I bought a 1991 4 runner with a 3.0 and auto. It's got 135,000 miles on it. 3 days after i bought it i changed the oil and it promptly developed a knock. I pulled the front diff and dropped the oil pan hoping it was a rod bearing. It's not. Looks like a main. Best i can tell either the motor or tranny has to come out to get to the mains. If i go to that much trouble is it worth the risk just doing bearings or maybe a crank kit or am i asking for trouble? Basically i don't wanna do the job twice. Should i just get a reman motor or try to find a lower mileage used unit? Are the bottom ends on these things known for being problematic? The truck is from New Mexico and is MINT. That is the only reason i'm even considering fixing it. Maybe i should just cut my losses and move on. I need some advice from people that are experienced with these things as i'm not.

Thanks.

 

AFAIK - the bottom end on these motors is fairly stout. I KNOW the crank is. I think cracking the HG gasket could be opening a pandora's box, so I'd try to avoid doing that if it hasn't popped yet and hasnt been replaced. If it has, I'd do a full rebuild then join in on the turbo thread going on in the 95.5-02 thread. (They are talking about turboing both the 3.0 and the 3.4) The 3vze I think is a prime candidate for turboing...

 

Do everything while you are in there! Bottom end on the 3.0 is solid... since the rest of the vehicle is mint, it's worth fixing IMHO. Good Luck and keep us posted. As you can see there are several members that can help if you run into problems!

Bill

 

After my recent top end rebuild and successful running...my bottom end developed a knock. So if ya pull it then I would either say rebuild fully or go with orient engines remanned motor.

 

Thanks guys. It's gonna have to wait for awhile but i'll go the reman route. No funds right now. Hopefull by spring.