I just bought a Mitsubishi Montero 1990 V6 4d and it appears it has the second version crankshaft bolt (the skinny one) and has not been upgraded with the newer bolts that are recommended (I used a mirror to look at the one on the vehicle and it was skinny past the bolt). It has 146000 miles. Do I need to worry about getting the bolt replaced? The vehicle is working well, but it does not have many highway or offroad miles.

Also, will replacing or cleaning the air flow sensor improve the MPG greatly?

Thanks very much from a novice (I have used Pajeros overseas for years but I am not mechanically inclined).

YES to the bolt question! Get a new washer, too. One whole lot easier to deal with at this point than waiting for it to possibly-eventually break.

You can try cleaning the MAF, but if you're getting anything close to 15 MPG, you're as good as you're going to get, in all likelihood.

Welcome to the Wire.

John B.

If you're looking to improve your fuel mileage the best thing you can do is a proper tune-up. Replace plugs, wires, cap & rotor, fuel filter & air filter, set the ignition timing, clean your MAF, and make sure your tires are correctly inflated. Other correctable things that can affect your mileage would be incorrect wheel alignment, carbon build-up in the intake and combustion chambers, using dino oil that's too high of viscosity for your driving conditions, and carrying extra weight in the vehicle. If everything listed above is in good shape then you're probably getting as good of mileage as your vehicle is going to get.

Well then what kind of miles are on it if not highway or off road?

What fuel mileage are you getting now?