Thread: Engine knock

i guess why im not convinced its a flange gasket just yet is that when i rev the engine while stationary it really doesnt make that much noise only when I let go of the accelerator then it carries on. but when i put the car under load it makes noise under acceleration??? maybe my mind has had enough for today hope that makes sense

thanks for all the comments so far and went out and checked the manifold bolts and yes they were lose so tightened them up when i worked out the flange was bent over the bolt end YAY.. damn hard to get too underneath when hot....

Went for another test drive and results are below. however no change unfortunately. did quieten the deacceleration noise but perhaps not convinced that is the problem however happy to hear your comments on the road test.

[ame=http://www.youtube.com/watch?v=R176OtiG5HA]YouTube - road test 2[/ame]

[ame=http://www.youtube.com/watch?v=IE6Qx7UqpkQ]YouTube - road test return[/ame][ame="http://www.youtube.com/watch?v=IE6Qx7UqpkQ"][/ame]

Whilst out in Jordan, our guide had a similar problem with a V8 - knocking especially under load. I mentioned that i would ask the experts when i returned ot Australia. It sounds similar to the problems mentioned here though could it be camshaft or wear related?

Any help would be much appreciated

Paul

Originally Posted by daisee

Whilst out in Jordan, our guide had a similar problem with a V8 - knocking especially under load. I mentioned that i would ask the experts when i returned ot Australia. It sounds similar to the problems mentioned here though could it be camshaft or wear related?

Any help would be much appreciated

Paul

Camshafts don't change their tune under load. So it's either exhaust or something like main bearings.

Originally Posted by spike076

thanks for all the comments so far and went out and checked the manifold bolts and yes they were lose so tightened them up when i worked out the flange was bent over the bolt end YAY.. damn hard to get too underneath when hot....

Went for another test drive and results are below. however no change unfortunately. did quieten the deacceleration noise but perhaps not convinced that is the problem however happy to hear your comments on the road test.

YouTube - road test 2

YouTube - road test return

My 2 cents worth, could be a buggered timing chain flopping around, esp. on overun, big end/main bearings sound more like someone tapping the inside of the cylinder block, something like a "Bonk" "Bonk" usually louder under overun, try this, run engine up to 1500rpm and hold it for a few seconds, let go accelarator and quickly drop back to idle, if the bearings are shot you should hear it loudest then. Also if bearings are shot oil pressure should be well down. Another thing could be a crook lifter, to check the timing chain put a hose/screwdriver to the timing cover and listen, hope you get it sorted, Regards Frank.

mine is making the same noise too just started on drivers side middle tightend exahst used a screw driver to the ear and cant seem to find it
worse when cold and on over run really anoying im not using water or oil either and its not loose trumpets im looking for help on htis subject two ill keep an eye on this thred cheers

tightening the manifold and flange bolts will not fix it if the gasket is shot. We have same issue with a steel shim gasket on the dump pipe we know is shot. Makes exactly the same noise as this one, a little less, but same fluttering.

Hi everyone quick update I have pulled off the rockers to have a look at push rods just as I was curious and all seems fine. Have 1 loose trumphet but nothing that bad.

Did some research on the rave manual about engine noise there recommendation is that it's either main or big end depending on which test you try. For those that are having similar noise issues two tests to try.

1. Locate where the noise is coming to the closest cylinder and disconnect that spark plug lead. Start engine and see if there is difference in noise. If so then it would suggest main bearings.

2. Remove serpentine belt or main belt whichever you have and start engine if noise is quieter then this would suggest big end bearings.

So guess what im doing over Christmas break.

Now it would appear that it's main bearings in my case so pulling the engine out hopefully not too much damage to the crank. Whilst out will give it a freshen up. Really didn't want to pull the engine down as it's been no trouble and once you start playing I could end up with more problems later.