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Matt, Mechanical Engineer
Category: Toyota
Satisfied Customers: 22761
Experience:  BEng hons Mech engineering, in auto industry 22 years
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I have just bought a 6 year old Toyota Aygo. It's a lovely

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I have just bought a 6 year old Toyota Aygo. It's a lovely little car though quite a noisy engine. I am concerned about a rythmic knocking sound when i am going 30-32mph. Is this normal as it doesn't seem to affect the driving of it? I know a few people with the same car and they don't have this problem. Otherwise I am
very happy with it.
Thanks, Julie
Hello Julie

is the noise related to engine rpm at all? or it just occuring in 1 gear at this 30 mph?
Customer: replied 3 years ago.


It only happens in 3rd and 4th gear and goes slightly faster or slower depending on the speed i am going. It's more noticable when i am travelling along steadily rather than when i am speeding up or slowing down. At higher or lower speeds it doesn't happen at all.

Hello Julie

I'd suggest checking for worn mountings - check the tightness of the engine and gearbox mounts and their condition - this is best done by using a jack to take the weight of the engine off the mounts and seeing if any cracks or splits open up in the rubber.Also check the tightness of the mounts bolts

I'd also check that th exhaust isn't touching the car body anywhere as this can produce knocking sounds

if thats all OK then check for a

Worn drive shaft joint - typically these won't produce any vibration unless badly damaged but they can be noisy or 'clonk' for a long time beforehand, turn the steering to full lock and look at the drive-shaft rubber boot there should be no rips or tears in it and the suspension should be clean and dry of any grease. If you reverse at a reasonable speed with the steering on full lock a worn joint will 'click'.

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