Synthetic Oil in 99' Tacoma

I've had my Tacoma a little over a year now and have been slowly bringing everything up to date and replacing what needs to be replaced. It's a 99' Tacoma with a 3.4L that has 370k miles on it, I've been thing of switching from dino oil to synthetic but I've heard people warn about switching on older high mileage engines. What are some opinions on this topic? The truck already has an oil leak, would it make it worse?

 

I can't comment on if it would make it worse or not but let me ask you this, do you intend on changing your oil every 3k or so? If you intend on consistent oil changes and maintenance, why not just leave well enough alone?

5W30

 

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I use whatever's on sale.

 

depends on your leak......
......gasket leak could be accelerated if switch to different oil with different detergents.....

IF its a seal leak....thats what high milage oils and tranny fluids are for....
they have a hail marry bail out move.....stop leak additive.........plump the seal to slow leak and make it last a little longer....
......but at the demise of the seal.....everntually.....


Oil doesnt mean jack.....changing it.....often, is what matters the most.....
detergent oil means all the crap is in suspension.....going thru engine over and over.....

Cheapest on the planet I've found......napa syn blend for $12.99 5qt....on their monthly ad slick......
Also on their platinum filters, if you catch on that 20off sale.....you can get these as good as the K&N racing ones, for about half the price.....

 

That's cheap. I had no intentions of changing to synthetic but Mobil 1 is so cheap now (especially using a factory rebate/refund/whatever) why not? I had already done valve covers and front seals. They needed changing before.

Jeez valve covers and the like used to be bi-annual things when I was young. Even on imports.

 

Think only big payoff to highend oil is if you have a newer much more expensive engine....
VVT, turbos, direct injection, then for sure pony up for top tier......
most only come that way now.....

 

I, too, have a '99 3.4...automatic. 276,000. Runs like a scalded dog. Switched to full synthetic 2 years ago. I do my own oil changes and have observed that the used oil is remarkably cleaner than what the conventional used to be. Plus, with newer synthetics, I go lots longer between changes...just sayin'

 

I would use dino oil with that many miles. Somebody took care of it with reg oil for years. I have heard too many stories of leaks after. If your a Toyota freak you will change it all the time anyway

 

That a lot of miles so first of all congrats are in order!!!

Synthetic will be more likely to leak, yes. I'd stick to conventional 5W30 and keep doing regular OCI.

 

We have a 1999 Toyota Tacoma, and we run Castrol full synthetic 5w-30, and we don't have any leaks, but we changed to full synthetic before it went over the 100,000 mile mark.

 

Synthetic is not magic.....neither oil will fail in modern formulations.....
its the trash that builds up....dont matter which.....you could have glow in dark oil...still the same...

So some oil gives you a free pass.....whats really happening is your space age oil....
is efficent at transporting trash round and round in your engine ......for a much longer period....
thats crazy.......


You could try that with the toilets in your house......save some water......
and keep visitors away.....

 

I would be more concerned about cold startups......
I add almost half a bottle of lucas for that.......makes the oil 'Tenacious'......

 

Only reason a synthetic oil would cause a leak is if the seals are only holding because of guck and grime.

 

If oil changes have been performed regularly and according to OEM specification you’ll have no issues

 

yeah the leaking will leak more but fwiw my taco has 250k and all i put is synthetic mobil1 high mileage amd oem filter and washer

 

My 99 Prerunner has had Castrol Syntec black bottle for 250K miles. The inside of the motor is like brand new. I like it because now that it's getting old I can really run a long time between changes. I still would never change over to Synthetic with high mileage

 

No earthly idea what was run in mine for its first 180,000, but it gets synthetic now. No leaks.

You might consider switching to a high mileage oil, the only thing they're really better at is swelling seals.

Do you know whats leaking? It might be a simple fix.

 

Man oil is cheap.....magnetic plug hangs on bottom of pan waiting to be reinstalled...
Got it down couple min to drain.....couple to refill....

Mines city stop and go....so it gets changed every 1200mi.....filter every 7.5K.....

Helping cousins for last 60 years........I've seen some bad movies........

Same thing for coolant.....religiously every 2 yrs.....and not the new stuff......real coolant...

 

100% this. Determine what's leaking and fix it.