350z grunting noise 5 secs or so after pulling of only after startup.

[350David]

Posted this in 370Z forum by accident!

Has anyone else experienced a strange 'grunting' noise (almost like an angry gasp) after starting up, about 5 secs or so after pulling off? Doesn't happen after a stop, just startup and only lasts a second. Seems louder when engine has been off for a while and cooled down. Worried it's something nasty but it's just started over last couple of days. Has anyone had this problem or knows what it could be?

 

Thanks all.

[Toon Chris]

It's a complete guess but possibly connected to the aircon system? They can wheeze and gasp from time to time.

You may be able to simulate it by building up the revs slightly with someone listening under the bonnet?

[350David]

Thanks Chris, funnily enough I thought that this morning when I took the car out. I'll try that revving idea and see if it does it on standstill. It might be a timing coincidence but it seems to happen just after changing into 2nd gear. But my driver side window motor is getting fixed this week so I have been using the AC more recently so, who knows?

[Toon Chris]

-oops, repost-

Edited June 7, 2016 by Toon Chris

[colesl4w]

Posted this in 370Z forum by accident!

Has anyone else experienced a strange 'grunting' noise (almost like an angry gasp) after starting up, about 5 secs or so after pulling off? Doesn't happen after a stop, just startup and only lasts a second. Seems louder when engine has been off for a while and cooled down. Worried it's something nasty but it's just started over last couple of days. Has anyone had this problem or knows what it could be?

 

Thanks all.

 

Does it sound like when your ABS comes on? Like a spring unwinding/grinding? If so, this is competently normal. Your ABS will occasionally self test on startup.

[Alex350z]

Mines done this for as long as i can remember, its like it lets out a big sigh as i get to the end of my street, as if to say "here we go again"

[Dave6188]

Pretty sure it's normal, I only ever get this on cold start, might be something to do with the auto choke/fueling as the car is just warming up, my opinion anyway.

[350David]

Thanks everyone! Relieved to hear generally that it doesn't sound like anything too serious. I'll leave it for now, see how it goes and hope it doesn't get any worse.

[GT Driver]

I reckon this is the ABS self check - happens at about 5-7mph after pulling away after a fresh engine start. Completely normal.

 

(FYI if you get up to that speed then immediately put your foot on the brake you can feel the self-check vibration up through the brake pedal - like if the ABS was actually applied)

[350David]

Thanks mate - I've noticed it does seem to be just after a gear change from 1st to 2nd gear but definitely only after startup.