blitz

Setright, you're describing something that I've been experiencing on my 2.5 II for a couple years now. The best way to describe it is the "slow boil". After a drive, I can always force vapor out of the cooling system by squeezing the top hose. If I don't squeeze it out, I sometimes get the gurgle noise when I blip the revs to 2000. My theory is that incomplete air removal from the cooling system after changing the coolant begets a slight perpetual vapor bubble formation during subsequent normal operation. My concern is that this leads to the runaway situation of: minor hot spotting -> dimensional distortion -> minor gasket leak -> combustion gas entry -> overheating -> warpage. I'm going to get that funnel-tool thing and see if that doesn't make a difference.

Strakes, if you have an isolated stretch of road near you with some curves and almost no traffic, take some time to learn the new handling characteristics of your car while pushing the limit of adhesion though the turns and easing off the throttle mid-turn (just be ready to quickly jump back on it to straighten out). With the bar set at the stiffest setting, your car will develop a distinct tail-out attitude midway though the manuever. It's better to re-adjust on your own terms rather that wait for a surprize emergency accident-avoidance situation and loose it.

Nomad, you've but scratched the surface. There's a fair amount more deterioration going on. I 'spose it depends on whether the argument centers on the only base stock itself, or the entire motor oil as a package. The VI improvers are that universally present in multigrade dino lubes become permanently sheared with use. That could qualify as "worn out". Also the tendency of these polymers to coke up into the top ring groove (especially on new piston designs with the rings pushed right to the top) is offset by the detergency and solvency of the brew which unfortunately gives up the ghost with mileage. Oxidation and nitration will chemically change the brew and cause it to thicken. Linear additive depletion is a given. So while the base stock never wears out, the motor oil as a package, does. Semantics?

IMHO, use a dealer tranny filter. It's not likely that you'd ever have to replace it more than once during the life of the vehicle unless you rack up some ungodly amount of miles, or tow constantly and heavy. The factory filter was installed so tightly on my '02 that I was almost resigned to thinking it was impossible to remove. Also, once the filter is loosed or punctured, a lot of fluid comes pouring out and continues to trickle out (of the valve body) for over an hour, so have a big, wide drain pan and lots of towels handy. My manual indicates that any Dexron III fluid is acceptable but doublecheck your own before proceeding. I've been using M1 tranny fluid with favorable results.

Thanks Tiny. My question arises from the fact that the A/C fans: 1. Wear out. 2. Are huge resource hogs. 3. Are not nesessary at speeds above 25mph / 40kph. It bugs me to think that the fans may be running in concert with the A/C compressor when I'm cruising on the highway. Is it possible that someone knows the answer to this question?

When my A/C compressor operates, the engine cooling fan operates along with it. OK, normal. Alright now when I'm cruising down the road using the A/C, does the engine cooling fan still operate in concert with the compressor?

99, the interesting thing is that my M1 10W-30 noise was in a brand new engine (under 10k miles). Although not a scientific conclusion by any stretch of the imagination, I swear there's something different about PAO lube with regard to it's ability to damp mechanical noise (given a uniform viscosity for sake of comparison). PAO's just seem "drier" and more "rigid", whereas dinos & POE's seem to be "juicier" and "springier". There has to be some quantifyable property of oil which falls outside the standard newtonian measurements of "viscosity", "viscosity index", and "viscosity under sheer". Something in regard to the fluid having a particular natural resonant propery under excitation or something like that, and it would be related to a different molecular lattice structure.

Good question. Castrol, Pennzoil, and Quaker State have all offered various 5W-50's in one form or another here in the states over the last 10 years or so but for some reason Mobil hasn't. The closest we get is the 0W-40 and the 5W-40 SUV. I currently run a 50/50 mix of M1 10W-30 & 15W-50 in the summer. I had tried all M1 10W-30 but I could hear a rod making noise at hot idle.

Yeah, the water method works good to sort of "heat-shock" the carbon off the piston face. The solvent method does a bit more by way of dissolving deposits from the intake ports and intake valves as well.

You might want to do a search of this USMB archive, I swear not less than three weeks ago someone posted a symptom that was exactly the same as you describe. I don't recall the name of the thread tho.

I changed the tranny filter on my '02 last summer, and had such a difficult time getting it off that it was practically in two pieces by the end of it all. After the usual philips screwdriver through the can just wasn't giving the torque (the screwdriver was bending) I ended up hammering a 15" long rat-tail file through it, and had tranny fluid running down my forearm into my armpit by the time all was said and done. I've never before owned a single car such as this one where so many simple maintenance tasks somehow suddenly become extremely difficult mid-job. Anyway... by the time I got the filter off, the guts were hanging out and it looked like a standard pleated paper style filter, although the media may be tweaked for tranny duty. I don't recall seeing any ceramic, but I wasn't looking real close on account of being both aggravated and relieved.

Good info, I'm gonna crawl under my Impreza and see if there's anything similar going on.

Adding resistance in series with the AIT sensor will advance the timing, so you might actually see a slight mileage improvement. You will however need to use premium fuel. As far as whether you are capable, only you know that. I'm a firm believer that a person can accomplish anything they want to. The worst consequences of a mess-up? Well, you could poke your eye out, scratch the paint on your fender really bad, and completely toast your ECU. Just don't mess-up. Problem solved. The best manual is probably the factory manual, unless someone else has a better suggestion.

In a nutshell, I added resistance in series with the IAT sensor. This is a pretty long thread. Read back through it, then copy and paste the part you don't understand, and I'll gladly work you through it.

Well, you might want to check the manual for each model to make sure but I'm fairly certain that MAF-type FI systems don't include (or require) an AIT sensor. The '93 is almost certainly a MAF system, but I'm not sure about the '98. Sorry for not being much help. :-\ You really need to own a manual for each vehicle you own, if you plan on mastering that little technique of "do-it-yourself" type problem attack. It costs a bit for sure, but it's well worth it over the long haul.

jseabolt, thanks for the link. I'm looking at my '02 manual, and for temperatures down to 0*F, 10W-30 & 10W-40 both are listed. Also directly below that is a little section which is easy to overlook called "severe driving" where it gives the blessing for the following grades: SAE 30 SAE 40 10W-50 20W-40 Clearly Subaru has no problem with the use of oils having a viscosity thicker than water if the situation warrants it. If the consumption persists or worsens and you get no satisfaction from either the dealer or SOA, your surest bet would be to go with a 15W-40 HDEO fleet-lube like: Pennzoil Long-Life, Delo 400, Delvac 1300S, etc. for summer. This'll drop your consumption and keep the motor clean. Might have to switch to something a little thinner for the Tennesee winter tho.

Yeah man, I'm interested in the link. I've been looking for this tool locally for about a year and all I get is strange looks. I just visited Lisle's website and can't seem to find it there.

It just occurred to me that you're working on an '02 Legacy, and I'm working on an '02 Impreza. I'm thinking that the manual section numbers and connector numbers may not exactly correspond, although the circuit should be identical. Shoot me your e-mail address at blitz@flash.net and I'll shoot you back a pdf of the diagram page that I worked from with a few notes about the placement of the resistor, and you should be able to easily transcribe it over to your vehicle and drawing without any problem.

Other than the need to be aware of potential electrical system voltage/discharge at low RPM, and/or during times of high accessory usage, you've also got issue of the non-standard accessory drive-belt size to contend with, so you'll need to document the belt part# and keep it with your manual for future reference. The last issue is that of crank harmonics. The best info I've been able to glean on this subject is that the ultra-short Subaru crank suffers little from inherent harmonics with the exception of one sharp resonant peak which occurs in the upper RPM range. Exactly what that RPM is, is unknown to me and there appears to be zero conscensus on this issue. My opinion is that if Subaru didn't think it was important to have a three-piece harmonic damper, they wouldn't have included it.

Remove the initial air intake section that draws hot air from the radiator (the one with the single bolt in the front), and replace it with a short section of aluminum dryer vent hose bent at a tight right angle like a short elbow and use that to draw air in from the hole in the fender. This'll give you a 40* reduction in intake air temperature. That's a 4% increase in torque across the board for 2 bucks. Can't beat that. Advantages: Quick Easy Inexpensive Effective Torquey Quiet (except for a nice added boxer snarl at 5k RPM). If you're like me you'll appreciate not having to listen to the obnoxious honking intake drone that a performance intake will give you, and you'll also appreciate keeping the torque below 3k. Also line the lip of the fender hole with a length of silicone tubing that you've slit lengthwise (just like for the Ganzflow intake) to keep the aluminum from rattling on the sheetmetal.

It's been so long since I did this that I had all the underhood work soldered, taped, and tie-wrapped. I had to go back and refresh myself on all the specifics. The drawing that I worked off of was WI-83 (only drawing I had to work from). The connector you're refering to I believe is E25, and the leads that I dealt with were 4, & 3. 4 being the sensor signal, and 3 being the combined sensor signal ground and shield ground. These are the two leads that I tied the added resistance across (in parallel with the sensor, so it loads down the sensors output voltage). The sensor is a high impedance crystal that generates a small voltage and almost no current, not unlike a piezo. The remaining two leads (1 & 2) are the heater which is not involved. If you follow the rear sensor harness up to the engine bay, you'll notice that it becomes accessable at a 10-pin connector under the airbox. If you remove the whole plastic intake system including the airbox, you'll have unfettered access to this area. The color of the two wires I jumped across were an unshielded white (signal) which transitions (splices) to a shielded cable at that physical location, and and unshielded blue (ground). 100k is the best number to start with, then work your way down until the "iffy" throttle tip-in diminishes, then go one more for good measure. It takes several full driving "events" to log any numerical change, and I typically drove around for about a week with a given value before I rendered any assessment. The changes are very subtle as this ECU control mechanism is only a trim and not a master controller of fueling by any measure, but it was just effective enough to get rid of the lean tip-in that always creeped me out when pulling into moving traffic. I don't even think about it anymore. Don't work with the ignition on and don't apply voltages (ohmmeter measurement) to unknown ECU I/O. Normal operation proceedure. I'm anxious to see good results. Keep the group posted and if you run into a situation, don't do anything dumb, just ask.

Sounds like something is physically causing the throttle mechanism to stick or bind. Do a thorough visual on the complete throttle linkage train. Don't drive the vehicle until you straighten the problem out. Start at the accelerator pedal and make sure that it's not binding or getting caught on the floor mat. Check the full length of throttle cable to make sure it's not kinked or pinched anywhere. Check the throttle-shaft pull mechanism, the cruise-control cable, and the master return spring for free operation. Lastly check for dirt, deposits, or grunge in the throttle-body. If you live in a rural area, it's not uncommon for birds or mice to build a nest on your engine block.

Thanks 777. The manual says that the marker lenses are just snapped-in and to just pull them straight out. HOLY COWW (yeah 2 w's) what a piece of crap design this thing is!!! I had to pull hard enough so that I actually deformed the body sheet metal slightly, and had to spend time re-forming the shape of the opening with my fingers. The headlight comes straight out of the front once all the bolts are removed (which is where I had it), but there's a secret hidden clip on one end that needed to be weaseled loose. The problem was knowing which way to pull. Changing all the lamps once every three or four years is a good way to avoid spending unnessesary time with officer friendly.

I'm no expert, but from what I've read, the best place to start is pretty much what you'd expect: free up the exhaust. I think the STi needs to have the wastegate ported in combination with any serious exhaust restriction reduction to keep boost-creep at bay. http://forums.nasioc.com/forums/forumdisplay.php?s=&forumid=91 is probably a better forum to search for the type of info that you're seeking. Good luck!

Specifically an '02 OBS, for purposes of bulb-changin'. Also I need to remove the amber marker-lamp cover and sneak a new lamp in there. It looks like it just snaps out, but I don't want to hear the wrong kind of snapping noises (if ya know what I mean) TIA