Switched to synthetic, using oil, now what?

[ENafziger]

With 17,000 miles on the odometer, I recently switched to Rotella 5w-40 synthetic oil. I took a couple trips pulling some medium size loads (~8,000 lbs), and now 2,000 miles later I'm 2 quarts low on oil. The truck never used any oil before, and I assumed with 17k miles on the truck, I'd be alright switching to synthetic. What do I do now? Will the rings seat if I continue to run synthetic, or do I dump it out and go back to petroleum for awhile?

 

[Heavyweight]

You have typed what you should do. I would drain the oil out, fill with 15w-40 and see what happens. Then, report back in so we can all know! Good Luck.

 

[betterthanstock]

With 17,000 miles on the odometer, I recently switched to Rotella 5w-40 synthetic oil. I took a couple trips pulling some medium size loads (~8,000 lbs), and now 2,000 miles later I'm 2 quarts low on oil. The truck never used any oil before, and I assumed with 17k miles on the truck, I'd be alright switching to synthetic. What do I do now? Will the rings seat if I continue to run synthetic, or do I dump it out and go back to petroleum for awhile?

Synthetic sticks to the engine, so when you check oil level wait overnight (to drain back into oil pan) before adding. I bet you will have a high level now if you added.

 

[amsoilman]

With 17,000 miles on the odometer, I recently switched to Rotella 5w-40 synthetic oil. I took a couple trips pulling some medium size loads (~8,000 lbs), and now 2,000 miles later I'm 2 quarts low on oil. The truck never used any oil before, and I assumed with 17k miles on the truck, I'd be alright switching to synthetic. What do I do now? Will the rings seat if I continue to run synthetic, or do I dump it out and go back to petroleum for awhile?

I agree with "betterthanstock". A good quality Synthetic oil will stick to the metal much longer, so therefore you need to make sure when you check the oil, the engine has not been run for at least 5 hours.



I have seen this many times with Amsoil synthetics, which are PAO/Ester based.



Wayne

amsoilman

 

[pwr2tow]

With that reasoning in mind the mobil 1300 15-40 I just put in must be just as good as synthetic. It was 1 1/2 quarts low after filling with 3 gallons, starting, running, and then checking the oil. The next morning it was still 1/2 quart low. This dino mobil 1300 15-40 must be really superior stuff.

 

[pwr2tow]

In my opinion 5-40 is toooooo lite of an oil for a diesel. I have experienced the same thing on previous trucks and the engine is louder also.



Just a for your information, Rottela 5-40 is not a full synthetic, but dino based oil highly refined to mimick synthetic.

 

[GHarman]

I see absolutely no reason to use 5W-30 oil in a diesel unless you are operating at arctic or sub arctic temperatures. 15W-40 Amsoil pours at -38 degrees F. It is far superior to any of the other oils available. I use this oil all year long here in Colorado at 9000' elevation in my 1st gen Cummins. I do agree that you need more miles on your engine before the switch. Just a note; I have used 5W-30 oil in gassers and have found that the light oil doesnt lubricate adequately when you are climbing mountains, working the engine hard. GregH.

 

[Diesel Power]

In my opinion 5-40 is toooooo lite of an oil for a diesel. I have experienced the same thing on previous trucks and the engine is louder also.



Just a for your information, Rottela 5-40 is not a full synthetic, but dino based oil highly refined to mimick synthetic.

5-40 is still the same opperating viscosity only flows better when cold, that should be an advantage, i agree to your second part

 

[ENafziger]

Considering I drain the oil and go back with a petroleum based for now, how many miles should the truck have on it before switching to synthetic? I realize that the Rotella is not a true synthetic, and that it is really just an ultra-refined dino oil. I hadn't yet decided to go with Schaeffer's Supreme 9000 or Amsoil, and thought by running rotella synthetic I was just putting in a better quality/better refined petroleum oil. Am I hurting anything by swapping back and forth?

 

[pwr2tow]

5-40 is still the same opperating viscosity only flows better when cold, that should be an advantage, i agree to your second part

I know what your saying and chemical analysis would prove your right, it's just that from personal experience it seems to be thiner at operating temps due to the extra noise the engine makes and even seems thinner when you dump it for an oil change. It could also just be sycological I guess but every brand of 5-40 I have tried seemed the same way, toooooooo thin. I have also noticed the same thing about every weight of oil be it S or C rated. The closer the numbers to true weight seem to have a better effect on the engine at operating temps.

 

[betterthanstock]

5w-40 synthetic is not thinner at higher temps, it is actually thicker! Cummins says 15w-40 will actually give you better highway mileage because it becomes thinner at higher temps.

5w-40 changes viscosity more slowly, so it starts out thinner at cold temps, but does not thin out as quickly at high temps, which is better at turbo protection.



pwr2tow, you can look up the specific viscosity of most brand oils at 100 deg celsius (normal operation temp). There is a certain range, and some oils that call themselves 40 are actually 35 weight, in order to claim better mileage than the competing brand.

 

[DieselFiend]

I seriously doubt you'd have 2 quarts of oil "sticking" to engine parts somewhere. Thats a whole lot of oil. Here are some possible solutions according to my experience. You'll lose a quart to a quart and half in the filter after changing the oil. Sorry if you're already doing this but start the engine and let the oil circulate then recheck the level and fill again if necessary. Also, with thinner oil at cooler temps, you could be getting more blowby than you would with a 15W-40 Just my take. Hope it helps.

 

[Heavyweight]

Enafziger, we are only limited to information you have provided. If we assume and or the amount of oil you supposedly lost is true, switch back to 15W-40 and run it for a while. Then let us know of the results. To replace current 5-40 with any brand 5-40 may work, but you will be wasting your money and time. Fill up with either Delo 400 or Delvac 1300 Super 15w-40. Watch the oil level like a hawk and report back in to us.



I would not purchase Amsoil 5-40 or equivelant at 7-8$/QT to end up with the same results. You are going to get every opinion out there, but it's your time-money and oil consumption!

 

[Diesel Power]

accually you should get less oil consumption with amsoil vs conventional oil

 

[GHarman]

Pardon my typo on the diesel oil in my post it should have read 5w-40 not 5w-30. Regardless, my contention still stands; 5W-whatever is to light of a viscosity oil to be used in a diesel engine above 0 degree F. . Arguments can be made, but, please explain to me HOW ( operating viscocity?) 5W-40 and 15W-40 have similar characteristics. Sure 5W-40 flows but that is not the only attribute that is important. GregH

 

[redram]

With 17,000 miles on the odometer, I recently switched to Rotella 5w-40 synthetic oil. I took a couple trips pulling some medium size loads (~8,000 lbs), and now 2,000 miles later I'm 2 quarts low on oil. The truck never used any oil before, and I assumed with 17k miles on the truck, I'd be alright switching to synthetic. What do I do now? Will the rings seat if I continue to run synthetic, or do I dump it out and go back to petroleum for awhile?

question for yuo - have you previously pulled similar 8000 lbs loads in the first 17,000 before using the 5W40 Shell product?

If not, you may have worked the engine harder and it is still seating the rings and it had NOTHING to due with changing the oil viscosity. Just a thought.

 

[GanzJN]

I think your using to lite of an oil. Try using 15W-40 Amsoil. Its the best out there, also they make a cleaner ad that so it will clean the engine.

 

[ENafziger]

question for yuo - have you previously pulled similar 8000 lbs loads in the first 17,000 before using the 5W40 Shell product?

The heaviest I had pulled with the dino oil was in the 4,000 lb range. It was only after I changed to the 5-40 Rotella synthetic that I pulled the 8,000 lb load. It may very well be that the rings are still seating. If this is the case, will the rings fully seat using the synthetic Rotella (I realize this is not a real PAO base syn), or does it take petroleum based oil to seat the rings properly?

 

[redram]

The Shell Rotella 5W40 is a good oil and there is no need to change this oil out until you are ready for an oil change.

Keep track of your oil consumption (say check it every time that you fill up with fuel) and write it down with the truck mileage and make notes if you tow or run very high speed or left the truck idle ofr 10 hours!!! anything that would potentially be a reason that oil consumption might change.

You be fine. I've had a Cummins Pickup since 1990 and have 375,000 miles of running them around and yes, oil consumption will vary depending on load and speed. But you are fine.

 

[Diesel Nut]

I switched over to Amsoil 5W-30 Heavy Duty Diesel Oil at around 5K miles and have not had any issues yet. I know I run my truck hard, but not that hard. I have 11 and some change on it now.



In fact, Amsoil says it is perfectly safe to switch it over new.



Something else is going on. How hot was the ambient during your trip?