sound since new,and its getting louder.she thought it was normal! she told me that a technition at a local oil change brought it to her attention (he was under the truck on the grease rack)that goes back to the fact that i found its louder at the oil pan.since she thought that the sound was normal,she didnt file a complaint with the dealer,so now that it is out of warranty.....

[garyk1970]

going to replace motor.link to repair guide was a dead end.only question i have is;will the torque converter slide out,or will i have to unbolt it from the flywheel?

[Flash75]

Gary, You need to unbolt the converter or it will stay on the flywheel.

I hope changing the engine corrects the knock. FWIW, I don't think the problem is a main bearing knock, they almost always make more noise when the engine is at speed and under load. Good luck.

Clifton

[garyk1970]

thanks for the reply.im am pulling the motor this weekend.what are you thinking of whats the problem?our plan was to pull engine put on a stand ,spin over ,remove oil pan and hopefully find the problem.rod,wrist pin,main bearing,cracked flywheel(could not see all of it when in truck)who knows.if we find the problem i will post it and let you know.thanks Gary

[Flash75]

I don't know what the problem is but I do know from past experience that rod and main bearing knocks will knock louder when the engine is loaded.
It would be interesting to know what your oil pressure is at idle and at road speed. Some after market oil filters cause problems, but that is usually at start up. If it does have an aftermarket oil filter I would switch it to a Toyota, Wix or a NAPA Gold. For engines where the filter sits almost upside down or horizontal I recommend not using Fram, STP and Walmart filter to name a few. The problem could be something external like exhaust manifolds. fan clutch or front pulley. I think valves could rattle at low speed and not be noticed at driving speeds. I wish I could be more helpful but the fact it only happens at idle or low speeds makes it tough to figure. If you find something please let us know.

Clifton