LastBoyScout

where can i find a low temp thermostat.

I think the stock is 185°

I would like a 160° thermostat.

DAVE Sz

iTrader: (2)

Why would you want a low tems thermostat? Most people buy higher temp ones so that the fans don't turn on so early. Btw all auto parts stores have them. Austozone has like 5 different kinds and temps. Did you check any stores around you or did you just ask here first?

liqidvenom

iTrader: (6)

thats the kind mod people wit camaro's use. u run a lower temp thermostat and it cause ur engine to run i guess richer or something and get u alittle more hp. i asked this before but i didnt get an answer.

LastBoyScout

LOL. well Big D, as the old saying goes to ASSuME makes and A$$ out of U and ME.

Autozone, Advance Auto Parts, O'Reiley's, and Napa all said they can only order stock thermostats.

Stock, not low temp. That is why i was wondering of someone like Jet makes them for the Max. I cannot find anyone and i just want to get that engine running cooler. Thought some of the peeps on the Org might know.

I dont know why anyone else does not use it. It basically retards the need for the fans to run as much since the stat allows a cooler temp run through.

Heat = lower HP.

Any useful leads or links appreciated.

Thanks in Advance.

DAVE Sz

iTrader: (2)

Doesn't the STAT just control when the fans turn on? I think you got it backwards. A low temp STAT will cause the fans to be on much more than a high temp STAT since the fans will turn on when the temps reach 160 instead of 185. I might be wrong here but what the hell. Either way it's weird, I just got a STAT for a buddy from autozone. They had 3 different heat ranges, low, stock, and high.

Jime

iTrader: (10)

If you are interested I can tell you how to modify the stock thermostat to open at a lower temperature. Its very easy and you can have it open at any fixed temp you want.

You can also put a manual switch on the rad fans for low or hi speed as well.

Some people don't recommend you run a lower thermostat because the car was designed around a 185 or whatever it is. Mine is set now for approx 175.

I did a write up on this a long time ago and no one seemed to be interested.

SkoorbMax

The MEDIUM ones from autozone are also stock, right?

Anyway, you'll notice a barely significant increase in power by going to a low thermostat. You will also be contributing to problems caused by running an engine chronically cold. I can't even remember them, but it isn't particularly good for the engine.

mansurxk

iTrader: (14)

i think its that the piston rings remain cooler and they dont expand enough so the pistons wind up wearing down the rings prematurely

Jime

iTrader: (10)

Wonder why NISMO sells them for the 3.5L? Of course you have to have a reason for using one. A stock engine does not need this.

NISMO Thermostat 350Z / G35
[THERMOSTATZG] $124.95

MSRP: $159.95

Fits 350Z and G35's

This low-temp thermostat for the VQ35 engine is a direct bolt-on replacement for the original. It opens at 154 degrees F compared to 170 degrees F for the stock Thermostat. Ideal for supercharged, turbocharged or sustained high RPM engines. Includes new Gasket.

http://www.performancenissanparts.co...roducts_id=263

SkoorbMax

Can anyone confirm that the MEDIUM ones from autozone (I actually bought autozone brand) are the right temp range? Haynes calls for 180-194 I believe. When my car is fully warmed up the needle is NOT QUITE fully horizontal, but only short of horizontal by a few degrees.

krismax

iTrader: (15)

Im interested can you repost it.

LastBoyScout

me too. go for it bro

Jime

iTrader: (10)

Coolant Thermostat Mod


This is what the thermostat looks like removed. They are designed as a once piece unit which includes the outer casing which connects to the hose from the rad. To find it follow the rad hose. There are 3-10 mm head bolts connecting it to the engine block and it removes quite easily after draining the rad and removing the radiator hose. For an explanation of how they actually work read this. http://auto.howstuffworks.com/question248.htm


Two screws connect the actual thermostat to the housing. Try and keep the parts together so they don’t get mixed up. In the bottom of the housing you can see the thermostat shaft channel where the end of the shaft is inserted.


The theory behind the mod is that the wax which controls the opening and closing of the thermostat through it's expansion, shortens and lengthens the shaft inside this thermostat shaft channel. What we are going to do is make the shaft longer therefore opening the thermostat sooner. We accomplish this by inserting a small spacer in the bottom of this channel. The length of the spacer that I used was approximately 1/16” or .0625”. You just place the spacer in the channel and reinsert the shaft and screw the thermostat back together. My thermostat now opens 10 Deg F sooner.

After screwing it back together I then placed the whole assembly into my electric kettle with a thermometer and turned it on and watched to see what temp it opened and closed at. It moves a considerable amount so its very easy to monitor its progress. If yours doesn’t open and close at the temperature you want you simply remove the two screws and insert a longer or shorter spacer and repeat until you get the temperature opening you want. It may be best to try this before modification so you can log the opening and closing temps of the stock thermostat.

Note: Make sure when you assemble the thermostat that the jiggle valve is located in the top of the housing. You will understand what the jiggle valve is when you look at the thermostat seat. It just allows a trickle of fluid through at all times.



This is the size of spacer I used. It is a PC board standoff spacer that I cut off with a hacksaw. The other colored spacers I located later are pins from a door lock tumbler which I got from our local locksmith. This just gave me a bunch of different sizes to try which is easier than cutting your own.

Anyway that’s it, very simple just a small simple metal spacer in the bottom of this channel and the thermostat will open sooner, at what temp depends on how long the spacer is, adjust to your choice or just make one the same length as mine, make sure to test before reinstalling.

Jay93SE

Hey guy's, check out the TSB's, under Heat/Thermostat issues. Nissan used a 169F stat in Pathfinders and trucks, which also use VQ's. They actually reccomend changing the cooler stat to the stock 180F one from a Max. So u know they will interchange!

krismax

iTrader: (15)

Just completed doing this ,got the pins from the door lock tumblers. I went to the lock shop to buy them and he just gave them to me for free, sizes .062 , .070 , .100 ,.120. It took some fighting to get the spring compressed , i could not imagine trying the .100 or .120 but they would have been way to low anyways.
The thermometer is a cheap one so im not sure how accurate it is stock appeared to be at 182. I used the .070 and thats the one i'm staying with, it looks like its set at about 166-168 F.
Once its installed on the car ill know the exact temp because my scan tool will show it. If anyones interested i will post the final results when its on.

maximus_pr

iTrader: (3)

so after all is good to run a lower temp stat right?

Wills98MaxSE

i'm curious, why not just add a bottle of water wetter to the coolant reservoir to get nearly the same results?

this does sound interesting, when the time comes that my thermostat goes, i'd be interested to have one that's a little cooler than 185 degrees

03BlkSETE

iTrader: (3)

Jime,

Thanks for the info. Will this trick work on the VQ35? Would you know if the Nismo thermostat fits the VQ35 Max?

Thanks

flashover

Water wetter saved my wrecked Bonneville from overheating!

krismax

iTrader: (15)

I used water wetter from redline and i noticed no relief from it. My car fights to stay under 200 F, I will do the fan switch mod to and then when i rev to 8500 rpm ill be fine

BEJAY1

iTrader: (19)

Curious, how much H20Wetter did you mix with what ratio water/coolant? What were airtemps & conditions when you had trouble staying under 200?

maximus_pr

iTrader: (3)

i wonder is this stat swap may affect on stop and go traffic or maybe very long trips on a place so hot like where i live

maximus_pr

iTrader: (3)

bump blah blah blah

nismology

iTrader: (8)

Just for everyone's information, you can use 2-3 drops of dish soap and get the same results. Water wetter does not necessarily reduce coolant temps but it relieves some of the surface tension of the water making the heat transfer a lil more efficient.

maximus_pr

iTrader: (3)

i may want to do this i think my stat is not working ok thinking about changing next month so if anyone know the parts # for the lower temp stat let me know

Jime

iTrader: (10)

Tried it on the VQ35 got it to lower a bit but not worth the effort. The design is very similar but will not go lower like the 4th gen thermostata will.

Not sure on the Nismo thermostat.

03BlkSETE

iTrader: (3)

Apparently the email notification works again (just got 40 new emails). Thanks for the reply.

A329878

Hi ! Jime
I can't see the picture ,the link doesn't work ........
May i have the picture ? Can you post it again?


Thanks you very much

ryant35

iTrader: (3)

I replaced the thermostat in my old Camaro with a 135 degree and the car ran 50% better, smoother, faster, and it sounded better. I could only imagine that changing a max's thermostat could only be good.

s0ber

iTrader: (7)

wow, thats really cold

Loe max

iTrader: (6)

The cats won't like it for vary long.

nismology

iTrader: (8)

The engine is supposed to run at a certain temperature, period. There is actually MORE internal friction in the engine when it's below operating temp.

Sounbwoy

iTrader: (2)

What he said...and yes, the amount of coolant will make a difference as to how effective Water Wetter is. Best with straight water is how most racers who use it do it. Personally, I wouldn't go much lower than 170, but hey, whateva..

ardika

iTrader: (3)

This is an interesting topic. I used to live in a place near equator and the ambient temp. always hovers around 90-110 F. Many European cars used to fail back then, since their stat opens "late", causing the engine to overheat badly. Almost 90% of driving involve sitting in a traffic jam for a long period of time, where several hours seem to be the norm. Mechanics recommended changing the stat to lower ones, or completely by sticking it open all the time. This cures about 85% of victims of overheating. YMMV, but this is what I reckoned from back then.

Having said that, if we change the stat to lower temp., say at 150F, would the car actually run at 150 F? I always thought that the car would probably run hotter than 150 until the fan kicks in at 180 or whatever the stock temp is. Until then, when it was running from 150-180, the fan will stay off and the water temp would actually will vary, depending on whether you are sitting on traffic or doing a "light load" cruise.

The only problem that I could see when one runs a lower temp. stat is when it comes to winter season. The water temp would hover close to 150 due to very active cooling (*much* colder air hitting the radiator).

Hence, my conclusion is that lower temp. stat would not necessarily harm the engine if the engine operates at higher load or at elevated ambient temp (situation where it generates a lot of heat). It would make the engine runs colder at winter time, especially during light load (cruising on the interstate at 65mph @20F), which could cause increase in engine wear.

ardika

iTrader: (3)

I recently flushed my radiator with 11 gallon of distilled water and I did drive around between flushes. Based on my experience, the car would not heat up as fast as it normally when I filled the whole cooling system with distilled water. It took longer to reach the half-mark based on the dash reading.

However, as soon as I add one gallon of Toyota Red and Water Wetter(at the end of the flush), it reaches op. temp as fast as a stock Maxima would.

You could test this too, by trying to operate your heater when the entire cooling system is filled with water. It does not heat up as quickly as it would.

nismology

iTrader: (8)

The T-stat regulates temperature by cycling open and closed all the time. That's the whole point of it. It regulates temperature so you don't have to. A mod like this would be useless. Like i said before, the motor is designed to run at a certain temperature, PERIOD. If you're a serious racer and want to improve your cooling, an aftermarket radiator is where it's at. Because the goal should be improving cooling capacity, not lowering the target coolant temp. And like i also said, there is LESS internal friction at operating temp than otherwise.

ardika

iTrader: (3)

nismology:

I understand your point about increasing cooling capacity, but how come people in Indonesia/other tropical countries usually bypass the stat completely and solved the overheating problem with no ill-effect for "older" European cars (to this date, even new ones need to be retrofitted from what I heard?).

Say, we have the 150 stat. In situation where the engine have high loads, and thus generates a lot of heat in a short period of time, having a 150 stat would probably be better rather than having a 180. Since when the stat starts to open at 180, the engine might be a goner (due to extremely rapid temp. increase). Plus, if the stat opens at 150, we would probably won't see the coolant temp. at 150 during since the engine is working hard or the ambient temp. is really high (race engines or sitting in a traffic jam where cars sit inches from each other at 100 F is not uncommon in Bangkok or Jakarta).

nismology

iTrader: (8)

The t-stat starts to open before the target temperature is reached. Just like a wastegate that starts to dump exhaust from a turbo before the preset PSI is reached to avoid overboosting. I don't think there's a situation where the temp would rise too quickly for the t-stat to react in time.

PS:And like i also said, there is LESS internal friction at operating temp than otherwise.

ManualMaxima

iTrader: (10)

i work at autozone and know for fact that we carry low, stock, and high temps in stock. we also have fail safes that when your thermo dies it locks open so you do not over heat.......i use water watter on my bike and noticed a good change in about 7 - 10 degress lower temp.....i have not added to the max yet but you can add as many bottle you want. **** you can go 50% water wetter and 50% antifreeze but it will run a **** load of money.

TurboMax67

I work at Autozone also, and I can tell you for a fact that unless you have a high horsepower setup, your not going to see any gains at all. There is really no reason to use a lower temp therm if you just have a couple budget upgrades.

You can't really compare gains engine to engine, some old muscle cars run better at a warmer temp, other cars run better at lower temps. Its just based on the engines design. When Nissan redesigned the VQ engine for the Maxima, they probably didn't foresee a bunch of people upgrading our engines to the point where we might need a lower operating temp. Unless your boosted, I wouldn't begin to worry about it.