I've had a 94 LS 3.0 for about 16 years. Only mods are OME shocks and a recently replaced engine, and that's where the weirdness began. I used the vehicle in my work in the wind and solar energy biz and, for about 4 years, a 600 mile bi-weekly commute from Atascader and Healdsburg - both in California.

Like amny Mits V-6 engines, mine started leaking oil from the rear cam plugs and the front seals. The oil pressure was trending down, so I decided on a rebuild - but then found a factory new engine of the right conformation a fellow had in Sacramento at a good price. Replaced all the seals and gaskets, timing set, balancer and etc, etc.

Even since the swap the engine has gotten hot on steep grades and/or very hot weather at higher RPM's. The water pump, thermostat, hoses and so on are all new and the radiator was replaced by a local shop about 6 months before the swap - with a single row, of all things. Not what I would have chosen but that's what happened. With our insanely hot weather lately I don't dare take it where I used to for fear of dreadful things happening.

So, my question is this: should I fork out (even) more money for a two-row, or might it be something else???

 

I think it's normal for engines to be running a bit hot when going uphill and in very hot weather. My 01 montero's temp would read normal in Los Angeles but would rise up a bit in palm springs specially in those long freeway sections that goes uphill. Engine temp goes back to normal after a few minutes of normal driving.

 

Unfortunately, this is more than a "little hot". On low speed, steep mountain grades I have to pull over and let it cool or it'll boil over. My original radiator was an all copper and brass 2-row and the temp never went past just shy of mid-range, even pulling a heavy trailer, the back full of gear and 2 adults - in the heat of Summer. I suspect that a single row just isn't adequate.

 

How many rows does the stock montero radiator have?

 

All the one's I've seen, including my old '89 1st gen, have 2. About 98% of the one's available on the net have one. Why so many are produced with such low cooling capacity is a complete mystery to me.

 

Because they are cheaper and easier to produce.

 

If Mitsubishi decided to use 2 row radiators on our montero then we should stick with 2 row radiators. Was looking at rockauto and I was surprised that they don't sell 2row radiators.