Somewhere, down where the headers meet up with the block or below, there is a knocking sound coming from my engine. It does it at idle and is not heard at driving speeds. It is intermittent and does not cause any change in operating conditions. The temp, pressure, vltge, accel, etc... is fine. But it really doesn't sound like it can be a good thing. Thinking maybe the oil pump going, but that would throw a code or be noticeable. Someone else who listened thought it sounded like something hitting the oil pan. I'm not sure what kinda shavings or whatever else for whatever reason could cause that. Help me out here.

 

thanks for the help

 

I don't think anyone wants to be a pessimist, but knocking low in the block is usually not good news. It often turns out to be a big end rod bearing failure. I'm sure there are other less serious things it could be and I hope that's the case. I don't know without looking at my manual - anyone - can the crank and rod ends be inspected by pulling the pan.

 

at only 45k miles?

 

any new ECU codes? check even if engin light is not on! knock sensor code will not trip check engin light

 

Just pulled 0505 (no problems). Palm Harbor, that's like 2 miles from Clrwtr!

 

45K original or since rebuild? If rebuilt can you go back to the rebuilder for opinion or diagnosis. If original, that would be unusual for major failure. Like I said it might be something relatively minor. Can you run the car on a lift or ramps to be certain where it originates? At the least I'd change oil and strain for shavings, pull the pan to see whats in it, or cut open the oil filter.

 

Ok, just put it up on the ramps and went underneath to inspect. I used a s***hescope to listen at different areas.
1). I did not detect the noise at the oil pan
2). I did detect the noise at the valve cover (leading me to believe that this is where the noise is originating)
3). I did also detect the noise at the exhaust manifold

In response to the recent post, yes, 45K original miles. Someone suggested that it may be the Knock sensor, but from what I've read, I don't think so. The ks basically works by sending varying voltages back to the PCM which correlate to low-high levels of detonation/spark knock so the PCM can set timing accordingly. Now if the ks was not functioning properly, it should throw a code. I dunno.

 

Pat on the back to a man who gets things done. Not the KS. At some point you'll have to pull the valve cover and see what's going on in there. Hope it's the front one. Good luck.

 

Yes, the front one. I'm wondering at this point if it could be a bad plug causing spark knock. But then again, a code should be (but isn't always) thrown.

 

ok well my car makes the ticking at idle. i had always assumed it was the valve train making the noise. but i dunno. maybe im thinking of somethin other than what u are describing

 

There's always the soft clicking from the injectors at idle (it's fast because there are three clicks per revolution, is that right?) Then there is a metallic knocking from a valve/cam problem (it's much slower, once per two revolutions.)
Borrow a compression tester and compare the front three cylinders. Give you a quick check for valve/cam problems.

 

Exactly, big big difference. Not necessarily once per two revs I believe, but at a slower and/or intermittent pace depending on the problem. Think it could be caused from a bad plug??

 

Dunno....Hope so

 

I have some intermittent clicking also. I was thinking it could be the timing chain.

 

Oh well, I'm left with no option but to take it somewhere and have it looked at. The first time in 6 years I've had to have someone else do work on my car. Now if I can only find a decent place to take it..

 

a neighbor's son who owns an auto shop looked at it today. he said he thinks it could be the crank pulley. it does have a little bit of a noticeable wobble to it. doesnt seem to be anything related to the crank itself or any connecting parts in the motor though. He said to find out if this is a common or semi-common problem with this car and go from there. I'd assume that since this car is 7 years old, it is possible the pulley needs to be replaced/or tightened up. Has anyone else had this problem???

 

I have something similar, an intermittent faint knock at idle. I don't have any codes other than 05 05. I am not using any oil. I never worried about it until reading your post. I always guessed it was related to a Serp belt or pulley.

 

does your pulley seem noticeably wobbly from top view? I know that this sound resonates through everything. We're both pulling 0505 and not consuming oil or having any other problems.

 

I checked and it dosen't look wobbly to me. The noise sounds like a rod knock
but I doubt it is. I have 95,000 on it.

 

I should also add that it a very faint noise and not easily heard.

 

well i wouldnt say that this is a faint noise

 

Maybe we're talking about two different problems or the same problem
at different stages. I've noticed for at least a year in my case. It hasn't gotten worse either. Like others have said it's unlikely you have a major problem at 45K.

 

I would think it is different since in my case it went from no problem to very noticeable and not so faint. But who knows, automotive engineering is not an exact science. Lots of grey area.