What is this? Knocking Popping Tapping noise from the engine bay no codes

[ermax]

I also vote for valve train rather than bottom end. To rule out the pulley you are suspicious of, try running it without the belt for a few seconds.

[humfrz]

Originally Posted by arren123

Humfrz,

Give a listen to this one and let me know what you think. It's from a cold start the next day. It is pretty loud when I move to the passenger side.

Well, it still sounds like something in the valve train.

I'm guessing that one of these puppies has come unglued/weakened/broken.....


humfrz

[Ultramaroon]

Originally Posted by arren123

Humfrz,

Give a listen to this one and let me know what you think. It's from a cold start the next day. It is pretty loud when I move to the passenger side.

Augh, that shit is toast. I'm surprised it's still running on all 4.

That's a real bummer but it will get much worse if you keep running it. Valves are not meant to handle impact loads.

[arren123]

Originally Posted by humfrz

Well, it still sounds like something in the valve train.

I'm guessing that one of these puppies has come unglued/weakened/broken.....


humfrz

Hopefully it is something in the valve train.. I'll take head work over bottom end work. That's assuming that the valve didn't mar up the top of the piston.

I'd expect a misfire code though and so far there are no codes.

[humfrz]

Originally Posted by arren123

Hopefully it is something in the valve train.. I'll take head work over bottom end work. That's assuming that the valve didn't mar up the top of the piston.

I'd expect a misfire code though and so far there are no codes.

I reckon that if a valve dropped far enough for the piston to hit it ........ the engine wouldn't still be running as well as it is ......

Did you oil up or eliminate that idler pulley you first suspected ... ??

Have you taken it into the dealership as you mentioned you might do .. ??


humfrz

[stevesnj]

Doesn't the belt just run the alternator and AC? if so try removing the belt and start the car. No sound it's a pulley bearing or something stuck. It's very loud but check the exhaust gasket on that side if you can.Dunno how easy that is though. Weird thing is the engine isn't bucking or have a misfire sound like combustion or exhaust is affected.

[Sportsguy83]

Originally Posted by stevesnj

Doesn't the belt just run the alternator and AC? if so try removing the belt and start the car. No sound it's a pulley bearing or something stuck. It's very loud but check the exhaust gasket on that side if you can.Dunno how easy that is though.

Alternator, AC and water pump. definitely a quick check is to run it without belt for a few seconds.

[stevesnj]

Originally Posted by Sportsguy83

Alternator, AC and water pump. definitely a quick check is to run it without belt for a few seconds.

Ah the water pump too.. Gotcha. Yeah a cold start would work

[Ultramaroon]

Originally Posted by stevesnj

Ah the water pump too.. Gotcha. Yeah a cold start would work

No harm in running it without the belt for a minute, even at normal temp. Valid test.

[arren123]

OK. Here's what I found out so far.

I thought that a spark plug may have backed itself out so I checked #1 and #3 on the passenger side and they were tight. Then I pulled the plugs out. No clues from the plugs, they look normal. I didn't bother with #2 and #4 since those a difficult to remove with all the injector/supercharger hoses in the way.

I took off the belt and popped the charge pipe off the supercharger so the engine would get air. Started the car for a few seconds and still had the loud sounds. At least it eliminated quite a few things: pulleys, a/c, alternator, supercharger, etc...

Checked for anything loose and couldn't find any. Removed and broke off the main clip of the decorative Subaru intake cover (oops). Nothing loose under there.

No codes and engine seems to run smooth otherwise.

I have a diagnostic scheduled for Monday. Hoping they will have a loaner car for me as promised.

[humfrz]

Originally Posted by arren123

OK. Here's what I found out so far.

I thought that a spark plug may have backed itself out so I checked #1 and #3 on the passenger side and they were tight. Then I pulled the plugs out. No clues from the plugs, they look normal. I didn't bother with #2 and #4 since those a difficult to remove with all the injector/supercharger hoses in the way.

I took off the belt and popped the charge pipe off the supercharger so the engine would get air. Started the car for a few seconds and still had the loud sounds. At least it eliminated quite a few things: pulleys, a/c, alternator, supercharger, etc...

Checked for anything loose and couldn't find any. Removed and broke off the main clip of the decorative Subaru intake cover (oops). Nothing loose under there.

No codes and engine seems to run smooth otherwise.

I have a diagnostic scheduled for Monday. Hoping they will have a loaner car for me as promised.

hmmmm........comments/questions:

I've never had a spark plug "back out" on anything .......

Codes ...... have you checked with a code reader or just no codes showing on the dash .. ??

Are you going to drive the car between now and Monday ..... except to the dealer .. ??

Keep us posted.


humfrz

[humfrz]

Well, arren123, here's what you need ........ garrrrenteeed to fix whatever is ailing your car's engine .......


humfrz

[arren123]

Originally Posted by humfrz

hmmmm........comments/questions:

I've never had a spark plug "back out" on anything .......

Codes ...... have you checked with a code reader or just no codes showing on the dash .. ??

Are you going to drive the car between now and Monday ..... except to the dealer .. ??

Keep us posted.


humfrz

I've never had a spark plug back out either, but it was easy enough to check and hope for an easy fix.

I'm not driving the car between now and Monday. I'm getting it towed to the dealer since I still don't know the actual cause.

I just plugged in my Ecutek and used the DTC tool to verify there were no stored codes.

On the side note of doom and gloom..
There was a YouTube video I ran across where the guy had a rod/bearing issue. One of his comments "Ended up being a spun Rod 4 Bearing, apparently it wasn't out of the normal on the early first batch engines due to a front oil valley cover issue (passages too narrow or something along those lines). I got a replacement engine under warranty and it was fine ever since. The early engines have a #1 with an eagle looking logo stamped on the front cover, revised front covers have a #2 with no eagle. Sure they've done more revisions since then."

I looked at my cover and I found the eagle and I found the #1 on it

[humfrz]

Originally Posted by arren123

.........................I looked at my cover and I found the eagle and I found the #1 on it

What date was your car built ....??


humfrz