Funny knocking noise. confused!

Ady

Ady

Member +
right, for a few weeks now, i have been hearing a funny knocking noise. i can only hear it when the engine is idling and at operating temperature.
ive been worried because it really sounds like part of the engine trying to get out!

but the thing is... i cant hear it if i lift the bonnet and put my ear to the engine, i could only hear it from inside. last night i came to the conclusion that the noise is coming from somewhere near the drivers side of the firewall.

and if i put my ear to the skuttle pannel (where the drivers windscreen wiper attaches) i can hear it really clearly.

has anybody experienced this before? i am so confused, i just cand find where its actually coming from :homer:
 
C

CaL

Guest
could be the plastic shit sheld off a pulley...mine used to do it....when no weight was on the front end it would hit...and when you just leant on it...it would go.....try fidlin around for obvious things
 
Greg0r

Greg0r

Member +
this is exactly the same as what i get, i can hear it inside the car and only when at normal temperature. When i listen under the bonnet i cant hear it.

Can you hear it when you rev the car and let the revs drop??? to say 4k revs and lets them drop back down?
 
L900CMC

L900CMC

Member +
On my car it was the fuel filter,changed it and the knocking went away,does it slightly speed up wen you rev the car?
 
GTti

GTti

Member +
All you need is a Screwdriver and an ear.


Put the screwdriver head on parts of the engine and the handle to you ear, you can hear inside the engine very well. Try the sump first to check it isn't worn bearings, other than that it's probably a pulley or something.
 
GTti

GTti

Member +
Greg0r said:
this is exactly the same as what i get, i can hear it inside the car and only when at normal temperature. When i listen under the bonnet i cant hear it.

Can you hear it when you rev the car and let the revs drop??? to say 4k revs and lets them drop back down?
Click to expand...

That has worn big ends written all over it. Screwdriver to sump! Had exactly the same when my bearings were screwed in my 106 Rallye.

It was OK at lower oil temperatures due to it's viscosity, but as the oil warms and thins the clearance is less so the knocking becomes apparent.

Thicker oil will help you for a while.
 
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Greg0r

Greg0r

Member +
thing is its been like this for months, ill have to try the sump check first...

thanks tho, good bit of info. (fear if it is my big ends, how much am i looking at for them and the labour??? rough idea?)
 
Ady

Ady

Member +
180kph said:
might be a loose bonnet.
Click to expand...
its not the bonnet, thought that first!
Greg0r said:
this is exactly the same as what i get, i can hear it inside the car and only when at normal temperature. When i listen under the bonnet i cant hear it.

Can you hear it when you rev the car and let the revs drop??? to say 4k revs and lets them drop back down?
Click to expand...
i can only hear it on idle, but i cant hear it above 1500 rpm.
L900CMC said:
On my car it was the fuel filter,changed it and the knocking went away,does it slightly speed up wen you rev the car?
Click to expand...
yes it speeds up with the engine but i have to rev it very slowly to hear it, all other noises drown it out above 1500 rpm
GTti said:
All you need is a Screwdriver and an ear.


Put the screwdriver head on parts of the engine and the handle to you ear, you can hear inside the engine very well. Try the sump first to check it isn't worn bearings, other than that it's probably a pulley or something.
Click to expand...
i will go and put my screwdriver to the sump now!
 
Ady

Ady

Member +
mate that is THE BEST tip i have had all year!! i could actually hear everything in the engine, i could do that all day its amazing!

its definately not coming from the sump, i put the screw driver on pretty much every part of my engine and had a lot of fun listening to everything, but the sound wasnt even coming from the engine itself.

i put the screwdriver on the firewall where i thought it was coming from and i heard it very clearly, then i poked it right down into the scuttle where i could hear it clearest.

its around the area of the brake servo??
or somewhere behind the dash??

its a relief that its not my engine, but im really still none the wiser.
 
L900CMC

L900CMC

Member +
yes it speeds up with the engine but i have to rev it very slowly to hear it, all other noises drown it out above 1500 rpm

Sounds exactly like my car,wens the last time the fuel filter was done?Mite aswell rule the cheap options out
 
GTti

GTti

Member +
Probably some sort of rail or line or some auxiliary part of the engine knocking. Just keep looking and you'll find it.


Although I would suggest Greg0r's issue doesn't sound as healthy.
 
M

Monty

Member +
L900CMC said:
yes it speeds up with the engine but i have to rev it very slowly to hear it, all other noises drown it out above 1500 rpm

Sounds exactly like my car,wens the last time the fuel filter was done?Mite aswell rule the cheap options out
Click to expand...

It sounds like a sticky tappit! If the noise increases with the revs then thats what it will most likely be. Check oil level and increase it if it needs more. Give it a good run after more oil is added to get it around the engine and then listen again.
 
Ady

Ady

Member +
Monty said:
It sounds like a sticky tappit! If the noise increases with the revs then thats what it will most likely be. Check oil level and increase it if it needs more. Give it a good run after more oil is added to get it around the engine and then listen again.
Click to expand...

its definately not that, with the screwdriver trick, i can clearly hear all of the cams spinning, and i can pretty much hear each individual cam.
definately not tappets.
 
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