3.0-H6 cold start roughness

J

JDC

Question: I have had a new 2004 3.0-H6 Outback for a about 5 weeks. I like
the vehicle a lot, it is very peppy, but when the car starts cold it revs up
and down and the idle sounds somewhat rough. Once I get underway, this goes
away and the car is very quiet. Is this rough startup, normal?
 
Question: I have had a new 2004 3.0-H6 Outback for a about 5 weeks. I like
the vehicle a lot, it is very peppy, but when the car starts cold it revs up
and down and the idle sounds somewhat rough. Once I get underway, this goes
away and the car is very quiet. Is this rough startup, normal?

If the revs are going up AND down during warm up,
sounds like the AC compressor is cycling. Are
you starting it with AC on, or defroster blowing?
 
If the revs are going up AND down during warm up,
sounds like the AC compressor is cycling. Are
you starting it with AC on, or defroster blowing?

I also have a 2004 3.0-H6 Outback (35th Anniversary Edition), and I am
experiencing the same rough start problem. In the mornings when I
leave for work, my Outback will sometimes take two tries to get
started, at which point it will run extremely rough for about 30
seconds (sounds like it's running on about 3 or 4 of the 6 cylinders),
with the idle speed going up and down several times, as if it can't
decide if the engine is cold or warm.

Even with all power accessories turned off (air conditioning,
headlights, stereo) the problem still happens. Strangely enough, it
doesn't happen every single morning, but on most mornings it does
happen.

I was thinking about pouring some fuel injector cleaner in the gas
tank and seeing if that remedies the problem. If that doesn't work,
I'll probably video tape a cold startup and then bring the car and
camcorder into the dealer service manager and let him see what is
happening. In my opinion, my new car should be starting on the first
turn of the key, and it should run smoothly afterwards.

If anyone has any other experiences with this, please post. Thanks.
 
JDC said:
Question: I have had a new 2004 3.0-H6 Outback for a about 5 weeks. I like
the vehicle a lot, it is very peppy, but when the car starts cold it revs up
and down and the idle sounds somewhat rough. Once I get underway, this goes
away and the car is very quiet. Is this rough startup, normal?

What kind of gas are you using? My wife's OB had the same problem.
She took it in once and the dealer sent the ECM out for a replacement.
That didn't fix it, so she took it back. The dealer checked
everything and found nothing wrong. The dealer said that it was
running roughly at startup because she was using regular gas (87
octane). I thought it was bogus, but she started buying better gas
and the problem went away.
 
What kind of gas are you using? My wife's OB had the same problem.
She took it in once and the dealer sent the ECM out for a replacement.
That didn't fix it, so she took it back. The dealer checked
everything and found nothing wrong. The dealer said that it was
running roughly at startup because she was using regular gas (87
octane). I thought it was bogus, but she started buying better gas
and the problem went away.

I'm using Premium grade gas, the expensive stuff. Thanks for the
suggestion, though.
 
Question: I have had a new 2004 3.0-H6 Outback for a about 5 weeks. I like
the vehicle a lot, it is very peppy, but when the car starts cold it revs up
and down and the idle sounds somewhat rough. Once I get underway, this goes
away and the car is very quiet. Is this rough startup, normal?

ISTR that "hunting" at idle was an indicator of an intake manifold leak of
some kind, at least for some engines. Dunno about your car/engine.
 
There is a TSB for this. Make an appt. with your service dept to get the
computer flashed. The problem had to do with the engine parameters and
where the various values fell within in a range. The range was too tight
at cold startup and would produce the symptoms you describe. I had the
same problem and now it runs fine.
 
Null, do you happen to have a TSB number for this, or maybe a URL link
to more info on the Internet, so that I can point my local dealership
service manager in the right direction? I'd like to get my hands on
the documentation of this TSB if at all possible. Thanks.

David
 
I second that. It would be useful to have the TSB in hand at the dealership.
I have not found it online.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Members online

Forum statistics

Threads
13,889
Messages
67,365
Members
7,365
Latest member
BespokePowerhouse

Latest Threads

Back
Top