Offroad-Express

Yea a cooler running engine can wear parts quicker than an engine at operating temp, right? Isnce a jiggled the temp sensor that is currently in there and cable tied it tighter my gauge reads at about 88'c running temp. That is about correct isn't it? Guess it just looks high to me because I'm used to it being lower. Will see what temp the new sensor and gauge (in the factory sensor position in the engine) gives me tomorrow.

88c is fine.

Yea thought so. Ok will chuck the new gauge in tomorrow and just watch it over the next week or so and see how I go. Hopefully going up decent hills with my foot up it it won't shoot up too much. Driving to Supercheap today with my foot up it for about 4 seconds it went up to 90/91'c.

If it does end up being a bit high with driving it even fractionally harder than "normal" I'll prob just put the 71'c thermostat I've got back in and see what that does (with an accurate gauge/sensor this time).

I dont understand how people that take the tempeture of their engine so seriously rely on unreliably reading factory gauges or $9.95 supercheep temp gauges that all read different and in reality tell you nothing about what the actual temp really is, surely when your trying to save your $5k+ engine from cooking an investment of $100-$150 (equilivent of 1 tank of gas) in a good quality gauge that is accurate and reliable is a pretty small price to pay, thats not a dig at the thread author but just a generalisation of what I often keep seeing over and over on here

bronx89 wrote:Yea thought so. Ok will chuck the new gauge in tomorrow and just watch it over the next week or so and see how I go. Hopefully going up decent hills with my foot up it it won't shoot up too much. Driving to Supercheap today with my foot up it for about 4 seconds it went up to 90/91'c.

If it does end up being a bit high with driving it even fractionally harder than "normal" I'll prob just put the 71'c thermostat I've got back in and see what that does (with an accurate gauge/sensor this time).

Here is my recommendation....
Putting in a lower temp thermostat isn't going to resolve whatever your underlying problem really is.
Sounds like the engine may have initially gotten too hot, especially driving on sand at low speeds doesn't help.
When cruising down the highway at a good 80 or 100km/h, the engine cooling system shouldn't really need the fan. Your fan will not travel faster than the air rushing through at 100k.

Do you have an electric fan?

I've found struggling up hills, across sand and towing puts an awful strain on the cooling system. Unless the cooling system is working at its optimum level, you will face problems.

So, I recommend the following just to make sure your cooling system is running well....

- Take out your thermostat and test its open and close states at various temps. You can use your after-market gauge and sender and boil some water. A good time to test your after-market gauge also. Or buy a new thermostat as they can under perform after being cooked.
- Flush your entire coolant out of the radiator, block, heater etc. Take off all the hoses, stuff the tap hose down them and flush all the old coolant out.
- Take your radiator out and have a really good look at it. Even a slight mud coating through the cooling fins will reduce its effectiveness greatly. Clean it out.
- If the radiator looks a little suspect with rotten fins etc, take it to a radiator recon shop and get their advice.
- Refill the coolant with a good mix of water/anti-freeze.

The TD27's with auto love to overheat, so I solved my problems with a powerful electric fan setup and no matter how hard I push it now, those fans keep it at the perfect temp.

There are many gauges out there, Supercheap have just changed their range to the SAAS brand, which are rated very well in other countries and are not too expensive. Mine are very accurate. However buy cheap and you can get what comes with cheap....nasty.

Have had my whole cooling system apart, checked, flushed and topped up with a lot of coolant to water. Thermostat is brand new. Gauge and temp sensor are also now brand new. Auto trans fluid doesn't run through radiator, it goes through a big Davies Craig 8cyl cooler that I have fitted. Have a switch hooked up to the AC/aux fan which can be forced to turn on without turning the AC on.

Don't think there is any underlying problem. Have never had it reach those temps (on standard gauge as aftermarket (old) one wasn't working properly at the time) before. I think it was because it was taking a hiding trying to rush back to the start of Muriwai with a massive surging tide - we got a bit side tracked and left it a tad late so we were stuck in the shitty super soft stuff from bombers to the start.

Just let the truck get to operating temp in the driveway after fitting the new sensor in the factory position and the new gauge and it sat at 88'c on the new 82'c thermostat I have. Does that mean if I chuck the (practically) new 71'c stat back in it would have a running temp of about 77'c? 77'c wouldn't be "too" low, would it?

With regards to your comment Sadam_Husain, since when have SCA sold $10 gauges? The ones I get from there range from $40-60 and haven't failed me once. The one that WAS in my truck was a Chinese brand I think - hence why I decided to replace it as well as the shitty temp sensor that was in there. I don't know anywhere where you could get a gauge and sensor for $10 - and yes you'd be stupid to put something that cheap and expect a reliable reading. That doesn't go to say that you need to spend $120 on something that will though.

bronx89 wrote:Just let the truck get to operating temp in the driveway after fitting the new sensor in the factory position and the new gauge and it sat at 88'c on the new 82'c thermostat I have. Does that mean if I chuck the (practically) new 71'c stat back in it would have a running temp of about 77'c? 77'c wouldn't be "too" low, would it?

88 does sound fine. I don't think installing the 71 thermostat is going to help you in those situations in the sand. When its fully open, its fully open and its not going to do anymore than that. After that it will come down to how quickly you can cool the liquid as it passes through the radiator.
You may see a difference, probably under idle or just normal motorway cruising. But thats not really going to be a problem.

Your original situation is fairly extreme for these trucks. Its at their limit unless you start really modifying them to handle higher performances.

I would leave your 82 thermostat in and since you have checked everything else, if you want to go further, your next step would be to look at cooling it faster.

Oh one other thing, your trans cooler. As its the V8 one, probably like mine, then if installed in front of the radiator will still add to the heating of your engine coolant. Its debatable whether the in-radiator or external ones (mounted in front of radiator) make the engine coolant hotter.??
I've read stories for and against each option when it comes to heat transfer to the main radiator.

fullthrottle wrote:Oh one other thing, your trans cooler. As its the V8 one, probably like mine, then if installed in front of the radiator will still add to the heating of your engine coolant. Its debatable whether the in-radiator or external ones (mounted in front of radiator) make the engine coolant hotter.??
I've read stories for and against each option when it comes to heat transfer to the main radiator.

? I don't get what you mean.. How would it heat the coolant still??

And yep I suppose what happened on the weekend would be an absolute extreme for the truck. Will leave the 82'c one in and just judge timing better on the beach to stay off the soft stuff unless in the dunes. Next time I take it for a decent road drive I just hope it stays at 88 - we'll see!

bronx89 wrote:? I don't get what you mean.. How would it heat the coolant still??

With the trans cooler mounted in the front of the radiator, the air will pass through the trans cooler, be heated up and then passed onto the radiator.

If you have the trans cooler mounted so it is contacting the radiatior, then the situation is worse because you have heat conductance via the metal.

It is in front and not touching. I am sure at the speed the air goes through the auto cooler it would not be able to heat up enough to heat the coolant inside the radiator... Would it?

bronx89 wrote:With regards to your comment Sadam_Husain, since when have SCA sold $10 gauges? The ones I get from there range from $40-60 and haven't failed me once. The one that WAS in my truck was a Chinese brand I think - hence why I decided to replace it as well as the shitty temp sensor that was in there. I don't know anywhere where you could get a gauge and sensor for $10 - and yes you'd be stupid to put something that cheap and expect a reliable reading. That doesn't go to say that you need to spend $120 on something that will though.

sweet sounds like you've got everything sorted there mate

bronx89 wrote:It is in front and not touching. I am sure at the speed the air goes through the auto cooler it would not be able to heat up enough to heat the coolant inside the radiator... Would it?

typically no. BUT it does remove some of the cooling ability of the air as the air is a bit warmer due to the auto cooler.
this is why its a good idea to mount the auto cooler where the water in the radiator is at its hottest. that way the warmed up air can still do some cooling. keep the auto cooler away from the colder part of the radiator.

tweake wrote:typically no. BUT it does remove some of the cooling ability of the air as the air is a bit warmer due to the auto cooler.
this is why its a good idea to mount the auto cooler where the water in the radiator is at its hottest. that way the warmed up air can still do some cooling. keep the auto cooler away from the colder part of the radiator.

Yep that's what I was thinking. My cooler is mounted in the top right corner of the radiator so that'd be the hottes part of the radiator too. Cheers tweake!