97 SL2 dohc loud knocking sound coming from engine. sounds like somebody beating inside of valve cover with a hammer. compression checks ok. oil level is good. no obvious problems with cams or lfters that can be seen after removal of valve cover.

Takes about 1 1/2 hours to figure it out. I can remove both valve covers in about an hour. 15 to 20 minutes to see which one is bad, if one of them are bad. Lifters and rockers arms usually make a ticking sound. Knocking is usually the piston rod. could be bearings at the crank or the wrist pin at the top of the rod. I've seen valve springs broken and only cause a ticking noise.

it sounds like a critical internal failure is eminent . if the oil pressure is ok,it could be a bent or broken valve as the exhaust leak can let the valves cool to fast and warp. however it sounds more critical than that. do a compression test on that side and see if the #'s are consistent.

could be anything from belt noise to lifter tick to rod knock..lifter tick is under the valve covers..rod knock sounds like hitting the block with a hammer..if its rod knock see what your oil pressure is.. should be around 30 to 45 psi cold..warm will be as low as 15..depending on oil type..most lifters can be adjusted by removing the cover and doing adjusting depending on the vehicle..good luck

the knock sensor changes the timing of the motor when it senses knock ,it sounds like the wire may have come off ,it sounds as if when you press the gas the timing should advance and it sounds as if its not advancing thats why you are hearing a clattering noise on accelerating.if you keep driving it like that you can do engine damage

I do not know what your mileage is but if you are over 110,000 in a DOHC then a cam chain is in order unless it has already been done. when you do it get a kit as the are guides, sprockets, and a tensioner needed as well. when you are putting it back together do the serpentine belt tensioner and the dog bone motor mounts. generally a cam chain sounds more like loud whirr than click. sticky valves click, but that generally goes away as the engine warms up. a/c clutch could make a click cutting in and out if the system is dry and there is nothing to compress. have you tried this in park with the hood open and someone else hitting the gas pedal to hit the magic rpm? you might see something attending the click or get some better idea as to exact location.

Most likely cause is a hydralic tappet. Mits are well know for top end noise. Note we are talking about a tapping or clicking sound not a knock. You can try using an engine flush product if the noise is getting bad and then changing your oil. Generally if the oil is not changed regularily eventually the tapping noise gets happens.

lifters tick and noise is upper end of engine if lifters are making noise could be from a bad valve,bad lifter ,push rod ,oil pressure,rocker arm - need to take do compression test find out if valve problem and which cylinder is problem also take off valve cover and check for proper oiling of valve head and look to see if and are damaged or loose-------a knocking sound usually comes from lower end of engine,rod knock etc.and thats usually rebuild of engine

Do a wet/dry compression test and determine if it's the piston rings or the valve seals.

I'd consider some fresh, clean oil & filter change first of all, if it hasn't been done . drive it for a while providing it isn't too bad, & see if it goes away, if not get back to us.

hi is it miss-firing as it sounds like a knocking noise can be anything but if you can feel it on the accelerater pedal then the noise sounds like its on the inlet valve side which would transfere the noise up the throttle body where the accelerater is located it could be something as simple as a tappet come loose to a burned valve you need to have a look do a compression test and take the rocker cover off see if theres anything come loose yates210456