[Romy]

I've been browsing this forum and others looking for solutions to the issues I'm finding with a car I recently bought. But, there are a lot and I want to get some confirmation and advice. It's a 2001 Outback Limited with about 200k. I got it for cheap due to body damage (which I fixed already), a hellaciously dirty interior (which took a whole day to clean), and a few check engine light issues. I've sorted the problems I was aware of (body damage, O2 sensors, PCV valve, timing belt & water pump b/c there were no records, knock sensor, one axle) but encountered a few more when I took it on a 2400 mile road trip.

On the trip it made an insane noise when going around a turn at low speed - a sort of clunking coming from under the seat or around the tunnel. It goes away at high speed, and once started, doesn't need a turn to continue. Tires are brand new and all of the same size. I suppose this is torque bind? I'll be flushing the tranny as soon as I get the line pressure gauge in the mail to check out a few other things. It takes a bit longer than it should to get into gear from N to D and the tranny fluid was overfull when I checked it. I'm also going to flush and change the diffs. I thought this noise might be due to the mounting bushings in the rear diff, but they look good.

It randomly overheated going over two passes in NV - yet it was unaffected climbing multiple passes that were much higher and steeper before and after this. I caught the overheating before it was really too hot and pulled over pretty quick. The coolant is fine, a block test prior to the trip didn't show any head gasket issues, but now I'm not so sure. Around both heads there is a bit of moisture, as well as oil leaks onto the exhaust from somewhere else. It's pretty oily under there and I want to pressure wash it at some point to try and pinpoint the leaks.

The other day it randomly didn't start when it was raining out (the only correlation I could make). After intermittently cranking it for a while I got it to start, but I can't make any sense out of why it wouldn't. Exhaust stank of gas, but that probably had a lot to do with my pushing the pedal down in hopes of it catching and revving.

It also randomly drifts on the highway. If you let it coast, it will pull to the right upon giving it some gas. I haven't been able to find info on that one.

So, any help or diagnostics would be greatly appreciated. My current plans include:

- Line pressure test the tranny as per the manual
- Change the tranny fluid / filter
- Change the diff oil
- Drop in some injector cleaner

For head gaskets, I'm assuming either six star or 2.5T gaskets? And oil leaks can be caused by (if equipped) and oil cooler and what else? Valve covers? I heard there might be some other small plastic plates somewhere that leaks too? Any advice on the trans? Does that sound like torque bind? Any ideas about the drifting?

Thanks very much in advance!

 

[Romy]

I changed the fuel filter and round 1 of the trans oil. The old ATF was some funky stuff, pretty dark. It shifts and drives better now; the torque bind has minimized a bit and the downshifts from 4 -> 2 are smoother, although they're not always perfect. I'll change more of the oil later today, and do some trans tests with freeSSM.

It also randomly didn't start again. It would kick, but not catch, almost like it wasn't getting fuel or had no spark. After a few times, I assumed it might have been flooding itself, and pushed the pedal down while cranking. With the pedal half depressed, it started, and then was fine. I turned it off, and it started right back up. Seems odd. From searching, could this be the coolant temp sensor?

 

[Romy]

Well, apparently my 2001 has the older TCU, so I can't communicate with the trans via freeSSM. Oh well. I just finished trans oil change #2 so we'll see how it drives. The u-joints are in good shape and the center carrier bearing seemed ok when I looked at it - but how do you check it?

Plugs and plug wires have been changed already. I'll look into the seafoam thing you're talking about. I should say that when I pulled the old plugs and plug wires, none had oil on them. There was a bit of corrosion on two connectors on the coil pack, but I cleaned them up and added a bit of dielectric grease to everything.

The front end is tight minus one inner tie rod, which is on order. Hurricane Sandy is messing with the shipping times as it should have been here a few days ago already. But then again, priorities on the east coast are understandably shifted. I does not seem to drift as much as it did now that the ATF has been changed, but it still does a little. Once I change that tie rod (and both rack and pinion boots) I'll update if that fixed it. I'll also check the mounting bushings as you suggested...good call.

BTW, IACV stands for what? Intake air control valve?

 

[Romy]

I got rid of the drifting - both inner tie rods were bad and are now replaced and the car's aligned. Drives much better.

However, I'm unsure if the trans has torque bind. From what I've read, it seems torque bind appears when making tight turns and causes the shudder/vibration due to tranny fluid skipping past where it should be. I changed the tranny fluid a few times, and although the trans now shifts better, the torque bind-like symptoms of shuddering have not gone away. In fact, it always shudders upon acceleration from a stop when going straight. Not really at all when turning in a tight circle actually. It sounds like the u-joint or driveshaft carrier bearing, although both of those look fine. The noise is coming from directly below the center console. If the trans is screwed enough to have torque bind all the time, would this make sense? Doesn't seem like it to me. Maybe a trans mount? I'll check the u-joints and driveshaft bearing again next time I'm under the car.

I'll update when I figure it out in case anyone else runs into this issue.

 

[Romy]

does use of the FWD fuse have any effect?

I'll put it in today and check. I suppose that would rule out torque bind - good idea

 

[Romy]

A couple things that stick out here: Shudder and hard to start. The "knocking" is still up in the air.

If you have access to a scan tool that would allow you to look at live data, you may want to check the output of the front AF sensor. It could be running rich on fuel which would cause a shudder on acceleration. The hard to start issue seems like a sticky IAC valve. Clean it and see what happens. Could also be a poor signal from the ECT, engine coolant temperature. If it is sending the wrong temperature to the ECM it can be difficult to start.

Start with the engine performance first and then see how the transmission reacts. All the transmission controls rely on engine data to function.

The drifting, good call. Two things that cause drifting is tire pressure or loose suspension/steering.

The hard start problem has somewhat subsided. It's done it to me twice, and there's little correlation to when it happens. I use the car daily, and start it probably 4x per day, so I'd say the hard start problem is highly intermittent. Although I'll check the IACV anyhow, because at 200k w/ no maintenance records, who knows. Any possibility of it being the TPS?

I have a new (yet uninstalled) ECT sensor, but man is it a pain to get a wrench on the installed one. I have to do head gaskets at some point and will get to the ECT then.

I should mention that it currently has the check engine light on again. It originally had a P0420, which cleared when I cleaned the PCV valve. Then I smogged it, and it passed with flying colors, so the catalysts are ok. But then the P0420 came back after 3000 miles, so now I've replaced the PCV valve.

After replacing the PCV, the CEL went off for about 50 miles, but then came back on. I didn't want to clear the computer again because I want to read the tranny codes. I'll read the OBD II today to see what the CEL code is this time. I have gotten misfire codes (P0303 & P0304) previously, which I'm assuming has to do with the head gaskets being shot (although it has only overheated twice thus far, and soon after the misfire codes came up.) I do keep a close eye on the coolant temp and it stays pretty solid, although the fan runs often when idling.

I'll pull up the AF data while driving today and see what it gives. Although I don't follow why running rich would cause a shudder - it's definitely not an overly rich condition, as the engine runs smoothly under all these conditions.

So, for today, I'll:
- Read AF ratio while driving and see what's going on
- Check the new CEL
- Plop in the FWD fuse and see what goes down with the shudder
- Report back.

Thanks to all who have posted for all the help / tips! This car is proving to be a huge PITA, but I still really like it.

 

[Romy]

TPS hardly fails but it could create issues with the acceleration and transmission.

If the engine runs rich on fuel, it will lose power. Same with too lean. You just need to see what the computer sees to determine what's going on. So far, you're on the right track. At least your not blindly throwing parts at it.

I drove to my other job monitoring lambda on the first oxygen sensor and the rich condition on the second. Everything seems normal. It hovers near lambda = 1 except when I let off the gas / let is coast, where it goes lean (normal). The 2nd O2 sensor correctly captures when it is rich / lean based on the first O2 sensor. Still have a P0420 btw, so possibly I'll put a spacer or whatnot between the exhaust and the 2nd O2 sensor, as it says the threshold voltage is below spec.

On my drive home I'll run it with the FWD fuse in and see what happens.

 

[Romy]

Plugs and plug wires are Bosch. Never had a problem with them in the past on countless other cars, but there's always room for a first.

With the FWD fuse in, it no longer shudders. So this seems to indicate that it has something to do with power going to the rear wheels, but still seems like it could be the driveshaft bearing or u-joint, in addition to the possibility of torque bind. I also check the trans trouble codes and found none (via the flashy AT Temp light technique).

I'll crawl back under the car tomorrow to put the skid plate back on, and will check the driveshaft again. Is there supposed to be any play in the driveshaft bearing?

 

[Romy]

Did the rear O2 waveform or voltage alter rich/lean as in he video on my post in P0420 Diag; post #13? http://www.subaruoutback.org/forums/66-problems-maintenance/49537-p0420-diag-2.html

As with any bearing, it's design is to allow rotation of the suspended part(s). The carrier bearing doesn't hold much weight but can wear, generally the isolation bushing will rot, often the bearing dries out. There should be no movement in the assembly.

Just a shot in the dark, but have you checked the rear brakes? Parking shoes? If its not in the transmission it may be a mechanical issue with the rear brakes causing extra load on the drivetrain when torque is applied. I had this ONCE a few years ago where the brake was holding on a wheel due to a bad seal in a caliper. Subsequently causing a vibration and occasional popping noise. Rebuilt the caliper and the issue was resolved.

It's in rain-mode here in the Bay Area, so I'll look when it stops later this week. Good call about the rear calipers as the parking brake needs to be pulled pretty good in order to hold the car - they may just be worn and in need of some service. I believe the last time I looked the carrier bearing allowed a little radial motion.

What program are you using to monitor the real-time signal in graphical form? FreeSSM doesn't seem to do that...