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bbear

2001 Legacy, engine racing (3500 rpm) from cold (10C)

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Hello,

This is my first post to this forum and am I hoping that someone will be familiar with an annoying issue my 2001 Legacy L Wagon has had, almost from new.

 

Many times I have asked my dealer to investigate, and a couple of times it was left at the dealers overnight but they have never been able to reproduce the problem. Here is a description:

 

When first starting the car in the morning, the engine revs go straight up to around 3500. I reverse out my garage and the revs drop (obviously, as I am loading the engine) but when I dip the clutch the revs go right back up again. The car takes a couple of minutes of driving down the road before they settle down to normal.

 

This only happens during certain times of the year and seems to be somewhat temperature and possibly also humidity dependent. The problem happens more often when the temperature gauge reads around 8 to 10deg C. (outside temperature can be about 4 degrees lower due to my furnace room keeping my garage warm overnight).

 

I have read in these forums of issues with cold start but these seem to be at much lower temperatures and don’t sound like quite the same problem.

 

I was wondering if anyone has any idea what could be causing this and if there is a fix?

 

My car is a Legacy L Wagon, 2.5l gasoline engine. It has 185,000 kms on the clock, but as I mentioned, this problem started happening almost from new. Because it has been doing it for so many years, I have always been concerned that long term this is not going to be good for the engine.

 

Thanks for your help

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That is too high considering that that temp isnt all that cold in the grand schem of things. Just out of curiosity what would happen if you let the car idle, how long would it take for the RPM to drop? Time it please.

 

What would happen if it did not sit in the garage over night?

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worth a look under the IAC cover.

my 1997 legacy outback had a cracked magnet.

cold starts would result in high idle maybe 2000-2500 which came down after a few minutes.

will wear on the clutch.

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That is too high considering that that temp isnt all that cold in the grand schem of things. Just out of curiosity what would happen if you let the car idle, how long would it take for the RPM to drop? Time it please.

 

What would happen if it did not sit in the garage over night?

 

My car is always in the garage overnight, partly because of security but also it means I don't have to scrape the ice off the windshield every morning. My wife has the car every morning during the week and so I don't want her to have to clean the screen down now that it is winter. I can try leaving it out overnight at the weekend however.

 

The problem is that it is so random. Sometimes there will be a period of almost a week where it does it every day, then it won't do it for perhaps a month. The random nature makes it next to impossible for me to be able to demonstrate to anyone. When I do hit a period where it is doing it regularly, I will try to record a video of it doing it.

 

I have tried just letting the car idle and it does eventually return to normal revs. It has been a while since I tried this so I can't be certain but I recall that it takes in the order of three minutes. It is a similar time to what I might expect it to take from a normal cold start (with normal revs) to dropping down to normal idle when it is warm.

 

I think the best thing is for me to pay attention a little more when it happens again and try to keep a log of when it happened, the temperature reported by the car, the garage temperature (I will have to go and buy a cheap thermometer) and the outside temperature, etc.

 

Hopefully with it being winter, it will start to happen more often, although that is no guarantee as it can do it in Spring and the Fall.

 

Note, I picked up my car from having a minor service today. I asked them to watch out for the cold start problem, but of course it didnt do it. They did check the 'codes' and said that there was nothing in the log which indicated any problem. I don't know much about this though, so perhaps this sort of problem woud not result in a 'code'

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worth a look under the IAC cover.

my 1997 legacy outback had a cracked magnet.

cold starts would result in high idle maybe 2000-2500 which came down after a few minutes.

will wear on the clutch.

 

Thanks for the suggestion. Is it easy to remove the cover, will I need special tools? Is it easy to put back?

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I like the broken IAC body theory. That fits with cold (plastic contracting making a vac leak).

 

Learn where the IACV is. Next time it does it spray the AICV with some water or carb cleaner, if the RPM changes, that is the source.

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I like the broken IAC body theory. That fits with cold (plastic contracting making a vac leak).

 

Learn where the IACV is. Next time it does it spray the AICV with some water or carb cleaner, if the RPM changes, that is the source.

 

Thanks, I will give that a try next time it happens. I just looked up 'IACV' and now I know that stands to Idle Air Control Valve, I realize that is the part the guy at the service desk said they could try cleaning at the next service (190,000) as it is a major service. Maybe the service guy had heard of similar issues before.

Are these expensive parts, is it something I should take a gamble and just get it replaced replaced anyway?

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i have seen some problems with the neutral position switch on the standard cars it wears and dosent make the conection to fix give it a turn inwards to crush the aluminum washer a bitt to move the senser closer to the trans to compensate for wear

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Seems to me I remember seeing in the FSM somewhere that the highest cold start idle should be no more than about 1800 Rpm. And that was at something like -40F degrees.

Unless the ECUs temp sensor is bad, this should either be a stuck idle control valve or throttle plate, or a manifold air leak.

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i have seen some problems with the neutral position switch on the standard cars it wears and dosent make the conection to fix give it a turn inwards to crush the aluminum washer a bitt to move the senser closer to the trans to compensate for wear

 

I wonder if this is the problem however as the high revs on startup has been happening almost from new. Sound an easy thigh to try though, so worth a go.

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Thanks for the suggestion. Is it easy to remove the cover, will I need special tools? Is it easy to put back?

 

Here's a thread that discusses it, no special tools but the cover may have some glue holding it in place. pull the cover straight up iirc, there is a strong (and brittle) magnet that wants to fight that.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=98281

 

Here's what the IAC looks like with the cover off

 

http://i444.photobucket.com/albums/qq166/89ru/EJ25/P1040145.jpg

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the outback that we were having cold idle problems with turned out to be 2 litres low on coolant toped it off and problem was gone

 

Thanks, I will keep an eye on the coolant level. It should be ok at the moment as the car had a minor service on Thurs. I think the coolant was checked as part of the service but I better make sure.

 

The next day after the service, the cold start problem happened again, but only took about 30 secs to settle down this time. Didn't have a chance to lift the hood to check on anything.

 

Temperature in my garage (according to the gauge in the car) was 6C, and outside it was -2C

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