Im hoping this will be an easy one for you guys

I have an engine noise that sounds like a deep chatter or maybe knock. Its only apparent in the cabin though, clear as day. In the engine bay though I dont hear it. It increases with RPM but not a lot. Otherwise, car seems to actually run pretty good, its just this noise...

I just replaced the intake manifold and gasket (had coolant leak and manifold was corroded), rubber fuel lines (sprung a leak - now braided), and did the cold sensor bypass kit (cleanup). Not sure if its related, but FWIW. The car was also sitting for a few months while i was on work travel so havent driven it much at all lately. Of course I just changed coolant and oil change as part of all this. I also changed the cap and rotor today but it was making this noise before that.

Here are vids of the noise inside the cabin and engine bay. Thanks for any help!

http://www.youtube.com/watch?v=kA00M...ature=youtu.be

http://www.youtube.com/watch?v=n3OFS...ature=youtu.be

 

I can't tell anything from the videos.
What happens when you put it in gear? forward & reverse?
You're probably going to have to work harder to track down the exact source of the sound.
If it could be your blower motor, try unplugging the power wire or pulling the fuse for it.
If some trash went down your cabin vent it can cause rattling in the blower motor until you clean it out.
If it's coming from the drivetrain, then I would get under the car and check if it's the transmission. Sometimes a broken front pump will make a rattling sound until it breaks worse.

 

thank you for the reply. this is what im looking for is ideas.

i just disconnected the hvac blower with no change in results. I dont think its an interior sound it just resonates the most inside the cabin.

Putting it in gear (anything but park) makes the sound deeper and louder and slower. Quite loud in the cabin. Since the RPM is lower... I'd say it sounds worse just slower rate. Bit afraid of a rod knock since read similar behavior with respect to RPM (less apparent at higher RPM/under load).

Is it a valid test to pull spark plugs while running to see if noise abates? I saw someone do this on youtube. Can I pull from the distributor cap (with pliers for safety)? At least then might give a clue if its and engine cylinder problem?

How would i check if its the transmission? Stethoscope? I wouldnt be surprise given how the sound is louder in the cabin and the trans is the closest component. But its something that is at least rotating with the engine, even in park. Doesnt sound like top end on engine. Just sticking my head under the car is hard to tell. Its not even as loud as in the cabin. If you werent looking you might not notice anything underneath as far as noise.

 

or perhaps disconnect each injector is easier and safer than disconnecting plus wires?

 

do you hear the noise with the engine off but the key in the "run" position?

Also, what type of car were you inside when making the video? I didn't realize a 3rd gen could be so quiet

 

maybe a exhaust leak? it sounds like a sputter

 

Well I think you are the winner...

Today:
-Inspected the flexplate (looks fine)
-Unplugged each injector individually, still had noise. (hope that rules out a rod knock or internal engine problem)
-Held the throttle open @2500 rpm and smoke was coming out from around the exhaust manifold (see video below)
-Did a compression test and all cylinders between 180-195.

It does appear that there may be some fluid(oil) coming out from the exhaust gasket and burning (See second vid). Around the middle two exhaust ports the manifold is discolored like it looks wet almost. I'm hoping this is just because, I also badly need to replace the valve seals and some oil is going out the exhaust?

So my plan is to do the valve seals (intake seals on both intake and exhaust if I understand correctly). Then I can do the exhaust, and I have a hooker 2055 set thats been sitting in my garage for a loong time that I might as well put on while Im at it. Will the 2055 manifold fit onto the stock y-pipe? I know it doesnt make sense but I would like to do one thing at a time. If so then once all is working good I can go back and do the y-pipe, cat, and cat-back later on.

Smoke:
http://www.youtube.com/watch?v=cU86a...ature=youtu.be

Fluid/bubble(wait for flashlight to come on):
http://www.youtube.com/watch?v=v7orM...ature=youtu.be

Thanks..

 

OK, I took off the exhaust manifold and found that in the second port from the front there is a good amount of oil residue. this is what was leaking out from the port and smoking. See attached photo..

Could this be caused just by a bad valve seal? I know I have needed them (for years). But the other ports look fine. Or maybe a valve guide just for that port?

Or do you think something on the bottom end? The spark plug did have lots of oil on the threads, but not on the plug itself. Combined with the noise, its worrisome. But as I stated above the compression test results appear normal..

Recommendations?

Thanks..

 

Cleaned out the port and reassembled. Based on the age look of the crud it appears its not a new issue.

Still get some smoke and can see wet oil come out of that port. Not very much smoke, but more on throttle.

Any opinions? Its off to the shop tomorrow, I tried the valve seals but with the rope trick could not get the keepers out of the rotator. So Im going to let the pros with proper equipment do that.

Still have the woodpecker noise.. but the engine seems to run just fine, good oil pressure and doesnt overheat.. idles pretty nice.

Got my smog notice, so now its urgent. Dont think the tech will pass visual if he sees the engine smoking

 

Did you ever resolve this? Mine is making the same noise and I can only hear it in the cabin. What's common here is that I replaced my fuel lines with braided ones.

 

Still sounding the same. I never did figure it out.

I got the valve seals done and that stopped the smoking anyway.

Running fine for the most part, but yeah still have the noise, and just in the cabin.

 

I really think it's the braided fuel lines. Mine has the exact same noise and I can only hear it in the cabin. It sounds awful like a rod knock, but the sound doesn't follow those symptoms like getting really loud from load and deceleration. Through a stethoscope the fuel lines are loud as hell with the same sound I hear in the cabin.

 

Sounds like a bottom end noise. You can tell by how fast it's knocking. If it was top end it would be half the speed of that sound. If you said it was burning oil Id shoot towards piston slap. Then again you say valve seals stopped the oil burning. Id check that port again. Surprised it's still running two years later.

 

It doesnt get much mileage these days.

The fuel lines do run under the vehicle to the rear, so I guess its plausible, though I dont know why they would cause noise as such. Maybe with rubber there is an isolation, but now with braided metal any noise is basically transmitted from the engine thru the lines?

I would think bottom end noise you would hear in the engine compartment as well. I dont have a stethoscope but two years ago I put a 2x4 on various places of the engine and then both tried to feel and hear anything on the other end but there was nothing. yet its clear as day sitting in the car.

The shop couldnt find the source of the noise either...