jdsdj98

THIS IS NOT A DINO VS. SYNTHETIC THREAD. PLEASE DO NOT POST RECOMMENDATIONS REGARDING THAT ENDLESS DEBATE.

Just read through some entertaining oil related threads after searching, but did not find any questions or answers along these lines.

Regarding the '01 Tacoma in my signature, in looking ahead to its first oil change under my ownership, I'm wondering how to play it the safest. The truck is extraordinarily clean and appears to have been well maintained throughout its life. However, I don't know whether the previous owner used dino or synthetic oil. I bought from a dealership, and of course, they wouldn't provide me with any contact info or meaningful information with regard to the truck's historical specifics.

Filtering my concerns down to 2 questions:

1. How would you approach the first oil change (@ around 101k) on a used 3.4 of unknown history, i.e. dino or synthetic? I'm a dino guy, but am willing to make the switch if it means not popping leaks. I hesitate with blindly switching to synthetic because of the "high" miles - I know synthetic proponents advise making that switch within the first 10k.

2. Is there any conceivable way of making a reasonable determination as to the type of oil this truck has been running throughout its life? I can't really think of any way to do that.

Again, please answer only in the context of this scenario. I'm not interested at all in starting up yet another dino vs. synthetic thread. That's been hashed out far too many times here.

Thanks.

Belize Off Road Team

I recommend flushing the motor then run Castrol (i recommend Truck and SUV syntec blend). It is obviously specially designed for SUVs and Trucks...but that would be my choice.

86tuning

If you bought the vehicle from a dealership, they would have changed the oil when they inspected it. And you'd be dreaming if you thought they put synthetic in. So a UOA won't tell you anything.

IMO you will be perfectly fine using any 5w30 oil. Look inside the oil filler hole for crusties and sludge. If it's clean looking in there, you can drop in any synthetic oil, and deal with any future leaks by replacing seals. At 100k you're due for a timing belt change anyways, so you could simply reseal the front while you're there.

On the other hand, these engines have a good reputation on running for many hundreds of thousands of miles on regular oils.

jdsdj98

They couldn't provide any verification of timing belt maintenance, so I negotiated a new one into the deal. I'm good to go on that front.

And yes - It's obvious they did an oil change, based on the filter and oil condition. But only one person out there knows what ran in it for the 96k leading up to that, and I don't have any way of finding him/her.

My main concern is upsetting equilibrium at 101k. It has no leaks anywhere, and I certainly don't want that to change.

cackalak han

Hey, make sure that they use OEM belts for your timing belt change. Most non-Toyota dealerships will put in some aftermarket part, which I'd not recommend. Nothing fits like OEM.

As far as the oil change, if you want to use dino, just use dino. Then at your first oil change (4-5k miles), send your oil into www.blackstone-labs.com for analysis. It'll be the best $22 you'll ever spend.

Also, don't forget to change out all of the fluids (transmission, diffs, xfer case, etc.) and probably due for a tune up.

jdsdj98

Bought it from a bowtie dealer, and I honestly can't speak to whether the timing belt is OEM. Their service manager started name dropping when I mentioned my preferred local Toyota shop, and stated that he has a Toyota background, but I know that means absolutely nothing at all. I did get the opportunity to have them dig the old one out of a trash can to show me its condition, which served as proof that they actually did the replacement. Unfortunately I rarely trust a dealership or mechanic, especially over a sales transaction.

I've already changed the rear diff oil & flushed and changed the ATF. Have the coolant, front diff., and t-case on my radar, although all are at healthy levels and condition. This truck doesn't appear to have ever seen anything other than pavement, so I don't have much concern for the front diff and t-case from a 4WD standpoint. Everything works as it should.

I just really want to make sure I take off with the oil changes correctly. I will look into doing an oil flush and also look into having an analysis done after the first drain. Those are options I hadn't considered. Thanks for those suggestions.

Unzie22

I believe you can run either style oil in the new rig. The 3.4L is a great motor and not hard to maintain while still being super tough. In all likelihood the vehicle was serviced at the dealership by the previous owner, if not an express oil change place. The best way to be safe is to run the oil you've got until it's due and have it analyzed, it can give you a very accurate representation of the condition of your motor. Bottom line is the 3.4 will give you at least another 150k if you take care of it, whether or not you run syn. The biggest difference of course is the price between synthetic and conventional oils.
However just in case, it is a good idea to take it in for an oil change and check-over at a shop.

cosmophonic12

I've replaced two timing belts with two different vehicles (at dealers) and both come with a sticker indicating they've been changed. one sticker in on the opening hood of the air box cover and one being face up on the back cover that hides the belt.

RobD

Might not be possible in your case, but can't you take the VIN to a Toyota dealership and have them pull the service record? The local dealer did that with mine and was able to tell me every service event it had listed, even though it was 17 years old and from another province.

Perhaps the PO had it serviced through Toyota.

jdsdj98

Did that with 2 dealerships and a local Toyota shop before I bought it. No one has any records on it. I guess I could start calling every drive-thru lube shop in town, but I don't plan to do that.

Hilux808

Here's my opinion:

I got my 4runner when it had 97k miles on it, 22RE 4 cylinder but I knew the previous owner never ran synthetic. I ran it anyway and I lucked out, no leaks until my front seal went out on me about 20k later. I wanted to run synthetic no matter what just because of the performance, protection and extended drain intervals. I was willing to take the gamble and if it leaked I would just fixed it anyway. I never like having a vehicle with fluid leaks and the I can assume the engine internally stays a lot cleaner with the synthetic in it, at least that's what all synthetic oil manufactures want you to believe.

There's really know way of knowing until you actually try synthetic...it could take some time anyway if you chose to run synthetic and your engine started to leak, depending on how much gunk is blocking a potential leak. Another thing to be aware of is that today's oil's, synthetic and non-synthetic are built a lot better then they ever have been so even if the previous owner was running conventional oil you're probably in pretty good shape as far as your engine is concerned. Unless it wasn't changed for long intervals I'm sure you'll be OK. One way of finding out is by asking how your engine performs...does it sound normal? Any knocking? Does it start up and idle OK assuming the compression is still good?

One thing that helps an older engine is running a heavier weight. I started running 20w-50 or straight 50 shortly after I got my 4Runner. You might want to try at least 40w if you find your truck drinking 30w.

SoCalPaul

Run what you're comfortable with. I like synthetic but I drive a lot & drag out the oil changes. If you're concerned about synthetic, use a quality dino or blend & you'll be fine.

Gerdo

Run dino if you like.

Run Synthetic if you want. You're not going to get leaks because you switch to syn. High miles or not. PS 96k isn't high miles. I switched over to syn at 150k.

There is no problem jumping back and forth from dino/syn/dino.

With used vehicles I always assume that nothing major (maintance) has been done.

RobD

Wow...that's bizarre. You'd think at some point it might have had to have even a warranty repair.

jdsdj98

I thought so, too. It's been a local vehicle its entire life (one thing I DO know about it), so I was surprised.

Gerdo - You're the first person I've heard say that so straight-forward. I've always been under the impression that a motor that's been living on synthetic oil is more prone to leaks if switched back to conventional oil, hence my concern with running this thing on conventional oil now.

However, some research earlier today led me to believe that switching is more a problem with "older" vehicles, although no one really specifies what constitutes "older."

And I approach a used vehicle the same way - assume that everything needs to be done. I've given this truck a thorough bumper-bumper inspection and addressed the most glaring items first, with a to-do list that I'm picking my way through. That said, I'm really happy with it and feel good about the deal I got. I just want to make sure I'm maximizing its useful life, and establishing a good maintenance baseline right here at the 100k mark.

Hilux808

If you're not leaking with synthetic you probably won't be leaking with conventional. Synthetics are superior to conventional in their ability when it comes to engine cleanliness. Gerdo said that you can go back and forth and that synthetics will not cause leaks. If you're engine is sealed properly (as if your engine had all new seals and gaskets) then this is true; however if you do switch to synthetic and conventional was always used before that there can be a possibility that a leak will develop. Over time conventional oil can build up in an area where a leak could be present. Conventional oils do not "clean" as well as synthetics, therefore a slight potential leak could be blocked due to the oil gunk (sludge). It's only after switching to synthetics that you could notice a leak, given the time that it takes for the synthetics to dissolve and sluge present in your engine.

Synthetics by itself do not cause leaks (it's still an oil, not an acid that just eats through everything it touches) but their ability to clean away dirt and sludge is what allows itself to find leaks that existed before but were simply plugged by sludge build up.

Consider "older" engine to have at least a 100k if not more. Time is an issue too. An engine with 100k in 3-4 years will be less likely to have fluid leaks compared to a engine that has 100k and is pushing 10 years, etc.

ARB1977

Change the oil and enjoy the truck another 100K or more. Dont over think it, just change it and move on.

91TPU

i run synthetic in everything. never caused an oil leak.

as for an engine flush i would not recommend that. ive worked for dealerships and none of the machines they use for flushes are factory recommended. they are add on sales and are NOT recommended by the factory. B and G is a leading producer. If it were a brake flush or a coolant flush i would feel differently, but in terms of flushing the motor with harsh, heated detergents, i would not.

my personal opinion is to switch to a high quality syn or syn blend.

jdsdj98

Overthinking is a problem of mine.

Thanks for the replies, guys. I've got a better idea of how to approach this now.

wizzells

I'll add my 2 cents here, because why not!

You can go from a synthetic to a dino and vice versa. THIS WILL NOT CAUSE LEAKS or any other problems for that matter. If you're concerned about switch over to synthetic at that mileage, dont worry about that either. I switched mine (unknown history) to Mobil 1 at 115k and here I am pushing 145k with no adverse affects. My main reason for switching over was extended drain intervals and cold start protection in the winter. The car sits outside 24/7 and we see temps as low as -20F in the winter here.
Run whatever suits you best. If you desire extended drain intervals, go synthetic, otherwise regular changes on dino wont wreck your engine either!

**edited to add that I would not do any type of chemical flush either. There is a good chance that if there is any accumulated gunk inside the engine that it can break loose and clog an oil passage internally which can cause oil starvation. The only safe way to do this type of cleaning, internally is gonna be Auto-Rx. It's the only cleaner I know of that works slow enough to dissolve buildup yet do a good job of cleaning in an effective manner.