MN (2.5hp) High Engine Temperature Thermostat Modification

[Homer]

Mine would be lucky to be 5 mins.
However just using the gauge is probably not a good indicator. For example my needle doesn't move at all and then after say a minute or so it jumps to quarter and goes up from there.

Could just be your sender and gauge as I'm sure it wouldn't take that long...only reason I could think would be the thermostat has been removed?

[rodeddy]

hi,
my thermostat is in, in fact i had actually did the thermostat mod to it drilled a small 1/16 hole in it (see earlier part of this thread) - I'm wondering now whether this is contributing to the issue?
Im thinking of buying a new one, not drill a hole, and replace it.
Thanks for the info. It appears about 5 min should be the norm.
cheers, Rod

Mine would be lucky to be 5 mins.
However just using the gauge is probably not a good indicator. For example my needle doesn't move at all and then after say a minute or so it jumps to quarter and goes up from there.

Could just be your sender and gauge as I'm sure it wouldn't take that long...only reason I could think would be the thermostat has been removed?

[SEJ GLX-R]

Sorry for taking a bit to reply to this but I have not had time to test it until today.

I started in my garage with the scangauge coolant temp on 14° and the outside air temp on 11° which dropped to 9 & 10° once I started driving.

I drove 3kms at under 60km/h stopping at 2 traffic lights and then did 3kms on the freeway.

At 5 minutes, 32 seconds, the coolant temp passed 82° and at 6 minutes, 15 seconds, the gauge on the dash was at it's normal mark, (which for me is slightly past the half way).

The only time I have found it wont reach the operating temp is when it's just idling due to the engine fan which was the same prior to the mod.

[rodeddy]

hi,
that's heaps great info, and mine with 1/16 hole, which is smaller than your 1/8, should do the same...
I can't understand why its not ??
I might take it out and replace... perhaps there is an issue with my thermostat opening too early or not fully shutting off...I could take it out and try it in a pot, but will buy a new one to be sure - and check before i instal
Appreciate the effort !!
cheers, Rod

Sorry for taking a bit to reply to this but I have not had time to test it until today.

I started in my garage with the scangauge coolant temp on 14° and the outside air temp on 11° which dropped to 9 & 10° once I started driving.

I drove 3kms at under 60km/h stopping at 2 traffic lights and then did 3kms on the freeway.

At 5 minutes, 32 seconds, the coolant temp passed 82° and at 6 minutes, 15 seconds, the gauge on the dash was at it's normal mark, (which for me is slightly past the half way).

The only time I have found it wont reach the operating temp is when it's just idling due to the engine fan which was the same prior to the mod.

[rodeddy]

I bought new thermostat, drilled a small 1 mm hole, installed it today.
The small hole must work ok also, as i got all the coolant back in, obviously no air lock. Took it for a drive.
Outside temp was 14 and it took only 6km and about 6 minutes to reach full operating temp.
So all is good
Thanks to all for effort and info, cheers, Rod

Sorry for taking a bit to reply to this but I have not had time to test it until today.

I started in my garage with the scangauge coolant temp on 14° and the outside air temp on 11° which dropped to 9 & 10° once I started driving.

I drove 3kms at under 60km/h stopping at 2 traffic lights and then did 3kms on the freeway.

At 5 minutes, 32 seconds, the coolant temp passed 82° and at 6 minutes, 15 seconds, the gauge on the dash was at it's normal mark, (which for me is slightly past the half way).

The only time I have found it wont reach the operating temp is when it's just idling due to the engine fan which was the same prior to the mod.

[RHKTriton]

Just for interest, mine is ml and as I'm replacing the harmonic balancer I decided to do the coolant, thermostat and cap while I'm at it.

I could only track down a thermostat at Repco (cost enough), it looks like it has less flow capacity than the original.

There are temps stamped on the units, Mitsui 76.5. And Repco 77degrees.

[RHKTriton]

Just for interest, mine is ml and as I'm replacing the harmonic balancer I decided to do the coolant, thermostat and cap while I'm at it.

I could only track down a thermostat at Repco (cost enough), it looks like it has less flow capacity than the original.

There are temps stamped on the units, Mitsui 76.5. And Repco 77degrees.

[rodeddy]

hi,
i can't give you any info re the ML. But with the MN, the original mitsubsihi was better design and flow than the Tridon brand...and was only around $35

Just for interest, mine is ml and as I'm replacing the harmonic balancer I decided to do the coolant, thermostat and cap while I'm at it.

I could only track down a thermostat at Repco (cost enough), it looks like it has less flow capacity than the original.

There are temps stamped on the units, Mitsui 76.5. And Repco 77degrees.

[Hornet75]

Hi all
Just did this mod this morning as like the rest of you, experiencing higher than wanted engine temperatures.
Before hand, running around town at 60ish, ambient temp in low 30's Ultragauge was showing low 90's. At 100kph plus, Temps got over 105 with no load or towing. Way too high for my liking.
Drilled a 5/16th hole and now Temps have dropped to 84-90°c. Much more to my liking. Still think I will change the viscous fan clutch though, as it's done close to 160k and when locked up is still easy to move.
Thanks for the heads up. This issue has been doing my head in.
Considering changing the coolant over to the Evans Waterless Coolant in preparation for a big trip to Cape York or Simpson Desert in 2016.

[RHKTriton]

Does seem high Hornet, my ml and Vito had never shown above around 90. The Vito even had an aux heater as the engine was battling the generate heat in colder weather (wish I'd kept that bit).

I ended up leaving the original thermostat in as the replacement was not looking up to task. Just keep it as spare part.

Re fans; the viscous unit is going soon, replacing with electric. The fan currently seems to be on more than desired.

I'm going to place the electric radiator fan as far right as possible and then rig it so that the ac fan can also kick in as backup.

I saw on Chevy site last night that Colorado in US has shutters in grill to block air for better economy, until airflow is required.

[colin b]

That coolant sound like the cat's pyjamas but, being a cautious type, I would like to hear opinions from some authorative sources like the R.A.C. or N.R.M.A. before using it. The motoring landscape is littered with the bones of "breakthroughs" which failed to live up to their initial hype and the bills incurred by those who were sucked in.

[motoz]

That coolant sound like the cat's pyjamas but, being a cautious type, I would like to hear opinions from some authorative sources like the R.A.C. or N.R.M.A. before using it. The motoring landscape is littered with the bones of "breakthroughs" which failed to live up to their initial hype and the bills incurred by those who were sucked in.

The spiel the guy gave about it on that quality piece of infotainment '4WD TV' sounded like total BS to me.
I've put it in the Hyclone category !!!

[kxboss]

Had the recall done on mine with the 60,000k service a 4x4 dual cab 2012 build, they left a big air bubble in the system, two litres of water later, car running normal again. not going back to Gateway

[RHKTriton]

I was checking on that waterless coolant - effectively straight coolant - a couple of articles I read put me off in the end.

Save your money, we have proven long life coolants that can be cheaply topped up if required.

From memory, one article covered tests that showed water to have better heat transfer capacity than the goop.

[Hornet75]

I can see how the waterless coolant has its benefits of not turning into a gaseous state. Water/coolant does separate when the water turns to steam. This steam cannot return to a liquid until the surrounding liquid and metal Temps drop below 100°c, hence staying in a gaseous state, hence not doing its job. I did learn something in chemistry class at school, even though I usually read surfing and 4wdriving mags during class lol.

On another issue, viscous fan hub. Replace with a brand new Dayco unit yesterday, though it doesn't disengage and just roars from cold to 90°c. Now I sell these, and I'm the one at work who handles warranty claims (I'm a spare parts interpreter). I've never heard of having to give them time to loosen up, but has anyone else had issues with new fan hubs not disengaging?

Cheers
Bill

[Longranger1]

Just doing a service on my truck now. I checked the factory fill coolant and it is around 17% Brix and the new Mitsubishi genuine coolant is about 31% Brix when I measured it with my refractometer. The new stuff won't get rid of heat as well as the original so it depends more on the cooling capacity of the radiator to deal with it.

Great thread Sej! Bleed hole in the thermostat coming up!

[Longranger1]

Just doing a service on my truck now. I checked the factory fill coolant and it is around 17% Brix and the new Mitsubishi genuine coolant is about 31% Brix when I measured it with my refractometer. The new stuff won't get rid of heat as well as the original so it depends more on the cooling capacity of the radiator to deal with it.

Great thread Sej! Bleed hole in the thermostat coming up!

[Crash486]

Since I'm getting high temps thought I better look for a thermostat with a jiggle pin. Read above that the Tridon high flow wasn't as good as OEM. Then found these ones by Slant - Offset thermostats
http://www.gatesaustralia.com.au/products/automotive/passenger-car-and-light-truck/cooling-system/thermostats/stant-offset-thermostats

Supposedly designed for Japanese vehicles and say
"Stem, spring and heat motor is offset from the center of the thermostat flange
A “jiggle pin” located in the offset flange of the thermostat allows release of trapped air behind the thermostat

Air lock and leakage hinder the operation of a thermostat during engine warm up. The offset design with the jiggle pin valve helps the engine to reach its designated operating temperature more quickly and precisely"

Unfortunately there are no models listed for my 2010 Triton in the catalog - have to give them a call.

[Cowboy Dave]

Why not just remove what you have and drill the hole? I have and I can tell you it was well worth the effort. Wish I'd done it a long time ago.

[gazman152]

Why not just remove what you have and drill the hole? I have and I can tell you it was well worth the effort. Wish I'd done it a long time ago.

What average temp difference resulted when you did the Mod Dave?

[Cowboy Dave]

At freeway speeds I was averaging around 95 (post overheating service campaign) and now I am averaging around 88.

[gazman152]

At freeway speeds I was averaging around 95 (post overheating service campaign) and now I am averaging around 88.

Thanks Dave. Sounds well worth it. Mine sits on 95 at freeway speeds at moment. About 88-90 in back streets. 1/8th hole in yours?

[Cowboy Dave]

Yeah exactly, even used the imperial drill bits for a change.

I've uploaded a page from the manual that I took with me. Doesn't show much.

My tips from having done it recently:-

* have extra coolant on hand. I drained 3 litres from the radiator (it was then empty) but it took 6 litres when I refilled it it then took another 500ml or so in the following days after it drew a little more coolant from the recovery bottle
* you will lose coolant when the thermostat comes free so stick some plastic over the top of the alternator to prevent it drowning in coolant
* the 3 12mm bolts you need to undo are maybe 50mm long and take a while to get out. Access to them is hard. The one on the bottom right I did entirely by feel.
* I removed the tube between airbox and turbo.
* I also moved the small vacuum line that goes to the base of the turbo and un-clipped the two wiring clips for the wiring harness there which impedes access. Once unclipped you can pull it out of the way a bit.
* I couldn't get a socket onto the top left bolt but I was able to get a thin foot long ring spanner onto it which gave me enough purchase to crack the seal
* the bolts looked like they'd had some thread lock of some sort on them so I cleaned the threads and put thread lock on them when reinstalling them
* I left the hose on the housing and left both in situ while I had the thermostat out
* my thermostat was stuck in pretty tightly, it took more force than I was expecting to free it. The rubber ring which forms the outer seal for the thermostat can be removed while drilling.
* when you do drill make sure you clear the raised lip - mine was fine on the I was drilling from but on the other side scored that lip. No biggie but it meant a small amount of extra metal to file down when knocking the rough edges off the hole I'd drilled.
* the hole goes at the top when reinstalling
* replace intake hose and wiring loom and vacuum hose. Can't hurt to clean the air intake while you're there
* refill the radiator, leave the cap off, run the engine, turn the heater on and top up the radiator when the level drops as the pump pulls coolant through to replace what gushed out when the thermostat popped free
* wash away any spilled coolant as it is nasty stuff
* use a milk crate to stand on for improved access to the bolts etc


Hopefully that helps. It took me longer than it should have, mostly because access is just stupid tight.

[gazman152]

Thanks Dave. Nice and detailed. I'll have a crack next rainy day.

[coughy]

well i know this is a old thread but i removed the thermastat today and it wasnt opening very well
so i bought a new one
holy F**K me they are dear
it was $97 but i got it for $50 so im very happy with that
the one that i removed didnt have the jiggle valve in it and was sealed mmm
maybe the reason why mine runs hotish
so i removed the jiggle and the hole was 1/8 so i left it and run the car now she sits on 88c was before 93-95c
so lets see if i get any airlocks
as well as i bought some genuine coolant 5l for $50 was a costly exercise .
but a nother job done