1 Lucky Texan

Yeah, I doubt every car has the problem, but who knows how many have slightly low pressure or are pumping oil with 'aspirated' gas in it from the sump? Or how many wrecked engines just got replaced or went to the junkyard with un-examined cracked pick-up tubes. (I hope mine doesn't have a crack - how do I know?, but if I EVER have an opportunity or need to take the pan off, I'm installing a killer B or similar pick-up)

intake valve(s) open when it shouldn't be?

is it possible a vapor/vacuum line to the canister/tank purge system was pinched or knocked loose? You might use an OBDII scanner to see if any codes are pending.

AFAIK, rear sensor just tests cat conv efficiency. Front O2 is used to adjust A/F ratio. Might be interesting to see what the long and short term fuel trims are set at. My scanner will only read that if I have a CEL on though - maybe someone here knows a way to retrieve that info. what's the mileage/condition of the car? Any other work done during the clutch work? Or right before? crank angle sensor could be intermittent, knock sensor, some similarity to a bad engine temp sensor and those often won't set a CEL.

surprisingly, I've read lately of MAF problems not throwing a code - but yeah, it seems unlikely it'd be this intermittent. But moving old hoses around might lead to a cracked one somewhere - maybe sensitive to 'flex'. You might let the engine idle and try pushing/pulling on wire and hose bundles, in an attempt to replicate the problem. maybe a ground was disturbed? you could T a vacuum gauge into it, run it into the cabin to monitor when the engine misbehaves. Might help with diagnosis, maybe just confusing though as I'd expect a stumbling engine might have weird vacuum anyway. Someone else here might have some insight on that. maybe try an ECU reset.

did you coincidentally get 'bad' gas? Maybe throw some HEET in the tank. any CEL codes?

Code may still be stored, or 'pending'. I'd try to get it read (Autozone type places will do this, get the actual P0xxx code, not just the suggested stuff from A'zone) Intermittent problems can be tricky to pin down.

In hot weather conditions, supposedly you don't need much higher viscosity because the engine runs at 170-210 degrees regardless. But, similar to your example of oil 'running out', to me, seems that 40W is gonna hang around in bearings longer while my car sits in 105 degree temps all day while I'm at work. Plus, when you turn a car off, latent heat can rise - further thinning oil. Worn engines may benefit from slightly higher viscosities too, but I was surprised that Ivan recommended such high W (for Winter) viscosities being 'up north'.

look on the inside of the TB covers for anyplace where the belt may have been rubbing. I've read of people hearing a knocking noise from a flopping timeing belt. If the alt pulley is suspect, but you're not quite sure. Take it to O'Reilly's or someplace to be tested. Should hear it make noise during the test. Also, compare the way it feels to the one they will try to sell you. While you're there, consider getting a new radiator cap, and a Stant Xacstat t'stat 170deg., and maybe a headdgaset test kit.

maybe we should backup. what problem are you having? Did you throw a code that indicates an EGR problem? anyway, I think it's clear that, the diagram linked is not the actual EGR valve - though perhaps the EGR valve is vacuum controlled. On newer cars though, I think it's electrically controlled so - that diagram's description may be a misprint of some kind.

Sounds like you may have 2-3 problems. At the age of your car, almost anything made of rubber could be bad or is risky to run. That includes seals and hoses. If the radiator had excess pressure but the overflow tank was not full, 'boiling over', I'd be concerned about radiator caps, coolant thermostats (only use OEM t'stats or possibly the Stant Xacstst 170deg. - others won't work well in soobs) and possibly radiator clogged-type problems. Might not hurt to use one of the chemical headgasket test kits from the parts store to help eliminate that possibility. The rad. fans on some soobs have a complicated schedule hinging around coolant temp, A/C use and ambient air temp. But I have no idea if that applies to your 95. In most cases though, if the car is warmed up and the outsides temps are high enough to require A/C, I'd expect both fans to be on when the A/C compressor is on. If the car has been driven when in an overheated condition, there certainly could be internal engine damage. Perhaps you could idle the car with the hood up, and try to pin down the noises location. In my recent experience, power steering noise is a whine caused by bubbles sucked in to the PS fluid but, certainly PS pumps could fail. Again, try to pin down the location of the noise. A weak TB tensioner might let the belt knock against the inside of the TB cover. oops! - looks like everyone woke up the same time today! - uh, what they said

on that drawing you linked, looks like they're showing it mounted behind a plate which itself is mounted to the front of the pass side strut tower ('A') with a 'brace-section' probably going to the inside of the fender.

At present, I use Walmart's Supertech 5w-30 in the winter, and I switch to Shell Rotella T6 5w-40 in the summer. I need to note, I change every 6 months - not mileage, because of low use on the cars. The wife's OBW probably averages 5500 miles between intervals, but my 06 WRX maybe just 3K between changes. And, probably 10w-30/40 is all we need, just that 5w is the most common on the shelf it seems. doesn't mean my cars are immune from any design problems on Subaru's part though!

I wonder if any of these rod bearing failures are related to cracked oil pick-up tubes/low oil pressure? http://www.killerbmotorsport.com/index_files/OilPickupStory.htm http://forums.nasioc.com/forums/showthread.php?t=1553337&highlight=killer+b+oil

if the oil pan is dented, you may need to inspect the pickup tube for cracks. Just because the oil light isn't on, doesn't mean you have adequate oil pressure. it only lights below 3-4 psi. If you used a real gauge - never mind.

but, but, what about 255s ?

how do you do this?

glad I'm using synth oil and accelerated oil changes - but that sucks. when did they change the angle? Is an 06 WRX in the range of having a high rod angle?

??? Could you expand on this. The front diff is open, and shares its lube with the manual transmission. but yeah, glad it was fixed and ,sure, tell us what fluid your mech used.

why were the wires mangled what city are you in get a new mechanic how many miles on the car has it been well maintained and what is it's general condition any modifications or wrecks or recent work done is the Check Engine Light on

not that I'd be any good at fully interpreting them, but a couple of ideas occur to me, one would be freezeframe data - or otherwise retrieving short-term and long-term fuel trims. I believe they should both be quite low unless there's a problem. Also, maybe monitor the vacuum with a gauge. There's some old school diagnostic approaches with that thing. kinda wondering if a vacuum leak could fool the system into an incorrect A/F ratio. I had a nissan once that would intermittently stall - it was a bad 'motor control relay' but it was a 'hard' failure, no rough idling. Just, turned the car off occasionally.

you seem pretty good with auto stuff, but I didn't notice if the car had O2 sensors changed, originals at that mileage are probably lazy or bad. you did mention Engine Temp Sensor right?, not gauge sender. The ECT can be bad without throwing a code. Do you have a code reader? any pending cat system codes?

well, the front diff may have needed fluid but, it's the automatic transmission that contains the 'wet clutch pack' and Duty Solenoid 'C'. So, you could try a transmission drain/fill with fresh fluid(if the fluid is quite old, do 3 d/f cycles to get mostly new fluid). If you have read up on binding here you already know that your tires must be the same model and wear and inflation, etc.

well, a quart has likely overfilled the tranny. Again, not knowing anything about the car, or it's maintenance, it could have just lost some over time. Or, whoever did the maintenance last time underfilled it. The stick has 2 marks near each other at the bottom - that is low and 'normal' levels for a cold engine. So, it may have been an OK fluid level for a cold car. The marks further up are for measuring the fluid when it is hot. 9 qts can expand quite a bit with temperature. Be prepared to get some of that fluid back out of there unless there is a leak or it was low on fluid. Again, that stick is very 'high resolution'/sensitive. You have to add 1/2 pint at a time and sneak up on the proper level. Was the fluid very dark and/or smelly or bright/clear red?

well, you said it changed with engine (not car) speed about 3-4 times in your original post. yeah, could be wheel bearing, kift front of car, try grab tires at 12 and 6 oclock positions and try to sigt up and down, ANY detectable movement requires further inspection for bearing or balljoint or other problem, even a millimeter of movement. Also, if one hub feels hotter after driving thena the opposite side, could be wheel bearing or brake problem. Of course, there are axles and the front differential that can make noises.