Community Forums

jim58 · 03-26-2020, 07:53 AM

I was reading on other non-rv forums about oil usage of the 8.1. Quite a few reads on part of the issue being something called oil burn off. Some report changing the tstat to a 180 degree stat has helped.

Would like to hear thoughts from the mechanics here.

Thanks

Jim58

Skip426 · 03-26-2020, 10:04 AM

If your having an oil consumption issue , please add some info on your engine/RV .

Miles on the engine ?
Current brand and oil viscosity ?
Amount of oil being lost ? miles per quart ?

BTW. There has been an issue on the 8.1l with intake manifold gaskets and bolts having to be replaced due to oil consumption, not sure of the years involved. I'll see if I can track down the post .

Unplanned Tourist · 03-26-2020, 10:06 AM

I seldom use more than a quart between oil changes (5,000 miles)

If you are using oil, do you have a blue puff of smoke out your exhaust after coasting down a hill? If so, it's likely valve seals that are done for.

I still have the factory 190 thermostat also.

Happy Glamping.

Waiter21 · 03-26-2020, 10:15 AM

I'd keep the thermostat at OEM temperature. The electronic fuel injection system relies on a specific temperature to operate optimally. If the engine temperature isn't at operating temp, the ECM (PCM) may not go into closed loop. You may also get a SES light and a code that the engine isn't reaching operating temperature.

Verify the PVC valve isn't clogged, this will cause oil burn. Also, run the next higher weight. i.e. instead of 5w30, I run 10 w 30. Thinner oils can get past the rings easier.

As for oil consumption, My 1999 V10 burns a quart of oil every 12 - 1500 miles. I don't like it, but Ford says this is acceptable (I haven't had a vehicle burn this much oil in 40 years, and I run vehicles out to 300 -400 k miles.)

yeloduster · 03-26-2020, 10:53 AM

I think the OP is asking specifically about the 8.1L GM engine in his Workhorse chassis motorhome.

General Motors specifies oil consumption as a maximum of 1 quart per 100 gallons of fuel. Most of us get in the vicinity of 7 MPG so their spec for our application is 1 quart per 700 miles! That means a quart about every 1.5 - 2 tanks of gas.

They will not do warranty work on any 8.1L engine using less oil than that. Of course, they ain't doin' warranty work on ANY 8.1L engine anymore!

My 2003 8.1L engine in my Workhorse chassis uses about 1 quart/1500 miles. That is about the same as my old 454 (7.4L) got in my previous MH. I might use more oil than some of you because I live in the mountains and may work the engine harder than you do.

If you use less than 1 quart per 700 miles I suspect it is normal unless you have visible smoke. I would leave the t-stat where it is. I would use the oil specified by General Motors. Add a quart if it is low.