Clatter when accelerating and decelerating

[Perinchery]

There is a strange clatter from my engine bay every time I accelerate and decelerate...It comes for a sec or two and then disappears...It is more pronounced when the engine is cold...
However when the engine is warmed up and running at a steady speed the engine is very smooth...It only at low speeds like in stop go traffic when i accelerate and decelarate the clatter comes..I hv changed the Belt tensioner and still the clatter does not go away...Wots wrong..is it the engine (103400 miles) But if so shouldn't the clatter be constant...??
Any thoughts..??

96 C220

[stox]

Check your engine mounts.

[jnenad16]

are u sure its coming from the engine, it might be trans chatter? do you feel any vibrations?

nenad

[jnolte]

a small exhust leak can sound like a clatter

[SLAMMED_C]

could it be piston slap?.. if you say its more pronounced when cold and isnt as bad when warm.

[loudandheard]

I had the same problem, but it happened after I changed my motor mounts. I was worried about what it could be because the sound is unnerving. I took it to get check out and they ended up taking off the heads and told me that it sounded like it was coming from the cam or cam adjuster. It cost me almost $800 to find out where the sound was coming from and they didn't even know if it was from there and the problem was never fixed. They told me that it is safe to drive like that, but to bring it back if the sound increases or if I start having problems. I have driven the car like it is for about 3000 miles and so far I haven't had any problems. The sound persists, but I don't want to spend money on a whole new cam or whatever that part was. The shop quoted me like $1500 more and they were not sure if that was the actual problem, so I just left it alone.

[trymonlam]

i had a similar sound. it sounded somewhat like a distance jackhammer. the problem turned out to be the exhaust tip on the custom exhaust installed by the previous owner. the inner lining was not exactly intact. so at about 700-1000 rpm, it clattered and resonated through the pipes, so it sounded like coming from the engine bay.

[Perinchery]

Thx for all the inputs...
It does feel like coming from the engine bay...
I hv changed the motor mounts and the transmission mounts recently....and the belt tensioner thinking that could be the reason...
Piston slap...I doubt...if was so wouldn't that come even when idling or cruising...??
Nenad there is no pronounced vibration as such...when the clatter happens or otherwise..
I will chk for exhaust leaks....and the engine and transmission mounts again...
Could it be anything other than the engine..??

96 C220

[knvs]

try exhaust manifold. One of mine was cracked so when i would excelerate at low speeds i would hear a clattering sound.