Knocking sound from engine - help diagnose *video* - Toyota Nation Forum : Toyota Car and Truck Forums

gregzbutt · 05-27-2011, 07:09 PM

Hello everybody. I've been tooling around on TN for a long time with my Camry and just recently picked up this corolla. 1998 non vvti 1zz with a stick shift, about 138k miles. It runs terrific, much quicker and responsive than the 3sfe in my old camry. However, I recently noticed it's been making this knocking sound that's got me worried it might have bearing issues. It happens between 2 and 3000 rpms, and usually only in 1st and 2nd gear, put sometimes in higher gears when I'm going up a hill or when the engine is under load. It's been persistent and happens whether the engine is hot or cold. If I had noticed this on the test drive I don't think I would have bought the car. At first I was thinking it was the valves out of adjustment, but lately I've been fearing it's a prelude to a spun rod bearing. I was hoping some of you guys with more experience diagnosing this stuff could help me out. I made a short clip i posted on youtube...

You Tube

The serpentine belt is making a lot of noise so its harder to hear, but right between the 7 and 12 second marks it stands out a bit as I'm reving it. If i had noticed this on my test drive I would have never bought the car. Other than this knocking sound, the car runs great and I love it. I hope I don't have to drop an engine into it my first month of ownership...

Thanks for your help guys.

Greg

sam333 · 05-29-2011, 01:13 PM

Its hard to tell from a video , but it sounds higher pitched than a bearing knock. I did hear the sound. Buy a auto stethoscope and track it down.

gregzbutt · 05-29-2011, 05:11 PM

I agree after watching this a few times, and even trying to show my friends last night its hard to hear over the rest of the engine noise. I'll try and track it down some more.

2damaxsupra · 05-30-2011, 11:56 PM

My car makes the same noise around 3k rpm. I just ignore it and it has been problem free for over 3 years.

Highway_maniac · 05-31-2011, 02:39 AM

Try the following: take it out for a spin. Try to reproduce the sound. Let go of the throttle - if the sound goes away it's your injectors that are noisy. If it does not go away, it's something else.

I've got a 3ZZ-FE engine (EU 1.6 vvti), also with a knocking sound. Dealer says it's the injectors. Driving on the highway (or at idle) I can hear the sound (ticking sound I also hear a bit in your video). When I let go of the throttle - no sound. Press the throttle a little - sound starts, full throttle - sound, but not as load as only little throttle. When lifting/letting go of the throttle, the fuel injectors stop injecting fuel, thus no sound.

gregzbutt · 05-31-2011, 09:24 PM

Thanks for the comments guys. I take comfort in knowing that others have similar sounding engines that are trouble free. I have read quite a bit about how these are noisy engines. My old camry was also very noisy, (especially injectors) and continues to run well despite its blown head gasket turning my coolant black with oil. I haven't been able to trace the sound to a specific area of the engine yet, but I do have an update!

I had the car at a local shop and told them about the noise. Upon investigating it, they discovered that one of my transmission mounts was installed UPSIDE DOWN!!!! The previous owner had replaced the clutch a few months back and ended up having to replace the transmission after a flywheel bolt came loose and grenaded the original. Must be the shop neglected to take note of how corolla transmissions are supposed to be installed. The mechanic mentioned that the whole engine and transmission were actually pushed off center a bit and left little room for the engine to vibrate and move like it was supposed to. After they flipped the mount right side up, and another broken engine mount was replaced, the car now drives like a dream. It feels like a lexus compared to the wild child it used to be. Much much quieter and smoother. I drove home and I could hardly hear any engine noise at all. It wasn't until I popped the hood and revved it up a bit that I heard the knocking sound again. Its now so subdued I'm thinking its more valvetrain/injectors and not as severe as I previously thought. I'm still going to try and track down the source of the sound for peace of mind. I'll keep you posted.

Thanks so much for the help.

Cheers!
Greg