305 TPI.. bone stock

changed thermo to 160*
New water pump
stock radiator
owner before me put in twin spal fans(pretty large) kicks on at 190*
using 50/50 water coolant mix
1 bottle water wetter

using an autometer gauge, temps are reading 225* fans at on at max
stock gauge reads 240*

dont know what im missing here... car has 148k miles, dont know if i need to be looking at the diverter valve or something else..

help! what else can i check???

 

ok have you tried to take your thermo stat out and run it? i was going though the same thing and wheni did it no longer ran hot. i changed to a new thermo stat and the problem still occured. so i just left it out and i have never had a problem yet. and have you had it flushed yet that could be it too.

 

in town or on highway? Is the stock air dam located directly under the radiator in place?

225* is not overheating in these cars - they were designed to run that hot.

Changing to a 160* stat is going to make things potentially worse than better. On a TPI car, the ECM takes water temp readings from the CTS on the stat housing, and changes timing/fuel accordingly. a 160* stat is too low, the ECM will get a lower reading, and thus could make the car run rich thinking it's cold. 180* is the lowest you should go.

Also, on a stock TPI car, the ECM controls the primary fan. It's programmed to come on at 210 I believe. The secondary fan comes on from the fan switch in the pass side head - it's a 230 switch I believe. The A/C will also always make the secondary fan come on, regardless of the temps.

You could get a lower temp fan switch for the pass side head, that way the secondary fan comes on earlier if you like - but if you are running 225, that's just stock op temps.

Your factory guage is not accurate - very few of the stock guages these days are given their age. You could replace the sender for the guage (driver head) and see if it reads closer to the Autometer numbers, but I'd trust the Autometer guage reading before I trusted the factory guage readings.

If it's that high on the highway - make sure that air dam is under the radiator - fans don't do any good at highway speeds, and the air dam is critical. You should run closer to 200 on the highway regardless of the ambient air temps of the day.

Also, take the top rad cover off, and tilt the radiator towards the engine far enough to get the vacuum handle in there - alot of debris collects between the A/C condensor and the radiator (leaves and junk) that block the lower portion of the radiator from getting air. I've seen leaves in them covering 3/4 of the radiator - they really like to accumulate in there!

 

well this is while driving sometimes...when its 85+ degrees outside.. my stock fans are gone. the previous owner changed them to large twin spal fans that move A LOT of air.. but the temp will always remain the same if not edge slightly higher to 230* but not go over..

my car is a 92 so the thermo housing doesnt have the sensor, thats in the head.

160* thermo just makes the fluid start flowing at an earlier temp... in my case i had a 180 and changed it out... i will reach 190 within 5min-8min of driving so i needed the coolant to start flowing sooner to the radiator.

my last 2 thirdgen's never hit 200*.. always was around 190* with 180 thermo's, 1 bottle water wetter, 50/50mix and sitting in CA stop and go traffic with 80+ degree's...

so i basically tried to mimick my old set up but this car just doesnt like it.. im thinking of switching this mechanical autometer to an electric one and putting the sending unit in one of the ports on the front of the intake manifold... for some reason this yahoo put a mechanical one with the tube coming from block... ???

and yes ive bled the system about 2 times.. i even jacked up the front of the car to allow the air to get to the radiator.. the cap is a 16lb cap... and i did this with the heat on so the flow of the heater radiator will go.

 

Yours is operating in the correct heat range!

My 84 bone stock HO runs 220-240 on a summer day with the a/c off!

 

As mentioned above. Really important. Do you have an intact air dam under the front of your car? Usually scrapes going in or out of driveways or over road dips unless you cross at an angle or really slow?

 

I bet with a 180, or stock 195. Ideal would be to find an 185-190 thermostat. you'll do better. but its not that bad the way it is..

 

airdam is there.. but im replacing it due to age and wear...

as mentioned before... i had the 180 thermo...

but listen guys.. about the thermo... the higher the temp, the longer the coolant has to wait to get to the radiator.. i already stated that i can reach operating range of 190 within a few minutes.. by me putting in a 160 just lets the coolant get to the radiator sooner than 180 or 190.. in my case this is about 1-2 sooner... once the thermo is open, it stays open..

i'll report back once i change out the air damn today..

 

I understand what you are saying. But with a 160 thermostat, it prolly never closes. So therefore the coolant doesnt actually cool down enough when going t hrough the radiator. trust me i ran a 160 and was running hot. went to a stock 195 and am good. It's worth trying to change the stat and see what it does.