Subaru

Have Subaru questions? Ask a Subaru mechanic and get answers ASAP

Ask an Expert,
Get an Answer ASAP!

Osmond, My 2006 subaru legacy has a rough idle in the cold…

Customer Question
Osmond, My 2006 subaru...

Osmond, My 2006 subaru legacy has a rough idle in the cold which affects the electrical system( lights, fans). It goes away once the car is at temperature I changed wires, plugs cleaned Mass air flow sensor, cleaned pcv valve and just tested my alterantor and it is reading 14.5 -14. 7

Mechanic's Assistant: Thanks. Can you give me any more details about your issue?

It does not throw a code I also replaced the engine temp sensor and put sea foam in to clean the engine. Still same problem

Submitted: 2 years ago.Category: Subaru
Show More
Show Less
Ask Your Own Subaru Question
Answered in 8 hours by:
1/24/2016
Subaru Mechanic: peterpete190, Auto Technician replied 2 years ago
peterpete190
peterpete190, Auto Technician
Category: Subaru
Satisfied Customers: 33,355
Experience: Auto repair Technician with 17 years experience.Past ASE and other certifications.
Verified

My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.

Since there is an electrical fault with the rough idle and is most affected when cold or in the cold this sounds like a possible electrical connection fault causing this here.Inspect the battery cables for any issues and if any issues are found this will need corrected.If the cables are corroded they will need cleaned and if they are damaged they will need replaced.If these are or were already checked and found o.k. let me know so we can continue.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Ask Your Own Subaru Question
Customer reply replied 2 years ago
I verified the cables are clean and undamaged.
Subaru Mechanic: peterpete190, Auto Technician replied 2 years ago

Can you tell me how the electronics are acting up on your vehicle here,what they are doing when this occurs?

Ask Your Own Subaru Question
Customer reply replied 2 years ago
It only happens when i start the car. It is worse in the cold. The idle is "missing" every so often and when it does, it affects the lights as they dim. Once the car is warmed up, I have no issue.
I cleaned the ground wires and it still did it. I also tried some belt dressing on the altenator belt and that appears to have had an affect. I will know for sure later today when I start the car up as it is cold here.
Subaru Mechanic: peterpete190, Auto Technician replied 2 years ago

If the belt was slipping around the alternator this can cause this type of fault here and the cold will affect the belt from gripping on the alternator properly.I have had to replace the belt before when it was worn slipping like this here.If you applied belt dressing and this helped the issue here this may be the case and the belt may need replaced to correct this fault.I would check and see if this is the cause here as well as make sure the alternator connections are clean and tight.

I would have the alternator tested as well as even though it is putting out voltage the amperage from it may be weak when cold causing this here and it may need replaced.

Thanks Pete

Ask Your Own Subaru Question
Customer reply replied 2 years ago
It happened again today despite the belt dressing. Other than the alternator, could there be another cause
I will follow through to test the amps
Subaru Mechanic: peterpete190, Auto Technician replied 2 years ago

It sounds like an electrical fault here.I would have the amperage tested from the alternator and maybe check for any loose or damaged battery cables at the battery or alternator and starter.Check for any loose or damaged wiring for this fault.

Thanks Pete

Ask Your Own Subaru Question
Customer reply replied 2 years ago
I went and started the car, put the voltometer on it, had my wife turn on the air conditioner, high beams, radio and the voltage stayed the same, no drop so I assume the amps are fine.Any other thoughts.
Subaru Mechanic: peterpete190, Auto Technician replied 2 years ago

This is a tough one for me to answer fully myself.I will have to open your question up for others here to see if anyone else can assist further.I hope you can get this resolved with ease.

Thanks Pete

Ask Your Own Subaru Question
Customer reply replied 2 years ago
Pete:Have you heard from anyone else about what may be causing my issue?
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a subaru mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask peterpete190 Your Own Question
peterpete190
peterpete190
peterpete190, Auto Technician
Category: Subaru
Satisfied Customers: 33,355
33,355 Satisfied Customers
Experience: Auto repair Technician with 17 years experience.Past ASE and other certifications.

peterpete190 is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry.

Stephanie PElm City, NC

used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future.

David L.Richmond, TX

9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much.

PhilMarysville, CA

Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible.

CharlesWalnut Creek, CA

As a single woman, I really appreciate an excellent and affordable opinion.
Thank you Geordie, I will not hesitate to contact justanswer in the future!

SueCharleston, WV

Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff.

JimCastleberry, FL

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

< Previous | Next >

Meet the Experts:

Kevin C.

Kevin C.

Subaru Master Tech.

1,727 satisfied customers

34 years of Subaru service experience, ASE Master Technician.

George H.

George H.

Subaru Certified Technician

1,349 satisfied customers

ASE Master Tech 15 + Years

Tim Mohr

Tim Mohr

ASE MASTER TECH

418 satisfied customers

30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL

Matt

Matt

Engineer

373 satisfied customers

Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing

Chris(aka-Moose)

Chris(aka-Moose)

Subaru Technician

332 satisfied customers

16 years of experience

Ron Z.

Ron Z.

- Subaru Tech -

260 satisfied customers

18+yrs experience. State Inspector and Subaru Diagnostics

Don - Mo Lurch

Don - Mo Lurch

Subaru Mechanic

193 satisfied customers

Heavy Line Mech, Race Shop Owner, Mobile Electronics.

< Previous | Next >

Related Subaru Questions
1997 Subaru Legacy L Postal Car. Engine will not idle on its
1997 Subaru Legacy L Postal Car. Engine will not idle on its own and runs really rough when trying to keep running.… read more
tamaz22
tamaz22
60 satisfied customers
Subaru Legancy: What would cause a 1996 Subaru Legacy AWD with
What would cause a 1996 Subaru Legacy AWD with a4-2212 2.2L SOHC to start when cold only if you hold the accelerator pedal to the floor and sometimes it starts. After it is warmed up there is no probl… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
I have an 08 subaru legacy gt limited, with a rough idle
I have an 08 subaru legacy gt limited, with a rough idle throwing misfire codes on all 4 cylinders. So far, I have replaced the intake manifold gaskets, the maf sensor, and the fuel pump. The fuel pre… read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
Subaru Impreza WRX: I am working on a 2002 subaru impreza wrx
I am working on a 2002 subaru impreza wrx 2.0 turbo I have a readining on oxygensensoe at idle of 3.71 volts is this a wide band sensor or is there bleed over from heater circuit. it shows 0 voltage a… read more
Arench
Arench
President
CT State GED w/ Honors
1 satisfied customers
2001 Legacy Outback: engine running..running rough..weather..iat/MAP
carguy1, I was on here reading your conversation from a little over a year ago with a person who was having an issue with their 2001 Legacy Outback with the 2.5L non turbo engine running rough at idle… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
legacy outback: runs rough..it warms up it runs..runs great..gas pedal
my legacy outback 2.5 has check engine lite on and it misses and runs rough will the thing is cold but after it warms up it runs great.! i have changed the mass air flow sensor but that changed nothin… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
1998 subaru legacy outback: runs fine..) closed loop is reached..rich
1998 subaru legacy outback 2.5 runs fine cold when (i am assuming ) closed loop is reached runs very rich… read more
JacobTD
JacobTD
Diagnose Specialist
Master
46 satisfied customers
98 subaru legacy outback: sensors, disconnected mass air flow to see
Have 98 subaru legacy outback that will not start on cold mornings. Have replaced fuel pump, battery, cam&crank sensors, disconnected mass air flow to see if it would start with it disconnected, no co… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
Subaru legacy ls: 2.5 liter AWD and i..gas pedal..dies..ignition coil
I have a subaru legacy ls 2.5 liter AWD and i have had this car almost a year now and it worked fine all throught winter here in fairbanks alaska but now whenever i press down on my gas pedal too hard… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
I have a 1996 Subaru Legacy Wagon. My engine is idleing very
I have a 1996 Subaru Legacy Wagon. My engine is idleing very rough. I just had new plugs and wires installed in March 2010. I removed the plugs - cleaned them and re-gaped them. Still no difference. I… read more
Steve7654
Steve7654
Service Manager/ Technician
4 satisfied customers
98 Legacy GT: sus 2.5 5 spd..non-turbo 165k...previous owner
'98 Legacy GT sus 2.5 5 spd. non-turbo 165k. Airbox modified (removed by previous owner). foam air filter, I keep it clean and oiled properly. Poor idling when cold, I live in Utah, it gets cold. I ca… read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
Subaru Legacy: I put the third O2 senor on my car..check engine
I have a 06 Subaru Legacy. I put the third O2 senor on my car in November 09. In January 10 the check engine starting on and off. Found out that the code was P0137, the O2 sensor again, as well as cod… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
1998 Subaru Legacy Outback: run fine..the ignition coil pack
I have a 1998 Subaru Legacy Outback that will start and run fine, but if you turn the car off will not start again when the engine is hot. The car will start and run fine after the engine has cooled t… read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
1996 subaru legacy outback: stalled at a light..rough idle and loss
1996 subaru legacy outback stalled at a light and would not start for 2-3 min. When it started rough idle and loss of power. Let it run for 5 min cleared up??? No check engine light came on. Happened … read more
Tim West
Tim West
Service Manager
Computer/ Automotive certifications
16 satisfied customers
91 Subaru Outback: rough..it warms up..under load..check engine light
I have a 91 Subaru Outback that runs inconsistently rough after it warms up. The car back fires while under load and returns a check engine light. I don't have the codes though. With a tech friend of … read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
93 subaru legacy: engine light..cooling fan..spark plugs..lean
I have a 93 subaru legacy that is hard to start when its cold ,engine light is on but I cant get any codes out of it . when i turn on the key both cooling fan go on . spark plugs seem to be on the lea… read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
1997 subaru: driven..engine or manifold..im idling..cools down
My 1997 subaru out back legacy will not start for a long time after i have driven it and turned offthe engine. If i pour water on the engine or manifold, it will start and run ok, sometimes until i st… read more
Archer
Archer
High School or GED
31 satisfied customers
2002 Subaru Legacy Surges at idle and slow throttle response,now
2002 Subaru Legacy: Surges at idle and slow throttle response,now CHECK ENGINE light came on. What is up?… read more
karrs2fix
karrs2fix
Master auto technician
Vocational, Technical or Trade Scho
548 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x