its an 88 4runner, 3.0 auto with 210k. basically im wondering the history on the 3.0 and the A340H, what problems are usual at that mileage? is it a safe buy?

 

Welcome!
Mine's an early '89 4Runner with the same set up. 201K miles. A solid truck! Of course, have it checked by a reputable mechanic and pay close attention to these areas: Tie-rods, idler arm bushings, U-Joints and rear wheel bearings seem to be good for 200K miles (+/-); most of the V6's develop small oil leaks around the valve covers, the oil cooler and the rear main seal - rarely anything big enough to worry about; Starters can be a problem, but follow the tips on Roger Brown's site and you'll do fine (The last tip about adding a relay is an awsome idea!). Roger's site. If the tranny won't shift into OD when it's cold, change the thermostat before you do anything else (long explanation). Watch for rust around the rear wheel wells and the A-pillars if there's a sun/moon-roof.
Good luck with your new toy and be sure to post a pic.

 

and find out about the head gaskets too. the 3.0 was bad with head gaskets.

 

What is the explanation? Because I was under the impression that this is normal.

 

Probably should have been clearer. If the air temp is cold, but the engine and tranny seem to be at normal operating temp and you still can't get into OD, then you may have a thermostat problem. The thermostats on the 3.0 have a habbit of sticking open by just a hair - just enough to keep the engine cooler than it should be. The difference hardly registers on the temp gauge, but the computer won't let you into OD until you've gotten the temp up by running higher rpm's in 3rd for awhile. Everything was designed to run at a certain temp, so the computer tries to keep everything at that temp to help with wear and emissions.