Subaru running rough, help!

[grumple4]

Greetings my fellow Subaru friends, 

 

My 1993 Subaru Legacy is not feeling well and I am hoping somebody might be able to help. A couple symptoms have arisen, which may or may not be connected:

- idling rough sometimes

- check engine light comes on periodically

- very strange high pitched noise coming from dash area

 

I will try and sum it up somewhat briefly.

 

So, a few months ago the car started idling rough. I live in Minnesota and it happened right about the time winter set in, so that may or may not be a part of it. It was only happening once in awhile but it ran fine once it was going. Eventually my check engine light started coming on sporadically. It came on compleletly randomly- in any gear (it's a manual), any speed, any condition, etc. As soon as I clipped together the green diagnostic cables, the light went off and the car ran fine. The car has even not started a couple times but I just clipped the diagnostic cables and the car started. It took a few months but pretty sure I got the light to tell me code 21- the coolant sensor. 

 

I was talking to my buddy who is really good with Subarus and he was saying that the sensor might be going bad but that definitely wouldn't affect how the car runs. I picked up the sensor today to replace and hope to install it tomorrow but I'm wondering if anybody has any suggestions? What else would cause it to idle inconsistently like that?

 

So the last piece is, which I would really like ideas on, is the noise. This has been going since I have had the car (3 years or so). It only happens when it's cold and the duration depends on how cold it is. When it's maybe 20 degrees or so, the noise only starts when I am going maybe 30 mph or so and last until the engine starts warming up. However, when it's maybe 0 or below (it started in around -20 a few weeks ago) it starts right away in 1st gear and goes for quite awhile, again until the engine warms up. It's kind of a high pitched winding noise that you would hear from a plastic gear spinning too fast. 

 

Perhaps this is too ambiguous to diagnose but any ideas would be appreciated! Thanks!!!

 

Eric 

 

 

 

 

 

 

[Subieguy]

Wrong forum

[nipper]

Hell yes a coolant sensor will make the engine run poorly. Without that sensor functioning, the computer can not tell how rich to make the fuel mixture, or when to lean it out as the car warms up. A really bad CTS would keep the car from starting on cold days.

 

When was the last time the lubricants were changed. A 1993 would have a spedo cable (i think). You will have to listen more carefully, as there are very few things spinning behind the dash. Does the noise change when you depress the clutch pedal? Does i change when you apply the brake pedal? 

[grumple4]

nipper, 

 

Thank you for the response! That is good to know that the CTS can actually make it run poorly. I didn't get a chance to install the new sensor today as my 19mm socket wasn't deep enough, hopefully will get to it in the next few days. 

 

I'm not sure about the lubricants so it's probably been awhile. The noise doesn't change from what I have noticed with the clutch, brake or any other sort of action of the driver, it's all dependent on speed and how cold it is. I will attempt to listen to it this week as it will be in the -15 range again and let you know. Thanks much!

 

Eric  

[nipper]

I think the noise may be the spedo head or cable, but as with all noises, if it is not sitting in my driveway I can't be 100% sure.