Motor noise only at certain RPM
#1
Motor noise only at certain RPM
Alright so my car makes a noise which sounds to me like a heat shield or something vibrating. It only occurs around 2000 to 2500 rpm. Sometimes depending what gear you are in it wont do it at all. Its almost like the engine needs to be at a certain frequency. From inside the car it sound like a heat shield but when under the hood reving it almost sounds like it is coming from inside the motor.
The car had a metal beat racing splash shield which I removed because I thought it was that. It does not seem as bad but it still does it. I have checked all the heat shields and all seem fine. The car runs great and was actually just tuned yesterday and made decent power for the limited mods the car has. It has no check engine light or anything either.
I just want to see if anyone else had a similar issue. Thanks
The car had a metal beat racing splash shield which I removed because I thought it was that. It does not seem as bad but it still does it. I have checked all the heat shields and all seem fine. The car runs great and was actually just tuned yesterday and made decent power for the limited mods the car has. It has no check engine light or anything either.
I just want to see if anyone else had a similar issue. Thanks
#2
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I have this too, from about 2k-3k RPM. The frequency of the noise doesn't seem to change with RPM or speed though, so I don't think it's anything in the driveline and haven't worried too much about it.
#5
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I remember when I went to a racing shop. Pray that it is not rod knock which I seriously doubt. Now as far as other things to check out now the timing blet it may be on its way out.
That's what I saw you can start out by checking out the timing belt take the camgear cover off and leave the car in neutral and turn the crank pully manually and maybe the timingbelt has a piece of the belt slapping up agaisnt the camgear plastic cover. Just throwing in my two cents thats all. Keep us posted also post pics if you can.
That's what I saw you can start out by checking out the timing belt take the camgear cover off and leave the car in neutral and turn the crank pully manually and maybe the timingbelt has a piece of the belt slapping up agaisnt the camgear plastic cover. Just throwing in my two cents thats all. Keep us posted also post pics if you can.
#7
Thanks guys. I actually just had the timing belt done 2 days ago too and it did this prior.
The noise does not change with the rpm (if it does its not very noticeable). If it makes the noise and I hit the gas to put the motor under heavier load it stops. It does not seem to increase with rpm.
My fear is the noise is rod knock but wouldnt I hear the noise through a broader range of rpm's? Not just 2000-2500 rpm.
The noise does not change with the rpm (if it does its not very noticeable). If it makes the noise and I hit the gas to put the motor under heavier load it stops. It does not seem to increase with rpm.
My fear is the noise is rod knock but wouldnt I hear the noise through a broader range of rpm's? Not just 2000-2500 rpm.
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#8
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My noise sounds almost just like yours. It's most prominent when cruising, and goes away under heavy load or decel. It's also not super loud, it's not anywhere NEAR as loud as the rod knock videos I've seen. Mine at least is a lot slower than rod knock would be at 2-3k RPM. I'd guesstimate it to be ~5hz.
#9
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Thanks guys. I actually just had the timing belt done 2 days ago too and it did this prior.
The noise does not change with the rpm (if it does its not very noticeable). If it makes the noise and I hit the gas to put the motor under heavier load it stops. It does not seem to increase with rpm.
My fear is the noise is rod knock but wouldnt I hear the noise through a broader range of rpm's? Not just 2000-2500 rpm.
The noise does not change with the rpm (if it does its not very noticeable). If it makes the noise and I hit the gas to put the motor under heavier load it stops. It does not seem to increase with rpm.
My fear is the noise is rod knock but wouldnt I hear the noise through a broader range of rpm's? Not just 2000-2500 rpm.
#12
I think the heat causes something expand the slightest bit and that causes this noise. I just need to get some time to get under the car after it has warmed up to check this out.
#13
EvoM Staff Alumni
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Thanks guys. I actually just had the timing belt done 2 days ago too and it did this prior.
The noise does not change with the rpm (if it does its not very noticeable). If it makes the noise and I hit the gas to put the motor under heavier load it stops. It does not seem to increase with rpm.
My fear is the noise is rod knock but wouldnt I hear the noise through a broader range of rpm's? Not just 2000-2500 rpm.
The noise does not change with the rpm (if it does its not very noticeable). If it makes the noise and I hit the gas to put the motor under heavier load it stops. It does not seem to increase with rpm.
My fear is the noise is rod knock but wouldnt I hear the noise through a broader range of rpm's? Not just 2000-2500 rpm.
This happened to me back in '03 when I had to do a head gasket in my car basically in the dark with a mini mag light. I about had a heart attack when I heard the sound upon initial test drive. I would also caution against taking it to high rpm's with the shaft out of phase like this.
mitsuorder
#14
Your balance shaft gear spun 180* out. You need to take it back to the person/shop who did the work. They are going to have to take the timing belt back off and rotate the balance shaft gear to get it back in phase.
This happened to me back in '03 when I had to do a head gasket in my car basically in the dark with a mini mag light. I about had a heart attack when I heard the sound upon initial test drive. I would also caution against taking it to high rpm's with the shaft out of phase like this.
mitsuorder
This happened to me back in '03 when I had to do a head gasket in my car basically in the dark with a mini mag light. I about had a heart attack when I heard the sound upon initial test drive. I would also caution against taking it to high rpm's with the shaft out of phase like this.
mitsuorder