Slow after tune-up/timing belt changed

I recently had the 105 and 120k service done (car has 115k so I just did them both) on my 05 LGT MT and I swear the car is SIGNIFICANTLY slower now. I also had a camshaft position sensor replaced at the same time (car was stalling and had CEL lights). It doesn't even feel like it is a turbo anymore. The shop says that the car is in 'default mode' because they reset ECU, and that the car will get better over the next 100 miles or so.

 

Is that true? It sounds flaky to me, but this is a pretty reputable shop...

 

Could they have screwed something else up during the service (cam timing wrong, wrong plugs)? The car runs great otherwise and gets better mileage...it is just SLOW.

 

Ideas? TIA

Cam timing possibly. How's the idle?

The car runs great in all other respects...starts easily, idles smooth, gets great mileage...it feels like I only get about 1/2 the power...

May be they knocked a vacuum line off of the turbo system. Isn't there some little sensor forward of the intake manifold on the top right hand side of the engine that has a vacuum line going back to the turbo?

For timing belt on a Subaru, I'd stick with a dealership or an import shop that specializes in Subarus. It's just too much work to trust just any guy with a set of tools and an Alldata subscription to do it properly.

and that the car will get better over the next 100 miles or so.

 

True... but not for the 1/2 performance... !

Since the car runs great otherwise I would check the vacuum lines and also the wastegate on the turbo.

 

And I would also check the turbo itself - just in case someone lost a nut into the exhaust or intake and jammed it. That would really suck.

This is ridiculous. This morning I couldn't keep up with a Prius going over the coastal mountains...and I don't think he was even racing me. Can anyone tell me more about the vacuum lines to the turbo? Do they need to be disconnected for a timing belt change or major tune.

 

By the way, the shop was Kunos in Redwood City...they came highly recommended and specialize in Subaru, Toyota, and Honda/Acura

Default mod will not cut your power in half.

 

When you plug the negative battery cable for a minute or so it resets the ECU. The care should run fine.

 

I did my own timing belt and the car was the same afterwards. They messed something up.

For timing belt on a Subaru, I'd stick with a dealership or an import shop that specializes in Subarus. It's just too much work to trust just any guy with a set of tools and an Alldata subscription to do it properly.

What's so special about the timing belt in a Subaru...

^^^^ +1

 

Not much, if you've done one timing belt, you can do em' all.

 

I'd bring it somewhere else and have them check the timing anyway though.

I vote on screwed timing belt job.

 

They are feeding you BS. Look up vacation pix with timing belt info, have them remove timing belt covers and count the teeth on the belt as the vacation pix say.

What's so special about the timing belt in a Subaru...

 

4 camshafts ==> more chances to screw up

 

Apparently they took advantage of this opportunity...

Exactly -- the more there is to line up, the greater the chance someone wasn't taking their time. It's not rocket science but it isn't a Civic either.

Okay...here is the latest. The mechanic said that the car has no faults stored in the ECU and they checked the cam timing and it's okay. They can see that the turbo starts to spool up, but for some reason doesn't reach full boost. They suspect two possibilities: 1) the car is dumping the boost because it is detecting a knock due to bad gas, or 2) the turbo is bad and not generating full boost.

 

I doubt that it is the gas because I have filled the car a couple of times, and I have trouble thinking of a failure mode where the turbo just 'kind of' works.

 

They say the next step is to dig into the turbo to see if it is functioning correctly--4 hrs of shop time (ouch). We agreed that I should run a few tanks of gas through the car just to make sure it isn't the gas.

 

Are they overlooking something (bad knock sensor?) that would cause the car to dump boost??

 

Any help is greatly appreciated!!

 

By the way--the shop did this diagnostic work for free (kudos to Kunos of RWC)

Any number of issues could cause your turbo to be limited to wastegate pressure (which is what it sounds like). Resetting th ECU should put you back to full boost if it's bad gas. If you reset and no full boost, it's most likely not bad gas. If it is full boost, then it may be the gas, so drive carefully so you don't over knock at first, and then run until you can put better gas in.

 

Bad turbo? - that's a stretch considering it happens to "fail" right after they work on your timing belt. I would have them check for vacuum leaks... Other's may chime in here as several things can contribute to turbo only reaching WG duty. Not enough info to tell from this end.

Subscribed.

May be they knocked a vacuum line off of the turbo system. Isn't there some little sensor forward of the intake manifold on the top right hand side of the engine that has a vacuum line going back to the turbo?

 

 

Did they check for a vacuum leak ? That's the easy fix.

1, Get a compression test pronto:mad:

 

2. If compression test is ok, the timing belt is a half tooth off. Common for 4 camers.

 

3> my bet is the belt is a half tooth off. That can impact the timing by as much as 20 degrees, but you won't always throw a code.