Card in spokes / VW sound...

I have a card-in-bike-spokes sort of sound that seems to kick in at about 2k rpms, and only happens when on the accelerator. It's not terribly loud, but enough to notice. It started happening only recently. The sound might also be described as slightly pneumatic-sounding, like an old VW engine. If I were to guess, it seems to be coming from the passenger side of the engine compartment. Any ideas?

I recently had one of the power steering hoses replaced, and it's been throwing EGR codes occasionally which I've been postponing addressing, I don't think they're related, but I figure it's worth a mention.

Hiya Kilna

Just to be safe..first thing I'd check is a bent/warped fan blade dinging
the radiator as engine moves under acceleration...
.....after that I'd suggest a 6 pack of Newcastle, and come on over
so we can figure it out!


:_beer:

Jo

If it were happening on decel rather than accel, then I'd say check your CV boots. Since it don't cost nuttin & is easy, check them anyway.:)

Could be an exhaust leak.

you do not have a card in your spokes?

JK I would concur this sounds like a beginning exhaust leak

Having the same, and it's intermittent. It's not an exhaust leak, as the CEL gets tripped by exhaust leaks (code P0442). Only on accel, not on decel....that's the only thing that remains constant.

Might want to check your egr if it's loose. I had the same diesel sound for a bit when accellerating. Tighten it up will eliminate the noise if that's the issue. Do a search on loose egr on this forum. Good luck.

I get a sound like that and it is the ventilation fan, not engine related.

There's a fan casing above the right foot of a passenger you can pop the bottom off to see if the sound is from that small fan.

For me, it seems like it's coming from the driver's side.

Quote:

---

Originally Posted by ron

Might want to check your egr if it's loose. I had the same diesel sound for a bit when accellerating. Tighten it up will eliminate the noise if that's the issue. Do a search on loose egr on this forum. Good luck.

---

X2 on Ron's suggestion. The EGR nut tends to come loose at times (IIRC it takes a 21 or 22mm wrench to snug it back tight. A crows foot head with an extension and a socket driver works pretty good), and adding some anti-seize to the threads allows for a more even torque.

X2 on the good luck too.

OK, so since it was throwing codes, and the old one was looking a bit haggard even though it was only a couple years old, I replaced the EGR and cleaned the EGR tube... whelp, turns out that was not the source of the noise. I think it's gotta be exhaust related now, the sound has gotten louder and sounds even more pneumatic than it did before. Understood about the CEL, could it be an exhaust leak in combination with a faulty sensor, or a leak which is after the sensor? The sound is definitely originating from the front or underside of the car, not where the vent fan is.

Bummer...

I thought we'd nailed it when ya came over :(
That "splutter" of gunk from EGR sure looked like a leak.

Is it still only under load, or will it make noise when sitting?

Jo

I do think the EGR was in need of replacement, it just wasn't the source of the noise.

Yes, it continues to only happen under load. Since the clearing of the EGR my engine sounds a bit deeper, more throaty, but it still has the putt-putt noise.

Heya Kilna

Do you have a Go Pro you can rig up under there...
...pics may help... and sound might narrow down source.

Jo

Had a rusted heat shield break loose and was banging up against the metal. Sounded nasty when you gassed it. Once removed, the sound was eliminated.

With the engine running and someone stepping on the gas, use a gopro, like Jo mentioned, or something to track down the source under the vehicle. Good luck.

Hadn't thought of the gopro... only problem is I need a way to mount it such that it has the widest field of view, it's not going to capture much unless I can get it further away from the chassis. I'll figure something out.

Have PVC, will travel. :)

Quote:

---

Originally Posted by ron

Had a rusted heat shield break loose and was banging up against the metal. Sounded nasty when you gassed it. Once removed, the sound was eliminated.

With the engine running and someone stepping on the gas, use a gopro, like Jo mentioned, or something to track down the source under the vehicle. Good luck.

---

Not the heat shield, it's something else. I have a GoPro, will try to get some recordings this weekend.

So, it was a break in the exhaust pipe leading to the passenger side catalytic converter. Must have been on the upper side because me, Jo, and others had looked under there and not seen it. It finally sheared at 80MPH on the freeway, leaving my wife to scramble to the next exit while the truck made horrible noises. A tow and a weld later, sounding better than it has for years.

At least it wasn't catastrophic . Glad it's fixed

Quote:

---

Originally Posted by ron

Had a rusted heat shield break loose and was banging up against the metal. Sounded nasty when you gassed it. Once removed, the sound was eliminated.

With the engine running and someone stepping on the gas, use a gopro, like Jo mentioned, or something to track down the source under the vehicle. Good luck.

---

same with mine - rattling heat shield - it was hard to replicate from under the vehicle when stopped tho