Switching from Synthenic to Dyno Oil?

dirtfan85 wrote:
I have used rotella 15w40 in my kenworth. it has a cat 3406e engine takes 11 gallons of oil. 9 gallons of rotella 2 gallons of Lucas oil stabilizer. it has 1.5+ million miles on it.

That is a lot of miles so your method seems to be working well for you.

Does the Lucas oil stabilizer help keep down the effect of diesel dilution?

I have had good luck using Lucas Hydraulic Oil Booster mixed with the UTF (Universal Tractor Fluid) to get the additive package back up to par vs changing it out at $10 a gallon. The back hoe holds 22 gallons and the MF tractor 8 gallons.

I have used rotella 15w40 in my kenworth. it has a cat 3406e engine takes 11 gallons of oil. 9 gallons of rotella 2 gallons of Lucas oil stabilizer. it has 1.5+ million miles on it.

I can not find the leak and have tried looking with a flash light and mirror. I wish it was on a slide out.

You are probably right about switching to sythetic as the catalyst of the leak. It wouldnt be the first time thats happened for sure. While it didnt actually eat thru a seal or a gasket, it did wash away the old gunked up oil that was blocking the dino oil from getting thru the leak path. Unfortunately you have let the genie out of the bottle so to speak, and even dino oil will leak there now. The "scab" has been removed.

As I said, if it's a rubber based seal or gasket the lucas should work. If it's a paper based gasket it will most likely continue to leak until you fix it.

Can you tell where the leak is specifically? Like a valve cover or somewhere. It may not be a hard leak to fix correctly.

If you need to you can redirect the oil leak by using some of the metal type duct tape they sell at lowes and home depot. You can pretty much form that tape into shapes and stuff, just clean the oil off the surface so it can stick first.

RVUSA wrote:

Gjac wrote:
I was hoping that by going back to dino oil in the gen set it would stop or slow down the leak.

If the leak is because of a bad rubber seal like a crankshaft seal, then some "lucas engine oil stop leak" will fix it, but you will have to add it every time you change oil in the genny. If it's leaking past a paper gasket then you will have to fix the gasket. If it's leaking from a bad sensor (oil pressure etc) you will have to replace the sensor. Or live with the leak.

But you cant fix a leak by changing the viscosity of an oil. Even 90 wt. racing oil will leak past a poor seal.

Do you know where it's leaking from?

I can find the leak, but it is leaking on to the bottom plate and unto the muffler. I believe the oil leak was caused by switching to Syn in both my high mileage tow car and the gen set. I will give Lucas stop leak a try.

Gjac wrote:
I was hoping that by going back to dino oil in the gen set it would stop or slow down the leak.

If the leak is because of a bad rubber seal like a crankshaft seal, then some "lucas engine oil stop leak" will fix it, but you will have to add it every time you change oil in the genny. If it's leaking past a paper gasket then you will have to fix the gasket. If it's leaking from a bad sensor (oil pressure etc) you will have to replace the sensor. Or live with the leak.

But you cant fix a leak by changing the viscosity of an oil. Even 90 wt. racing oil will leak past a poor seal.

Do you know where it's leaking from?

RVUSA wrote:

Gjac wrote:

Jarlaxle wrote:
Oil is oil. Use whatever oil that meets the requirements that you can get the cheapest.

This is what I do but have some observations. I switched to WM syn 10-30 for MH and tow car about 6-7 years ago. First drain on syn in MH noticed a lot of small chunks of carbon in oil, other than that no improvement in MPG or lower operating temps. When I put it in my 2002 Toyota Corolla it leaked around the pan for several oil changes and several re torquing of the pan bolts. Same kind of carbon deposits in oil change with the syn. I had a slight oil leak in my generator when I used syn I made it much worst. I will go back to Dino oil for the gen set, but will use what ever is on sale for the tow car and MH.

synthetic oil is a high detergent oil. It will get under and loosen old dino oil that has coked onto the engine surfaces. It is most likely the reason you see those little chunks of carbon.

"I will go back to Dino oil for the gen set"

I believe you will find the recommended oil for gennys is typically high detergent oil. For the very reason explained above. Dont use plain old oil in a genny. You cant change the oil enough with cheap dino to offset replacing it because it coked the oil rings up and died.

You are trying to save a buck but putting yourself at risk of spending thousands upon thousands. Price a engine swap, and then cost it against the savings you'll get from what ever is on sale oil vs. synthetic. you'll see, hopefully.

Pablum. After watching dozens of vehicles run up huge miles (saw 640K on one car) on whatever bulk oil the owner got the cheapest, I realize that oil is oil! My big Tecumsah generator has run 19 DAYS straight, it runs perfectly with probably 5500+ hours....all it gets is regular 15W-40 oil.

Mobil 1 High Mileage warns not to run it more than 3K-5K miles for the first 2 fills because it can junk up the filter with the crud it will cut out of an engine that has been on Dino for year.

RVUSA wrote:

Gjac wrote:

Jarlaxle wrote:
Oil is oil. Use whatever oil that meets the requirements that you can get the cheapest.

This is what I do but have some observations. I switched to WM syn 10-30 for MH and tow car about 6-7 years ago. First drain on syn in MH noticed a lot of small chunks of carbon in oil, other than that no improvement in MPG or lower operating temps. When I put it in my 2002 Toyota Corolla it leaked around the pan for several oil changes and several re torquing of the pan bolts. Same kind of carbon deposits in oil change with the syn. I had a slight oil leak in my generator when I used syn I made it much worst. I will go back to Dino oil for the gen set, but will use what ever is on sale for the tow car and MH.

synthetic oil is a high detergent oil. It will get under and loosen old dino oil that has coked onto the engine surfaces. It is most likely the reason you see those little chunks of carbon.

"I will go back to Dino oil for the gen set"

I believe you will find the recommended oil for gennys is typically high detergent oil. For the very reason explained above. Dont use plain old oil in a genny. You cant change the oil enough with cheap dino to offset replacing it because it coked the oil rings up and died.

You are trying to save a buck but putting yourself at risk of spending thousands upon thousands. Price a engine swap, and then cost it against the savings you'll get from what ever is on sale oil vs. synthetic. you'll see, hopefully.

I was hoping that by going back to dino oil in the gen set it would stop or slow down the leak.

Gjac wrote:

Jarlaxle wrote:
Oil is oil. Use whatever oil that meets the requirements that you can get the cheapest.

This is what I do but have some observations. I switched to WM syn 10-30 for MH and tow car about 6-7 years ago. First drain on syn in MH noticed a lot of small chunks of carbon in oil, other than that no improvement in MPG or lower operating temps. When I put it in my 2002 Toyota Corolla it leaked around the pan for several oil changes and several re torquing of the pan bolts. Same kind of carbon deposits in oil change with the syn. I had a slight oil leak in my generator when I used syn I made it much worst. I will go back to Dino oil for the gen set, but will use what ever is on sale for the tow car and MH.

synthetic oil is a high detergent oil. It will get under and loosen old dino oil that has coked onto the engine surfaces. It is most likely the reason you see those little chunks of carbon.

"I will go back to Dino oil for the gen set"

I believe you will find the recommended oil for gennys is typically high detergent oil. For the very reason explained above. Dont use plain old oil in a genny. You cant change the oil enough with cheap dino to offset replacing it because it coked the oil rings up and died.

You are trying to save a buck but putting yourself at risk of spending thousands upon thousands. Price a engine swap, and then cost it against the savings you'll get from what ever is on sale oil vs. synthetic. you'll see, hopefully.