Groan, vibration, and power loss

[knobbler]

You might check your cat to see if it's plugged . The groan could come from exhaust being forced through the plugged cat when throttle is opened.

I'd thought about that as well, but it turns out a helpful burglar took off with the cat and replaced it with a straight pipe.

I think I'm on to the cause, though; I checked my throttle valve linkage again, and it's way out of whack.  I haven't adjusted it on account of throwing my back out, but I'm about to grab a stick to bite on and get it sorted.  We'll see what comes of it then.

[mo.eagles]

I'd thought about that as well, but it turns out a helpful burglar took off with the cat and replaced it with a straight pipe   
http://forums.amceaglesden.com/Smileys/default/rotfl.gif

[knobbler]

Alright, so the throttle valve linkage wasn't way out of whack.  It was completely and totally wrong.  See, when I had checked it before, I still wasn't very familiar with how it should be set.   Combine that lack of familiarity with my failure to solidly parse the TSM instructions, and the result is my completely overlooking the fact that the clamp was rust welded to the trombone slide/clevis pin looking end (I actually had to twist the pin and break it free).

Long/short, my linkage may as well have not even been there, but it's now properly set and Eagle seems to be driving a lot better as a result.  We'll see if it fixed the problem once I get to the testing hill tomorrow morning.

[knobbler]

Well hot .  I don't want to get my hopes up too much, but things are looking better.  I went up the testing hill this morning.  At the point where nastiness generally occurs, we actually shifted instead of having any of the unpleasant effects I've described in this thread. 

This is the first time there's been a proper shift at this point since this stuff started happening, so it's seeming as though there were a lot of problems that existed independently, but showed symptoms under shared conditions. 

[vangremlin]

Good deal!  Glad things are improving for you!

[amarshall]

Fingers crossed that the fix holds!  Always nice to get a win.

[knobbler]

I appreciate the hopes and well-wishing!  It saddens me to report that this did not end up fully correcting the problem.  Got the power loss and rubbing groan again today, though it was on a flat road under an attempt to quickly accelerate.  I even went up Intermittent Problem Hill without trouble. 

Eagle's been my daily driver as I work on getting the Gremlin up and running, and as much as it bums me out to think this way, I think I'm going to have to sell it.  I don't want to kick the can down the road, but I just don't have the time or resources to direct towards fixing this wagon up to the degree it needs and deserves.  If anyone's in the PNW region and wants a fixer-upper, let me know.  I'll gladly take a running AMC of pretty much any model in trade.

[knobbler]

I wanted to post an update on this in case anyone else finds that they're having a similar issue.  In the time that's passed, the situation continued to worsen to the point where Eagle didn't feel safe to drive.  As the condition worsened, I was able to get some more info.

The sounds and feelings were becoming more extreme, so they were easier to pinpoint as coming from the front.  I also started getting a really hard shudder when coming to a stop, which made me look at the brakes again.  When I had checked the brakes before, I saw no indication of anything sticking, warping, or wearing unevenly, but this time I got the IR thermometer out after a particularly rough drive and saw the front wheels were well over 100° on a day of 70° outside temps (at best).

Long short, the calipers have been grabbing, but since the issue had not gotten bad enough, I wasn't catching them in the act.  Corrosion of the pins definitely played a part, but I'm still trying to get everything smoothed out.  Not sure if the calipers have bad seals, if there's particulate getting stuck in the lines, or if it's something more exciting, but I can say that this ordeal has been caused by degradation of the brake system with some other problems muddying the waters.

Thanks again for the help, all!

[rmick]

I have had the lines degrade on the inside but outside looks good. When it goes bad internally it may allow fluid to flow to the brake but not allow fluid to return acting as a check valve. I have also had brake caliper pistons stick and not release when pedal is released. Fortunately these pats are still available.

[knobbler]

Very, very fortunately, they're still modestly priced, too!

The interior of the lines is my #1 suspect right now because of exactly what you'd said.  This wagon is on its 3rd MC since I've owned it- first had a worn piston, second was a really crappy "rebuild" job from a parts store chain, and the current one is a new unit that has been doing what it should, far as I can tell.

Between the corrosion and the 1st MC having a dissolving piston, I'm wondering how much contaminant could still remain in the system (despite the repeated bleedings).  I don't think it's too long a shot for some rust particles to have huddled up together somewhere (like in the prop valve), only to get stirred up when heat, vibration, and fluid flow wakes them up.  I may be wrong, but the fact that my fluid starts going dark really quickly (couple weeks or so?) after a full bleed seems to support that idea.

I think what I may do when time allows is a total flush of the brake system with my buddy's vac pump.  Just keep pulling fluid through until it's clear, drive it around, then do it again.  For now, I'm stopping and going when I need to, so I'm going to just keep an eye out to see what the wagon tells me.

[amarshall]

Thanks for posting the updates.  Too many of these threads trail off into nothing.  Glad you've figured out which system is causing you problems, at least.