Setright

Hmm, a turbo engine has the potential for quite good economy, since it actually re-uses the hot gases to drive the turbo impeller, instead of just dumping them like a non-turbo. However! Using the performance available will hurt economy. Basically, your right foot decides. I would have jumped at tha chance to buy your car, too. But, to actually answer the question: A full exhaust system would be the way to go. Right from the headers, down pipe, up pipe, through a sports catalyst (keep it legal) and into a free flowing rear silencer. With a remapped ECU you could gain 25-30bhp. More important, you have much sharper throttle response due to less restriction. If your light on your right foot, you could also increase your mileage by a few percent.

Well, head gaskets are the weak link in this car, and your symptoms do point in that direction. Of course a proper flush and re-fill (Gnuman to the rescue!) would be a good place to start.

Sorry powderhound, but I would have gone through the same points as Blitz, and I was in a hurry :-) Having said that, the symptoms you describe now don't sound like clogged hoses. These would just cause erratic idle, not the systematic up and down you are experiencing. I think you need to remove your IAC and clean it thouroughly. Not sure what type your 98 model uses. Is your air filter nestled behind the headlight or just behind the throttle body? IAC must be causing this. The engine runs fine at speed right? IAC is the only thing that would cause the up/down idle. Or heaven forbid, the ECU could be faulty. Gunk in the IAC would cause it to stick and react much slower than the ECU expects, which is why the idle doesn't run wild, but just isn't stable. Very old spark plugs might play a part, but I think you'd get rough running at higher revs too.

Good point: Short journeys mean condensation inside the engine block. Mix it with the unburnt fuel that slips past the piston rings, and maybe some of the "oil fog" and presto: Sludge! Now, any oil will be hard pressed to avoid leaving an emulsion on the filler cap and maybe the dipstick too, but a synth would surely fight a more valiant battle. This does underline that synth is useful in compensation for non-ideal driving conditions. Lots of short trips at one extreme and lots of high rev, high speed work at the other.

I'd just like to chime in and thank Blitz for offering top quality advice!

60k miles? Time to consider replacing the fuel filter, spark plugs, and depending on engine: The timing belt!

Yep, drain cock is on same side as the top rad hose, only right at the bottom. Often on the side of the rad. Get under the car, remove the protective plastic shield and you will have good access. Mount the new hose on the engine first and fill as far as possible through the top hose. Then connect it to the rad and top up from there. This method avoids large air pockets forming.

99obw, an engine left overnight will have drained as much oil as one that is having it changed, if not more - I trust you don't wait four hours for the oil to drain during changes? The only difference is that the "straw" that is used to suck oil up from the pan will be empty after an oil change. The pump is still full and the filter has been filled by the DIY mechanic! So, I accept that "dry cranking" after an oil change will make a difference, but only by the smallest of margins. The sort of margin that might be noticeable once the engine turns past 200k miles. Even then, only in oil consumption, not bearing failure. Still, hats off for obsessing about maintenance! Too few people do it. By the way, Bobistheoilguys "Timken" machine is also useless. The oil is not supplied under pressure, like it is in an engine bearing.

Sounds good, an HG job would have been an big waste of money. CO in the coolant could stem from the boiling filling the overflow and then as the coolant gets pulled back during the cool down it pulls some air back in. The air in an engine room could easily contain some CO.

By the way, the gearbox swallows 3.5 liters of oil, and has to be filled through the gearbox dipstick pipe. In fact, you should probably start by checking the level of the oil in the gearbox before you do anything else. It's the dipstick that's tucked away near the rear of the engine room on the passenger side.

A worn throw-out bearing will usually rumble/whine/rattle when you apply pressure to the clutch pedal. Half way down is often the loudest position. Bad main bearings in the transmission will rumble in neutral at standstill, and will go quiet as the clutch pedal is pushed down, since the internals stop moving. These bearings will also make an assortment of noises on the move. Some transmission noise is normal: A whirring sound is perfectly acceptable. It's when the noise becomes an uneven rumble that you need to consider worrying. Sudden, catastrophic transmission failure is very unlikely, so you don't have to spend a whole load of money, just because the gearbox is getting noisier. Long-term neglect might just increase the size of the bill... I would strongly recommend that you drain the gearbox oil and fill it with a good quality 80W or 90W transmission oil. The drain plug has a magnet in it. If this is covered in a lump of metal shavings then your bearings are on the way out. (A thin layer of small metal bits is normal.)

99obw just disconnect the crank angle sensor. No amount of cranking will start the engine. Of course, as Frag has thankfully pointed out already, you would have to do this EVERY morning. We Sube owners are luckier than most, our oil pumps are cleverly designed so that the oil doesn't drain back into the pan, meaning quick pressure increase on start-up. (Part of the EJ22 development, and who would dis that engine??) Also, our filters are bottom mount, meaning they can be primed during oil changes. PLUS! Our igniton/fuel systems let the engine crank for longer if the ECU registers a low engine temperature. Thus priming the bearings. (Some BMW engines do this too, notably the V12's which can take a LONG time)

I would like to take this opportunity to express my scepticism with respect to BITOG. The theories are home-brewed and the tests used to verify them are irrelevant for internal combustion engines. For example: The "four ball wear test" is designed to test bearing grease, not engine oil.

Crank seal is a MUST! BE sure that they pull it out without scratching the crankshaft. Cam seals are a good idea, but not essential. They can be replaced "locally" without taking everything apart again, if they fail in the future.

SmoothLegacy: Power steering fluid is "not a service item". However, I like to suck up as much as possible from the reservoir and refill with fresh fluid. The total capacity is about 600ml, and you should be able to suck out 100ml. Do this once a week for few weeks and you'll have replaced nearly all the fluid! There is no drain hole. Purging air out is done with the engine running and swinging the steering slowly from one extreme to the other. Preferably driving very slowly in a big open area. Hold the steering at each extreme for a second or two. You can hear the fluid recirculating.

Yes, but that's cause they have the same engine, but the 03 weighs 300kg more!!

That's affirmative, Cookie! Stick with what keeps your partcular engine happy. I wish I lived in a year-round warm climate :-(

YEah, I had never had any piston slap up to 50k miles. The I decided to try Redline 10W40...and it started. Drained the oil after about 100 miles. No diet of Mobil 1, 0W-40 or 5W-50 has been able to cure it. Slo5oh, I think you're climate may explain why you get less slap.

99obw, I don't think anyone here is offended. Just a sober discussion. Now, I did not read all three in detail, but I did notice that one car was an Audi S4. This has a high performance engine which could be running a slightly rich mixture and cause fuel dilution of the oil. I know the UOA has a low value for this parameter, but gas is volatile stuff and a large amount may have evapourated before testing. Hmm, 2001 S4? Isn't that twin-turbo? Could be that the driver has been cooking his oil by shutting off the engine after a hot run. Just hopeless guessing I know, but for me there are too many unknown factors that may have contributed to the oil thinning.

Filling through the top rad hose is the trick to getting only a small air bubble. For more of my ramblings search for "coolant replacement" without the bubbles :-)

OR: As BrusBrother already suggested, warm it with a hair dry and peel gently. This will not leave any residue.

Just read in a local car magazine that Honda's hot VTEC engines also have cold engine piston slap. Article says not to worry. Still, I don't get: My 1990 EJ22 NEVER slapped, even with over 180k miles on it.

Scott beat me to it! Fill the filter, it can swallow a great deal, you just need patience to let it settle. On the drain plug washers: My local Authorised Subaru dealer insists on using flat aluminium washers. I get one free with the oil filter. No leaks, tighten to 40Nm.

yari: The black shims are part of the standard brake pad kits from Subaru. The car should have them on already? Otherwise, you'll have to get them at a dealer.

Mobil 1 0W-40 is a very good oil! What's this talk about it shearing? Porsche, Mercedes, and the tuner AMG recommend this oil. Most are on a 15,000km interval. Which is quite reasonable. However, as has been mentioned above, why go for a 0W oil in your climate Axxiom? M1 5W-40, 5W-50, or possibly 15W-50 would probably serve you very well.