Lippard9202

ok guys, heres what I have going on. I drive an 86 Iroc TPI. My rad fan hasnt been working right for about a year now, it just hasnt been coming on when it should, other times it just spins with the ignition in the on pos. engine off.. so I finally connected it to an interior toggle. works great now, flip the switch, fan come on. stays on untill I tell it to stop. I had also been having a thermostat problem as well, it just stayed OPEN. it would take forever to warm up, then it would over heat with the fan not working. so I replaced the thermostat with a 160* thermostat. gauge says Im running about 170 ISH. then that night, I did some reading on how a low temp thermostat will cause the computer to think it is in warm up mode and run rich. well, it did. and it KILLED my gas mileage. was at about 22-24 mpg, the 160 thermostat dropped it down to 15...... so, I went to the autoparts store and got a 195, and a new gasket. put in a pot of water first, didnt open until AFTER 220. so I exchanged it for another 195* thermostat. put it in the pot, opened around 200*, so I put it in my car, bled the air, and it shoots up to 250* and just stays there, (I do not forget to turn the fan on...) I then likewise return the SECOND 195* thermostat and got another. put it in the pot, tested it, opend JUST before 200*. so I put it in. STILL OVER HEATS! the hose running from the top of the engine to the top of the rad gets hot, but does not feel very pressurized. I opened the rad cap, and could see a steady stream of coolant coming from the passenger side of the car, so that means the water pump is good I am pretty sure the gauge is working, the gauge was reading 100* until I changed the temp sensor in the driver side of the engine. but the gauge was fixed BEFORE I put the 195*s in there. the rad cap is good, it is brand new, and Im not leaking coolant..... what do you guys think? thanks in advance for your answers guys.

TransAmGTA88

When is the last time you completely flushed the system? I'm assuming everything is stock on the motor? Stock radiator? Have you changed the timing at all? Are you doing all of this sitting in a garge or are you actually taking it out and test driving it?

Going back to the 160 thermostat, what can actually happen (had it happen to me) is that the car heats up quick esp. on a summer day and the thermostat is open all of the time, it doesn't allow the coolant to stay in the radaitor long enough to cool it down. So I went to 185 thermostat, which helped some what. I have aftermarket flexlite fans that pull 2500cfm on a switch, along with a 4 core Be-Cool alum radiator and still have cooling issues (I run straight water with a royal-purple cooling additive). My computer is disconnected, I'm running a procharger with a blow-thru carb.

Lippard9202

yeah, its all stock, rad fluid is very fresh. havent messed with the timing, i let it warm up, then I did drive it. Im betting on the gauge being bad. I know the rad hose gets hot, and soon the rad fan blows hot air through the radiator. guess I need to fix the gauge or something similar...

ninetyone

iTrader: (2)

you can use a temp gun like they use in restaraunt kitchens and point it at the thermo housing. A 160 wont make your car think its in warm up mode and it wont keep it in open loop mode either. With a 160 in there you should be running at approximately 170-180 degrees. Fan should be coming on at 176 degrees with a 160 thermo,but you need the change done in the chip for that.

Lippard9202

we have a cheapo therm gun. Ill do some shooting with it tomorrow. but like I had said, I have the fan wired to a toggle switch, so it comes on when I want it to. BUT if the lower temp thermostat didnt make the computer think it was in 'warm up mode" (for lack of what else it may be called) what would have taken 7 mpg away? haha, not that it matters a whole lot. but if its doing that, something is different enough to make a difference no?

ninetyone

iTrader: (2)

misadjusted timing

ninetyone

iTrader: (2)

I have run a 160 thermo and monitored it with my laptop and it went into closed loop just fine. Yep came right out of open loop (warm up) just fine

sonicwolf89

i have been having cooling problems with mine.. it never overheated before i took my 350 out of the truck i had it in and now it runs close to 210 except for early in the mornings when its really cold outside. does anyone think that it could be the way the front bumper is designed that it doesnt have enough air hitting the radiator? i know that if the bottom fan shroud is missing or has a big piece missing from it that will cause it to overheat. friend of mine at autozone had that happen to him when he took his off.
though i just remembered when i cut my hood to make room for the new carb with the adapter on the quadrajet manifold it never got over 200 degrees on the guage. just a thought buy maybe with a cowl induction hood the air moves good enough to keep it cooled down? i put the hood back to stock and it runs hot again.

Lippard9202

so my timing is off... it randomly adjusts itself? haha, Ill have to get at that next then...

ninetyone

iTrader: (2)

could be either your hold down bolt or its the chain

Lippard9202

ok, well I think I made a mistake on my mileage, used to be a majority of highway driving I calculated in back when I did it last, I let the car sit for a few months, now i have a lot of city driving. didnt dross my mind until lastnight.
but I know the thermostat is opening up. I shot the thermostat housing with the thermo gun. it read right at 197* +/-. where would be the most accurate place to shoot for actual engine temp? my gauge SEEMS fine. just sweeps way psat where the thermostat opens... :/ still settles down at about 145*-150*...cant go on forever though! haha

ninetyone

iTrader: (2)

factory gauge is not accurate. The first long line you come to is 190 degrees

ninetyone

iTrader: (2)

more than likely on the highway you are running aboout 180 degrees or so

Lippard9202

I cant even spell with numbers... haha, I meant the gauge settles at 240-250.....

TTOP350

iTrader: (8)

Guys a 160 T-stat is just fine with theses cars and that doesn't have anything to do with open or closed loop or milage.
I have no idea where this internet story comes from, stop the madness!!!

ninetyone

iTrader: (2)

I agree! i ran a 160 for years. Always went into closed loop almost immediately like it should. My heater was weak tho

Lippard9202

I did find it wasnt the thermostat that wrecked my mileage, all that city driving.......... so itwill NOT hurt anything to run a 160* thermostat with the stock computer?

ninetyone

iTrader: (2)

It may richen it up a little,not sure

Lippard9202

that would hurt mileage wouldnt it? that was what the "warm up mode" i dont remember the name it was given) did, rich afr untill it warmed up.

ninetyone

iTrader: (2)

its called open loop, it is for apprx. 90 seconds

Lippard9202

so open loop only lasts for 90 secs regardless of what stat is in use?

ninetyone

iTrader: (2)

to go into closed loop 3 things must be met:

1.certain coolant temp( i believe 166 degrees)
2.a timer in the ecm
3. o2 sensor function

Lippard9202

I do appreciate you responses ninetyone... you have helped alot. as has everyone else who has posted, either directly or indirectly, getting me curious, leading to me doing searches... thanks! and MAN! I about asked a dumb question in this post. but I found my answer. with the first white tic above 100* on the gauge being 190, i was hoovering right around there with the 160* stat... so Ill use it again, and see if it stays at that temp.

ninetyone

iTrader: (2)

That is about right for a 160 stat. Sometimes in the summer i ran about 195-205 with mine on a 100 degree day! There are like 4 little lines between each long line on the stock gauge. The first LONG white line is apprx. 190. Glad your happy! Later

Lippard9202

success update! the 160 keeps it cool. however, if I turn the fan off for a bit, and let it warm up to almost 220, it doesnt cool back down. as long as the fan is on right when the stat opens it stays at the first white line it comes to... it goes 100, white numberless line, 220, numberless line and 260. just for reference.

ninetyone

iTrader: (2)

if u are running a 160 thermo,then your prom(chip) needs to have the setting to turn your fan on at 176. then off at 166. You cant just run a 160 thermo in a computer controlled vehicle.

ninetyone

iTrader: (2)

what is happening is your 160 thermo opens a little after 160 ,but your factory fan is programmed to come on at 226 degrees. So the hot coolant is just circulating through the radiator and motor til your fan finally comes on at 226 degrees to finally cool down that coolant in the radiator. Then the fan is set to turn off at 220 degrees. So go figure

ninetyone

iTrader: (2)

hows the air dam under the front of the car? if it is messed up,u will not run cool

Lippard9202

c'mon now guys... I have a toggle wired up to the fan. I can turn it on before the ignition is even on...

Lippard9202

it cools just fine if I leave the fan on before 190*, at idle, or highway. but I am looking for one in the junkyard later in the week when I can get there. but the air dam is missing, haha, that has been on my list as to find a new one. I have been doing alot of work on my car lately. so the air dam wont be gone for much longer.

ninetyone

iTrader: (2)

you never want that. You can wear out the fan prematurely,not to mention it is pulling a lot of voltage from the battery. If you are not into chip burning,then buy a hypertech fan switch to match your thermo

Lippard9202

yeah, im not into burning at all. Ill need to get a chip or 2 when I get the 400 in place of the 305, so to get a chip, you need to use tuning software and preferably a dyno right?

Lippard9202

chip burning software, not just changing the computer

ninetyone

iTrader: (2)

you dont need a dyno.

ninetyone

iTrader: (2)

what do u expect without an airdam? Also make sure your thermo is good

Lippard9202

I must be thinking of a different tuning chip or something. idk. so Ill and find somewhere to get a chip for the fan, then Ill have to fix the relay. it went bad, so I wired the toggle.

ninetyone

iTrader: (2)

You need prom burner, blank chips, laptop,aldl interface cable, and a program like Tunerpro,Tunercats. and u need to learn

Lippard9202

I know for a fact the thermostat is good. put it in a pot, does its thing. and the temp gauge is right at 190 +/- 10 degrees, even at 50+ mph, that is with the fan on. but like I said, I know the dam is gone, thats next on my list to get.

ninetyone

iTrader: (2)

your timing is off i suspect

ninetyone

iTrader: (2)

get an airdam and check ur timing ,fix your fan issue first. get an automatic fan controller or hypertech automatic fan switch

Lippard9202

so what all can you program chips to do/control? now Im considering getting all that stuff as opposed to getting chips as I need them.

Lippard9202

alright. so a relay, and a chip. and an air dam. looks like Ill be having more room in my wallet, for more money..... haha

ninetyone

iTrader: (2)

relay? u said ur fan works

ninetyone

iTrader: (2)

download Tunerpro and see.

Lippard9202

I controll my fan with a toggle, whatever the little device on the side of the radiator is I assumed was a relay. it doesnt like to make the connection when the temp gets to where it needs to come on, I used a toothpick for a couple weeks to jam the circuit together. now I just use a switch in the meantime

naf

iTrader: (7)

It's not overheating unless the radiator is boiling over.

You don't need to burn a new chip to lower your fan on temp. You can get a lower temp switch for the head and simply connect the sender wire from the relay to it, instead of the ECM.

Another option is an adjustable fan controller switch that mounts in the radiator. It will do the same thing.

You don't even have to remove the sender wire connection to the ECM if you don't want. Just splice the lower temp fan switch into it. The ECM grounds this wire to engage the relay.

If anyone is using a toggle switch, I hope they're tying it into this sender wire from the relay. The fan pulls around 20 amps when it comes on and near that when it's running. Who wants to run 10/12 wire into the cabin and pay that much extra for a switch that handle the load? And how much voltage drop is all that length of wiring causing?

I'm also a little confused as to how the water could be running through the radiator too fast to cool down. By that line of reasoning, wouldn't it also be running through the engine too fast to heat up? The issue with too much pump is not flowing the water too fast, but creating the possibility of cavitation. A high flow pump may create enough of a low pressure head that vapor pockets form, which don't have the cooling capacity of water.

Running too low of a temp is bad. The motor oil needs to get above the boiling point of water in order to, you guessed it, 'boil' the water out. Water in oil forms acids and acids form sludge. I wouldn't go below 190, but that's just me, apparently. I like my motors and try to take care of them.

Lippard9202

good to know about a lower fan on temp. and I tried 3 different 195 stats... the gauge read right at 250*.... wasnt comfortable with that at all, but I shot the thermostat housing with a thermo gun, it read right at 200... that means the stat is opening. the same thing is happening with my 160 AS FAR AS THE THERMOSTAT housing reading right at 165ish with the thermo gun. and with the toggle, its not hooked directly to the battery, its spliced into the fan control module(?) on the side of the radiator. the little cubed box.

gsxrfann

Could someone post some pics of where to splice? And maybe even give a detailed how to???

naf

iTrader: (7)

Good deal.

Also make sure you have a well tuned motor. The engine generates heat to produce power. The more efficiently it runs, the more power you get with less waste heat.

Lippard9202

gsxrfann, Ill take pictures of where I spliced into, where the ground went, how I wired everything and describe how the switch works. and naf, Im not TOO concerned with the tune, it has had plugs, wires, cap, rotor, seems like something else also. cant remember at the moment. and I love your motto... haha