Colorado RG overheating issues

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Joined: September 14th, 2013, 4:13 pm

Colorado RG overheating issues

Unread post by boehamian » March 25th, 2019, 9:54 pm

Ok here goes try and keep this short as its been an ongoing issue. Just after some advice.

Car specs (relevant to issue)
Colorado RG LX dual cab chassis 2014 model
ARB bar work (bullbar, side rails and steps)
Hella Rallye 4000 HID converted and hella dual row 30 inch lightbar
Engine remap
265 75 16 tyres, standard rims

Engine is running hot. A little hard to explain but I shall try.
Normally around town it runs just under quarter line on the temperature gauge. When it run out on the highway it would go to just under half. No matter if I had the trailer on behind and what load I had in the car, sitting on 130 it would not go above half.

NOW the temperature is more linear. Temperature changes per the speed a lot more linear. the faster I go the higher the temp goes. Under 70 - 80km/h the temps would sit just over the quarter way mark. over 100 - 110 it would go just over the half way mark. The faster I go the temp gauge follows it up linearly ( if that makes sense). All of this happens without the trailer on behind. So it seems to run hotter than usual all the time.

Point of notice
Originally noticed it when towing trailer down south when the heatwave was going (over 40 degrees all the time) temp gauge sat at just over 3/4 all the way on that trip while sitting on 110km/h. Could not go over. when I got back the viscous fan was replaced.

Went on a trip to Darwin for xmas and towed the camper up to Darwin. Was sitting on similar temps whilst doing 120km/h. So a little difference was made when replacing the viscous fan. When I got to Darwin I took the radiator out and cleaned the radiator fins and made sure there was no mud in it (which there was a little as I was doing some mudding a few months before. Did clean it straight after mudding but didn't pull it out). only a little bit of mud came out of the radiator. Also cleaned intercooler and other coolers whilst I was there. Drove it back down with 1 degree difference, but still sitting on 3/4 on gauge.

Work done already
viscous fan replaced under warranty
radiator been dropped and cleaned by myself (along with other coolers cleaned as well)
thermostat has been replaced
taken back and dealer said nothing wrong. Beside the fact that I took it back out and did a recording of all the sensors (through OBD2) at all speeds. By the time I got to 140km/h the engine coolant temp warning came up on the dash. Dealer blamed the third party OBD2 reader saying the data can not be verified, and their reader could not read any fault codes).

Things I am thinking next.
Radiator is clogged, but not fully blocked as the temperatures are linear, still cooling but not fully functional. Am yet to put a FLIR or a laser temperature reader onto different parts of the radiator to check its temp all over the radiator.
Has anyone got any suggestions?

P.S sorry for the history lesson of my car but tried to keep it short and sweet.

Peter Aawen
Posts: 20907
Joined: June 17th, 2005, 8:01 pm

Re: Colorado RG overheating issues

Unread post by Peter Aawen » April 3rd, 2019, 8:56 am

You say it normally used to run OK & temp gauge would never go but 'Now' it runs hot & the gauge displays a linear increase related to speed .... It sounds like there was something that happened before the 'Now', was there an event?? What occurred that prompted the change, or is it just something that developed over time??

Those questions aside, temp gauges that go up to one temp & stay there, or even those that have one 'around town' temp & another 'on the highway or towing' temp have probably been purposefully 'damped' by the manufacturer! Engine temps DO NOT behave like that in the real world, they go up and down as the load on the engine/cooling system changes; they go up and down as the viscous fan cuts in or disengages, or as the thermostat opens & then later shuts..... But because there are many drivers out there who don't realise this, and many who panic if the needle goes up a bit more towards the top end of the 'normal' range as the load increases, despite that being perfectly safe, manufacturers the world over 'damp' the reaction of their OE temp gauges to keep the punters happy cos the needle never moves!! IMO a needle that sits in one position & never moves, or even a gauge like yours that once showed an around town temp that didn't vary & a Hwy temp that doesn't vary with load & temp changes, those gauges are worse than useless cos they kid people into thinking things are fine when they may not be & they frequently won't show a sudden temp increase until it's too late to do anything!!

A temp gauge SHOULD go up & down as the load changes &/or the fan cuts in & out or the thermostat opens & shuts! If the needle goes up & down to reflect those changes but stays within the 'normal' range, then all is good! And if the needle starts climbing toward the top of the 'normal' range more than usual, then a competent & aware driver at least has a chance of doing something to reduce the temp load before the temps become too high & go over the top of the 'normal' range & into the 'over-heating' range! Most gauges have a bottom mark, another mark up close to 'High/Hot' that shows the top of the 'normal' range, and then a top mark that might even be Red that shows the engine has over-heated - a needle sitting anywhere BELOW that 'close to High/Hot' mark shows the temp is still OK, even if it's getting close to the mark. And the needle SHOULD go up and down anywhere in that 'normal' range to reflect the changing loads on the engine & as the fan cuts in & out or the thermostat opens & shuts!

Are you sure your temp gauge isn't just showing the reality of what the temperature is doing as the load changes etc, instead of still trying to keep you ignorant about what's REALLY happening?

Sorry about the even longer reply than your question, but you did ask! ;)
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