Very Loud Valve Noise or Pinging on '01 Outback Limited

[bored155]

Originally Posted by grossgary

have you tried listening to what part of the engine it's happening at? rev the engine while standing there with the hood open? use a stethoscope if you have one, mechanics stethoscopes can be had for like $10 from harborfreight. (moved from lower down in post to here) I would listen for noise at the front drivers side of the engine - right behind the plastic timing belt cover under the A/C compressor. the tensioners can fail and slap around, making what is usually called a "knocking" sound so it doesn't sound immediately the same but those words aren't technical. they can only make noise under load sometimes. with the timing belt cover removed you can see the tensioner bouncing around, but you won't be able to see the tensioner/belt with the cover in place.

The noise seems to be coming from the driver's side of the engine, and only presents itself when under decent load (>50% throttle) AND between ~2,200 and 2,600 RPM. I have tried reving the engine by hand with the hood open and it does not happen when in neutral or with no load on the engine. What should I look for on the tensioner as far is wear is concerned?

Originally Posted by grossgary

check the engine block, fuel injectors valve train, timing covers, rear of the engine, etc.

Visually, everything appears in very good shape and is pretty clean for 140k. Small leak from the oil pan gasket, but that's easy to fix. So small right now that it doesn't appear wet and my oil level doesn't drop at all between changes, might wait a bit on it.

Originally Posted by cardoc

Can you record the noise and post it? It would help.

I'm afraid that at the moment all I have to record the noise would be my cell phone or my Canon T2i, neither of which have great audio that would be able to capture the noise over wind and engine noise . My brother and I do have a production company though, and when he's back from the Sundance Film Fesitval tomorrow or Tuesday I could possibly use his digital audio recorder taped to the inside of the engine bay with a wind sock and filter on it and try and get you some noise samples.

Thank you all for your feedback, very much appreciated

[cardoc]

Are you sure your getting proper fuel flow? Pinging under load indicates detonation which is lack of fuel for a burn and its exploding.

[bored155]

I am not sure I am getting proper fuel flow at all. Is that something I can easily measure?

[bored155]

Looked back at the first page- again, it's been awhile. If I can't find someone within driving distance with the right cable and software to read some data from my car's computer i'll buy the Tactrix Openport. What values or sensors would I be looking for readouts on?

[bored155]

From the NASIOC website I found this relating to my ScanGauge II:

SCANGAUGE ii - XGAUGE codes for Subaru Vehicles
====GAUGE============TXD=======RXF=====RXD======MA TH====NAME===UNITS=====
1. HorsePower - 00 - 400080000000 - 0000 – 000A00170000 - HPR - HP
2. TurboBoost in PSI - 686AF1010B - 0441850B0000 - 2808 - 00910064FF71 – BST - psi
3. TurboBoost in BAR - 686AF1010B - 0441850B0000 - 2808 - 000A0064FFF6 – BAR - bar
4. Manifold Air Flow g/s - 686AF10110 - 044145100000 - 2810 – 000100010000 – MAF - g/s
5. Open/Closed Loop - 686AF10103 - 044105038000 - 2808 - 000100010000 – OCL – hex*
*1:= Open, not yet warm 2:= Closed, normal 4:= Open, due to high load 8:= Open, system failure 10:= Closed, but something's wrong
6. Short Term Fuel Trim - C233F10106 - 04410506 - 2808 - 00C80100FF9C - SF1 - +/-0-99
7. Long Term Fuel Trim - C233F10107 - 04410507 - 2808 - 00C80100FF9C - LF1 - +/-0-99
8. 02 Sensor values - C233F10115 - 04410515 - 2808 - 000100020000 - O21 - 0to99
9. Air To Fuel Ratio 1 - C233F10124 - 04410524 - 2808 - 05B900800000 – AF1 - Ratio
10. Air To Fuel Ratio 2 - C233F10134 - 04410534 - 2808 - 05B900800000 – AF2 - Ratio
11. Lamda 1 - C233F10124 - 04410524 - 2808 - 006400800000 – LA1 – 0.8 – 1.2
12. Lamda 2 - C233F10134 - 04410534 - 2808 - 006400800000 – LA2 – 0.8 –1.2
13. Coolant Temp - 686AF10105 - 03104410505 - 2808 – 00090005FFD8 – FWT – oF


Fuel trim or air to fuel ratio? Which one would help more to figure out if i'm getting enough fuel?

[cardoc]

LTFT in the positive means the computer is trying to add fuel which means a lack of fuel delivery or there's a vacuum leak.

LTFT in the negative means the computer is reducing fuel because the engine is running rich due to bad plugs, wires or clogged injector that is streaming the fuel instead of spraying it.

Any LTFT value over 2.5 should be addressed. Especially on an H6 where the fuel trim values are spread out between the two sides.

In a H4 you only have one value for both banks so if the trim is pos, check the fuel delivery first then vacuum. On Turbos, you also have to check for any leaks in the intake system from the MAF to the throttle.

[Glennda5id]

I am not an expert with fuel trim data , but 2.5 seems a bit low to be considered running lean.

[cardoc]

LTFT over 2.5 is low, but an indication that something may be occurring to cause it. On H6s when the trim differs more the 2.5 side to side the engine is running uneven.

[bored155]

So after programming the LTFT gauge in, it did not work :-(. The values were for a forester, I was unable to find ones for the Outback. I see my IGN (Ingition Timing) going as high as 40 and staying there when I have my foot in it; is that normal? At idle it's around 15, casual driving it is between 20 and 30. Between the same RPM that I can hear the clatter (2300-2800), my engine feels like it's vibrating a bit more than at other RPMs. Can feel it shaking side to side. Normal?

Thanks!

[cardoc]

The timing will be anywhere from 10' to 60' depending on the engine load calculated by the ECM and signals from the knock sensor.

Looking back over the thread and course of events, just for giggles unhook the battery for a minute or so and hook it back up and see what happens. Leave the test plugs alone this time. The green ones.