need an opinion

Messages
33
Location
cleveland
I have a 99 nissan altima. has 78,000 miles on it and its mostly highway. the engine seems to be leak free from oil. I was thinking of switching to mobile 1 so i can change it every 3 months(7,000 miles) instead of a month in a half. the other oils like amsoil, redline etc... seem to be better but i want an oil i can buy at walmart or at a parts store readily available. one of my ?'s is that if switching to synthetic that it may open up any leaks that dino fuel has sealed in the engine. is that true? also when switching to synthetic should i use an engine cleaner? will an engine cleaner clog up my oil pump with the sediment left over? what kind of engine cleaner is good? any suggestions are appreciated.
 
Messages
508
Location
milwaukee
I just switched my truck to Amsoil at 34,000 miles. I used Auto-RX to clean the engine with my last oil change before I switched. It worked great. I only ran the oil about 1,800 miles and it was black, darker than it was at 3,000. I think it's the best way to clean your engine before you switch over to synthetics. I tried to switch my 96 minivan two years ago and it leaked a bit, so I switched it back and no more leak. I treated it with Auto-RX this summer, so maybe I'll try and run Mobil 1 again this winter. It's at 95,000 miles now.
 
Messages
372
Location
Rancho Cucamonga, CA
I'm certainly no expert on synthetics, but my understanding is that "synthetics in high mileage engines will leak" is a wives' tale. Lot's of people on this board recommend AutoRX for a high mileage engine, but I don't think cleaning out the engine is a requirement prior to using synthetics. In fact, Mobil 1 specifically states that you CAN mix their synthetic with dino oil without harm. You'd probably be "pure synthetic" after a couple of drains on the stuff.
 
I just switched to M1 after 60,000 on a Saturn. Runs Smoother with more pull through Acceleration. K&N air and oil filters. Go ahead make the switch You be happy. No need to clean but certainly no harm in doing it either. The M1 in itself should clean things up a bit over a few changes. I too was driving 3,000 miles a months looking to get about 6,000 off the M1 per fill
 
Messages
718
Location
Central Texas
At about 85k I put my Saturn on Mobil 1 and at 100k I put my F-150 on Mobil 1. Both had lived on a steady diet of Penn 10w-30. Neither leaked oil before or after the switch. Now the Saturn was an oil drinker before and after the switch to Mobil 1. My Mobil 1 phase only lasted a year or so. The overall cost/performance advantage of using Schaeffer's simply over powered the convenience of Mobil 1.
 
Messages
3,705
Location
Chattanooga, TN
I have swithced some over, one at 30,000, one at 49,000 and one at 57,000. If engine looks clean on inside from what you can see and is operating fine it is up to you to try a cleaning agent. My experience with the switch is that in approximately a year or so you may see some seepage in seals or oil pan gasket etc. Most of the time a simple torque job will stop the seepage others go away by themselves and some never do. I have had some seepage in all of the ones I have converted but the above have elimiated them. So expect some seepage but go on the belief it can be eliminated once it occurs. You also need to get to your mark gradually, do not go from your current schedule to 7000 in one shot as synthetic oil by itself will do some clean up.
 
Messages
5,785
Location
Dixie
I strongly recommend using an engine flush before changing to Amsoil - particularly if you intend to run extended drains.... For engines with over 50k miles or engines that haven't been well maintained, I'd run the AutoRX for 750 miles with a new oil filter ....If you have some patience, this is the most effective way to clean an engine. I've used this stuff 4-5 times and it really works! For engines with less than 50k miles that have been fairly well maintained, I'd run the Amsoil engine flush for 20-30 minutes at two times the normal idle speed - again change the oil filter first! Even with 3000 mile oil changes and conventional oil, you will always have some high temp deposits that you want to remove before using a PAO/Ester synlube for the first time. TooSlick Dixie Synthetics
 
Messages
233
Location
Pullman WA
I've got a 92 buick skylark that seeped a little oil and I still switched over to synthetic (mobil) and to honest with you it dosen't leak any more oil now than it did on convential oil, I think that people think that oil is just going to start gushing out of an older engine using synthetic. If you read the back of a mobil 1 bottle it will state that it won't harm old seals, etc. This car had 110,000 miles and was 10 years old when I switched. I use maybe a half quart of oil between changes (6 months) and the benefits of using mobil 1 make the switch viable to me.
 

JHZR2

Staff member
Messages
46,117
Location
New Jersey
I switched my 1983 MB 300D to synth delvac 1 this winter, at 190K, now at 200K+ and no problems... Maybe leaks were the case in the past, but I havent seen it happen. JMH
 
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