97 Subaru Legacy Engine Knock

[Guest EQUALIZERplus]

Old Glory,

 

I have the same problem with my 97 Leg OB. Its disturbing when its cold, but quiets down after warm up. BTW, the mileage is a bit higher at 137K mi. I'd like to go at least 400k, but have some doubts if this is causing wear and tear. Don't like the prospect of going to a heavy oil additive.

 

eq

[Guest Dickens]

Hm, looks like I didn't attract the attention of the people I was trying to reach. Hopefully the CCR people will reappear soon ...

 

My last (long) post is the most current info that I could find. Most of it is documented in the outback list archives. I don't think there's any paperwork from SOA floating around other than the "engine noise is normal" paper that some people receive when they initially complain about it.

 

I still need to know if the engine experts consider this problem harmful. If it is then I'll fight to get it fixed. If it's just noise then I'll let it be. Annoying, yes, but if not harmful, I'm not spending the time & money to get the engine rebuilt to fix it.

 

(Data point: my rear main seal was replaced at first service.)

[Guest monovich]

If you find anything out, I'd love to know. I absolutly HATE "the sound". It's a serious strike against the percieved quality of the engine, regardless of wether or not it's detrimental. I shouldn't have to listen to engine clicks in my cabin with a car that is only 2-3 years old.

[Guest SmashPDX]

Ditto that, interested in hearing from the engine experts here too.

[Guest ccrinc]

Sorry guys: been really busy lately and when I tried to answer a couple of nights ago, my answer disappeared into thin air! (arrggh!) So, sitting here in greasy sweatshirt...

1) Both the 2.2 and the 2.5 have the problem with the screws backing off from the back plate.

2) Piston slap/wrist pin noise is not usually detrimental. Will it shorten engine life? Oh, maybe from 200K to 175K. It's mostly just damn annoying!

3) There are no replacement pistons that I know of. SOA gets a factory shortblock, puts your heads and everything else on it (then sells us the shortblock, cheap, to rebuild! teehee)

4) If damage is going to occur from the oil pump problem, it could be immediate or over 100K miles: there's no pattern.

5) Best thing to do is put a manual oil pressure gauge on and see what the pressure really is.

If your noise doesn't disappear when the engine warms up, I would think there is a collateral problem. Bitch, bitch, bitch! To your dealer that is. Keep it up until they do something.

Hope this helps: let me know if you have other questions.

 

Emily

www.ccrengines.com

[Guest AWD Fan]

In regards to piston slap, there are replacement pistons made by SOA to fix the problem. I know because I had them installed on my 98 Forester(same engine as the OBs)

 

On cold startups, I would get a distinct metallic knock that was different from the solid lifter noise. To make a long story short, I complained and complained and finally met with the district technical manager. He offered replacing my pistons with "countermeasure" pistons. He even showed me a memo written by SOA explaining that the slap is a result of the skirtless pistons and will not harm the engine. The memo goes on about if the customer complains enough, then use these countermeasure pistons.

 

I didn't get to see how the pistons were different but the fix completely got rid of my piston slap. That was 30K miles ago and my engine is running as smoothly as ever.

[Guest Dickens]

Really! What did you have to do to get that fix? Also, where are you at? Can you provide documentation?

 

I thought someone had mentioned new pistons a long time ago, but the messages fell off the board (wish we used a board system that had infinite archives!)

 

I will have a webpage up this week on the sube engine noises/problems with an email address for submissions.

[Guest AWD Fan]

I had my repair done at Carlsen Subaru in Redwood City, CA.

 

The entire process took A LOT of time and patience. I first took my Forester in to Stevens Creek Subaru but they blew me off telling me that I was hearing normal lifter noise. Unconvinced, I took it into Carlsen Subaru. Bingo -- the mechanic heard the slap, wrote it up as abnormal and scheduled me for a short block swap.

 

I brought my Forester in a couple weeks later on my scheduled date. Two days later I get a call from the Serivce Rep that they want to consult with SOA before going forward with the swap. Apparently, the mechanic spoke with the district technical manager (DTM) about my case and he was asked not to do the swap until the manager could take a look at it himself. I was fairly pissed at this point since I was out of my vehicle for two days without anything being done to it.

 

A month later, I finally get to meet with the DTM. During this time, I had to keep calling and bugging the dealer to arrange an appointment. The DTM was apparently working on some "emergency" cases up in Alaska and wasn't available (I suspect that this was the master brake cylinder case, but I digress). I even called SOA to get a case # assigned. Anyway, the DTM spends five minutes revving the engine and listening and says "yep, you've got piston slap". He goes on explaining that the noise is caused by the shortened piston skirts on the 97-98 DOHC engines but that the noise is not harmful. He also pointed out that the short block swaps were unsuccessful since they didn't fix the source of the problem. Finally, he offers me a fix using these "countermeasure" pistons. According to the DTM, these pistons are machined to tighter tolerances to fix the slap. He added that the fix is only offered in severe cases or when the customer complains A LOT (like me).

 

It took another month afterwards to finally get the parts and complete the repair. It was a long, drawn out process, but well worth it to me. I can now drive my vehicle in the mornings without that awful slap.

 

Let me know if you need any more info. I might have the repair order somewhere.

[Guest Dickens]

Great! I've heard of the countermeasure pistons before, so maybe my memory isn't that bad. That'll go onto the site. I really wish I had that original email ...

 

Nice to hear Carlsen was on top of it. I generally like them, being a dedicated Sube dealer. Their service staff is friendly and knowledgable.

 

Thanks very much for your detailed report!

[Guest AWD Fan]

FYI the part numbers for the pistons were:

 

12006AB410

12006AB420

 

There are two types of pistons in our engines. An "A" type and "B" type. Depending on the engine, there can be all four "A"s, "B"s or a split of each.

 

You can see this by looking straight down on the block towards the front end by the passenger side headlight, I believe.

 

Good luck!

[Guest Dickens]

So there is! Actually, it's a sticker on the fuel line, with a big 'L' or 'R' indicating the side of the engine. The first line must be the piston part number/spec.

 

R has last four digits 420 and left has 377. I wonder if this is the weight of the piston... and peculiarly, the left side has the noise the worst. Curiouser and curiouser!

[eubulus]

Hello all!

 

I know posts about this probably exist but I've looked through the

threads and couldn't find one.

 

I have a 97 Legacy (about 47000 miles), well-maintained (by me and

dealer)

 

My problem is this:

 

When I start the car in the morning, I can hear a noticable knocking

sound coming from the engine.

 

This knocking continues (and as the engine warms up, turns into a

clicking, lite knocking sound inside of the passenger compartment).

 

I haven't tried my dealer again with this complaint, but about a year

ago I had it in to have it checked for this knocking sound and they

said they couldn't hear anything abnormal, only that Subaru engines

are noisy (which they are).

 

What could be the problem? And my other question is: What can I

say to the dealer to help them diagnose this problem? Does anyone

have a tech service bulletin that I can present to the dealership to

at least get them to acknowledge the problem?

 

And my final question (Sorry I know I'm rambling hehehe ) is this, if the dealer won't

do anything for me, will I still get the normal amount of life from this

car? (I love it, and my next car will be a Sube)

 

Thanks for help!

 

Chris

I just bought a 97 outback and it has the same noise I also have a toyota with the same noise when it is cold. Checking with a stethiscope the only noise I could find is the fuel injectors clicking. the toyota has 300k on it and it has had the noise since it was new.

[cookie]

they are usually aware of what Subaru is doing.

[swordsmanrex]

I have the same knocks at cold start but it "seems" to disappear after several minutes of driving.

 

Someone mentioned that it reduces engine life from 200k to 175K. What exactly happens when it reaches the end? A blown HG, or what?

[cookie]

and lose compresion a bit faster. Nothing catestrophic. We just have the equivalent of rebuiling a bit worn engine with loose piston skirts. I don't care for my slap on start up but it is so minor here in CA that I don't notice it anymore except when I am in or parking building with the windows down.

[tbdwcs]

Hi, The lifters in the 97 subaru were made smaller and the knocking ticking noise you here is a result of the latter. If you notice the noise is less noticable after the car has heated up due to expansion. Subaru fixed this problem in 98, why they made them smaller is a mysery. The knocking drove me nuts, no one could give me an answer. I brought this to my dealers attention and they replaced the small block for free which of course did nothing for the noise. I have grown accustomed to turning the radio up louder!

[The Dude]

I've been reading the Subaru boards for the last five years, I own a '99 Forester. I'll tell you this, it is extremely unlikely that Subaru is going to do any warranty repairs on noisey 2.5L DOHC engines. If the engine actually stops running during the warranty period Subaru will most likely cover it. Other than that, FORGET ABOUT IT. IT AIN'T GOING TO HAPPEN. The only 2.5L DOHC owners that got replacement short blocks, and there weren't many, were NEW car buyers who screamed really, really loud, and had the AGGRESSIVE support of the selling dealership.

Subaru will cover the 2.5L DOHC for the warranty period, but that is it, period.

These 2.5L DOHC powerplants are not good engines. There are very good reasons that Subaru developed the 2.5L SOHC engine.

It would appear that Subaru has decided to cut their losses with the 2.5L DOHC. They will cover their warranty obligations, but don't expect any post warranty "good will".

And in a way, Subaru is right. Four or five years from now, for most people the 2.5 L DOHC will just be a distant memory. No one will really care. In five years Subaru buyers will only care about the CURRENT engines and models. BTW, the 2.5 SOHC engine STILL has piston slap.