[Mk2] [NA] Something that has baffled me since ownership

[MR2HOT]

Guys

Since owning my Rev 3 NA, something has always baffled me which is whenever i start the car and pull away i hear like a woosh noise which sounds a bit like a dump valve on a turbo car. It does it every time i pull away and the noise only lasts a second but it happens every time i first pull away. I don't ever seem to remember my old Rev 2 MR2 doing this. It almost sounds like trapped air or unused air is released from somewhere when you first drive off. Is this normal? i presume it is as the car has always run great but its just something ive not heard on any other car before and since im lacking a turbo its certainly not a dump valve ha ha. Any ideas?

Liam.

[Loque]

Presumably it's not the induction kit? (if you have one fitted?)

[Donato]

As said, possibly the induction kit or aftermarket panel filter that's causing it.

[MR2HOT]

No its not induction kit as im running a standard box and there are no modifications to the car at all. Its very strange as like i say it does it every time i start the car up and pull away and then it does not make the noise at all when driving but if i turn the engine off if popping out then return to the car start up and pull away i get the swoosh noise again, it lasts for literally a split second and as it does it every time i presumed it was a standard thing that happened to the mr2s. Very srange.

[Ryan S]

Brake servo??

[9000rpm]

I used to have a celica GT4 (st165) and it used to make a stange noise for a few seconds the first time you pulled away after it had sat somewhere for a while, it sounds like an electric pump noise to me more than an air noise.

the car could be ticking ofer for ages and not make the noise but it would as soon as it moved and it saw some wheel speed. I think it was something to so with the ABS system but no idea what it was doing.

has you car got ABS and your ver 2 didnt?

[MR2HOT]

Yes my car has ABS on it and my previous Rev 2 mr2 didn't. Like i say i dont think anything serious can be wrong as the brakes work fine all be it the fronts do squeal a little but i checked the pads and there practically brand new.

[bobhatton]

Clutch?

[Loque]

Certainly is the obvious thing if it comes in when you're pulling away...

[MR2HOT]

Yeah but if it was the clutch it would do it every time i pull away which it does not, once i have started driving the noise is then gone and will not make the noise again until the engine has been switched off and started back up again. Its only the initial pull away once the car has been started. Its really hard to explain, i will try and get a video clip of it making the noise if it will pick the sound up and ill post it up for you to have a listen. Like i say its like a dump valve noise.

[Loque]

If it only does it once, sounds like a self test on ABS/PWS or something like that.

I eagerly await your video...

[MR2HOT]

[quote="Loque"]If it only does it once, sounds like a self test on ABS/PWS or something like that.

This is what i thought it might be some sort of self test of the power steering or ABS and was hoping it was a standard thing but i guess none of you guys have this noise unless you all have turbo cars. Anyone out there with a rev 3 na shed any light?

[MR2HOT]

Just been searching around on the net and other people have said about this noise and one guy said "its the ABS Priming itself as the wheels start to move"

Hopefully this is what it is, im just suprised nobody else on here has heard this noise in there car if this is what it is.

[synXero]

I can't say for sure but I had a rev3 NA without ABS and I don't remember that noise. Also my rev5 NA with ABS doesn't I'm relatively sure. Ill be sure to check.

[Loque]

I have a rev 3, N/A with ABS. I notice the priming noise that you speak of, but I don't notice it sounding like a dumpvalve... I'm driving home in an hour or so, I'll keep an ear out!

[Alex O]

Mine does this after hard braking to a standstill over bumps.

Pretty sure it's the ABS servo. No problems have arisen as a result in 9yrs of ownership.

Wouldn't worry about it

[asdrewq]

+1, ABS self-test. activates at ~2-3mph.

[MR2HOT]

Cool thanks for clearing that up and yes your right it makes the noise at a couple of mph. Im glad its normal and nothing to worry about so thanks for the reply.

And Alex its funny you say that as for the first time last week i hit some bumps while braking for a roundabout and it made the noise then too.

[raptor95GTS]

if youhave PAS and the steering wheel isn't turned for a couple of minutes and you're sitting at the lights the pump turns down to idle. When you start rolling or turn the steering wheel the pump speeds back up and it's pretty noticable if you dont have a stereo running at the time.