1997 2.5L DOHC Engine, Head Gasket & Bearing Failure

[Guest Commuter]

Just to forewarn you, this tale is rather long.

 

I have a 1997 Legacy Outback with the (infamous) 2.5L DOHC engine. My troubles began back in late March of this year. At the time, I had 258,000 km (160,000 miles) on the car, mostly highway driving. (I'm second owner of the car, having bought it when it was 2 years old, 66,000 km.) I “commute” 60,000 km a year.

 

I was checking fluids under the hood one weekend. I glanced at the coolant expansion bottle, but could not see the level from the outside, so I popped the cap. I don’t usually pay too much attention to the coolant since it never seems to change. You can imagine my surprise when I looked inside and found a thick black “gunk” coating the inside and sitting on top of the coolant. I stuck a screwdriver down in and it came out coated with the stuff. There seemed to be quite a scum there.

 

I immediately began thinking the worse. It certainly looked like oil. I looked at my engine dipstick again, but it looked fine and the level was not down any more than usual. I took the cap off the radiator and observed some of the same black gunk in there as well. I spent the rest of the day reading up online (i-club mainly) about head gasket failures. It sure seemed like a classic symptom. An interesting note is that I never once saw the temperature gauge move from its normal position. And believe me, with all the discussion of head gasket failures on this board at the time, I had been watching it pretty closely.

 

I called my dealer and a couple others the next day. The consensus seemed to be the head gaskets. I decided to start up the car to see what would happen. I had no idea how long the problem had been going on. There were no other signs. The car was running fine, no drips, no smoke out the exhaust, no overheating, etc. It had just been serviced about 6 weeks prior at the dealer and I probably hadn’t looked at the coolant in that time either. The car warmed up. The level in the expansion bottle raised some. Once fully warmed up, some bubbles started to come up through the coolant. To me, that pretty much confirmed the head gasket suspicion. I drove it to my dealer (highway driving), stopping a couple of times along the way. The expansion tank was filled almost to the top and bubbled, but did not overflow. The temperature gauge never moved off its normal spot. The service manager quoted me on a head gasket job. Sigh.

 

While I was at the dealer, I found out that they’d been seeing a rash of vehicles with head gasket problems. The one service writer was on the phone with a customer traveling in the States (I'm in Canada) who kept having overheating problems. They told me that they’d only done one or two head gasket jobs over the prior calendar year, but in the past couple of months they’d been doing about two per week! Most of these were on the Phase I 2.5L DOHC engines, but some were on the Phase II 2.5L SOHC engines. With the SOHC engines, they said it was usually leaks (dripping). Interesting.

 

I could not get the car in for several days. I hunted around for some used engines, contemplated putting a SOHC engine in, etc. The latter can be done (and has been done), but it has some challenges. I finally just decided to have the head gaskets done and leave it at that.

 

The dealer was kind enough to provide me with a loaner car. They were backed up and didn’t get started on it for a couple of days. (I didn’t care how long they took as long as they provided a free loaner.) Then it took a few days to tear down, machine the heads, do a complete valve job, etc. A leak (which turned out to be the valve cover gasket) added another day. So in all, about 10 days later, I picked up my car.

 

With all the discussion I’ve seen on head gasket failures with this particular Subaru engine, I wasn’t too surprised to be honest. Given the age and mileage on my car and the highway driving, I was hoping that if it was going to happen, that it would have already happened and that I was “passed” the likelihood of it occurring. No such luck. Oh well.

 

Now for part 2 of my story – the horror part.

 

I started up the car, got out and swapped some stuff from the loaner to my car. The engine sounded loud to me, but I dismissed it. I’d been driving a car with a quieter SOHC engine for nearly 2 weeks. I don’t usually hear my engine from outside the car when I start up, so I figured I was just being paranoid. By the time I got back in the car a few minutes later, it was already sounding much quieter. Just warming up I figured.

 

I drove in to work, about 100 km. The car seemed fine. I was hoping that the valve job might result in a little more zip (as one co-worker suggested), but no. At the end of the day, I drove back home. I was nearly home when I detected a little noise. It sounded like an exhaust leak at first, like a 'puffing' sound. A couple of minutes later, it was louder and was definitely responding to modulation of the gas pedal. A couple of minutes later, it was getting louder still. I was about 15 minutes from home or 15 minutes from the dealer (who I knew was still open as it was their “late” night). I decided to turn around. On the ramps, the engine was very rattlely sounding. The sound had definitely taken on a metallic tone. My heart was sinking. I kept going. A few minutes later, I pulled over. The engine was just hammering. I got out and popped the hood. It sounded awful. I shut off the engine and walked up to the corner to call the dealer. They sent out a tow truck. When I did get home, it was with a loaner car again.

 

The bottom end had failed somewhere. Of course, the speculation started. The bottom end hadn’t been touched during the head gasket job. Did something happen during repairs? Had there been coolant leaking into the oil? (This can apparently pit the bearings.) Was it my long life SynLube oil? (More on that later.) The dealer put in a new short block. They treated me really really well. I have no complaints with them. I’m in their debt. They split the old block. No. 3 con-rod (crank end) had failed. The bearing was almost gone. They said that the rest of the bearings looked to be in good shape. Main bearings were not pitted. Cylinder walls looked good, still had the cross hatched honing marks on them. There was no evidence of blockage of an oil passage.

 

This still left the question as to whether this was a gradual failure and just pure coincidence with the head gaskets, or whether it was a catastrophic failure. The dealer did not like the amount of sludge in the engine. I didn’t either, but the passageways were clean, cylinder walls looked good, etc. I have no idea what oil was used the first 2 years of the cars life (and apparently Subaru dealers in Canada were mostly using Quaker State back then). I had used Castrol Syntec before the SynLube. I did use Slick 50 a couple of times and some TuffOil (probably not the smartest thing). I was attempting to ‘quiet’ the engine, as I always found it to be a little noisier than I liked. The SynLube had only been in the engine for 70,000 km (and the graphite in the SynLube gave the sludge a very black look). So while I would have preferred to see a nice clean engine, I wasn’t taken aback at some sludge on the inside of the valve covers, or in a pocket back at the bell housing.

 

The dealer had flushed the engine twice with dino oil during the head gasket repair. They then put in the Mobil 1 that I’d provided. Mobil 1 was in the engine when the bottom end went.

 

I’ll try to cut the rest short. I attempted to do what ‘backward’ detective work that I could. I’ve been using magnets on the oil filters for a while now. The amount of material collected had reduced when I put the SynLube in, however, I found out in retrospect that the amount was ‘more than normal”. I didn’t know, I had nothing to judge it by. I cut open the filter that came off the car when the head gasket work was done. I found a “lot” of material collected, and there appeared to be larger sliver like ‘bits’ of metal. I got to thinking as well on some other points. My gas mileage had slipped a little over the past several months, perhaps 1 or 2 mpg. Not enough to be really sure, but enough to notice. A couple of times I had wondered if the engine was getting noisier. Again, hard to know. I attributed it the fact that we were just coming out of the colder winter months when one could expect more cold start up noise. I had thought a couple of times that I’d lost just a hint of zip on the car. That may have been true once the exhaust gases started pushing through into the coolant. I found it curious that it was number 3 cylinder that failed. That was always the side of the engine that made the “piston slap” noise. A noise that I’d complained about shortly after I got the car. (I was handed the “Shop Talk” notice about piston slap, nothing to worry about, etc at the time.) In hindsight, I have to wonder if it was con-rod noise all along. None of this is conclusive, but they all pointed in the same direction.

 

The final piece of the puzzle was to have the oil and anti-freeze analyzed. Somewhat to my surprise, I was informed that both were in great shape! There apparently was not enough oil in the anti-freeze for it to be “absorbed”. I can buy this. My oil consumption hadn’t changed. The oil showed no sign of anti-freeze contamination. It didn’t show any undo sign of (non-metallic) metal either. I still can’t quite figure that one out. The oil was probably sitting for some time before draining or pouring back into jugs. Perhaps it settled. (Recall, this oil came out ‘before’ the bottom end failure.)

 

I’m about 90% convinced that it was a long term failure. That bearing may have been fated from day one. I honestly believe that the SynLube probably extended the life of the bearing. It was probably the only thing that was still keeping it going. It probably would have failed in the near future anyway, but once the “extra” protection of the SynLube was removed during the head gasket work, the bearing “gave it up” in 200 km.

 

I’ve put 16,000 km on the new engine. Bare in mind, this is a Phase I block that was “available”. It is not a Phase II block. It is definitely quieter than my original engine ever was. My gas mileage has gone back up to what I was use to seeing (more supporting evidence). The power seems the same. I ran dino oil in it for a bit to appease the dealer. At 1500 km, I changed it (still dino). The filter magnets showed some captured bits of metal. I changed the oil again at 6000 km. Again, a bit of metal captured, but fine looking stuff now. I ran Mobil 1 from 6000 km to 12,000 km. Upon cutting open the filter, I had to really look to see where the magnets were. There was no more than just a dark stain/ring (more supporting evidence). At 12,000 km, I put SynLube back in. I’ll be curious as to the oil consumption level with this new engine. It’s too early to tell just yet.

 

I just hope that the head gaskets hold. What a story that is. My original gaskets were a 3 layer affair. Subaru has changed them a couple of times. The current gasket is a 4 layer affair. Interestingly, the SOHC engine has a thin single layer head gasket (even though it is virtually identical in shape). I found some information that throws some suspicion on the head bolt torquing procedure. Apparently it has changed along the way. (I didn’t like it when my dealer told me that some bolts seem almost “loose” on the newer vehicles when they take them apart.) I’m actually debating if I should ask my dealer to pull the covers and check the head bolts. We shall see.

 

And that’s about it. Sorry for the long tale. In all, I’m still quite happy with my Subaru. I still plan to keep it for a long time. I’m even doing some small upgrading here and there (spending more money). I’ve learned (mostly through this board) that the Phase I 2.5L DOHC engine is probably the weakest engine from Subaru in recent history. I was expecting engine work somewhere along the way, but had hoped that it would be at 350 or 400,000 km and at my choosing, not at 258,000 km and "fix me now". Sometimes you win, sometimes Murphy wins.

 

Commuter

[Guest PAezb]

Commuter,

 

That's quite a story, and now you've got me paranoid about my 96 Outback with nearly 83K miles.

 

May I ask what the final cost was to you for the rebuild?

 

Paul

[Guest drOutback]

i have heard about the bearing problem in the '96 Outback but not in the '97. From a local dealer i heard it was a bad run on bearings and they thought they had caught the problem early enough but now they know they didn't. I really don't think it is the way the engine is engineered because the foresters don't seem to be having the same problem.

 

That really stinks what happened to your Outback. I would suggest using Mobil 1 all the time.

[Guest nimeek]

Sorry to hear about what happened, Commuter.

 

Since I own a '97 OB with a DOHC 2.5 too, I'm a little spooked right now. Is this a common problem that I'm going to have to deal with in the future? Between this and the clutch problems that OBs seem to have, I might just sell it and get something else...

[Guest Commuter]

I don't want to spook anyone, but I thought I'd relay my story.

 

Head gaskets have become a known issue. It seems to me that the Impreza boys ran into it first with the 2.5RS of the late 90's, probably because the nature of the car and drivers led to them being "pushed" more. It seems that average "Joe Blow" drivers like myself are starting to experience it now too as other cars (Legacy GTs, Outbacks) get a little older and get a little more milage on them. CCR Inc has been seeing a lot of demand for 2.5L DOHC engine lately. Still, it should not be blown out of proportion. I know that I personally argued right on this very message board that just because some have had failures, it doesn't mean that everyone will. That was before my incident, but I still stand by it. One has to keep statistics in mind here. I'll make up some numbers for arguments sake. Let's say that other Subaru engines or just car engines in general have a 0.5% head gasket failure rate. Let's say that the Subaru 2.5L DOHC engine is 10 times worse than this. That would mean a 5% failure rate. That still means that 95% don't fail. Unfortunately (or not), it is that "10 times" thing that catches attention and sticks out like a sore thumb. I repeat, these are just made up numbers to illustrate a point.

 

I'm told that the bottom end failure is rather uncommon, however, most 5-6 yo cars would not have 258,000 km (160,000 miles) on them as I have. It'll be interesting to see what happens over the next couple of years as other cars get more milage on them.

 

I've never heard of this bearing problem with the 96 engines before. My car was a very early 97. It was on the road in Oct/Nov of 96. I'd have to check the build date. Can anyone tell me more about this bad batch of bearings?

 

As for cost... I got a couple of quotes around $1500 Cdn ($1000 US) for the head gasket job. Seemed to be the going price. This included machining the heads and doing a complete valve job. I can't tell you what the entire bill (with new short block) should have been. There were some special circumstances in my case and as I said, the dealer treated me "extremely" well.

 

Commuter

[Guest drOutback]

I meant wheels bearings. Sorry. And about the Subaru clutches, don't worry they simply need some expertise to operate smoothly because of the large amount of lining to allow the clutch to last a long time. My '88 with 50K on a new clutch shudders sometimes, but it's a mistake on the clutch let out on my part. here's an awesome link about suby manuel transmissions. www.spdusa.com/shifting.htm

[Guest SmashPDX]

Eeek. Now I'm getting a little more worried about the combination of "that tapping noise," slipping mileage, and slightly decreased power... umm... I think I'm gonna go poke under the hood of my 113,300-mile 7 and a half-year-old 95 later bye

[Guest Commuter]

Russ,

 

From everything I've come across (or rather lack thereof), I don't believe the 2.2L is plagued with the same problems. Perhaps others could comment.

 

Commuter

[Guest meep424]

The 2.5 block is a bored-out 2.2. Same block, but less-stressed; lower hp, thicker cylinder walls.

 

co-worker bought a civic 2 years back. Dealer told him if he wanted more reliability than a honda, he'd have to buy a subaru. (Conversely, said the civic, however, had a smoother suspension. Having traded a 96 civic for a 97 legacy, I concur). So- we shouldn't start that, "shoulda bought a honda..." stuff.

 

My '97 2.2 has been mechanically bulletproof. I'm pretty conservative now, but it's first 60,000 miles were all about WOT. It's had the "slap" since 3000 miles, and while it's increaseed, it's still quiet warm. Valves make a little bit of a tap-dance, but adding 1qt 10/40 to the 5/30 oil does nicely.

 

Running mobile 1 since 34,000 miles, the engine is spotless- no sludge, goo; just a slight "golden" color inside the covers.

 

At worst have been mysterious fuel/ignition probs that have been quirky, and an unhappy h2o pump stretched to 106,000 miles.

 

meep

[Guest drOutback]

We use Mobil 1and love it. We use the thicker 15/50W. The thicker weight might help the slap a little.

[dwalker]

Engine Rebuild....... Have a 96 OB and the Head Gaskets had failed at 159,000 miles. I did all of the work myself. Pulled the engine and did a complete tear down, new main bearings, connecting arm bearings, oil pump, water pump, took the heads to a machine shop that builds race engines and had them machined. New rings, complete gasket set, new igniter, coil, cam and crankshaft sensors and timing belt. Pulled the engine out, wasn't that hard. Only real issue was a wiring issue at the very end.. crossed the camshaft sensor with the #2 injector wire. Not hard to do. Total rebuild cost was about $2000, which includes all OEM parts, fluids, engine hoist rentals (2) and few new tools.

 

 

So.. It can be done... and a lot better if you have the patients..

 

Dan

Chicago

[blitz]

Commuter, calculate the number of days that the car faithfully took you to work and back without bearing failure, then realize it failed the next day after it was serviced. The statistical implication is that:

 

1. Something was eroding the bearing prior to failure.

2. Some unknown anomaly as a result of the service finally failed it.

 

Really it was not one or the other, but both.

[Commuter]

Commuter, calculate the number of days that the car faithfully took you to work and back without bearing failure, then realize it failed the next day after it was serviced. The statistical implication is that:

 

1. Something was eroding the bearing prior to failure.

2. Some unknown anomaly as a result of the service finally failed it.

 

Really it was not one or the other, but both.

Wow... someone dug this up!

 

blitz... agreed... from my first post

I’m about 90% convinced that it was a long term failure. That bearing may have been fated from day one. I honestly believe that the SynLube probably extended the life of the bearing. It was probably the only thing that was still keeping it going. It probably would have failed in the near future anyway, but once the “extra” protection of the SynLube was removed during the head gasket work, the bearing “gave it up” in 200 km.

One further addendum to my first post. At the time, I "thought" I had oil in the anti-freeze. As I have since learned, the sludge (that I thought was engine oil) was most likely a bi-product of the combustion gases pushing thru the coolant. The testing of the oil and anti-freeze did not indicate any cross-mixing.

 

180,000 km now and 3 years since this all happened. The 'new' engine has developed some piston slap, but not bad. Knock wood!

 

Commuter

[blitz]

Wow... someone dug this up!

 

blitz... agreed... from my first post

 

One further addendum to my first post. At the time, I "thought" I had oil in the anti-freeze. As I have since learned, the sludge (that I thought was engine oil) was most likely a bi-product of the combustion gases pushing thru the coolant. The testing of the oil and anti-freeze did not indicate any cross-mixing.

 

180,000 km now and 3 years since this all happened. The 'new' engine has developed some piston slap, but not bad. Knock wood!

 

Commuter

 

I just noticed the original post date. Glad everything's alright.

[nipper]

On the 2.2 L, I ahve a 98 2.2 with 184K on the engine. Aside from the HUGE DENT in the back, the engine runs fine. I just got a check engine light (car is going to be totaled so i will live with that). Oil has been changed religously, and antifreeze changed every 2 years.

 

Only thing i noticed is that with the ac on the temp gauge climbs, ac cuts out, temp gauge comes down (typical cloged radiator sympton).

 

 

Now heres a question, im looking at getting another sooby once the dust clears, and im getting fearful of the 2.5L engines. ONce the head gaskets are replaced, is that a "do only once" job, or has anyone had it happen more then once. This would tell me if its a gasket design issue or an engine design issue.

 

nipper

[blitz]

I recall reading accounts of folks having had to do gaskets more than once.

 

Conversely I've read even more accounts of folks who have never had to deal with head gaskets in 200k miles.

 

Based on hard statistics, I don't know what the likelyhood of failure would be, but it would be an interesting bit to know.

[chef_tim]

Glad I read this whole post, reaffirms my decision to just replace the whole 142k 2.5 in my OBW with a CCR long block. Later, Tim

[Commuter]

Glad I read this whole post, reaffirms my decision to just replace the whole 142k 2.5 in my OBW with a CCR long block. Later, Tim

If I'd have had any indication that my conrod bearing was about to fail, I would have done the same. I was also looking at a used Phase II 2.5L engine, but felt there were too many hiccups on going that route.

 

I expect to have the car for a few more years yet. I'm not putting on quite as much mileage these days, but still a lot. I keep my fingers crossed.

 

Commuter

 

451,000 km on the car, ~193,000 km on the "new" engine.