VR6 on power 'chuffing' noise

[Fanjita 1]

Hi all,

 

Wondered if anyone with loud tappets like me could tell me if they get similar noises. I know I'm forever asking about engine noises but I'm hoping this one isn't major!

 

Basically at lower revs where the induction and exhaust noises are low, if i put my foot down I get a sort of chuffing noise as engine speed increases. I can best liken it to a model steam engine going some (if anyone knows what that sounds like!), not as loud of course. I'm wondering if it is just down to the noisy tappets sending noise out of the intake when the butterfly is fully open and not restricting it. There is none of this noise when im just holding speed (say 30) and as mentioned it will flare up as soon as i put my foot down. I hear it more when I'm in a high gear keeping the revs low.

 

The noise is originating from the front but as I can't recreate it on standstill, I can't say where exactly. It appears almost to be along with the induction noise, that's why I'm wondering if my loud tappets could be the cause.

 

I'm in two minds though, I fail to see how tappets enclosed in the rocker cover could be making noise down the inlet tract. That is unless of course the noisy tappets are getting amplified by the valves they are attached to?

 

As I said I'm hoping this is just tappets but worried this may be something more serious ie bottom end shells or something, although I'm not sure which point on a VR6s rev/load range do shells get noisier.

[Kevin Bacon 5]

Tappets make a very distinctive and rythmic tap when shot, and it's usually only one 1 or 2 cylinders. If they're all just a bit old and tired, the engine can sound a little clattery when warm.

 

A 'chuff', going by your description, could be a sudden intake of air?

I would check for air leaks, but it's not uncommon for engines to make a loud chuff as they gulp in air quickly. You should hear R32s do it, it's very loud and the intake manifold visibly collapses as it goes back to vacuum again :lol:

 

You definitely have the 'VR6 noise' paranoia too :D

[Fanjita 1]

Yeah that's fair enough, I did wonder if it's a consequence of having all these induction and exhaust modifications but didn't know. It just seems weird if that's a normal noise. Maybe I should try and get a recording of it?

 

Oh yeah almost forgot, I went over the whole vacuum system thoroughly, I can be pretty sure there are no leaks :clap:

[andy 0]

Definately not tappets if by chuffing you mean an air type sound. I wouldn't expect any intake or exhaust mods to contribute to that sort of sound either. Is the engine running smoothly when it makes said noise?

[Fanjita 1]

Definately not tappets if by chuffing you mean an air type sound. I wouldn't expect any intake or exhaust mods to contribute to that sort of sound either. Is the engine running smoothly when it makes said noise?

 

Runs perfectly, its less of an air sort of sound, it's really hard to describe though maybe i should try and get a recording. It isn't a slow hiss or anything, quite a high frequency which is why I randomly said a small steam engine :lol:

[Kevin Bacon 5]

Is the noise road speed or rpm based? I.e. does the sound continue if you dip the clutch and coast along? If yes, it's car related (something rubbing maybe?), if No, it's engine related.

[Purple Tom 0]

I know the VR6 has twin knock sensors but could it be pinking? I'm not sure whether it would run well (if at all) if the knock sensors were faulty, but if they were then it could possibly be pre-ignition, especially in the low rpm/high load conditions that you describe.

[Roger Blassberg 0]

Pinking/knocking is more of a metallic clattering noise than a chuffing. The engine will run with defective knock sensor(s),

 

Best wishes

 

RB

[VWVW 1]

Have you had your ISV Damper box removed on the VR6. Not sure if the sound is coming from that...mine has that removed and there is a distinct sound when on throttle.