Even the toyota dealer doesnt know this problem

[biggd963]

Okay so I have a 2004 toyota 4runner with the V8 engine. I have been have a very weird problem that has the dealer stumped on the problem. When driving and the car is at exactly 1400 RPM I hear a weird noise almost like an electronic noise/vibration if i take my foot off the gas it goes away and if i push the gas anywhere past 1400 RPM the noise is gone as well. It only happens at that specific RPM and it doesn't happen every time. It sounds like it could be coming from the dash right in front of the passenger seat but it could just be my ears playing tricks on me. Has anyone experienced this or have anything I can recommend the dealership check?

PS. Dealer thought it was a warped or cracked exhaust manifold but they checked it and it was fine. Also when the car is in park and i hold it at that RPM i haven't noticed the noise. Also the noise isn't very loud its just annoying when driving at night and the radio isn't on.

Thanks in Advance and if you need any more information let me know.

 

[TechWrench]

Okay so I have a 2004 toyota 4runner with the V8 engine. I have been have a very weird problem that has the dealer stumped on the problem. When driving and the car is at exactly 1400 RPM I hear a weird noise almost like an electronic noise/vibration if i take my foot off the gas it goes away and if i push the gas anywhere past 1400 RPM the noise is gone as well. It only happens at that specific RPM and it doesn't happen every time. It sounds like it could be coming from the dash right in front of the passenger seat but it could just be my ears playing tricks on me. Has anyone experienced this or have anything I can recommend the dealership check?



PS. Dealer thought it was a warped or cracked exhaust manifold but they checked it and it was fine. Also when the car is in park and i hold it at that RPM i haven't noticed the noise. Also the noise isn't very loud its just annoying when driving at night and the radio isn't on.

Thanks in Advance and if you need any more information let me know.

Since it doesn't make the vibration in neutral, have you tried manually shifting into 2,3, or 4 to see if it still does it at that RPM. If the RPM at which the vibration changes with a different gear, then it is drive train related. If not, then it is engine related. Maybe some type of harmonic resonance from the exhaust?

 

[biggd963]

interesting. thanks for the insight. The car is at the dealer right now who has taken my entire dash apart and cant figure out the problem still. If it is still doing it when i get it back i will try what you said. They tried to give me the car back Thursday saying that it was normal and I went to the manager and complained so they still have it now and have given me a rental. Hopefully by Monday they will have some type of resolution for me. This problem is very frustrating and they don't seem to think its a big deal. I told them to check the exhaust gaskets and make sure it's not that and he said he doubts it is but will look into it.

 

[BuckyBadger]

biggd963, you have discovered the wonderful Harmonic Vibration that has hit many of us on this forum at a particular RPM range while under load. And is the main reason I dread it getting colder up here as the harmonic sound gets more obvious when it is cold outside. This has been described on other threads as helicopter noise, droning, rythmic sound etc.

If you do a search on the forum for harmonic vibration or strange sound etc from you will find many threads on this issue and the many attempts we have made trying to get it fixed. There is a TSB to attempt to fix this for the Lexus but there is yet to be one for the 4R. Some member have even gone through formal complaints with Toyota to get the issue addressed.

here is the TSB for the lexus, they call it droning noise. There is a slight vibration for me but more the harmonic noise.



A STEERING VIBRATION & DRIVELINE VIBRATION/DRONE
CAUSE: INSTALL UPDATED PARTS FOR VIBRATION
ST004-04 STEERING VIBRATION & DRIVELINE
VIBRATION/DRONE

1 41196-60010 DAMPER, DIFFERENTIAL
2 90080-10167 BOLT, WASHER BASED H
1 52380-60061 SUPPORT ASSY, DIFFER
1 51405-35101 COVER S/A, ENGINE UN
1 45219-60090 YOKE, STEERING SLIDI
1 45203-60120 SHAFT SUB-ASSY, STRG
FC: 44,99
PART#: 41196-60010
COUNT: 1
2727 DRONE NOISE, SERVICE BULLETIN ST3010