Relatives just gave us a '94 4runner. It's perfect condition and religiously maintained. It has 190,000 on it.

But...

Previous owner has used 20/50 motor oil in it since the day he bought it.

Should I change back to the 10/30 recommended -- or keep going with 20/50 at this point? One mechanic suggested that if we go to 10/30 it is likely to start leaking all over at this point.

Would love your thoughts.

A secondary question... Not sure when the engines go out on this model. If it does, better to replace engine, or move up to '99 3rd gen?

Thanks.

 

Which engine is it?

 

V6 is all I know. Automatic transmission. Slow up hills

 

My 89 pickup has the 3.0 with auto, currently at about 250k. The motor is sure to be tired (was never great with the auto) at these high mileages but have seen them go to up around 275k. I like my 5 speed a lot better and it's been great for power since a top end rebuild.

As far as the oil, I have only ever used the recommended.

 

Thanks jslone. If this 4runner gets another 50K I'll be a very happy camper.

This issue with the oil are the ramifications of changing back to recommended after its run 190k of 20/50 in it. Would hate to jack up a perfectly fine engine.

 

It is unlikely to start leaking with slightly thinner oil. You will get lower oil pressure (but higher oil flow). This is why a lot of people switch to a more viscous oil with older engines; as the bearing clearances increase, the thinner oil has lower pressure, so the oil doesn't get forced into all the nooks and crannies.

Or so the story goes. I'm using 30w now.

 

Thanks scope.

 

Won't hurt to try recommended oil.

Might want to look for a new mechanic.

 

Thanks, I'll definitely be shopping for mechanics for it.

The concern of the mechanic is that it actually would hurt. Going to thinner oil would permanently remove sludge and such that is keeping it from leaking. So, if it started leaking/burning, i couldn't just go back to thicker oil because the leak barriers are now removed.

I have no clue if that is accurate or not -- but that was the concern.

 

Wouldn't you want the sludge out then? If it starts leaking then you fix the leaks and go another 50k... you could go to like 10-40... if you're going for another few months i wouldnt worry but if you want to make it last many more years then you might want to put in the proper oil... but hey... if it ain't broke....

 

Ooh! I love that! "I can't change my oil anymore, because clean oil would dissolve the sludge and the main seal would leak."

You know, he might be right in his own way, but if sludge is all you have between you and a leaking engine, you should find out now rather than while you're sitting on the side of the road.

Lots of people DO use thicker oil to hold up their oil pressure as the clearances slowly open up. I'm just not sure it's worth it.

 

I used 20W-50 dino oil in my 3VZE for years with apparently no ill effects. When I rebuilt the engine at 218,000 miles, I switched to Amsoil 0W-40 for better cold/starting protection. It never thins out to less than 40 weight at operating temperature & flows like 0 weight when cold. It ain't cheap, but I 'm actually using LESS oil & keeping better pressure than I ever did with the 20W-50.

 

Thanks Porcelain and Scope...

This sorta sums it up pretty well I guess...

"if sludge is all you have between you and a leaking engine, you should find out now rather than while you're sitting on the side of the road."

 

The only thing I have heard about switching oil and causing leaks. Would be from going from a traditional 100% natural oil that you have run for 200k miles and then switching to a fully synthetic super cleaning oil. even then I think that sounds interesting. But it might work for your mechanic. I had no idea what the po was running in mine for the first 200k miles but after i did my head gasket and timing chain I went back to recommended and have no problems. (with the truck that is)

I would just drive it and then fix it when it makes funny sounds or no sounds. Hey its a Toyota they run forever.