I've always used natural oil because thats what I assumed the previous owner used. I want to switch to synthetic but I've heard bad things could come from doing so after using natural for so many years.

I can't remember exactly what possible problems I was told could arise nor can I remember where I heard it but it had something to do with the deposits that form and casing leaks, etc.

Is this just a myth? I plan to just flush the system like I did when I switched weights, would that have any negative consequences?

as far as i know, i should not make a difference. But please correct me if im wrong...if anyone knows dif. i guess.

Depends on the mileage of your engine. usually cars with higher mileage 100k+ when converting from dino oil to synthetic develop leaks usually around the engine seals because of deposits left behind in the engine left behind by dino oil. The deposits keep oil from getting to those areas where the build up and the seals that are covered by that sludge harden over time. Then when you switch to synthetic oil, which has more detergent properties, it will clean away the sludge and leak out of those hardened seals. Your best bet is to use Auto-Rx if you have a higher mileage engine for a few runs. It will clean out those deposits in your engine and recondition your seals so you have a lesser chance of developing a leak. After a couple runs of it you should be fine. Unless you know that your engine has been maintained very well its life with 3-5k oil changes everytime, I'd play it safe and run auto-rx through a couple times and then you'd be good to go to synthetic. Hope that helps.

I bought the car at 126k miles and have changed the oil every 3-5k miles since then. it now has 167k.

that is exactly what I heard would happen. Auto-Rx sounds like a plan to me, although I havn't ever seen it I assume somewhere like Autozone will have it?

Thanks!

I don't think local autoparts stores sell it as I have gotten mine online. It is pricy stuff though at 26 a bottle. Heres the link if you're still interested http://www.auto-rx.com/index.html

*edit* http://www.auto-rx.com/pages/applications.htm

This post has been edited by hellsyphon: Oct 26, 2006 - 6:45 PM

ugh. is there anything similar that I can just pick up at an auto parts store?

It isn't due to contaminants. It is the smaller synthetic molecule.





Most contaminants aren't due so much from the oil itself but from the EGR and ring leakage.




And finally, one of the best engine cleaners is a bottle of natural based ATF about 500 miles before a oil change. The higher amounts detergents and zinc clean up the engine and help with sealing the pores in the cast iron liners.

transmission fluid? into the crankcase?

I've actually never heard of doing that...

I have done it not only to my Olds with a 3.1 197K miles, but to the celica too 124K.




I also work in parts, not car parts, some things a bit bigger than a tiny 1.8L.

Stef, it'll be fine. Like I said the other night, I switched right over to synthetic and its fine, I've been running over 2 years probably with synthetic, just a "cold turkey" changeover from standard to synthetic and it runs fine. However, I did learn to keep an eye more on the condition of the oil, since synthetic will help clean out your engine from the sludge of more primitive oils.

Heres a quick series of links I gathered just to show that theres no ill consequences of switching from standard to synthetic. Mobil reccomends flushing oil more frequently when you first change over, then after that you're fine.


LINKS-

http://www.mobiloil.com/USA-English/MotorO...to_Mobil_1.aspx

http://forums.nasioc.com/forums/showthread.php?t=46171

"Fact-
As long as the synthetic motor oil product and conventional motor oil product meet the viscosity and performance requirements outlined in the vehicle’s owner’s manual, you may interchange them with each other."

-QuakerState.com


Hopefully that helps.

yeah, I just wanted to see what other opinions people had on the effects of switching. I thought maybe I was the only one who'd heard of negative consequences. maybe if there was any advice on how to ease the transition since I think my valve cover gasket is already leaking a little I don't know if you noticed it the other night, its not too bad but some people ask about it. I'll show you next time.

I will probably just flush the system and watch it really closely.

This post has been edited by hurley97: Oct 27, 2006 - 3:13 AM

I did the same thing, except I switched prior to 100K. I did start losing oil, don't know where though, because the engine is spotless and no oil on the ground, nor am I burning any.. anyways... I was told to use a bottle of Lucas oil's synthetic oil treatment. How it was explained to me is that when you switch from dino oil to synthetic it cleans out the deposits and the seals relax. This product is supposed to soak into the seals and keep them from leaking. So far it works. Its 1 quart, and you substitute it for 1 quart of oil on your next oil change.

Synthetic oil has detergents in it that can break down sludge build-up from dino oil use over along period of time. Sometimes the sludge was sealing leaks so use of synthetic can open those leaks back up. While the synthetic oil does not technically "cause the engine to leak" it can have the same practical effect. I think the risk is rather minimal but it is a possibility. In general, synthetic oil will lengthen the life of your engine and, all things considered, is generally a good move even for a high milage engine. The real question is whether it is worth the extra cost. That depends on how long you intend to keep your car and the engine's current state of health.

I switched over from regular to synthetic about 1K ago. I have a very small leak, but I'm almost positive that was there before I switched over. I say go for it.

i switched my 7afe from penzoil dino to mobil1 full synth at 114K miles with out any problems, and i'm now running mobil1 synth blend 'clean 7500' because it costs 1/2 the full synth. i had no leaks, drips, or seeps that werent there before or werent due to age (seepy valve cover, just a small amount of oily buildup that i wipe off from time to time)

This post has been edited by Bitter: Oct 27, 2006 - 12:21 PM

well, I just did it... lets hope for the best

drained the remaining Castrol High Mileage 5W-30
changed the filter
put in a little less than 4qts Mobil 1 Full Synthetic 5W-30
put in a bottle of some No-Leak stuff thats supposed to stop leaks and re-condition seals and what not.

I just didn't get the LucasOil version because it was like $15 as opposed to $5 and I was already unhappy about spending twice as much on synthetic oil. but I'll get it next oil change, I'm sure its much more expensive because its good stuff.

I dont know if it would matter for our cars, but I work at a Motorcycle performance shop, we do all sorts of engine work from piston kits to port polishing and other head work. We dont recommend our customers to use synthetic oil simply because at high revs 10K+ its hard for the oil to stick to the crank sometimes starving the journals of oil. In fact some of the parts we use like Web Cams and our APE valve springs, we wont warrenty a motor that was run with synthetic.

I see that people have used synthetic and have had no problem so I assume this problem will not transfer to out low reving motors, but I still wont use it. My motor has 75K + miles and i would rather have a thicker lubricant in there. Just my opinion, not shuning anyone elses.

i was running mobil 1 full-syn for a very very long time. Then i started burning it a little bit (i run hard a lot, i like them country roads when i travel), and i decided to try out Valvoline's Syn Mix, and actually, i'm happier with it than the full syn mobil. So, do what ya do.