Recently I have noticed a ticking sound from the car.


What I can tell you:

It seems to emanate from the bottom of the car. I originally suspected an exhaust shield but after a quick inspection I found it not to be the case.

The sound is not audible from the engine bay(up top)...only when I stand behind the engine can I hear it.

So I can eliminate any pullies or anything like that.

I noticed alot of online material pointing to the purge valve but I have eliminated that as the sound is still present when it is disconnected.

I also double checked oil levels and they are fine.

The noise doesn't seem to change with the temp of the engine.

It does not seem to get louder under any conditions.

However the frequency of the tick seems to correlate with engine rpm...i.e. ticks faster when engine is reved.

The only time the noise is not audible is at low engine rpm(less than 1100).

There are no ecu codes/lights.

There have never been any temp issues and no missing oil or coolant.

Vehicle has 148k(purchased at 132k)

Things I can think of:

I have not changed plugs in the car yet; other than that all maintenance is up to date.

Maybe the ecu for some reason has increased the timing? reset ecu?

Things that worry me:

Doesn't sound like a slap or knock but doesn't mean it can't turn into one.

Doesn't really sound like spark knock bc that is audible on the top of the engine.

The fact the tick is consistent with engine rpm and that it comes from the bottom of the car.

knee jerk reaction:

Sounds kinda like lifter tick but again the only ticking i hear up top are the coilpacks firing.

I fear it is the onset of bearing failure....doesn't sound spun but definitely sounds worn.



Suggestions?

Only thing I'm thinking is to get a mechanics stethoscope and probe the side of the block/oilpan to get a better idea/find the exact origin of the sound.

 

Place a finger on each injector and see if one is f'ed up - this was common in our past lives with the DOHC.

 

uploaded a vid to a buddies photobucket.

http://s10.photobucket.com/albums/a1...ys%20%20Filez/

some reason it doesn't play sound from the site....probably bc flash was playing it and it is supposed to be played by the devilish quicktime. But when I dled it, it seemed to have sound.

 

okay, definitely not a bad injector.... I dunno dude, hope it's nothing too serious

 

I don't know... mine makes some of those sounds, I always figured it was an accy ticking.
I'll let you know if mine goes away after fresh oil change this weekend... gonna DIY Oil Change.

You can buy an automotive stethoscope that you "carefully" place on diff components while running to isolate the noise. Most of my engine noise comes from my ac comp and ps pump.

GL.

 

ill give it a shot tomorrow. for many months I have been using the vehicle in EC mode. i'll enable the compressor tomorrow and see if there is any notable change.

I will also check my fluid level in my ps pump but it was freshly flushed 4 months ago.

I need to Isolate exactly where this tick is coming from.

I will also place the mic under the front of the car.

but it def sounds like the origin is under the rear section of the engine/beginning section of the transmission.......maybe the off possibility a tq converter has backed itself out a little and hitting block web casting...guess i can remove the shield and take a peek.

I just dont know enough yet. I may have ot pay a local mechanic to investigate bc it is just too cold for me to be messing with it for any length of time.

 

It sound to be a 1/2 engine speed , So I would think you have some valve train lifters that need replacing
Cheers _PTEngineering

 

that's encouraging. so im guessing the lifter tap is being echoed through the exhaust?

had a mechanic take a quick look and he says it sounds like there is something in the exhaust rattling around.....that's definitely plausible since I had all 4 cats gutted....but not recently.

I'll call the guy that did the cats tomorrow and make an appointment to get him to inspect it and cross my fingers that it's just a piece of catalytic material.

im not convinced tho....the tick/rattle sounds too consistent to be something jumping around inside the exhaust.

 

think fortune smiles upon me. after using low-tech stethoscope(i.e. 2x2 piece of wood) didn't find any engine noises and traced rattle to resonator.

 

I was going to suggest the rattle might be coming from the resonator. My friends 208 AMG made the exact same sound, he replaced the resonator and problem solved!!

 

thanks peeps for the informative help! Bullet=dodged...whew!

 

ill post final update when problem resolved..

 

Just good old mechanicin . Glad to see you used what god gave you. eyes , ears
nose & touch. You developed common sense on your own. Good Show dohcfiend
Cheers _PTEngineering

 

Know you already got it, but for others coming here looking for help, an easy, cheap (might be in your toolbox) stethescope is a screwdriver/long screwdriver, conducts sounds just fine, and of handle to your ear, other end elsewhere. Of course keep away from moving objects, do not test electrical items, that sort of stuff. I do invite others to just try it for fun, on the fuel rail (chattering up a storm), water pump (whooshing away), alternator (if you can reach it) whiny *****, valve cover....we all hope normal soft chatter .

Another ticker for the 320 and 63 motor that I have seen is the canisiter purge solinoid, on the front of the driver's side strut tower, 2003 was first year with these on a CLK, loud as ***, not sure what years later but on my 2008 it has way more effort done there to mute it, but still loud!! Put your screwdriver on it to isolate this normal sound from any others of concern.

Glad you got your rattle found!

 

Werd on the long-azz screwdriver stethoscope!!!! good call.