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weird clacking noise


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this only seems to happen when I'm moving slow (<5 mph) or idling in gear, like at a red light. It's hard to explain but it's an irregular clacking sound, and it's very loud (and embarassing when sitting at the red light). I thought it might be loose heat shield or exhaust or something, but then it only happens when the car is in gear. Here's my best impression in writing,

 

clack...clack...clack clack...clack...clack clack clack...clack...and so on

 

Of course, everytime I try to replicate it and get under the car to look around, it stops doing it, so I don't even know where to start looking. Could it be a tranny problem since it only happens in gear? Any ideas?

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idling in gear while stopped? but not in neutral.. i guess throwout bearing. maybe a throwout bearing clip.. less $, same amount of work to fix :P

 

check your trans gear oil too, like subiemech said. maybe you'll luck out on the cheap fix.

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Your profile shows a 1990 Loyale, so....

 

I had a similar problem last summer. I characterized it like this: Only on deceleration, at about 2200 rpm. Like when you rev the engine at curbside and let off the gas, or coasting downhill in gear. And only when the engine was good and hot.

 

The rattle was my catalytic converter. I think the "brick" inside cracked, or it just got loose inside the housing. It took a certain frequency and backpressure to set it up in a harmonic rattle. Sometimes people on the sidewalk would duck like a machine gun was headed their way.

 

I used a stethoscope to narrow it to the exhaust (hard to do when the rattle was so touchy to reproduce). To be extra sure, I put the car up on jacks, ran it till it was hot, had my wife feather the accelerator while I slid underneath to isolate the sound 100% certain. Pounding on the Y-pipe with a mallet (hot or cold) never did any good, it didn't uncover the rattle.

 

I ended up with a new Y-pipe, which fixed the problem.

 

Worth checking..... If you can reproduce the sound at curbside, use a stethoscope (a l-o-n-g screwdriver or wooden dowel held to your ear).

 

-- Mark

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Great thread! I am having a similar problem, only it comes and goes. I always thought it was loose heat shields on the exhaust.......crawled under and checked, none would budge. The "Y" pipe joins the main pipe, there is a spring-over-bolt set that holds the whole mess together.....could this be the trouble?

 

Also, what/where is the cheapest/best place to get a replacement Y pipe? I need an O2 sensor anyway, so I can kill 2 birds with one stone :) .

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Weird, my Loyale does the same thing. I always thought it was just a loose heat shield or something. At about 2000 or so, the car makes a rattley "cank cank cank cank cank" sound - kinda like the drum line on "St. Anger," only less annoying.

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Yeah, I kinda figured living with it was going to be the best bet. It's been rattling down there since a few months after I bought the car, so I guess it must not be anything too serious. Just one of the EA82's "special features," I guess :) .

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as usual, as soon as I post a problem here, the solution presents itself...

 

The car finally did it for me when I got home last night so I had a chance to crawl under a look around. I'm 99.9% sure the sound is just coming from the heat shields just behind the donut. The sound seemed to just start out of the blue one day so I'm thinking either a rock got in there or something inside broke. I could stop the sound by pressing my foot against the pipe. I guess the pipes got to resonating just right when the car was at real low rpm.

 

In any case, I have an appointment at Midas tomorrow to get that exhaust mess cleaned up...this is just one of several exhaust problems anyway.

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Erik --

 

About a rattling catalytic converter....

 

I checked all the exhaust places -- shops and online -- and I found lots of options. But most were generic cats that had to be welded on, a few online sites have aftermarket Subaru Y-pipes but I had doubts about exact fit and heat shield quality...... And the best I could do was about $30 cheaper than going to a Subaru dealer -- honest. Got a Y-pipe at Lithia Subaru (Oregon City) for $240, I think it was. Not bad, considering. Midas wanted $350+ just to weld on a replacement cat.

 

Only other option for exact fit is a junkyard, but this is one thing that doesn't make much sense to substitute a used 100Kmile part. And in this area, I think it's illegal for JYs to sell used cats.

 

The spring-loaded bolts hold the Y-pipe to the mid pipe. Between the pipes is a lead donut. This should be replaced (about $10) if you're swapping Y-pipes. I think if the exhaust is rattling and it's not the cat, it's probably the heat shields. Either a spot weld broke, or a pebble got between them. As long as the mounting brackets are good, the exhaust itself shouldn't rattle.

 

I tried to live with the rat-a-tat, too, but it progressively got louder. I got tired of people ducking as I passed by, or the guys gathering round in the parking lots trying to diagnose the trouble. Once I left when two guys got into an argument whether it was a rod bearing or a timing belt pulley. A new Y-pipe has made my life a lot quieter...

 

-- Mark

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Ouch! on that Y pipe...............I was hoping it wasn't so bad, $$ wise. I have dumped over $700 into my car since Mid-December...........Thought I could take a break on the spending for a while..............My Pass. side CV boot is out too.................:banghead: . When it rains, it pours!!! :rolleyes:

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Put my car on ramps and crawled under it yesterday...............found out that I did have a missing bolt in the heat shielding at the rear of the Y pipe cat.......that cured half my rattle, but..........the CAT on the main pipe?...........The guts are loose inside, I shook it good when it was hot (welding gloves).

 

Also, I shook the the Y pipe and noticed the motor moves around a bit more than I thought; though the mounts appear to be sound. Tranny mounts seem to be "pre-loaded" toward the passenger side..........like the engine is torqued clockwise from the front? Is this condition normal or is it time for new mounts?

 

Sorry for the hijack.............

 

Back to "weird clacking noise"..........:)

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