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Erratic Screeching When Starting Engine

Datman

By Datman,
in General Maintenance

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Datman Contributor

Datman

Posted
Posted

When starting the car there's an erratic screech/chirping noise for up to 2 seconds and it's not always exactly the same noise. It does it more when it's cold than warm/hot but doesn't occur any other time. On the rare occasion it won't do it on a warm/hot start. Been happening for months and thought it was one of the drive belts. I re-tensioned the drive belts, no change. When I got around to checking them and replacing the fan belt it still did it. I took all three belts off and it still did it. Bugger!

The only belt left is the timing belt and it's not slipping teeth because you'd know. Could it possibly be the tension on the timing belt has reduced and the outside of the timing belt is slipping on the tensioner or idler bearings? That's the only thing I can think of.

Anyone got any other ideas?

Timing belt, tensioner and idler were changed at 97K, now has 160K.

Thanks

Martin

GTR-N1 Grand Master

GTR-N1

Posted
Posted

On a previous car I had, the symptoms were the same. My mechanic friend said that...

i) either one of the belts is not running straight from one pulley to the next; or

ii) one of the belts has a rubber compound that has gone hard & it takes a couple of seconds to soften enought to grip properly.

If it's the latter, you could test it by spraying or coating a bit of rubber trim conditioner on the belt itself, in which case you are probably better in the long run, to change that belt.

Can't think of anything else.

Tez

Datman Contributor

Datman

Posted
  • Author
Posted
  Terry_GT-R34 said:
On a previous car I had, the symptoms were the same. My mechanic friend said that...

i) either one of the belts is not running straight from one pulley to the next; or

ii) one of the belts has a rubber compound that has gone hard & it takes a couple of seconds to soften enought to grip properly.

If it's the latter, you could test it by spraying or coating a bit of rubber trim conditioner on the belt itself, in which case you are probably better in the long run, to change that belt.

Can't think of anything else.

Tez

I've eliminated the accessory belts as took the P/S, A/C and fan belts off the engine; started it and still got the same noise. I'll just have to pull the timing covers off and check the cam belt tension and make sure the tensioner and idler bearings are spinning freely. Could also be some sort of slippery substance on the outside of the belt causing some slippage.

Thanks for the response.

  • 1 month later...
central coast person Proficient

central coast person

Posted
Posted

........its not a belt problem its a power steering problem. i couldnt say what it is because i cant play with the car but it would be the pump or even simple as power steering fluid

the screech and then chirp makes me think its your pump and therefor the belt slips for a second tricking you into it being a belt :P

shaunvlc Enthusiast

shaunvlc

Posted
Posted

i have it too... its the starter motor. pop your bonnet, start your car (while your standing near the bay) and you can hear it comes from the rear of the engine bay. i assumed it was belts but it wasnt. its the mechnism in the starter motor not fully disengaging itself from the flywheel. either replace it or as they can get very dusty and dirty from brake dust etc take it out and give it a good clean. pretty sure they just dry up and need a bit of lubrication.

  • 1 month later...
Datman Contributor

Datman

Posted
  • Author
Posted (edited)
  shaunvlc said:
i have it too... its the starter motor. pop your bonnet, start your car (while your standing near the bay) and you can hear it comes from the rear of the engine bay. i assumed it was belts but it wasnt. its the mechnism in the starter motor not fully disengaging itself from the flywheel. either replace it or as they can get very dusty and dirty from brake dust etc take it out and give it a good clean. pretty sure they just dry up and need a bit of lubrication.

Exactly right shaunvlc; it is that, all you do is take the starter motor out, grease the shaft that the starter gear moves on and hey presto. Mind you the top bolt is a bit tricky, but don't let not being able to see it put you off a diy. Big thanks to Ed from AutoTech at Hume (ACT) for the suggestion - champion.

Edited by Datman

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