ckwaters Posted August 30, 2019 Share Posted August 30, 2019 I've had my 2008 Outback 3.0R for over a year and it makes some really ugly sounds at low RPMs. I thought it was the heat shields and tried every fix known to man until I finally removed them completely. And I still have the nasty rattle. Anything else near the front of the car that would sound exactly like a heat shield? I have a theory that maybe it's inside the headers or catalytic converter since those parts are layers of metal. Maybe those layers are rattling together? Link to comment Share on other sites More sharing options...
Catharsis Posted August 30, 2019 Share Posted August 30, 2019 Does it happen at all rpms, low rpms, when stopping or when stopped? In park? In drive? Is it definitely a rattle or could it be mistaken for a grinding at some rpms? Sent from my ONEPLUS A6003 using Tapatalk Link to comment Share on other sites More sharing options...
ckwaters Posted August 30, 2019 Author Share Posted August 30, 2019 At low RPMs, a range possibly from 500-1500 and only in gear. Never got it to happen when parked so I can't diagnose it easily. Link to comment Share on other sites More sharing options...
weswing04 Posted August 30, 2019 Share Posted August 30, 2019 One of my cats came apart internally and sounded like a loose bolt rattling inside the pipe. But it started as a heat shield rattle sound Link to comment Share on other sites More sharing options...
Catharsis Posted August 30, 2019 Share Posted August 30, 2019 At low RPMs, a range possibly from 500-1500 and only in gear. Never got it to happen when parked so I can't diagnose it easily.Sounds kinda like the noise I've been having then. I haven't been able to identify it yet either. Sent from my ONEPLUS A6003 using Tapatalk Link to comment Share on other sites More sharing options...
ckwaters Posted August 30, 2019 Author Share Posted August 30, 2019 I also suspect the internals of the catalytic converter or the headers. I saw this picture of a cutaway of the 3.0R headers and it looks like a horrible design. I can't wait to get some Raptor headers. Then I'll most likely get a couple of aftermarket catalytic converters. Something that flows a little better but cleans enough so I don't get any CEL codes. Link to comment Share on other sites More sharing options...
weswing04 Posted August 30, 2019 Share Posted August 30, 2019 Yup headers really wake up those motors Link to comment Share on other sites More sharing options...
Kozy Posted March 11, 2020 Share Posted March 11, 2020 Mine is making a similar kind of noise, around 1500rpm there is an audible rattle inside the car that sounds like it is coming from the header area. It’s there in neutral as well as on the move, might be there at higher rpm/speed but not possible to hear over road noise. Raptor headers are on the shopping list anyway, will have to move them up the priority list and hope that will fix it! Link to comment Share on other sites More sharing options...
ckwaters Posted March 12, 2020 Author Share Posted March 12, 2020 As an update to that, I got my Raptor headers installed a couple weeks ago and I still have that sound, only louder now. I get a loud rasp at about 3,500rpm. Not sure if it's normal but I don't think it is. I did my first Romraider log last night and see a lot of knock. I need to learn more about Romraider so I can pull some useful data with it and understand what it means. Surprising how much louder the exhaust is with the Raptor headers. Link to comment Share on other sites More sharing options...
Kozy Posted March 13, 2020 Share Posted March 13, 2020 That’s disappointing. I take it the raptors replaced all three of the cats? As a side note, if you’ve got them off the car, any chance you could have a look at the manufacturer and code stamps on them? Link to comment Share on other sites More sharing options...
Richard_Mtl Posted March 13, 2020 Share Posted March 13, 2020 Just a thought, but I had a similar problem and finally tracked it down to a rusted out disc brake dust shield on front driver's side. It would resonate at certain RPMs. Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 14, 2020 Share Posted March 14, 2020 Sounds like spark knock. How do the spark plugs look? Link to comment Share on other sites More sharing options...
ckwaters Posted March 14, 2020 Author Share Posted March 14, 2020 That’s disappointing. I take it the raptors replaced all three of the cats? As a side note, if you’ve got them off the car, any chance you could have a look at the manufacturer and code stamps on them? I replaced the 2 front cats with some 400 cell cats from Amazon and the Y-adapter is a Magnaflow. I'll have to get some pictures under the car and maybe take a video of the sound. Manufacturer and code stamps on the stock exhaust? I'll take a look tomorrow I guess. Just a thought, but I had a similar problem and finally tracked it down to a rusted out disc brake dust shield on front driver's side. It would resonate at certain RPMs. I thought of this too actually and bent them a little to make sure they're not contacting anything. Because it actually sounded a lot like that before the exhaust upgrade. The sound now is kinda hard to explain. I'll try to upload something later. Sounds like spark knock. How do the spark plugs look? Spark plugs were replaced a year ago with OEM plugs. I did it myself and the gap was already good straight from the box. Still the original coils. The car has about 130,000 miles on it. Link to comment Share on other sites More sharing options...
ckwaters Posted March 14, 2020 Author Share Posted March 14, 2020 I just uploaded some videos I took a few days ago to record the sound. Mostly around 3,500rpm but in the 2nd video I revved higher and the sound seems to persist all the way up the rpm range above 3,500. Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 14, 2020 Share Posted March 14, 2020 I'd have a shop put it in the air and have someone power brake it or run it up to speed. Check the simple things first like an exhaust leak or bad baffles in the muffler. If the whole exhaust checks out, I'm sticking with spark knock. Do you have an accessport or any way of monitoring knock and fuel trims? Link to comment Share on other sites More sharing options...
ckwaters Posted March 15, 2020 Author Share Posted March 15, 2020 I'd have a shop put it in the air and have someone power brake it or run it up to speed. Check the simple things first like an exhaust leak or bad baffles in the muffler. If the whole exhaust checks out, I'm sticking with spark knock. Do you have an accessport or any way of monitoring knock and fuel trims? I had the car up on a lift a lot while building the exhaust. I actually brought it to a DIY shop on a military base with lift bays and did all the fabbing myself except the welding which they did for me. Exhaust is all good. I have an OpenPort 2.0 and RomRaider. I'm new to it and don't know a whole lot about what parameters to log. Can you recommend what to monitor? I logged about a 5 minute ride around the block including a couple of hard accelerations. The parameters I logged were Roughness Monitor (all 6 cylinders), Mass Airflow, Manifold Absolute Pressure, Learned Ignition Timing, Knock Correction Advance, Front O2 Sensor (both). In the short time I was logging the "Roughness Monitor" logged 20 instances in cylinder #2, 37 in cylinder #3 and 310 in cylinder #4. So does that mean misfires or knocks or what? Doesn't sound good but I don't know how bad it is or what it means yet. Link to comment Share on other sites More sharing options...
08SpecB_DE Posted March 16, 2020 Share Posted March 16, 2020 The misfires are going to be the cause. The pinging comes from uneven burning of the fuel. I'd start with swapping number 4 coil with number 1 and see if the misfire follows. It may be a good idea to pull all the plugs again and check their condition. Raw gas on a plug would mean that coil is not firing properly. Link to comment Share on other sites More sharing options...
Kozy Posted March 16, 2020 Share Posted March 16, 2020 Mine is 100% heat shield rattle, it was doing it this morning on cold start and since it was dry for once, I took the opportunity to lay down and touch the cat heat shield. It is a definitely loose and rattling at certain RPM. Sounds like I need some Raptors! Link to comment Share on other sites More sharing options...
ckwaters Posted March 17, 2020 Author Share Posted March 17, 2020 The misfires are going to be the cause. The pinging comes from uneven burning of the fuel. I'd start with swapping number 4 coil with number 1 and see if the misfire follows. It may be a good idea to pull all the plugs again and check their condition. Raw gas on a plug would mean that coil is not firing properly. I have a feeling you've been right all along. And my car has probably been like this since I bought it. I average 18.1MPG and I've owned a 2005 H6 before that felt faster than this 2008. I'll be swapping the coils like you suggest in the next couple of days. I'll do another Romraider log before and one after and see if that confirms it. Thanks for the continued help! Mine is 100% heat shield rattle, it was doing it this morning on cold start and since it was dry for once, I took the opportunity to lay down and touch the cat heat shield. It is a definitely loose and rattling at certain RPM. Sounds like I need some Raptors! Definitely Raptors is the recommended cure for that. Hahaha. Sounds like a married man's excuse to his wife. Honey I need these because umm, safety and economy and stuff. Very practical. My wife is not happy with how much I've spent on this car. Link to comment Share on other sites More sharing options...
ckwaters Posted March 17, 2020 Author Share Posted March 17, 2020 As promised here are some pictures of the exhaust I made out of stainless steel mandrel bends. I did the planning, cutting and fitting and a guy that works at this shop did the welding. I didn't take many pictures while I was working on it because I could only get to this place one day a week and had to work quickly to get done before they closed. Link to comment Share on other sites More sharing options...
ckwaters Posted March 18, 2020 Author Share Posted March 18, 2020 Yesterday I jiggled the ingnition coil on the #4 cylinder just to see if it might make it have a better electrical connection. And today I was planning to log some cylinder roughness before swapping the ignition coils. But all of my logs had no roughness! I guess the connector just needed a better contact. So I logged 3 short runs with low, medium and full throttle through basically 1-3 gears. Looks normal I guess. There is some knock correction and fine knock learning but I don't know what that stuff means yet.light throttle.csvmedium throttle.csvfull throttle.csv Link to comment Share on other sites More sharing options...
ckwaters Posted March 18, 2020 Author Share Posted March 18, 2020 And just for fun I ran a dyno. The closest car I could find was an ASDM Liberty 3.0R 5AT. I manually entered tire size and weight of the car per Google search. The option by default is set to 3rd gear. By the time I was near 6500rpm in 3rd gear I was going way too fast for public roads so I had to back off before the dyno completed. But here it is. Does this look right? Not a smooth slope like you usually see in dynos. Link to comment Share on other sites More sharing options...
ckwaters Posted April 1, 2020 Author Share Posted April 1, 2020 Well, the knock returned. I took the spark plug out and it looks normal. I used a borescope to look inside my #4 cylinder that has knock. Does this look normal? I decided that I want to clean the fuel injectors while I have a few things taken apart. Link to comment Share on other sites More sharing options...
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