tomus1000

My truck has 27, 000 miles on it now and I think I want to change to synthetic motor oil for good. One of the service writers at the dealer (I don't really trust this guy, he doesn't give me alot of confidence) said that it is too late to switch. He said that after the switch, my truck would most likely leak oil. Is this at all true? I have a hard time believing this.

I want to switch everything to synthetic, motor, tranny, transfer case and both front and rear diffs. Give me some advice. Did I miss the window of opportunity?

gwhayduke

Nope.
I switched my Corolla at 91K and it now has 251K.

I put it in my 4Runner at 95K is now has 191K.

Just do it. It feels good.

OneTrickToy

Technically, you shouldn't switch after 30,000 miles. But there are ways to do it wouthout any problems. You are completely safe though. For those over 30,000 miles, you should switch to a sythetic blend for a couple of oil changes, then work in the full synthetic.

The problem with switching later in your engines life....Your gasket and seals get conditioned to the oil. The seals breakdown and build up gunk. When you switch to a full synthetic it ends up cleaning out the gunk and removing the protective barrier. Then the leaking begins.

This is the short answer that I have received from numerous gurus. It makes sense to me.

kps36

I have done many vehicles (I currently have 4) 'late' in life switching to full syn. If the vehicle has over 30k (as stated above) I will run a flush prior to the change over. My expeirence has been that the myths about syn causing leaks is just that...a myth. If you flush prior to the change, the syns actually 'help' the seals with some kind of expansion properties (ask your Amsoil guy about it)....I have a 95 Explorer with 102K miles (may not sound like much to you guys..remember its a Ford !) that does not leak/burn a single drop of oil ..and I did the change over to all-syn in that truck at 62K !!
my .02

rchavis

This thing about after 30K is something that started years ago when synthetics were just coming out. the synthetics made today are fully compatible with dino oils and will not cause leaks. They will in fact, help seals by swelling them to stop leaks. We are in different times. And technology has proven that with most things, new is better, if made right by people who take pride in there job.

ravencr

I just switched over a 97000 mile 1997 4runner to all synthetic Amsoil in everything. The only thing Amsoil recommends doing is running their product, Engine Flush, in your truck for about 15 minutes at around 2000 rpm right before you change the engine oil to synthetic. As far as everything else, the tranny and transfer case in mine has Amsoil universal ATF, and the axles are soon to have Amsoil 75/90 gear lube. Good luck!

Chris

gwhayduke

If you look at a bottle of synthetic oil, it will say that it it is 100% compatible with conventional (dino) motor oils. In fact they even run blends of conventional. If you want "rinse" the crankcase, do it with a short change of oil not those kerosene based "motor flush" solvents put out by Gunk and others. Just get a good motor oil for older cars (more detergents), do an oil change with new filter. Run it a week. The next weekend change your oil and filter again and swap in the synthetic.

You'll get a lot of good opinions on this board, but visit this oil board and you'll get some very good guidance based on science. They'll tell you you can swap at nearly any point in a cars life. You may get a little seepage but you can always use an synthetic oil for older cars to soften the seals up a little. I don't consider 27K a lot of miles.

The oil board also tends to recommend Mobile 1, Schaffers, and Amsoil. Stay away from Castrol Syntec, which is not a true synthetic.

Years ago, I did a short change on the Corolla with regular motoroil, just to rinse out the crankcase for a week. After 2 days my wife came home and said "I don't know what you did to my car but I want you to change it back." Synthetic will make your cars run better.

Just do it! It feels good!

Victor

Your Toyota is brand new as far as I'm concerned. Plenty of people switch to synthetic close to 100k. I did it when I first got my truck at around 130k and I haven't had a drop leak. Now if I could only say that about the power steering pump.

gwhayduke

Victor...
Just get some power steering conditioner...CRC brand is what I used. It worked like a charm.

waskillywabbit

iTrader: (-1)

I haven't priced synethetic oils, so how pricey are they?

How often do you have to change your oil if you switch to synthetic?

gwhayduke

Because the synthetic oils don't degrade as quickly, you can extend your service interval.

Some change at 3K
I change at 5K (unless it's real inconvenient)
Others change at 10K
Still others change every 6 months
A few brave souls change every 12
Tom & Ray of Car Talk fame have one vehicle that they've stopped changing oil in, just to see what would happen.

You know your own habits. If you do a lot of short trips, stop & go, etc. use a shorter change interval. Watch your oil. I believe that oil has a finite capacity to hold contaminants in solution. Once that capacity is reached, sludge begins to build up. So I change at 5K.

Highland Runner

I just changed to syn Mobil 10w-30 (18.88 for 5 qts at Wal-Mart)when my runner hit 200,000 miles. It is true what rchavis said about helping seals. Mine doesn't burn as much oil as it did with dino oil, only after the first change. They say it will improve even more after about the 3rd change. Thats when the syn should have completely cleaned out most of the crap in your engine. The web site that gwhayduke is very informative about oil, and filters.

Gadget

Your service guy is an idiot. You are not really letting those goofs touch your truck are you?

You can switch at ANY time.

If you want to read something that dispells all these BS myths on synthetic oils go to my site and download The Motor Oil Bible FREE and read through it. If you read the whole thing you will know more then 99.9% of the professional mechanics out there.

Gadget

www.GadgetOnline.com

nrgetic99

Ditto on Gadget's advice.

I have worked in the oil industry for 15 years and the sad thing for me is you can pretty much know what I know if you read the bible .

I switched my 99 to Amsoil 0W-30 at 40k. The combination of the synthetic and the 0W would have showed up and problems pretty quickly.

Its now at 65k and I a not using a drop btw changes (5 to 6 k)

David

Glenn

I switched to Amsoil at 175K, and it has not leaked a drop. The stories about synthetic motor leaking past old seals are exactly that-stories. Go ahead and switch. There are no downsides.

89-4run

I changed over at 176k miles

4runner4life

I changed over at 150k without any problems and have always made the change over to synthetics on ANY car I've bought without ever having any problems.

4x4CPOSEADOG

Noel,

I concur with what other said, from just reading some of the post here, it is never too late to switch to synthetic. So you go ahead and run to the nearest Amsoil/Mobil/Royal Purple dealer and get some synthetic oils. Run Noel run! Glad to see you back!


Noel

grobbins6

Gadget....tried to download the MOB and got an error.

Any other sources for that document?

boss hog

i switch from dino oil at 30.000miles to molbil 1 , 5w30 synthetic, i did not notice any improvement in gas milage, 3 months later i did and other oil change and notice a real improvement in gas mileage