bluebird Posted March 21, 2006 Share Posted March 21, 2006 Hello again, I have posted several messages in the last couple of days regarding the 1998 outback wagon I just bought. I have noticed that there is considerable valve noise when I first start the car in the morning. It settles down to the noraml subaru clicking level after it warms up. I know the valves are adjustable in this engine but assume if they were out of adjustment they would make noise all the time. Any ideas what is causing this and what I can to to correct it? Do you think an additve like Resiline(sp) might help? thanks in advance Frank Quote Link to comment Share on other sites More sharing options...
Gnuman Posted March 21, 2006 Share Posted March 21, 2006 Bluebird, that does not sound like normal behaviour for a valve tap, but it is notmal for piston slap, which is similar and very common on these cars. The noise is similar to a diesel engine, when the engine is cold, then goes away when warm. This is usually first noticed on cold winter mornings, fading away in the summer. Quote Link to comment Share on other sites More sharing options...
dxrflyboy Posted March 21, 2006 Share Posted March 21, 2006 You're probably hearing piston slap, if it quiets down after warmup. It's a common problem with all 2.5L Subaru engines. It isn't doing any serious damage and your car will still run for many miles with it. If you ever have to take your engine apart for another reason, such as head gaskets, you may want to consider installing some updated pistons (2 on the driver's side will eliminate the noise - the passenger side usually never makes noise). Subarus have good, hard iron cylinder liners, so cylinder and ring wear isn't a problem, but the pistons do scuff when they slap around in the bore. Quote Link to comment Share on other sites More sharing options...
a97obw Posted March 21, 2006 Share Posted March 21, 2006 I would guess that the "new and improved" countermeasure pistons that don't slap about when cold due to the short piston skirt design are ones that have a longer skirt. If that is the case, how can you possibly get away with only replacing one side of the engine with the new pistons? I should think the weight of the pistons would be waaaaaaaaaay different than the short skirt ones, and that can't be good! Quote Link to comment Share on other sites More sharing options...
Ranger83 Posted March 21, 2006 Share Posted March 21, 2006 Mileage? Temperature? Subarus are notoriously loud on cold start. It's an alloy block with a lot of steel components. check your oil level. If it's not low, try Castrol High Mileage on the next oil change. I found it to be much quieter on cold start. Quote Link to comment Share on other sites More sharing options...
bluebird Posted March 21, 2006 Author Share Posted March 21, 2006 Mileage? Temperature? Subarus are notoriously loud on cold start. It's an alloy block with a lot of steel components. check your oil level. If it's not low, try Castrol High Mileage on the next oil change. I found it to be much quieter on cold start. Yes sorry I should have given the mileage and temp. Car has 83,000 (one reason why I bought it) and even though it is suposed to be spring here is the Washington dc area it has been around freezing in the mornings I have started it so far. I guess I'm glad to hear it is piston slap in a way esp since yu guys think that isn't a problem. Is that Castrol high mileage referring the oil itself or an additve made by Castrol? I have two other subaru wagons 92 and 95 both have 2.2 and don't make as much noise on start up. I assume this is a 2.5 thing. Thnaks again for all the solid info. Frank Quote Link to comment Share on other sites More sharing options...
ctoth Posted March 21, 2006 Share Posted March 21, 2006 piston slap Quote Link to comment Share on other sites More sharing options...
nipper Posted March 21, 2006 Share Posted March 21, 2006 its a newer (after 95) sooby thing, mostly on the 2.5L . Its piston slap. As long as it goes away your fine. Its when it doesnt go away you have problems. nipper Quote Link to comment Share on other sites More sharing options...
dxrflyboy Posted March 22, 2006 Share Posted March 22, 2006 I would guess that the "new and improved" countermeasure pistons that don't slap about when cold due to the short piston skirt design are ones that have a longer skirt. If that is the case, how can you possibly get away with only replacing one side of the engine with the new pistons? I should think the weight of the pistons would be waaaaaaaaaay different than the short skirt ones, and that can't be good! The replacements are the same size and shape as the originals. They have a teflon coating on the thrust surfaces to prevent scuffing and slapping. Quote Link to comment Share on other sites More sharing options...
Ranger83 Posted March 22, 2006 Share Posted March 22, 2006 //Is that Castrol high mileage referring the oil itself or an additve made by Castrol? It's one of their oils. We had two 97 OBW's. One was much louder than the other on cold start, but they were both loud compared to inline fours. You should hear them below zero.... Quote Link to comment Share on other sites More sharing options...
Juan Posted March 22, 2006 Share Posted March 22, 2006 Don't worry about it. At 83,000 miles be more concerned with the ignition switch going out on you. Do you know which fuse to pull when you pull the key OUT of the ignition and the starter motor is still turning AND the engine is running? You should 'Chinese fire drill" this while you have time. It's coming. Juan. Quote Link to comment Share on other sites More sharing options...
nipper Posted March 22, 2006 Share Posted March 22, 2006 Don't worry about it. At 83,000 miles be more concerned with the ignition switch going out on you. Do you know which fuse to pull when you pull the key OUT of the ignition and the starter motor is still turning AND the engine is running? You should 'Chinese fire drill" this while you have time. It's coming. Juan. after owning 4 subarus all with high mileage at their demise, and from reading all the posts for the last few years, this is the first i've heard of this.... nipper Quote Link to comment Share on other sites More sharing options...
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