Strange Idle/engine sound

Discussion and technical advice for 84-89 AW10 & AW11 MR2. 3A-LU, 4A-GE, 4A-GZE.

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Jedd
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Joined: Wed Nov 16, 2011 12:20 am
Location: East Sussex

Strange Idle/engine sound

Post by Jedd »

Hi guys I've recently changed my oil pump and timing belt/aux belt and since starting the car again the car is making an odd whirring squeeling sort of noise. Also the Idle will go as low as about 500revs and sounds like its about to stall. However when you turn on the lights or anything electric in the car the revs rise slightly.
I'm pretty sure my timings are perfect as I've checked them with my mate three times and the last time they were bang on the marks after the rotation test but I've still got this problem. So any ideas? At first I thought maybe my aux belt was too slack but that doesnt seem to be the problem. A dodgey alternator perhaps?

Thanks in advance,
Matt.
elbon50
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Location: Stafford

Re: Strange Idle/engine sound

Post by elbon50 »

Jedd wrote:However when you turn on the lights or anything electric in the car the revs rise slightly


the idle up VSV increases the revs by 200 or so when an electric load is switched in Matt

That's normal

Peter
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Lauren
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Re: Strange Idle/engine sound

Post by Lauren »

Did you change the idler pulley when you changed the cam belt?
2020 GR Yaris - Circuit Pack :lover:
Jedd
Posts: 16
Joined: Wed Nov 16, 2011 12:20 am
Location: East Sussex

Re: Strange Idle/engine sound

Post by Jedd »

Yes Lauren new pulley and spring in there too.
jon_st205
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Re: Strange Idle/engine sound

Post by jon_st205 »

Crank pulley delaminating? Did you give it much grief during removal?
Jedd
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Joined: Wed Nov 16, 2011 12:20 am
Location: East Sussex

Re: Strange Idle/engine sound

Post by Jedd »

I haven't heated it up if that's what you mean, no. Although it was stuck on there pretty good.
elbon50
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Re: Strange Idle/engine sound

Post by elbon50 »

Jedd wrote:I haven't heated it up if that's what you mean, no. Although it was stuck on there pretty good.


Just pulling hard can damage them :(
Jedd
Posts: 16
Joined: Wed Nov 16, 2011 12:20 am
Location: East Sussex

Re: Strange Idle/engine sound

Post by Jedd »

Seriously? Ugh Okay then I suppose Ill get myself a replacement heh how annoying! While we're on the subject do you know if these two are the same size as the pulleys from our cars? Linky 1 and Linky 2 I can't find a lightweight one listed in the actual MR2 section. Also would there be a reason for me not to get the Single type pulley?

Matt.
un1eash
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Location: Leicester

Re: Strange Idle/engine sound

Post by un1eash »

Have you checked the timing with a light gun? When i did this and my pully had failed i could see the timing marks spinning around as the pullys moved freely of each other.

The outer pully is there for aircon (i think) so you should be fine with a single pully.

ps. PW@Woodsport has some used pulleys for sale.
jon_st205
Posts: 618
Joined: Sun Feb 19, 2006 9:37 pm

Re: Strange Idle/engine sound

Post by jon_st205 »

Yeah as above, I would check it is actually your problem before jumping the gun - I only mentioned it as it's the most likely culprit post timing belt change. Alloy ones on ebay for 76 quid (dual pulley type) if you wanted to go that route, though some argue that you should keep the harmonic dampener of the stock pulley. A quick search will throw up the relevant threads rather than re-doing that one again here.

Jon
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