Strange sound on very low / no boost.

Zee · August 17, 2010, 03:55:16 PM

Ah well, the offers there mate!

Yeah cheers for your help on that, it was so annoying it was ridiculous!
The boy racer part of me now wants a loud pschhhh, so I think I\'ll be on the lookout for a BOV haha

Thanks

playtime · August 17, 2010, 11:09:40 PM

Sorry for hijacking the thread, but finding it very interesting, because Ive just started my new FD from properly cold this evening, for the first time since I bought her (sitting a week), started on 2nd turn, was running about 2200, then suddenly a big Moo and a whoosh noise started! I was wondering what the hell, the revs suddenly dropped to about 1400, and a drone sort of noise was coming from the engine bay. I blipped the throttle and the noise went away as the revs dropped but kept coming back intermittently for the next 5 minutes. Once she was up to normal running temp, she settled to a lovely smooth tickover at about 950, and the noise was gone, but theres a weird wee clicking noise when blipping. Semms to be coming from in around the intercooler area. PS Im running twin aftermarket airfilters. Is this airpump on the way out? and more to the point, whats the airpump meant to do? Sorry for all the questions, but new to these mad rotary thingies! :Hammer

Zee · August 18, 2010, 02:44:10 PM

My knowledge of the air-pump is based entirely on this link mate:
http://www.fd3s.net/air_pump.html

So as Carl mentioned its good to pop it back on for MOT as you have more chance of passing emissions tests, otherwise disconnect it.

As for your symptoms I\'m not too sure bud, sorry

Zee · August 18, 2010, 02:59:56 PM

Try disconnecting it, and seeing if the sounds goes away. It won\'t harm the car not having it connected.

You can then either leave it off, or if you need a replacement let me know, I\'ve got the airpump from my old car.

JohnP · August 18, 2010, 06:10:01 PM

how high does it rev when u start from cold and for how long? have a feeling this is pretty normal for the first few seconds. however, not sure about the whooshing on idle =/

the moo\'s are a pretty standard side effect which can only be cured by piping/filter or disconnecting the air pump.

the clicking is fairly normal aswell for me, think its the airpump starting stopping? someone correct me if i\'m wrong.

playtime · August 18, 2010, 10:16:37 PM

Cheers lads. The clicking does indeed sound like a relay to be honest, and I must try disconnecting this pump thing. Engine seems in fine tune otherwise. Was worried, if I ran with the pump off, she would be even harder on the petrol than she already is. Wouldn\'t normally grumble as I didnt buy her for economy, but driving her back home to N.Ireland, she went through 130 notes of petrol and that was taking her easy, as I didnt fancy breaking down on the wrong side of the Irish sea :>

Zee · August 18, 2010, 11:11:31 PM

haha yeah I know what you mean mate, I drove her on the motorway with the pump connected and did notice an increase in economy, I don\'t think it was my imagination either!

The noise isn\'t as bad on the motorway, so it may be an idea to connect for those longer journeys!

playtime · August 20, 2010, 09:12:11 AM

yea, come to think of it, she seemed to be worse in the lower gears, but quietest when I was cruising about 65-70 in top. Car didnt really get cooling down for approx 17 hours, with only a couple of 2 hour snooze breaks in service station carparks and the ferry crossing. Silly question, but going by what I was reading on the link above, am I right in thinking, if you remove the air pump, the car will run richer? I have also read somewhere, if the cat is removed and a free flow stainless system fitted, the car would run lean. I thinking remove the pump, cat, fit a new system, and std ecu would be fit to cope? Maybe Im way off here?