1993 F250 using oil

[matpasch]

My 1993 F250 4x4 ext cab with 351 Windsor and 5spd seems to be using about 1 liter of oil every 1200-1500kms or so. The truck doesn't leak pil, no blue smoke or smoke at all, no smell. It has just over 300,000kms on the engine and just did a tune up, new pvc valve etc. Im running 10w30 right now up in vancouver Canada. wondering if I should use a heavier weight oil like 10W40 or 20W50? Would this harm the motor, in the winter, never gets that could here. I run 20W50 in my 70 Torino with a 460, but it burns blue and never sees the winter. thanks mat

[jim henderson]

At 300,000km, you may have some engine wear that could cause oil consumption.

I would run a compression test. Not sure what spec is for your engine. Wild guess is that you should see about 120-150psi in all cylinders with no more than say 10% difference from high to low. If you see two cylinders next to each other with low readings, I would suspect a head gasket leak.

If your cylinders read low. Squirt some oil in the cylinders to see if it is the rings or valves that are leaking. Leaky rings will burn oil. Could also be leaky valve guides but that won't show up for sure with a compression test.

Also check for water in the oil or oil in the water.

Check carefully for oil leaks. Use a bright light and feel around. Also put a big sheet of cardboard under the truck when you shut it down to see if there are any leaks there.

Heavier oil may slow any leaks or getting past the rings. But, heavier oil can get very thick if you get below freezing. 20W50 can be like taffy when it is really cold. Thick oil will cause more wear on startup if it isn't pumping around fast enough. Thick oil is a bandaid to get more miles out of an engine that has problems.

Good Luck,

Jim Henderson

[matpasch]

Thanks, I'll stick with the 10w30 are check more carefully for leaks and run s compression test. Thanks
mat

[pawpaw]

If it's been doing this for some time, things like the rings & valve stems could be carboned/varnished up, so maybe consider a dose of Auto-Rx 1500 miles before the next OCI, to slowly dissolve any deosits before the change, then switch to a "High Mileage" recipe oil in the brand your using & with the viscosity specified for this engine for your area.

If hardened seals are a problem, the High Mileage recipe has seal softeners in it that over time might help, along with extra detergents, dispersants & barrier lube like ZDDP or Moly, that might be worth consideration.

The Auto-Rx is a ester based product that has non solvent, good detergent dispersant properties, that can slowly get after, soften up & free up ring land carbon deposits & remove valve stem gum, varnish & carbon deposits that can mess with valve stem sealing.

The high mileage recipe oil with it's boosted ad pack could then keep things cleaner by holding more deposit causing byproduct crud in suspension for the oil filter to grab, or to be drained out on the next OCI.

More thoughts for pondering.

[jimandmandy]

Auto-Rx recommends a 15W-40 grade oil for the "rinse cycle" and you might just find that 15W-40 oil is what you actually need anyway. By the time the 5.0 in my 1994 got well over 100,000 miles it got Chevron Delo 400. It gets cold here, but not that cold. 15W is rated for Cold Cranking down to -20C.

Jim

[matpasch]

Thanks for the help, I'll see if the auto-ex is available her in Canada, and I'll post results after the treatment. Thanks again mat

[pawpaw]

You'll probaby have to order the Auto-Rx.
Here is a link to their website.
Auto-Rx Engine Cleaner Transmissions Motorcycles Stop Leaky Seals Oil Burning Increase MPG Better Gas Mileage Trouble Shifting ARX

You'll want to use it & do the rinse phase with mineral oil in the crankcase, then after everything is all clean & tidy inside, you can use whatever base oil you like, mineral, semi-synthetic, synthetic, full synthetic.

Will be interesting to hear how it goes, so keep us posted.

[matpasch]

thanks, ill look into it, see if i can order some and will post my results,
thanks again
mat