burbling noise

[Jimbo2000]

hey all

ok i'm starting to get annoyed

my car does an on and off burbling coming out of the exhaust, obviously coming from somewhere else

its basically: drive for half an hour, everythings sweet. then for no reason the car will start this bobobobobobobobobobobo soft burbling(think 4 bob's per second) its not robbing power or making it any harder to drive but it's quite annoying and you can see that the whole car slightly shakes along with it, had a water bottle sitting on the floor and was watching it vibrate along with the noise.

it dosnt do it during normal driving but when i come to a stop it does it while idling and also under really slight (0-5%) throttle

at first i thought it was a tunability problem as i havnt had my PFC retuned since tuning and was told its good for it just to iron out any prolems every 3 or 4 months or so.

*EDIT* forgot to mention (but thought it was obvious anyway but just in case) after a certain amount of time, say half an hour burbling it will just revert back to normal and drive fine for another amount of time and so on and so on

what is causing this?

[Driver]

I had the same thing on my n/a r33 but sumtimes it got to the point wher it was even more a really faint jerk when driving the car.

It was from the place i took it too to get it serviced and they dont know anything about skylines and the spark plugs were only loosly tightend. I took it sumwhere else and they fixd it up good

[Anquetil]

Does your car pop/backfire?

In my case it was poping/backfiring/burbling, and ended up being a simple air/vacuum leak.

[Jimbo2000]

yes it backfires, not a huge amount though, normal rich running skyline backfiring.

matter of fact at the last dyno day the dude said that its running richer than he would have tuned it to run.

thats why i thought it was a tunability problem but if it was that then it would be doing it all the time not just intermittantly right?

[sewid]

the powerfc is probably causing it. I have never been a huge fan of its idle control. It might need a tweak.

[Jamezilla]

Mine burbles and pops and farts all the time - needs a tune pretty bad. Next week...

Will let you know if this solves the problem.

[PHaT MR30]

this wouldn't be related to the tune, but i know when a flange broke on my exhaust it sounded different then once warmed up it went away. until i got beach on a speed hump that is and it wrecked my zorst totally