96 Legacy wagon idles like a choo-choo train

[Green96GT]

96 Legacy GT, auto, 180K

 

The idle isn't what I'd call 'rough' and I don't think it's a matter of the idle RPMs being low. The best way to describe it is that it "chugs" when it idles, but it's never failed to start, and has never stalled on me.

 

A few months ago the timing belt and pulleys were replaced when one of the pulleys went bad, apparently.

 

Is it possible that this problem is caused by a timing issue? I.e, the garage got the timing wrong, or the belt has jumped a tooth from a mistake in the repair?

 

Just looking for some ideas before I go back to the garage to have them look at it.

 

Thanks!!!

[Olnick]

Did the problem start after the timing belt job?

[Green96GT]

Yup, but not immediately. I few weeks after, at least.

[kaki]

Mine did the same thing a few months back...had just done a tune up...new wires,plugs but for some odd reason forgot to change the ignition coilpack...started chugging and actually bucking...changed it and took care of the problem...in the process noticed that one of the spark plugs wires had come loose..hope this helps.

[Olnick]

How is the "general maintenance" of the engine? As kaki mentioned, new plugs and wires can often make a difference (basic NGK plugs are fine, but be sure to use Subaru OEM wires.) New coil pack probably not needed.

 

New air filter, fuel filter, PCV valve. Make sure electrical connections at spark plugs are tight. Check vacuum lines for weak connections, cracks, leaks. Might even try a Seafoam treatment in the manifold!

 

I assume the CEL didn't come on or you would've mentioned it.

 

Just some thoughts. Good luck.