99 Legacy Wagon - vibration/no power when cold

[mscrimge]

Hi there, I'm new to the USMB system, and you guys look really knowledgeable. So, after having taken my 99 Legacy Wagon to two Subaru dealerships, as well as a few other mechanics, I had come to the end of my rope - until I found this message board.

 

First, a little background on the car. It's got about 56,000 miles on it, and I bought it used from a dealership back in 2002. So, you see we don't drive much, and when we do, it's for short trips (<5 miles). The problems with vibration and lack of power have been happening for a couple years now, but otherwise the car runs alright. Here is a detailed list of symptoms:

 

1. When car is started cold, and switched into “Drive” (D) gear, car is slow to switch gears when going up a hill or attempting hard acceleration (e.g., to get into moving traffic from stopped position). I have to press the gas pedal to the floor to get the car to switch gears in these cases. If trying to go up a steep hill when car is cold, car will slow down to a near stop until I switch gears manually or press the gas pedal to the floor. When pressing the gas pedal to the floor to switch gears in D gear, it may take a few seconds before gear will shift.

 

2. When car is started cold, and attempting hard acceleration shortly thereafter, car accelerates very slowly at first. After a few seconds of slow acceleration, it begins to pick up quickly.

 

3. When car is still cold, and stopped while in D gear, car vibrates. If car is switched into “Park” (P) or “neutral” (N) gear, vibrating stops. I have also noticed greater than normal vibration at speeds in excess of about 50 mph.

 

4. When moving car just across the street to comply with parking regulations, car leaves strong smell of uncombusted gasoline (not oil) in its wake. This smell is probably also noticeable when starting car and initially moving it anytime, but I only have a chance to notice it when moving car this short distance.

 

5. Car decelerates more quickly than expected on level stretch of smooth pavement if gas pedal is released (no brakes applied), as though something internal is resisting movement. This is particularly noticeable if car is cold. I also feel as though the car is not running smoothly, feeling some slight grinding and that there is some kind of load on the engine, other than moving the car.

 

6. Actual fuel economy is very low. Actual fuel economy is around 17 mpg city and 20 mpg highway. Fuel economy should be around 20 mpg city and 27 mpg highway. While I understand this may be due to many factors, it may also indicate an issue with vibration, fuel waste and resistance (see 3, 4 and 5 above).

 

7. When cold, starting the car, and switching into reverse (“R”) gear or D gear, and pressing down the gas pedal, the engine speed will pick up, but the car will not begin to move for a half second. When the car begins to move, the engine speed suddenly drops lower, often causing the car to jerk once due to the sudden acceleration.

 

8. When car is cold and stopped in D gear for a time, the car will vibrate excessively (as discussed in 3 above), and the cabin fan speed will be low. After a while (can't pin down the length of time) stopped in D gear, however, the car suddenly stops vibrating excessively, and the cabin fan speed increases, as though a load has been taken off the engine and electrical system. If I move a bit in D gear and then have to stop again (e.g., in line at a stop sign or in heavy traffic), this process will repeat itself. It seems to me as though this observation may also be related to the issue in 5 above.

 

Sorry about the length of this post, but I wanted to give a detailed list of symptoms. I also have a strong suspicion that all these symptoms are related to the same problem. No mechanic, including the dealerships, have been able to help me out so far with "any" kind of diagnosis! There is no engine light, no computer messages- so they say, "I dunno". My sense is that old fashioned mechanics could figure out problems without the darned computer! I'm hoping you guys can throw me a bone! Thanks a lot.

[rverdoold]

My car is doing exactly the same (91 legacy with 2.0l 4eat). It just has to do that everything is cold. The strong smell is because of the very rich mixture, this also is the point for the low fuel economy. Driving with rich mixture is very bad for your catalytic unit. I usually start the car and have to drive 40 miles. For everything under 7 miles i take the bicycle (holland, yep). Sometimes when it is moist and cold my car even stalls when i engage gear. It also takes 10 to 15 miles to heat up the transmission oil to engage the torque converter lock-up (more fuel efficient).

The shifting from D to N stopping the vibration just means that there is no resistance for the engine to pull on. The idle speed when cold is just in some resonance of the engine.

Just 5 miles in the cold is killing oil lubricated mechanical parts.

 

Maybe change to thinner oil, more suitable for the cold, cold is everything under 40F. I also try to never exceed 2500 rpm when cold.

Edited February 19, 2009 by rverdoold
adding information

[Rooster2]

Maybe this is too simple..........but has your car ever been tuned up with new spark plugs and spark plug wires? If so, when, and how miles were roughly on the odometer? The vibration when in gear, low gas millage, and poor acceleration suggest poor combustion. A tune up with new plugs and wires may fix this.

[OB99W]

[...]So, after having taken my 99 Legacy Wagon to two Subaru dealerships, as well as a few other mechanics, I had come to the end of my rope - until I found this message board.[...]

Some of the operation you've described is 'normal', or not too significant. See:

http://endwrench.com/images/pdfs/1999Info.pdf

http://endwrench.com/images/pdfs/ExhaustInfo.pdf

http://endwrench.com/images/pdfs/LegacyIdleSum04.pdf

 

Short trips, especially in the cold on vehicles with AWD, tend to lead to poor gas mileage. Lubricants are more viscous when cold, and the fuel/air mixture is significantly enriched while the engine management system is running 'open loop'.

 

Slow engagement into Drive or Reverse is a known problem with the 1999 auto trans (4EAT) -- it's caused by a bad internal seal. I'm surprised that Rooster2 hasn't mentioned a possible 'cure' for it. See:

http://www.ultimatesubaru.org/forum/showthread.php?t=87708

 

What maintenance (preventative and otherwise) has the car had?

 

By the way, sometimes a car that consistently sees short runs can benefit from a long, hard run, perhaps with Techron added to the gas tank.

 

I do find your #8 'interesting'; I'll have to give that one more thought.

[OB99W]

Further info on 'normal' 4EAT Phase-II operation, beginning on page 23 of:

http://www.endwrench.com/current/Current6/03/InsiderInfo.pdf

 

Personally, I'm not very happy with some of the design decisions made on the 99.