I'll start by saying this is not my first Mitsubishi. I had a Pajero for many years and before that two Magna’s and Sigma. Although they all had their small problems I loved them all. That brings me to my new little girl, MQ Triton 2016, with 140k on the clock and one small problem.

I’ve had my Triton for 8 months and in that time I have had use of it for little more than 8 weeks, not all at once but over the 8 months. Soon after taking possession of the car I noticed the coolant level had continued to build in the overflow. As the days grew hotter into September the overflow soon did just that, overflowed. The car was not overheating at this point. Just pushing out coolant.

This problem was noted with the dealership within the first weeks of having the car. The car was returned to the dealership and work started on the car to fix the problem. At first it was a new radiator cap and a coolant flush, mind you they had the car for a week for that!

The car was returned to me but as the weather got warmer the car started overheating and on a simple drive home from work one day in October it overheated, went into limp mode and that was it, cooked.

The car company said they couldn’t fit it into the mechanics schedule so it went to another mechanic they sometimes use. This new mechanic started work on the car around November 22. It was evident that the head or head gasket had failed and this was fixed under warranty. Mostly coming from the $5k extended warranty I’d paid for when purchasing the car. Apparently it’s common for dealerships to use the extended warranty they talked you into getting to cover their asses in situations like this! But at the end of the day what do I care, I just wanted my car fixed.

So…. just before Xmas 2022 I get my Triton back, just in time to take the family away for some R&R over the holidays. Not likely, it’s still pushing out coolant and risking overheating. So without risking a new head it goes on a truck back to the mechanic. A bit more research form the mechanic and it turns out this model Trion could have a problem with the block. So back to the dealership and warranty company to see who’s going to pay for what? Some weeks later they finally agree to pay for the extended repairs.

That brings us up to now. The car has a new block and head. Along the way it’s picked up a new radiator plus cap and an oil cooler and enough coolant to fill a small swimming pool.

My question to anyone who’s read this far is, why then is it going back to the mechanic Monday morning to find out why it's pushing coolant out the overflow??????????

Once again the coolant had not siphoned back to the radiator after the engine cooled overnight. Also when I opened the radiator cap it showed signs of compression and expelled gas. Needless to say there was no chance that coolant was going to move back to the radiator from the overflow against such pressure.
Hope someone out there has an idea of what might be the problem. in the meantime, I'm enjoying reading the post here. thanks everyone

 

If this is a Mitsubishi dealership then Contact MMAL customer care, its on their website.

MN tritons suffers with these problems, MQ is a different engine, and does not.

Blocked radiators and poor flow through the engine bay caused by aftermarket bullbars can cause issues. Have these been checked?