FLAcharlie Posted December 1, 2004 Share Posted December 1, 2004 My 97 OB 2.5L with 150,000 miles on it seems to have developed a knock over the last 20k miles or so. This specific symptom seems to only be evident starting around 80mph. I have tried switching from 87 to 89 gas and I believe this definitely helps. Some more background: This car is driven hard, due to a daily commute of 180miles. Half of the drive is around 65mph, the other half 75-80mph. It had the "major maint" service done on it about 30k miles ago (April '04). My question is two-fold: a) as far as I know this car has never had the "solid lifter maintenance" done on it. Is it too late to do that at 150k ? (maybe valves already damaged or something) Or is this still worth doing ? any tips on the engine knocking (and whether related to the solid lifter maint question) ? Other than the knocking, it runs great. I switched to Castrol high mileage oil about 4 oil changes ago (I do them myself every 3 weeks), and that helped A LOT. Must have cleaned out all kinds of crud or something, because it seems like it runs like it did a couple years ago. Also, I have had the K&N air filter in there for maybe 25k miles or so, I noticed a significant positive difference after putting it in. Quote Link to comment Share on other sites More sharing options...
Setright Posted December 1, 2004 Share Posted December 1, 2004 The solid lifters need adjustment every 62k miles. Basically the adjustment is to compensate for wear and the result of neglect is that the valves open less, and rob some of your power. It will have a profound influence on the engines smoothness, but I am not certain that it would lead to a knock. A solid lifter with a large gap usually makes a tick sound. Quote Link to comment Share on other sites More sharing options...
FLAcharlie Posted December 1, 2004 Author Share Posted December 1, 2004 This is the solid lifter maintenance that lots of dealers who don't have the special tool don't want to do, and claim they have to pull the engine to do it, the maint that should normally run around $400 or so including new valve cover gaskets. Every 62k ? I thought I saw where it was recommended at 105k. The solid lifters need adjustment every 62k miles. Basically the adjustment is to compensate for wear and the result of neglect is that the valves open less, and rob some of your power. It will have a profound influence on the engines smoothness, but I am not certain that it would lead to a knock. A solid lifter with a large gap usually makes a tick sound. Quote Link to comment Share on other sites More sharing options...
99obw Posted December 1, 2004 Share Posted December 1, 2004 Yes, it's 105k in the US for the EJ25. I would have it done if you plan on keeping the car. I did this myself at 120k or so and they weren't that bad yet, so I would think you are probably still safe. Do you mean a knock as in bearing knock or knock as in preignition or pinging? If you are experiencing pinging I recommend seafoam then a regimen of Fuel Power. Quote Link to comment Share on other sites More sharing options...
FLAcharlie Posted December 1, 2004 Author Share Posted December 1, 2004 > Do you mean a knock as in bearing knock or knock as in preignition or pinging? Gee, I dunno how to tell the diff. I had rather expected the noise was valve-related, hence my interest in the solid lifter maint issue, but then it occured to me to try some 89 gas to see if it made a difference, and I believe it does, so that means a knock issue it would seem. It's definitely not there in lower speeds. In fact, say I'm going 78mph and I notice the noise, if I slow up just a tad (say to 76) it will go away. If I then speed up the noise will likely return, and it stays there until I slow down. But I havent noticed it with the 89 gas. Yes, it's 105k in the US for the EJ25. I would have it done if you plan on keeping the car. I did this myself at 120k or so and they weren't that bad yet, so I would think you are probably still safe. Do you mean a knock as in bearing knock or knock as in preignition or pinging? If you are experiencing pinging I recommend seafoam then a regimen of Fuel Power. Quote Link to comment Share on other sites More sharing options...
cookie Posted December 1, 2004 Share Posted December 1, 2004 If it only occurs under load and higher octane cures it. I agree with the above that these cars carbon up and the Seafoam may help. As an engine wears oil gets past the rings too which also causes pinging. In the old days we just retarded the timeing, but you can't really do that now. Quote Link to comment Share on other sites More sharing options...
DerFahrer Posted December 2, 2004 Share Posted December 2, 2004 Hey, good to see another FLdian on here I'm going to say something weird and say it's not related to the engine at all... Pinging/detonation only occurs under load, whether it's at 20mph or 80mph. Bearing knock can happen anytime you punch the gas real quick, and Subarus rarely have bottom-end problems anyway. I'm going to say it's your speedometer cable. The situation you've described sounds exactly like an issue that Myxalplyx had on the XT6 boards, and there were many suggestions of a speedo cable... Only started around 80mph and stayed as long as he was going that speed. Quote Link to comment Share on other sites More sharing options...
FLAcharlie Posted December 2, 2004 Author Share Posted December 2, 2004 Interesting idea, I'll bear that in mind. Unfortunately, while it does seem it is running better on 89 gas, this morning I did hear the noise again, so the 89 gas did NOT make it go away, so maybe it is bearing knock and not preignition knock. I spent some time searching the board, and I guess now my concern would be the oil pump. Since the noise seems to start when I am "pushing" it (like 80mph), perhaps the oil pressure is low at that point. At 150k miles and with pretty hard driving I wouldn't be surprised to need a new oil pump. Hey, good to see another FLdian on here I'm going to say something weird and say it's not related to the engine at all... Pinging/detonation only occurs under load, whether it's at 20mph or 80mph. Bearing knock can happen anytime you punch the gas real quick, and Subarus rarely have bottom-end problems anyway. I'm going to say it's your speedometer cable. The situation you've described sounds exactly like an issue that Myxalplyx had on the XT6 boards, and there were many suggestions of a speedo cable... Only started around 80mph and stayed as long as he was going that speed. Quote Link to comment Share on other sites More sharing options...
PAezb Posted December 2, 2004 Share Posted December 2, 2004 Interesting idea, I'll bear that in mind. Unfortunately, while it does seem it is running better on 89 gas, this morning I did hear the noise again, so the 89 gas did NOT make it go away, so maybe it is bearing knock and not preignition knock. I spent some time searching the board, and I guess now my concern would be the oil pump. Since the noise seems to start when I am "pushing" it (like 80mph), perhaps the oil pressure is low at that point. At 150k miles and with pretty hard driving I wouldn't be surprised to need a new oil pump. Any chance that what you are hearing might be a noisy hydraulic tensioner for the timing belt? Quote Link to comment Share on other sites More sharing options...
FLAcharlie Posted December 2, 2004 Author Share Posted December 2, 2004 hmmm. I know nothing about such a beast, can you tell me more ? likelihood of complete failure ? or just noisy ? is the timing belt at risk ? if it is that, how much of a job to deal with it ? thanx ! Any chance that what you are hearing might be a noisy hydraulic tensioner for the timing belt? Quote Link to comment Share on other sites More sharing options...
99obw Posted December 2, 2004 Share Posted December 2, 2004 I would rule out carbon deposits first before looking at more expensive causes. A tank of 93 octane and some Techron might be a good start. Quote Link to comment Share on other sites More sharing options...
PAezb Posted December 2, 2004 Share Posted December 2, 2004 hmmm. I know nothing about such a beast, can you tell me more ? likelihood of complete failure ? or just noisy ? is the timing belt at risk ? if it is that, how much of a job to deal with it ? thanx !If you search the forums here for "tensioner" "noise" you'll find lots of discussions from members attempting to diagnose various engines noises from what *might* be mistaken for "valve chatter", "piston slap", "bearing failure" etc. I had spoken to a service manager at a local dealership some time ago about subie owners complaining of various engine noises (referencing my own concerns on my 96 OBW), he stated that the tensioner can often be the culprit of "knocking" or "tapping" coming from the engine, but not always necessarily in need of servicing. I'm not saying that the sounds you're hearing is the tensioner, especially since it seems to appear under load - but it may be something to keep in mind and be aware of. Certainly try some of the easier suggestions first that have been posted earlier in this thread. http://endwrench.com/images/pdfs/EngineNoiseInfo.pdf http://www.ultimatesubaru.org/forum/showthread.php?t=9136&highlight=tensioner+noise The quote below taken from the above link: * inspect the timing belt tensioner, the vibration can cause these to fail, look for signs of an oil leak from the hydraulic cylinder and signs that the hydraulic spring is weak. If the tensioner has failed the timing belt will be loose and most of the time you will get a tapping sound that sounds like piston slap or valve clatter. Eventually the timing belt will slip and you could end up with a catostrophic engine failure. Quote Link to comment Share on other sites More sharing options...
FLAcharlie Posted December 2, 2004 Author Share Posted December 2, 2004 Thanks for this very useful info, gives me some things to check. However at low speeds ( < 76mph ) I don't detect this noise at all. I also don't detect any oil leaks anywhere. It hasn't been in the shop in 30k miles though, and is otherwise in fine shape, so I guess I will take it in to the dealer here for their opinion. By the way, I've tried two dealers down here, one in Jacksonville, which I like very much and another in Gainesville. That one is also a Dodge dealer, and while I have nothing against Dodges, I would prefer to go with one that specializes in Subarus. When I tell people about why I like Subarus, it usually includes a testimonial of how much I have liked the Subaru dealers over the years. My daughter is still driving my '90 Legacy wagon with 240k on it BTW. Thanks again ! If you search the forums here for "tensioner" "noise" you'll find lots of discussions from members attempting to diagnose various engines noises from what might be thought of as "valve chatter", "piston slap", "bearing failure" etc. I had spoken to a service manager at a local dealership some time ago about subie owners complaining of various engine noises (referencing my own concerns on my 96 OBW), he stated that the tensioner can often be the culprit of "knocking" or "tapping" coming from the engine, but not always necessarily in need of servicing. I'm not saying that the sounds you're hearing is the tensioner, especially since it seems to appear under load - but it may be something to keep in mind and be aware of. http://endwrench.com/images/pdfs/EngineNoiseInfo.pdf http://www.ultimatesubaru.org/forum/showthread.php?t=9136&highlight=tensioner+noise The quote below taken from the above link: * inspect the timing belt tensioner, the vibration can cause these to fail, look for signs of an oil leak from the hydraulic cylinder and signs that the hydraulic spring is weak. If the tensioner has failed the timing belt will be loose and most of the time you will get a tapping sound that sounds like piston slap or valve clatter. Eventually the timing belt will slip and you could end up with a catostrophic engine failure. Quote Link to comment Share on other sites More sharing options...
cookie Posted December 2, 2004 Share Posted December 2, 2004 all the usual noises and can help you pin it down. The internet often fails us even on easy noises. I recall driving around with a customer after hearing the description of a noise. From their report I would have formed one impression and after the test drive I would have another. Quote Link to comment Share on other sites More sharing options...
DerFahrer Posted December 3, 2004 Share Posted December 3, 2004 FLAcharlie, right click and save as on this video (you need Quicktime to play it) and tell me if this noise is similar to what you're experiencing: http://mywebpages.comcast.net/thomasck/XT6-Pinging.MOV Quote Link to comment Share on other sites More sharing options...
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