thermostat

[tonupteabag]

i want to know what the difference is between the 2.4 and 3.0ltr thermostat i have read on here that the lower temp 3.0ltr is physically bigger than the 2.4ltr and that it won't fit, as it happens i was advised that it would be ok to fit the 3.0ltr thermostat to help lower the standard running temps as at the moment its about 90 degrees and i feel that is too hot for my liking hence the 82 degree thermostat bought ready to fit but after reading that they are different i would like some clarification just to be sure before i start to change it and find out it's wrong and save me time in messing about

[BUSHWHACKER]

A lower rated thermostat won't make the engine run any cooler.

Or do you mean the electric fan thermo switch?

[tonupteabag]

no mate i was under the impression that at 82 degrees the stat opens allowing the cooler water to flow through and keep it regulated at around 82 dgrees unlike mine which seems to be regulated at 90 degrees as is my understanding of the cooling system on other cars and i was presuming the surf would be similar if not the same..or am i way off and the japs decided to complicate things?

[BUSHWHACKER]

90 degrees is normal operating temperature for almost all engines, so a 82* thermostat would just allow coolant into the radiator sooner. The coolant temp will still be around 90* with the standard radiator.

The ideal solution to keep the 2.4's temperature down would be to fit a radiator from a manual Surf and install a seperate transmission cooler.

[Rustinho]

The only difference I can imagine it making is that it'll start circulating the water around the coolant system at a lower temperature. I don't see why it would make any difference to the running temperature of the engine because it's still the same fan, radiator, etc, cooling things down.

From what I can tell (and I am by no means an expert, I have just read an awful lot of posts on this forum & elsewhere) the main causes for overheating are a knackered/blocked coolant system and the transmission fluid acting as a heater in the coolant radiator and overheating the coolant when the tranny fluid is working hard (ie towing). There is a design fault in the head which causes them to crack but if that has been fixed with an updated head I reckon most of the worrying is unnecessary as long as your truck is serviced properly...

[Wolfracer]

While we're on about thermostats..

..where is the 3.0 diesel stat? Thought it would be near the top inlet of the rad, but obviously not. JFGI didn't return any positive IDs when I did it the other night, so gonna bow down to you guys and ask."WHERE IS IT!"
Problem with my cooling, but I'll keep that to my other thread...

[BUSHWHACKER]

..where is the 3.0 diesel stat? Thought it would be near the top inlet of the rad, but obviously not. JFGI didn't return any positive IDs when I did it the other night, so gonna bow down to you guys and ask."WHERE IS IT!"
Problem with my cooling, but I'll keep that to my other thread...

It's at the bottom/front of the engine, driver's side. Just follow the bottom hose on the radiator.

[tonupteabag]

i think the word is paranoia as to the cooling issues i'm trying to keep my temps down so i can't blow the head as this would mean scrapping my truck due to limited funds available as far as i can tell my cooling system works as it should heaters are toastie both front and back i don't suffer any coolant loss to my knowledge i've done the servicing so i know it's done right i've got a tranny cooler lined up to fit as well as an intercooler, i've done the viscous modification with new oil and dropped the temp at which the hub allows the fan to engage at its full potential its set at roughly 80 degrees and i've put an override switch in for the electic cooling fan so i can switch it on when i see fit (or it gets hot) i don't have a towbar so it won't be towing anything for a while, i think i've covered most of the things that can cause issues but i'm still PARANOID!!!!! lol thanks for your time in answering my post as i'm still learning the fine arts of toyotas, i'm not an average weekend mechanic as i've been doing mechanics for alot of years but a lot of early types of cooling measures that toyota use are old school and i didn't learn about viscous hubs as it was mainly electric fans for cooling when i was training so i needed the advice for earlier fan types, as for the stat i thought it would give me a 6 degree window for any errors that might arise but i have been educated again ah well they say you can never know enough

[tonupteabag]

90 degrees is normal operating temperature for almost all engines, so a 82* thermostat would just allow coolant into the radiator sooner. The coolant temp will still be around 90* with the standard radiator.

The ideal solution to keep the 2.4's temperature down would be to fit a radiator from a manual Surf and install a seperate transmission cooler.

i was running a citroen xantia diesel before the surf and that was consistent at 75 degrees no matter whether i was hammering it or driving steady, the electric fan kicked in at 85 degrees at times with stationary traffic hence the thoughts on the truck temps being high to what i'm used to running at as most cars i've owned have been between 78 degrees and 89 max at which the cooling fan kicked in hence the paranoia with my truck holding at 90 degrees

[dieselboy]

I had a Vauxhaull Corsa Diesel (work car) for a little while. The temp on that ran cool as well. (IZUSU engine 1.5D)

I was too, under the impression that when the stat opens / closes that the temperature of the rad water outlet will be regulated cooler if the stat opens at a lower temperature. We used this thought process when trying to keep our tuned xflow's and pinto's cooler! Burton Power even sold stats that opened at a cooler temperature for that reason.

Can anyone confirm the sizes of the stats? I'm pretty sure the 2.4 stat is smaller than the 3.0 one as the 2.4 sits in some kind of contraption near the head whilst the 3.0 one sits in the bottom hose where it bolts to the block. (took me ages to find it!)

[dieselboy]

hence the paranoia with my truck holding at 90 degrees

For what it's worth, The last few motorway journeys that have been on hot days, with the truck loaded, I have watched my temp guage creep off the position it sits at and the stalk of the gauge went over the symbol on the gauge (thats a poor explanation!)..
I found out today from another link that the guage increases at 110c. So, my truck has apparently been running up to and over 110c.

Never does this when I'm on my own! I want to fit a temp guage to see whats happening.

[BUSHWHACKER]

i was running a citroen xantia diesel before the surf and that was consistent at 75 degrees no matter whether i was hammering it or driving steady, the electric fan kicked in at 85 degrees at times with stationary traffic hence the thoughts on the truck temps being high to what i'm used to running at as most cars i've owned have been between 78 degrees and 89 max at which the cooling fan kicked in hence the paranoia with my truck holding at 90 degrees

Engine is transverse in a Citroen, probably a better cooling system, better cylinderhead design (waterways) and there would have been a bigger gap between the radiator and engine.
The Surf's engine bay is too cramped and the heat from the engine, turbo and rad has nowhere to go other than underneath. Bodylifts help a lot so do vents in the bonnet.

[Wolfracer]

Engine is transverse in a Citroen, probably a better cooling system, better cylinderhead design (waterways) and there would have been a bigger gap between the radiator and engine.
The Surf's engine bay is too cramped and the heat from the engine, turbo and rad has nowhere to go other than underneath. Bodylifts help a lot so do vents in the bonnet.

True, think we have to put a lot of it down to old technology. My 5.7 V8 FILLED the engine bay on my other car, and even after 160 mph runs and full throttle, the engine always maintained a steady temp. However, in traffic, there were waves of heat blasting out from under the wheel arches - think of dangling your hand out the window and being heated by a hair dryer not far away! No overheating issues reported in any of the LS1 Engines at all! (unless running BIG s/c's)
Like I said, its just old designs, and need to be treated as such. IMHO.

[tonupteabag]

True, think we have to put a lot of it down to old technology. My 5.7 V8 FILLED the engine bay on my other car, and even after 160 mph runs and full throttle, the engine always maintained a steady temp. However, in traffic, there were waves of heat blasting out from under the wheel arches - think of dangling your hand out the window and being heated by a hair dryer not far away! No overheating issues reported in any of the LS1 Engines at all! (unless running BIG s/c's)
Like I said, its just old designs, and need to be treated as such. IMHO.

yep very possible but i suppose my own paranoia is knowing of the cooling issues associated with surfs i know out of all the surfs it is a handfull that have failed dramatically but i have this in the back of my mind every time i start the truck