'91 Subaru Recommendation

[subaru1991]

Hello Oil Guys,

Have been reading lots of posts on this site for the past week or so, and have learned quite a bit. Hoping to get some advice on a new purchase.

Have a 1991 Subaru Loyale w/ 151k. Engine idles and runs pretty nice. Has a couple oil leaks, as they usually do, I’m told. Last owner did minimal maintenance. Original owner-up to about 140k, seems to have done decent maintenance.

Tomorrow, am going to change the nasty looking engine oil. It may have been in there for 11k and 2 years. Hope not, but it's a possibility. I’m in the Chicago area. Some of the Subaru guys tell me they like to run 15-40 in older Subaru engines. Would that be too thick for cold winter starts? Am looking for something that will keep the leaking to a minimum, but still allow cold starting. I've been told that this is an easy engine to get started on a cold morning. What would you guys recommend?

 

[Quest]

AutoRx and then use 5W30 for winter, 10W30 summer, Dino ok.

Make sure you replace the valve cover gaskets and also PCV valve.

 

[bulwnkl]

I disagree with the 5W30/10W30 recommendation. I run 15W40 in my 1991 Subaru (XT6) here. If it was parked outside I'd run 5W- or 10w30 in the winter. I have found with many older engines over time that 10W40 will many times see lower consumption than 15W40. I don't know why for sure, but the 10W40 is usually not an all-fleet oil and that may be a factor.

I am just finishing the Auto-RX rinse cycle on mine. It has improved the shiny-ness inside the oil filler/valve cover, but I don't know whether it has done much else yet.

Depending upon where you motor is leaking from you should not expect ARX to stop the leaks. Many of the Subaru engine joints do not use a traditional gasket. They use tons of o-rings and lots of form-a-gasket type stuff and the ARX will not and cannot help with leaky form-a-gasket joints.

Leaks or not, if you change the oil and filter, change the PCV valve, and do all normal tune-up and maintenance items regularly you'll likely be able to drive your Subie another 150k.

 

[subaru1991]

"Leaks or not, if you change the oil and filter, change the PCV valve, and do all normal tune-up and maintenance items regularly you'll likely be able to drive your Subie another 150k."

...now that's what I like to hear, BULWNKL!

Is there anything unusual about how the boxer engine oil needs? It has been suggested to my at other sites that these old 1.8 engines are not that picky about oil, and it would be best to use the thickest oil that will allow for cold weather starting, since I'd like to keep the leaks to a minimum. And Dino all the way, no matter what grade. Some folks have recommended Lucas Oil Additive, which I have no experience with.

What do you think?

 

[bulwnkl]

No experience with Lucas; probably wouldn't use it. I've tried 10W30, 5W40, 15W40, and 20W50 in this one I have now (it only has ~105,000 miles on it), and I'll be sticking with 15W40 or a 10W30/15W40 mix UNLESS the ARX slows/stops the leaking/consumption on straight 10W30 and I don't get any hammering with it. I've run Mobil 1 10W30 in it before, but it used too much of it and I didn't think it sounded as good as with dino, so I stopped wasting my money.