Noise when pressing the gas peddal

[dietsprite]

I recently purchased(week ago) the Qx4 2000 model with 215,000 km on it. It runs fine so far, however I started (or just havn't notice before) to notice that the the noise when pressing/holding on gas peddal is quite loud. Now i'm not sure if it suppose to be like that and is common for this type of vehicle or it is indication of a problem. So I don't know if I should be worried about it or just leave it alone for now. The sound can be described as sort of humming sound.

I drove a midsize mazda sedan before so I'm new to driving large vehicles.

[CanuckQx4]

You might wanna describe the noise

[dietsprite]

I would describe is as loud humming sound especially when accelarating from 0-60 KM/H after that the humming sound subsides.

[Towncivilian]

Is there any vibration during this acceleration, or just the noise?

Check engine oil, transmission fluid, differential fluid levels.

[dietsprite]

I beleive there is very slight vibration but mainly its the strong humming sound like a sound a car would make without a muffler but not as loud obviously.

I had full service when I got it everything should be up to standards with that regard

[Towncivilian]

Can you try to determine where the noise is coming from on the vehicle? Front/rear?

[Chris.m]

Have you checked your exhaust heat sheilds yet? If they are just a bit loose it can make a noise like you're describing.

For some reason every summer mine has a new noise like that that I have to fix.

[SBK03SE]

Welcome dietsprite!

Yea, I would also say heat shields too. It happens the loudest at low RPMs and idle. It only takes a couple seconds to remove them.

PS: Chris.m, liking the sig, the color looks really nice.

[Chris.m]

PS: Chris.m, liking the sig, the color looks really nice.

Thanks,

Its funny, I found a really good picture and cropped it to fit, thinking its a fairly original shot.... 30 mins later, I see yours...

meh, we both have good taste.

[dietsprite]

it seems to me that the sound comes from the rear of the car, the engine runs quitly probably something around the exhust area... I have no idea what are the heat shields or where are the located. Can I inspect them without jacking up the car.

Thanks SBK I'm happy to be here...as for the heat shields what do you mean by just removing them ? they don't need to get replaced by new ones?

[Towncivilian]

If you can crawl underneath the car, you can see the heat shields. Unfortunately, I can't find any pictures of the heat shields. Does this noise occur at all RPMs, or just a specific range?

There's usually no harm in removing the heat shields. They're probably to help prevent possible fires if you park over some dry grass or something, but we have enough ground clearance that such an issue would be unlikely. Maybe the heat shields prevent exhaust heat from radiating to other potentially sensitive areas, but many members have removed heat shields from their Pathfinders / QX4s without a problem.

[dietsprite]

I would say that this occurs mostly when accelerating and when just cruising i can still hear humming sound but not as much as when accaleraing. I don't think this is a problem with the muffler or exhust because this car was well maintained and it passed emission with no problems plus it was safty certified so I assume its not a major problem but this sound is really annoying

[Towncivilian]

The exhaust heat shields are more or less cosmetic, they pose no useful function in the actual operation of the exhaust system.

Does the noise get louder as engine RPMs and/or vehicle speed increase?

[SBK03SE]

Dietsprite is it possible to post a video or some audio detailing the noise?

@Chris.m, yes sir.

[BoostMyQX4]

Yes a video will help.....but please do not use your phone for video

[dietsprite]

ok i will use my iphone to record the sound and hopefully be of a decent quality post it here as soon as I can...

[dietsprite]

I did an inspection under my car today and was shocked by what I discovered which probably explains the loud humming noise. The exhaust pipe was completely unattached to the muffler and was kinda hanging an bouncing from side to side. The muffler's hole that used to connect the exhaust pipe was completely wide open so that must explain the noise. I was driving like this for a week + hope that it didn't do any unrapirable damage to the car

How do I post a picture from my computer ?