Clattering sound

[scrabble]

Hi

Just a quick one. Whenever I start my car in the morning or from a cold start, just before the engine starts there is a loud rattling/clattering sound coming from the rear? My mechanic thought it might be the starter motor not disengaging properly? The weird thing is, when I start from hot this problem does not exist? I am clueless as to what it could be? The engine is sweet and runs lovely so thats not the problem?

Answers on a postcard please.

Any ideas anyone?

Thanks

Kev

 

[GTTurbo]

Not to sure BUT it maybe an exhaust heat shield? Mine use to do this, it was a cat shield rattling.

The sound disappears as the metal warms up and expands, stopping the noise.

I cured mine by undoing the connecting nut and bolt and placing a washer between the 2 metal faces and tightening back up.

 

[scrabble]

A ha...I did think that! The noise starts to come back again when the car cools down. Only ever so slightly! The car is going in for the cambelt soon so will get it looked at.

Thanks Mossy

 

[WONGY]

Clattering or ticking?

I had a noisy tappet that made a clatter when cold and for about 10 mins.

Replaced the full set (24 of them) and its fine now

 

[scrabble]

Was that an expensive job?

 

[k1ano]

I also understand the camshaft de-phasers can cause rattling on startup ...

Martin

 

[Jamesv6]

I had a slight ticking from the air con pump if it's on when I start up. Listened to another vee the other day and that one's air con pump was making a heck of a row on start up.

Just my daft suggestion.

 

[Rich]

Totally different car but my MX5 used to make a metallic shimmery sound from the heat shield above the cat - it did this from hot though. I guess as the heat expands the shield it started to slightly touch the exhaust, or in your case it moves in the opposite direction away from the exhaust so the noise disappears.

 

[scrabble]

What are camshaft de-phasers???

 

[Spike]

Hi
Just a quick one. Whenever I start my car in the morning or from a cold start, just before the engine starts there is a loud rattling/clattering sound coming from the rear?

don't forget the dual mass flywheel, notorious on other vehicles for really bad rattle on startup. hope its not as these are EXPENSIVE, and engine out. they do break up inside and can explode (breakup) if pushed to the limit. this does make a big hole and coresponding mess when it happens.
take the lids off and the undertray if poss and see if you can id where the noise is coming from. a usefull trick is get a long screwdriver and place on the engine in differing places whilst pressing your ear on the end,i know it sounds stupid but it makes for a cheap stethescope.
sorry to be so cheerful.

 

[WONGY]

I heard you can do the clutch and flywheel without the engine out though a bit fiddly?

Normaly price for 24 tappets is a 1k gbp but I got a new set for 200.

Fitting is another 600 as engine out, cambelt out and replacement etc.

Since my Mk1 gearbox was blown anyways I decided to do the lot and upgraded to a Mk2 gearbox, new clutch - didnt change over to a dual mass flywheel cos I heard the Mk2 clutch / setup is weaker so fitted a Mk1 clutch to the existing Mk1 flywheel

Oh and added on KW's to finish it off so it was a bit of open heart surgery in the end

 

[scrabble]

Actually the sound is more like a vibration when I start it. It lasts for one second and its gone. It only comes back when the engine begins to cool down again. I know what a duel mass flywheel breaking up etc sounds like and its def not that. The car is going into Rentech next week. Hopefully they can find it on there diag machines ec.

 

[k1ano]

What are camshaft de-phasers???

The hydraulicly actuated variable valve timing units on the end of the camshafts which 'de-phase' the camshaft timing relative to the crankshaft - as part of the VVT operation ...

Martin