hublocker

I go a second hand 95 4x4 pickup in December.

I changed oil in the V6 shortly after I got it, draining an ugly black goop out of indeterminate vintage, then I put in Castrol GTX 5-30 and a Napa gold filter.

Yesterday, after 1200 kilometres, I drained it and it was black and ugly looking oil that came out.

The vehicle odometer is at 161,000 kilometres.

Is my new oil washing out the old crud from the previous owner’s infrequent oil changes?

Should I change again in 1,000 or 2,000 km to get that puppy cleaned out?

Is Castrol GTX 5-30 too detergent?

jerryp58

I would check my plugs for oil fouling and if they're fine, I'd change the oil every 1k or 2k until it stopped getting nasty so quickly.

Actually, I would use a can of "Motor Flush" on it like I did for a couple of older, high-mileage cars I'd bought in the past (actually I used a can on the first two or three oil changes). Some people don't like that kind of stuff and worry some large clump of crud will break loose and cause a clog in a critical area. I haven't had that happen but maybe I've just been lucky.

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Jerry
2004 Frontier, King Cab, XE, 4x1, 4-cyl, 5-spd

Bror Jace

"Is my new oil washing out the old crud from the previous owner’s infrequent oil changes?"

Yes. And this is a good thing. No, Castrol oils do not have too much detergency. I recommend using any-old cheap SL or SM dino oil and cheap (Supertech) filters and do a few oil changes of about 1,500 miles each. At least 2 more should begin to clean the crud out of this (obviously) neglected motor.

When the oil makes it to the 1,500 mile mark and still looks reasonably clean, you might want to try a 15W-40 gas/diesel oil as these DO have extra detergents and dispersants and will clean the motor out more thoroughly. But use the regular, cheaper stuff first. Best to do this very gradually.

Then I'd switch to one of the 'higher-mileage' oils as they have mild seal conditioners and you might find oil consumption is a bit lower with one of these oils in the sump. They won't fix an out-andout leak, however.

jerryp58:"I would use a can of "Motor Flush" on it like I did for a couple of older, high-mileage cars I'd bought in the past (actually I used a can on the first two or three oil changes). Some people don't like that kind of stuff and worry some large clump of crud will break loose and cause a clog in a critical area."

I would never use a "flush" unless I knew what was in it. Mild, ester-based cleaners such as Auto-RX are one thing. Old school cleaners like kerosene or other petroleum solvent products can DNF a motor in a hurry. One ate the head gaskets in my old Camaro a long time ago.

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--- Bror Jace