nube to sube oil change question

[briang03outbackk]

hello everyone new to the forum just bought my first Subaru 2 days agoit's a 2002 outback with the h4 2.5 with the 5 speed manual it has a lot of miles 160,000 but it is in really,really good shape and I pretty much stole it off the guy for 1200$so here's my question i'm going to change the oil just because I do not know the last time it was done and the guy I bought it from did not know any of the service info as it was his deceased sisters car so I don't know if it had synthetic or regular dino oil in it also I have a hunch it probably has the wrong weight in it because I live in the northeast (CT) and its kinda cold here at night (mid 30's) and when I first start it when it's cold I can hear the top end clicking pretty good for a bit until the car gets nice and warm, then it's quiet, I have a feeling it has 10w30 or 10w40 in it instead of the recommended 5w30 so what should I or can I do can I safely go back to the recommended 5w30? and should I go with either a synthetic, a regular old dino oil, or a synthetic blend? I'm going to change the oil tomorrow the reason I'm asking is because it has high miles and I do not want to cause any unnecessary leaks I also let it run for an hour in the guys driveway plus took it for a ride before I bought it just to make sure both fans came on and there were no overheat issues or check engine light or anything else you need to check when you buy an older used car the oil on the dipstick isn't too dirty but it def could be changed and the only other issues I saw were an old battery (I changed it to a brand new gold model 640 cca one I picked up at my local aap tonight) and low coolant in the reserve bottle I will def keep my eye on that because the only thing I keep hearing is these cars are head gasket nightmares and I don't know if they were ever done or not and not that it really matters but after having it sit in my garage for a couple days now there does not appear to be any fluid leak spots on the floor under it thank you everyone in advance glad to now be the proud owner of an 02 outback

[briang03outbackk]

also this off the mobil 1 site kinda makes me nervous just because I am questioning what type of oil was used in it previously if I go with a synthetic that you guys recommend
The only exception to this is with a higher-mileage engine that has never used synthetic motor oil, or with an engine that has used conventional motor oil and been poorly maintained. In these cases, you should still follow the same basic oil-change procedures (drain the old oil, remove the old oil filter, put in new Mobil 1 and put on a new oil filter), but you should follow a regimen of one or two shortened oil-change intervals. For instance, let’s say that your regular oil change interval is 5,000 miles. If you’re switching to Mobil 1 under the circumstances mentioned above, make your next Mobil 1 oil change in 2,500 miles, your third Mobil 1 oil change 3,500 miles after that, and then follow your normal 5,000 mile oil-change interval. The reasoning behind this staggered interval is that a high-mileage engine, or one that has seen infrequent oil changes, will likely have a considerable build-up of sludge and deposits. Mobil 1 will help clean the engine as you drive, but it will have to work much harder in a very “dirty” engine, and so it is best to change the oil more frequently for those first few thousand miles. After that, you can rest assured that Mobil 1 is continuing to keep your engine running clean and well lubricated for mile after mile

[1 Lucky Texan]

Synthetic oil definitely has the ability to hold 'varnish' in suspension and will often appear dark when changed (darker than regular oil for the same interval) and, as you mention, will begin cleaning that same varnish from the inside of an engine run with 'conventional' oil.

But, I'm not sure anyone has convincing evidence that 'varnish' inside the engine is particularly harmful. It 'seems' like it would be bad - but both engines and conventional oils are better nowadays than they were in the past.

I do my own maintenance and some repair work so, when possible, I upgrade parts and fluids. I use synth. 5w-30 in the winter and 5w-40 in the summer here in Texas. As my cars age, I am probably gonna stay with the Rotella T6 5w-40 year round.

there have been, and always will be sometimes heated discussions about engine oil.

You might enjoy reading at - Bob is the Oil Guy and see what oil analysis is all about. And search for older threads about oil.

just make a personal decision you can live with. Synthetic oil will not repair anything that's broken and cannot cover up any previous wear. On a used car with high mileage, it may be a waste of resources.

[bluesubie]

The sound that you hear is probably typical Subaru piston slap. According to the owner's manual, 10W-30 and 10W-40 can be used down to -4F.

If you're thinking of Mobil1, I would use the High Mileage version. Otherwise, other High Mileage oils like Valvoline MaxLife synthetic blend or Pennzoil conventional High Mileage should all work well.

-Dennis

[TooSlick]

If you change to synthetic, try something a bit more viscous like a 5w-40. The first batch of synthetic will slowly clean out built up sludge varnish deposits. What I'd recommend is to do the first two oil/filter changes after 5000 miles. Starting with the third oil change you can run 7500 miles between changes, or even more if you verify it through oil analysis testing.

Dont skimp on the quality of the oil filter! Use something like a Mobil 1, or one of these new Bosch synthetic media filters. These have more dirt holding capacity than a cheap cellulose filter and will also capture smaller particle sizes.

TS