One Nut

After driving around in 90* heat and a lot of stop and go,.. I noticed the temp gage was a bit higher than I've seen in the past also the oil pressure was a bit lower too. I was right at the 3000 mile mark and is now due for an oil change however, I want to run cooler to protect the motor. So my question is.... Which is the more desirable method to run cooler when ambient temps are high. The FAN MOD or the LOWER T STAT mod or both? Thanks for the info I've done a search but could not find a definitive answer.

fbgh2o

Fan Mod. Although I have both.

Philip P

by fan mod I'm guessing its the keeping the high on by jumping the relay? Is that what we're talking about here?

100plus

Fan mod. Although i have both too. haha. My fan does not off at all. I use my aircon as the switch. When the aircon is off, low speed fan stays on. When the aircon is on, high speed fan comes on.

soverystout

I have the ln 160 degree stat (no fan mod) and that does the trick for me. In 100 degree heat, the needle is never past the left side of the "0"

Optical TDI

I'm stock and also never past the "0" in regular street driving. If I change the water pump, then I would put in the 160 stat.

redridge

I love my fan mod....

stealthy switches,

ivangene

IMO fan mod does more for less

Dharn55

T-stat is the way to go. It will actually make the engine run a little cooler. The fan mod is fun, but the fans should turn on when needed without the mod.

One thing that owners should be aware of is that the temp sensor for the cooling system measures the temp after the coolant has been circulated through the radiators (therefore cooled to about the lowest temp it will get to) and returned to the water pump, but before it is circulated through the engine! This is also where the T-stat is located. What this means is that both the T-stat and the sensor are measuring the coolant temp at the point in the system where it is at the lowest temp. So when the temp gauge shows 180 degree that is after the coolant has been cooled down, the coolant exiting the engine flowing toward the radiators may (actually will be when the engine is warmed up) significantly hotter. So when the gauge says 180 degrees the temp of the engine is actually hotter than that.

ivangene

I agree with your statement about the measuring point Doug....No question about it!

but I personally think airflow is better than a lower opening point of the t-stat that in the end (rather 160 or 180) is wide open....either way, the thing is wide open and if temps are rising you need 1 of 2 things...more volume of water or more cooling of the water (via more surface area or more airflow)

so without major mods (adding 3rd rad) or other the easiest way to get the heat out is thru airflow...

this is an old debate, I doubt either one of us will convince the other which is "better" but that's my position and I am stickin with it (for now)

chsu74

Do you know if the temp sensor you are referring to is the temp sensor indicated for durametric readings or the climate control ecu reading? Those two readings are different.

We are obviously splitting hairs now. Personally, I would prefer the engine to run hotter than cooler in the dash gauge for fear of excess wear and tear on a cold engine.

What is the optimum operating temperature range for our engines? Which mod, fan mod or the T-stat, keeps the engine temp within that optimum operating temp better?

I vote for the fan mod because it allows me to keep the coolant temperature consistent with highway driving temperature readings while on local "stop and go" conditions.

logray

Just drive the car faster and it will get more airflow into the radiators.

Oh, and keep your radiators clean. :-)

chsu74

The third rad is useless in stop and go traffic with no airflow to aid cooling.

Dharn55

I thought that if the AC is running or the coolant temp reaches a certain level the fans are running at high speed anyway. So once the engine is up to temp (the stock T-stat starts to open at 180 degrees and is fully open at 220 degree I think) then if the coolant starts to get "too hot" the fans should already be running. Won't a fan switch just allow you to turn on the fans even before the systems turn them on automatically? I know I bought all the relays, etc. to make the fan mod using a tip switch and have just never gotten around to installing everything, but I was just doing it for kicks.

The low temp T-stat will start the flow of coolant sooner and allow full flow sooner which may have the engine run a little cooler except on really hot days when the controlling factor is going to be the size of the radiators. If I am correct about the fans running on high automatically then in hot temps neither the fan mod or the low temp T-stat is really going to do much, only more radiator capacity (i.e a third radiator) is really going to keep the temps down. IMHO

philooo

I don't understand why your temperature raise like that. I have been driving in 100F dry Texas and now in 95F humid florida and my water temp is always the same, not going up a hair.

Of course with those temperature I always run with the AC on, so my fan are running in full blown.

I think you might want to remove your bumper and clean your radiator.

Phil