Delica Canada | Mitsubishi Van Club

HI foiks,
Coles notes history.
Bought a L300 in Victoria. Got a general go over from a garage. Garage said that rad was bubbling and there might be a head gasket issues, but they did a dye test on the rad and it came up negative, so they said there is no head gasket issue.
Drove the van to Halifax, all was well.
Halloween weekend she started getting hot, like 3/4 of the temp. gauge. Very different from what the way she was.

Today, I drained the coolant to check the thermostat (start with simple stuff and hope for the best).
When I drained the coolant from the rad, it was greenish colour. But when the 'stat came out and all the "liquid" came out from the engine side, it was more brownish and looked more "watery". I took pic's of both,the brown spot on the white is from the engine side, the green stuff in the bucket is from the rad...damm, cant figure out how to post them here.

Also, I read in one of the manuals about the fan clutch "...if fluid quality decreases due to leakage, fan speed will decrease and engine overheating might result" and "when a fan attached to an engine is turned by hand, lightly, it is faulty"
My fan turns by hand very easily.

Anyone have any ideas what all this means? How can a fellow be 100% sure the head or head gasket is done?

Much Thanks,

brown fluid on the engine side sounds like the head or head gasket is leaking oil and coolant together. The clutch fan probably needs replaced of refilled but that is most likely not the issue.

You can get a pressure tester for the rad (some auto parts places loan them)... You want to put 10 psi in the system and see if it stays.... If you can hear pressure add the oil side of the motor you have problems... Compression test can also turn up leak...

The brown sounds bad but it could just be corrosion. If you have a head gasket leak, it will pressurize the cooling system and will overflow. If the coolant level was staying constant, something else likely the issue. The brown muck might just indicate that your cooling system is overdue for a flush, which also could indicate the rad is pretty gummed up. The cooling systems on these things can be a problem if not maintained properly. If it hasn't already been replaced, you could very well be looking at a new rad.

Thanks for the info so far.
I just confirmed that the thermostat that was in her did not open. When put in a pot of water and brought up to boil (had a digital temp. gauge to measure water temp.) there was no physical change in the 'stat.
I have a new one, and threw that in the pot as well. It started to open at around 87c and fully open at 91c.

I will try and flush the system and then put the new thermostat in and see what happens.

Head gasket leak will only pressurize the cooling system if the leak is between the compression side and the coolant side...

Head gasket could leak between the oil and coolant or many other combinations....

Sounds like the thermostat maybe the issue... but green in the rad, brown in the block... that is a serious plugged system....clean it really good...good luck...

I usually drill a small hole in my thermostats when installing to help bleed air out of the system and I only use OEM after way to many bad in the box garbage ones...

thedjjack wrote:Head gasket leak will only pressurize the cooling system if the leak is between the compression side and the coolant side...

Head gasket could leak between the oil and coolant or many other combinations....

True, but unlikely. Cylinder pressure is what usually blows a gasket, and when it goes there's a lot more coolant passages than oil passages around the cylinder. It's all a matter of odds, though no limit to the strange things an engine can do.

In this case it was the simplest and easiest, which in my experience is rarely the case!

Well....
I drained and flushed the coolant. Replaced the thermostat. Put it all back together.
When flushing it I learned that it is approx. a one beer wait while the system drains from the plug at the bottom of the rad.
I ran it with the rad cap off for 15 min or so, and did not see any bubbles, just some turbulence one in a while.
There was some gas vapor or something coming out once in while.
Took it for a 20 min drive, and I am pretty sure I have a totally different machine.

Temp. gauge rises to 1/4 scale, compared to 3/4 scale before which was normal before, and almost at the "H" when I realized i was in trouble. I have never see the temp this low.
I could even see it go up and down a bit depending on how I was driving.

I think I will check the compression and if i can find some way to pressure test the coolant system - without buying the $200 magical tester thingy - just to double check I dont have any issues.

Thanks for the input folks....and all the previous posts about how to remove the bit and pieces. My fingers were on the keyboard searching just as much they were on the tools.

That's great, and I wouldn't worry about going through any testing hassle; if you have a leaky gasket you will know it. if your readings stay low, your coolant level is constant, all is good. But the brown ick that you drained out still points to future cooling system maintenance.