Welcome to the North American Subaru Impreza Owners Club Tuesday October 21, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 05-10-2003, 02:52 PM   #1
Sam_P
Scooby Newbie
 
Member#: 17036
Join Date: Mar 2002
Location: Coquitlam
Vehicle:
2002 Impreza 2.5RS
Black

Unhappy Elusive Cold Start Issue

I'm having a problem with my '02 Impreza 2.5RS. It has 13k kms on the clock, and it has all the factory recommended maintainence done so far by the dealer at all the correct time intervals.

Before someone flames me, I know I should do a search first. But I'm really at a loss with what exactly to search for - I'm not exactly sure where to begin. The dealer has tried to diagnose the problem, but has come up with nothing and said it was not a known issue. Perhaps someone who has had this problem could just show me where to look. Any advice you guys could give would be much appereciated.

The problem is as follows - on cold starts, the engine would sound totally different. From idle to 2500 rpm, the engine would take on a completely different tone, extremely harsh and extremely rough sounding. It almost sounds like it putters. This happens in all gears. A good description would be it sounds like jackhammers in the distance, like a construction crew digging away somewhere far. Almost a vibrating noise. Above 2500 rpm, the engine sounds normal.

You know that growly sound flat-4s tend to make (when normal)? Well imagine that, and rough it up, make it growl more, but sound all out of sync. This is the sort of noise.

I know my description may not be very good, but this is the best I could come up with. Maybe if I catch it again I could record it.

The biggest problem is this - the problem is very, very elusive. Over the past month, I've cold started just about every day, but it's only happened on two occassions. The first time, it lasted a very worrisome 15 minutes and disappeared as I drove. The second time, I only drove the car 15 minutes and when I restarted the engine the noise was gone.

I brough it to the dealer yesterday, and they couldn't find any faulty codes from the computer (I didn't think they would, the CE light was never lit). They wanted to keep it overnight to do a cold start, but I doubted that they could make the problem appear, so I brought it home. They suggested that I just wait till the problem occurs more frequently, or is more repeatable.

So what do all of you engine gurus out there think? Has anyone experienced this with their Subaru?

I don't even know where to start. I know it has only happened twice in the past month but when it's happeneing it's very disconcerting.

Sorry for the long post. Any help will be much appereciated.
* Registered users of the site do not see these ads.
Sam_P is offline   Reply With Quote
Old 05-10-2003, 03:15 PM   #2
Pat L.I.
Scooby Specialist
 
Member#: 20498
Join Date: Jun 2002
Chapter/Region: NESIC
Location: West Haven CT
Vehicle:
2006 WRX TR
Aspen White

Default

while i dont have anything to solve your problem i will state that for the first 10 minutes when i cold start my car it sounds completely different then when it is warmed up, this i believe is normal. I just let my car warm up for a few minutes before i start driving it. and usually the noises are gone by the time i start driving.

and i hear some strange noises from the intake, and everything just seems to creak more.
i guess try letting it warm up longer. You also might want to let the dealer have it for a night and then cold start it in the morning. Just ask them if you can drop it off late at night when you are about to go home then just catch a ride home with a friend and pick it up in the morning.
keep this post updated im interested
Pat
Pat L.I. is offline   Reply With Quote
Old 05-10-2003, 05:43 PM   #3
dorikin
Scooby Newbie
 
Member#: 30640
Join Date: Dec 2002
Chapter/Region: E. Canada
Location: west with the night
Vehicle:
2012 impreza 2.0 ltd

Default

can you be any more specific as to what it sounds like?

maybe search for "piston slap" or "cam ticking" and see if that helps at all
dorikin is offline   Reply With Quote
Old 05-13-2003, 01:57 AM   #4
Sam_P
Scooby Newbie
 
Member#: 17036
Join Date: Mar 2002
Location: Coquitlam
Vehicle:
2002 Impreza 2.5RS
Black

Default

Basically, the engine makes a different, much rougher noise.

It doesn't want to rev quickly or smoothly...

I guess I'll wait till it gets worse.

Thanks for the two comments. I guess no one has come across this before.
Sam_P is offline   Reply With Quote
Old 05-13-2003, 10:38 PM   #5
Cujo31
Scooby Newbie
 
Member#: 19843
Join Date: Jun 2002
Chapter/Region: MWSOC
Location: St. Louis
Vehicle:
2000 2.5 RS Sedan
Silverthorn Mettalic

Default

If you've got a friend at a diagnostics shop, get your front o2 sensor scanned - as in have the voltage waves plotted as the car is driving.

When my front sensor was going bad, but not bad enough to show a CEL, I had similar symptoms.

I got a sensor plot, and the voltage coming from the sensor was very erratic below 4000 rpms, as sign it was going bad.

just an idea...
Cujo31 is offline   Reply With Quote
Old 05-13-2003, 10:41 PM   #6
Jejunum
Scooby Specialist
 
Member#: 15773
Join Date: Feb 2002
Chapter/Region: MWSOC
Location: Madison
Vehicle:
2011 Impreza WRX
Silver

Default

i have the same problem ... i think

question do you drive an automatic?

sometimes when the engine is cold I have a bit of hesitation then a surge between 750-1500 rpm ...
Jejunum is offline   Reply With Quote
Old 05-14-2003, 01:21 AM   #7
syncros
Scooby Newbie
 
Member#: 30032
Join Date: Nov 2002
Location: calgary, alberta, canada
Vehicle:
2005 Impreza wagon
black

Default

Could be the cam belt tensioner. I had cold start problems similar to what you've described - the engine sounded awful until it warmed up. The solution was to replace the cam belt tensioner. At least suggest this to your dealership as a possible cause - they may be willing to change it out to see if the problem goes away.
Syncros
syncros is offline   Reply With Quote
Old 05-14-2003, 03:38 PM   #8
Matt
Allergic to turbos
Moderator
 
Member#: 181
Join Date: Aug 1999
Chapter/Region: MAIC
Location: MAIC & Southeast
Vehicle:
2009 Forester

Default

Quote:
Originally posted by syncros
Could be the cam belt tensioner. I had cold start problems similar to what you've described - the engine sounded awful until it warmed up. The solution was to replace the cam belt tensioner. At least suggest this to your dealership as a possible cause - they may be willing to change it out to see if the problem goes away.
Syncros

I agree. I had the exact same problem on my '02 OBS and it happened at around 11k miles. New tenstioner and timing belt and it works great now.

Over time it will get worse and sound like someone is tapping on the block with a hammer. Its gets to a point where it will do it even when the engine is warm.

Best of luck,
Matt
Matt is offline   Reply With Quote
Old 05-14-2003, 07:23 PM   #9
obyone
Scooby Specialist
 
Member#: 16523
Join Date: Mar 2002
Chapter/Region: MWSOC
Location: Inbetween Hesco's and T-walls
Vehicle:
JDM Maxxpro

Default Re: Elusive Cold Start Issue

Quote:
Originally posted by Sam_P

The problem is as follows - on cold starts, the engine would sound totally different. From idle to 2500 rpm, the engine would take on a completely different tone, extremely harsh and extremely rough sounding. It almost sounds like it putters. This happens in all gears. A good description would be it sounds like jackhammers in the distance, like a construction crew digging away somewhere far. Almost a vibrating noise. Above 2500 rpm, the engine sounds normal.
Sorry for the long post. Any help will be much appereciated.
You're gonna want to read this. I think you may have had the same problem I had. My engine noise only happened when it was cold aswell.

http://forums.nasioc.com/forums/show...hreadid=297045
obyone is offline   Reply With Quote
Old 05-15-2003, 01:18 AM   #10
Sam_P
Scooby Newbie
 
Member#: 17036
Join Date: Mar 2002
Location: Coquitlam
Vehicle:
2002 Impreza 2.5RS
Black

Default

A massive thanks for all the replies.

I think I have a much better feeling for it now. Im 70% sure it's the problem being described in the thread obyone posted.

I remember the first time it happened it had been left outside overnight.

Thanks again, all!

P.S. Going to the dealer tomorrow, wish me luck! Will let you guys know how it goes.

Last edited by Sam_P; 05-15-2003 at 02:57 AM.
Sam_P is offline   Reply With Quote
Old 05-15-2003, 05:36 PM   #11
Sam_P
Scooby Newbie
 
Member#: 17036
Join Date: Mar 2002
Location: Coquitlam
Vehicle:
2002 Impreza 2.5RS
Black

Default

Ok, went to the dealer today.

I told them what you guys suggested, and they've ordered a new tensioner for me.

I'm not sure if they actually saw a faulty tensioner or even inspected it, but the rep said they've done this before for others. I was there getting other stuff looked at.

So I'm getting it fixed in a week or so. Didn't have to leave it overnight.

Hopefully it's under warranty and hopefully it'll get rid of the problem!
Sam_P is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cold Start Issues ejh25 Other Engine Management 6 09-05-2007 10:51 AM
Strange cold start issue mxboy15u UTEC 7 04-30-2007 04:55 PM
Cold Start Issues SubaruCO Forester Forum 6 12-03-2004 01:31 PM
Cold Start Issues seven881 Normally Aspirated with bolt-on Forced Induction Powertrain 8 11-13-2003 12:26 PM
WRX manual cold start issue ort5 Transmission (AT/MT) & Driveline 10 12-17-2001 03:54 PM


All times are GMT -4. The time now is 07:41 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.