friendly_jacek

I'm curious, both engine and tranny died on you?

2 possibilities come to mind: Lean mixture-problem with O2 sensor. Defective anti-knock sensor. Possibly both. Vacum leak would be a possibility in older cars but the O2 sensor should compensate for. Can you take the car to a dealer that treats the customers better than that (I know, hard to find)? You also have SOA and lemon law as possible resources.

I used rotella 5W40 for several years in my 2000 and never developed the piston slap. However, don't know % of people with the problem as not everyone will have piston slap I guess. Rotella synthetic is a very good oil. Group 3 but much cheaper than delvac. Similar heavy duty additive pack. Has the 40C viscosity a bit lower than delvac, in the 90 range. This year I will try Castrol syntec made in Germany 0W30 (aka castrol SLX), the only XW30 oil I know that has ACEA:A3 rating (HTHS>3.7). I will see if this will help with MPG vs rotella. It sounds like to cushion the piston slap, oil has to coat the cylinders. Light oil will not stay on the cylinder wall overnight, heavy oil will. I guess the esthers in Castrol magnatec/start-up oils coating the cylinder is just a marketing stuff. Another question is if one uses thick oil in low temp to decrease the sound of piston slap, would there be a penalty with increased wear in valvetrain and bearings?

good point, forgot about fuel filter, it should be changed every 30000.

Doughboy, Fix the F/A ratio (aka O2) sensor first. It is a weak point in 2000 subaru. There was a recall for it in 2001. They can fail without triggering the light and cause alarming drivibility issues. Search here and you will find several examples fixed by new sensor. BTW, there are surprisingly inexpensive in Subaru dealerships, 60-80$ (internet vs brick). As for the tranny, maybe the new fluid will fix it. Hopefully, as this is another soft spot in 1999-2000 subarus.

OB99W, look I didn't post just to argue with you but trying to help. I don't know why you are so defensive, but hey, its your car. Let me try one more time before I give up. The delayed/raised shifting you mention was indeed used in subaru AT in the past. It is called KDLH (kick down low hold) and is intended to make the engine warm-up quicker for emissions. The fact you failed to mention that it was used in old trannys without electronic control. I has not been used in more modern 4EAT. See the phase1 description page 8: http://endwrench.com/images/pdfs/4EATPh1Win04.pdf The phase 2 dosn't mention it alltogether and there is no reason to consider that KDLH is used in gen 2. Again, my tranny doesn't have it. "Faulty shifting when cold" sounds very vague. I would venture to say that you do have faulty shifting when cold. Why dont you get a new temp sensor, put it in a thermos with warm water, wire it in to the TCU and see if shifting improves? Then you can also compare the resistance with the stock one.

The problem with this thread is that 3 different people posted 3 different problems that resulted in a great deal of confusion. Steve, if you do more searches and reading on AT, you will discover that the jumps in RPM during shifts (so called shift flares) are very abnormal. It means that one cluch pack is engaging too slow, after another one already released. This will result in cluch overheating and burnout. Your tranny will fail, it is just a question of time. The possibilities include too low line pressure, clutch pack that is slipping, or TCU problems. To me it sounds like the "remanufactured" transmission originated from a junk yard and was not remanufactured at all. Or maybe a mismach between tranny and TCU? Get it fixed ASAP before the warranty expires. If you don't believe me, get a second opinion from a transmission shop.

Subaru webside has it listed all. In short, replace: engine oil+filter ATF air filter coolant spark plugs brake fluid Notice that it is 60,000 miles OR 60 months whichever comes first, so it should have been done a year ago. I mention this as I made the same mistake in my 2000 legacy.

To address the initial post, I had a somewhat similar story with 92 mazda protege that would have the delay on hot fluid, especially after high speed hwy driving. Eventually the tranny failed at 60000miles. The rebuilt tranny overheated on the first high speed hwy trip. That brought my attension to the aftermarket radiator that was installed after a major accident at 20000 miles. I put a tranny cooler and the tranny worked flawlessly for another 60000 miles when I got rid of the car. The hardened elastomer is a classical sign of overheating. I'm not saying that you abused the car, but I think that high speed hwy driving can produce very high tranny temps. Once I measured tranny temps in my toyota corolla and it was OK (175-200F) until I drove 80-90 mph with loaded car in summer, the the temp went to borderline 250F. I have both AT cooler and ATF temp guage in my 2000 subaru as I tow some and can tell you that the stock ATF temp light is set up very high as it never lit on mine and sometimes I have max temps 220-230F while going uphill with boat.

I respectivery disagree with your opinion. Please read the following and better description of 4EAT: http://endwrench.com/images/pdfs/4EAatPh2Win04.pdf Only lack of 4th gear is the difference in cold with this tranny. I have 2000 that is the same 2nd generation of 4EAT and never had the problem you described in cold. I had a similar behaviour of abnormally high shift points when TPS had connection problems and the TCU thought I was flooring the gas pedal. This is only why I mentioned that. But it was different since the TPS threw a code eventually and there was no connection with temp. However, TPS tells the tranny how high the load is, and you seem to have some problems with that too. Of interest, the first generation of 4EAT (up to 98) had indeed diffrent shifting map when the the ATF sensor sensed HOT (not cold) fluid, to cool down: http://endwrench.com/images/pdfs/4EATPh1Win04.pdf In retrospect, I remember than before AT failed in my nissan sentra many years ago, there would be a delayed shifting from 1st to 2nd on cold tranny. But since you had that since new, would not apply I guess. Edit: read page 10 from the http://endwrench.com/images/pdfs/4EATPh1Win04.pdf It describes the work of solenoid A decreasing the line pressure under some circumstances. Looks like you also want to investigate the droping resistor and tachometer signal.

The numbers you quote sound normal. If you drove up to the higher elevation, the MPG would be lower than returning down hill. My wife evarages 18-19 MPG in her small trips city driving and 24-26 MPG on hwy (24 with 80mph and 26 with 70mph) in her 2000 legacy wagon (AT). It used to be 10% lower before I replaced A/F ratio sensor.

If the ATF was never changed, the flush could possibly kill a tranny in some cases. If the tranny was properly maintained, no fear.

Cold temp in 4EAT only affects 4th gear, ie AT will not shift to 4th on cold tranny. What you guys are describing is totally abnormal. I would check TPS, as this affects the shift points. I would change fluid (subaru AT is very sensitive to maintanance neglect), filter, and maybe try one of the friction modyfiers. Finely, maybe the TCU went crazy on you?

Why not cleaning the MAF? It can be done by gentle spraying of the element in most cars. Don't know about WRX though.

A/F ratio sensor is basically a better (wideband) O2 sensor. The problem is they seem to fail quicker (at least the bosch ones subaru uses) than you would expect, sometimes without giving a clear error code.

Noid light, what a silly name. I had to check if you didn't make it up.

Weird, hope you did not fry ECU. Is this Actron PocketScan OBDII Code Reader/Eraser known to be compatible with Subaru? In theory, every OBD-2 device should if it uses ISO protocol, but in practice some are not.

There was a discussion in the past that some parts stores cross-referenced some engine oil filters to subary tranny filter by mistake. They may screw in but are not the same part.

I just had my 3rd tensioner replaced under warranty. The service manager said that there is a new supplier of the part. We will see. If you are not sure where the noise comes from, invest $6 in mechanic's stethoscope (Harbor freight tools).

All modern, detergent oils, SH and up are decent these days irrelevant of the brand. Last time I checked, oil marketed as penzoil was made by shell. I would suspect long oil change intervals or SA, non-detergent oil, still available at drugstores nationwide.

If you do a search here you will find that a number of people with 2000 had their AT replaced under warranty with the same problem, internal seal leak.

Sorry to hear this. HG is a known issue with subaru's 2.5L. Usually the external leak with 2000+ subarus was correctable with the conditioner additive. Did you pursue the conditioner as per the recall? Also, there is that 100000mile extended warranty on the HG. Regarding the piston slap, timing belt tensioner can mimic it very well. Using stethoscope helps a lot. It is another problem area in subarus. I just took mine in for third tensioner in my 2000 legacy. And yes, the wheel bearings, mine failed at 50-60000.

The link works. However, you have SOHV not the DOHV. Endwrench.com should have a newer procedure for the SOHV. Do a search.

I found the info I was looking for. Here it is if anyone cares: http://endwrench.com/images/pdfs/EngineNoiseInfo.pdf

Well, the wiggling of the wires near TPS does nothing. I'm not sure how to wiggle the wireing between the engine and the TCU/ECU. Yes, I have an OBD2 interface.