A friend of mine has a 93 4Runner with 150k on its second engine (275k on the body). His mechanic did a compression test and he's lost cylinders 1 & 4, which means a valve job. His mechanic is wary about doing a full valve job due to the age of the engine since (in his opinion) it'll put the entire top end back to OEM pressure and, since the bottom will still be at the 150k pressure, could cause problems with blown seals or other bottom end issues. So that leaves him with several options:

• take the chance with the valve job on his current engine;
• swap in a new Jasper 3.o engine (mechanics choice);
• swap in a 3.4 (needs donor equipment, mechanic won't do it);
• buy a replacement truck of the same era with less miles.

Let me know what everyone thinks so I can pass this along to him. He drives from Denver to Cheyene twice weekly and every weekend to breckenridge for skiing.

 

I have to wonder what kind of driving and/or maintenance your friend does to only get 150k on each of two Toyota engines....

Anyways, I understand the bottom end of the 3VZE is super stout. I would go for the valve job.

 

try shimming it first then if that don't work do a valve job. these motors are good to atleast 250k with proper maintenance

 

if your going to pull the motor to do heads its not THAT much work (or money) to put bearings and rings in it. (hone the cylinders assuming you dont find big probs with something)

if your not going to pull it, do the head work and bolt it back together and go from there.

 

I went through the same dilema . . . burnt #4 exhaust valve. But, I'm at 228k on my original engine. It seems clear to me that with so many miles that a valve job might not be such a good idea for the reasons you stated. For whatever it's worth, I decided to go with a Jasper and hopefully go for another 10 years or so. My truck is my DD and I rely on it for ski weekends in Mammoth among other things.

Putting a new engine in is also a great excuse for me to give the rest of the truck a facelift!!

 

I just rebuilt my top end and the mechanic is right...my bottom end is knocking now because it had 220k on it. If it makes it til February I'm swapping out this 3.0.