Probably worn engine bearings. When the engine oil is cool, it's thicker, sometimes just thick enough to keep a worn rod or main bearing from knocking.
A loud knocking noise in the motor of a car at high speeds is most likely the engine. There could be another issue with the transmission if the knocking only happens at high speeds.
The knocking noise during acceleration in a turn in a '93 Prelude could be due to worn CV joints or a faulty suspension component. As you apply power in a turn, the force on these parts can exaggerate any existing issues, leading to the noise. It's important to have a mechanic inspect and diagnose the source of the knocking to prevent further damage.
Some causes will:A leaky lifter will pressure up and quit, and can sound like a rod knock when the clearance is bad enoughA collapsed piston skirt will quiet down when the engine warms upA rod can knock under load or start up and quite down when oil pressure is applied. Its only going to get worse though.
Noises are impossible to correctly diagnoise when not heard. Take it to a garage when it ts making the noise.
check wheel bearings and cv joints if applicable
maybe the flap obove the left weel has com loose something youv left in te boot and forgotten about
I would say you either have a rod knocking or lifter knocking. I know in the 3.8 litre motors they are known to knock alittle when you cold start them. Most Grand Ams, Grand Prixs are like this. My sister has a 2002 Grand Am that does this and the noise goes away once it's warmed up. I would also double check and make sure your oil is full. get your car to a garage for a def solution.
posibly needs a new axle cv is bad
U Joints can certainly make noise after they've started wearing and are dried out. If you have concern about an unfamiliar noise, take the vehicle to a trusted mechanic or even the dealer. It's nearly impossible to tell you what the noise would be from a description like that.
The Hummer H2 is a 2005 SUT with the 6.0L Vortec and a Magna Charger supercharger. It runs great with plenty of power, but I'm concerned about some noise I'm getting out of it. When I first start it up, everything sounds fine. After running a mile or so, I start to get a knocking sound. I only notice the sound when idling, not when running.
An expert would have to hear the sound for a diagnosis. It may be your main bearings are knocking. If it also happens if you lift your foot sharply OFF the accelarator, then that's a sure thing. - Only way to check for sure is to fit an oil pressure gauge.
Possible lifters that are bad that could explain your ticking noise. It should cost you nothing by stopping by an Auto repair shop and have them listen to your engine.