Noise under acceleration

[SkinnyJoint]

(bump)

 

[SeminoleMan]

Just noticed that same issue on my car - definitely throttle dependent. I was getting on it a little today and could really hear it resonate off the curb I was driving near. Hope this doesn't translate to a bigger issue in the future.

 

[Moonman8]

Just noticed that same issue on my car - definitely throttle dependent. I was getting on it a little today and could really hear it resonate off the curb I was driving near. Hope this doesn't translate to a bigger issue in the future.

That's exactly when I hear it best (sound bouncing off a close curb). I was just reading a similar thread to this. Check the "Shifting Pains" thread in the P5 area. Turfburn from NSN suggested using Redline tranny fluid and upgrading the bushings. I have a TWM short shifter with Kartboy bushings but I still hear the sound sometimes, but not as bad since the change. The next thing to try for me is replacing the tranny fluid.

 

[brittania81k]

I have the exact same problem (at least we'll assume that for now). I have also mentioned this on SEVERAL other posts on here. I took mine to the dealer and they checked all my heat shields... all ok. Basically said they couldn't repeat it. I asked about the VTCS screw thing and the first guy told me he doubted it. They suggested bad gas, but I've tried several brands and grades, no change. I am going to take the head customer service manager for a ride when I have the time and I can make it happen. (It was her idea). Personally, I think it is one of 2 things:
1-the heat shields are coming under tension when the engine is loading due to the stock motor mounts, it was suggested to me that under heavy acceleration the motor loads up the motor mounts and that may be putting tension on the heat shields causing a rattle noise
2- it's the *#@^ VTCS crap and they just don't know it because a) they won't take it apart and look at it and b) no one has ever noticed a sound before the grenade went off under their hood.

I'll update when it goes to the dealer again. And let me know if anyone gets anywhere with this.

(note I have the auto-stick, not a standard)

 

[hopeful]

my buddy with a msp has an issue with the exhaust manifold bolts coming loose all hte time, dealer just retightens them apparently.

 

[santisurf]

I have the exact same problem (at least we'll assume that for now). I have also mentioned this on SEVERAL other posts on here. I took mine to the dealer and they checked all my heat shields... all ok. Basically said they couldn't repeat it. I asked about the VTCS screw thing and the first guy told me he doubted it. They suggested bad gas, but I've tried several brands and grades, no change. I am going to take the head customer service manager for a ride when I have the time and I can make it happen. (It was her idea). Personally, I think it is one of 2 things:
1-the heat shields are coming under tension when the engine is loading due to the stock motor mounts, it was suggested to me that under heavy acceleration the motor loads up the motor mounts and that may be putting tension on the heat shields causing a rattle noise
2- it's the *#@^ VTCS crap and they just don't know it because a) they won't take it apart and look at it and b) no one has ever noticed a sound before the grenade went off under their hood.

I'll update when it goes to the dealer again. And let me know if anyone gets anywhere with this.

(note I have the auto-stick, not a standard)

Good idea, donr' forget it could also be exaust but then it might not. i have teh same problemn though im going to get my engine checked this Wed and see whats going on!!! this sound sounds like my car is going to Tick Tick BOOM! so ( i hear it at 2500RPM and at about 3500 i can't hear it as much due to the engine noise. but im sure its there) will update!!! (thumb)

 

[djdanny5000]

maybe its somehting our cars just do because mine does it too and i was kinda worried but i see now alot of people have that same noise so maybe its just something about our cars

 

[Moeed]

I had a noise kind of liek this, but mine was that the wheel lug nuts were not torqued down, and the wheel was dangerously loose and was about to come off. I have also had the VTCS problem and trust me, you will know when its in there. Its a continous rattle at all rpm ranges, even in neutral. good luck.

 

[hopeful]

The noise I had turned out to be audible pinging (help) . Anybody else also on their second set of rod bearings now?

 

[Finaldo]

I asked the dealership a LONG time ago about this rattle I was hearing. It sounds like a knock in the engine. The dealership told me it was from a fluttering ECV. Some valve would flutter while revving, mostly while the car was cold. They said that Mazda was working on an ECU fix. I never followed up on it, but I should...

 

[hopeful]

mine WAS bearing knock, i've got scathed rod bearings to proove it, anyways changing them was a COMPLETE b**** and required drilling 2 holes into the tranny to pass thru a socket. so they maybe telling you crap, look into it and force em into a warranty?

 

[aMaff]

I asked the dealership a LONG time ago about this rattle I was hearing. It sounds like a knock in the engine. The dealership told me it was from a fluttering ECV. Some valve would flutter while revving, mostly while the car was cold. They said that Mazda was working on an ECU fix. I never followed up on it, but I should...

That's the VTCS. If it was happening while it was cold, that's exactly what it is. There's valves in the manifold that cause the air to "tumble," helping the cats light off quicker. They open all the way up after ur @ operating temperature. It's really nothing to worry about. If you look up the TSB here, all they really do is recalibrate how far closed the flaps go, so they don't hit anything.

 

[Moonman8]

Well, I found a solution to get rid of my noise (which I was hearing under heavy acceleration in the lower gears with the engine at operating temp). I did a little research and educated myself on detonation or "spark knock".

I think I was experiencing slight detonation by running regular octane fuel (which in the great state of NM is a whopping 86). The compression ratio on our cars requires a minimum of 87 octane, which for the rest of the country is classified as regular octane.

I then drained the tank to damn near empty and filled up with the medium grade (88 here in NM) and I haven't heard the noise since. If you're in an area that has lower than 87 as regular and you're using it because everyone says that regular is safe for our cars, then switch to something 87 or higher and see if the noise goes away.

 

[aMaff]

Good point. However, you don't need to run the premium stuff. Ur just throwing money away w/ the P5. But ya, you need to have 87 octane

 

[falsedawn]

Detonation, eh?
Hmmm, sounds strange. I would check your spark plugs for signs of overheating - are you using oem plugs with the correct heat range? I know some people use those "extended reach" plugs, which (effectively) advances the ignition slightly, probably making the engine more prone to detonation.
I thought detonation was more likely to occur when the engine is laboring, rather than accelerating in lower gears, anyway?

 

[roverto4]

funny u say that, i actually had a similar noise coming from under my old 2000 protege, many ppl said it was the heat shield, i took it to a few places but thats not what it was, never did find out what it was, but oh well... im happy with my noiseless p5 now

 

[Moonman8]

Yeah, I know it sounds strange for detonation to be occurring but I was running 86 octane when I was hearing the damn rocks in a coffee can type tapping. Then I increased octane to 88 (there's no such thing as 87 in NM) and no more noise. Maybe it wasn't detonation but increasing the octane was the only thing that made that noise go away. This is what I did and the parts I installed before increasing octane:

1)Removed VTCS butterflies and actuator rod (and cleaned the s*** out of the IM while I was in there)
2)Installed Kartboy shift bushings & TWM short shifter
3)Castrol Syntec 10w-30
4)Changed tranny oil to Redline MT-90
5)Changed spark plugs with OEM from dealer parts dept.
6)Installed RB Cat-Back and Injen CAI

Whatever was happening, the 88 octane seemed to have fixed it and it runs like a freakin' champ now!

 

[hopeful]

mine will knock on anything below 89. and yes motor will knock more in lower revs under load, higher rpms and the pistons just moving too fast to give it the time it needs to explode.

btw, listen to it very carefully, when i was dealing with this problem i found that i got rid of most of the audible pinging by replacing my plugs, but there was still a static kinda sound left, when i switched to 89 its all gone and smooth running.

BTW you will get s*** crap gas mileage, im getting about 250KM's to the tank right now, my car still knocks in the morning, i'll be swapping out the rod bearings again next oil change (POS.).

 

[Moonman8]

mine will knock on anything below 89. and yes motor will knock more in lower revs under load, higher rpms and the pistons just moving too fast to give it the time it needs to explode.

btw, listen to it very carefully, when i was dealing with this problem i found that i got rid of most of the audible pinging by replacing my plugs, but there was still a static kinda sound left, when i switched to 89 its all gone and smooth running.

BTW you will get s*** crap gas mileage, im getting about 250KM's to the tank right now, my car still knocks in the morning, i'll be swapping out the rod bearings again next oil change (POS.).

under what specific circumstances will someone get crap gas mileage?

for a newbie in this department...how does one go about replacing rod bearings? and how would I know if I need to do it? just a short-rundown if you wouldn't mind.

 

[Protege52003]

Yeah, I know it sounds strange for detonation to be occurring but I was running 86 octane when I was hearing the damn rocks in a coffee can type tapping. Then I increased octane to 88 (there's no such thing as 87 in NM) and no more noise.

i have had similar symptoms when using 87 octane.........i use 89 pretty much all the time now and it fixes the terrible noise......??????