meeklay812

When I'm at a stop light that takes a while to turn, say around 1.5 minutes or I go through a drive through, my car heats up super fast and i sometimes have to turn it off so it doesnt overheat. Whats the problem here? Thanks

Trickster

Do you have the air dam installed on your car and do your fans work? The air dam is located under the radiator and hangs down a little. you will often hear it scrape when you go over a speed bump.

meeklay812

Yes i do have the air dam and i havent looked closely to see if my fans work.

TA5LiterHO

Check to make sure the fans are working. Make sure your thermostat is good still also.

jconrad

How hot does it get? You're fan doesn't even come on until around 225º and it usually turns right back off after the temp starts to drop. There is a coolant fan switch in the side of the passenger head that controls the fan operation during normal driving, but if you turn on your A/C, the fan will automatically come on. If it doesn't, then there is an electrical problem.
When the car is around 200º, squeeze the upper radiator hose (with a rag covering your hand) and see if the hose is flexable. If it is not, then your thermostat is not opening.

CrazyHawaiian

If its happening at a stop then it not the airdam. Listen to jconrad's advice, its a good way to check the thermostat. Do you have the single or dual fan setup? I have 2 cars with the dual fan setups and I've had to replace both pass side fan motors in both cars within the past 2 weeks. Both cars were heating up too much at stops. Now I'm only a fan switch away from getting them both to stay at 180-200 in stop and go traffic in the sunlight at noon (thats my test hehe).

meeklay812

When you say squeeze the radiator hose, im guessing thats the one that goes from the radiator to the intake manifold? Sometimes it gets close to 260 but as soon as i start moving it will drop down to around 180....

jconrad

Correct, the upper radiator hose. And like I said, you can always turn on your A/C to make the fan come on whenever you want.
But first make sure the fan is even working. Those fan motors are only good for "X" amount of hours, and if the car has been through several owners, then you have no idea if it has ever been replaced. Let me know what you find out.

meeklay812

When i turn on the AC, the fan does turn on....I dont know if its normal or not but like every 5 seconds when the AC is on, the RPM's go up from 700 to like 1000 and it jumps a little bit. Does anyone know what that is?

jconrad

You're Idle Air Control (IAC) increases the idle when you turn the A/C on. IAC's are a common problem on these cars, but from what I've read, you can remove and then clean them up with good results vs. buying a new one.
let me see if I can find the post/tech article for it.

Here's the one to adjust IAC and TPS:
https://www.thirdgen.org/newdesign/tech/tpimod2.shtml


here is one on cleaning the IAC:
https://www.thirdgen.org/techbb2/sho...t=IAC+cleaning


and:
https://www.thirdgen.org/techbb2/sho...t=IAC+cleaning

BTW, the search button on this board is very useful

TA

iTrader: (1)

Your scenario tells me that you are not getting any airflow through the radiator when the car is not moving. First place to look would be the fan(s). You also need the inner shrouding in front of the radiator, or you will recirculate hot engine compartment air. Also, have you checked your coolant level? You might have a leak and are low on coolant.

If it cools down when you start moving, it is not a stuck thermostat, or the air dam. If the fan(s) are working properly, you might have a blown head gasket. When the car is cool, remove the radiator cap, and let the car warm up without it and idle. Look in the radiator, and make sure coolant is flowing, and when you give it a little constant throttle and let off, it does not blow a lot of bubbles in the coolant.

Good luck
Troy
So Cal

meeklay812

When i take the radiator cap off, the coolant is up to the top of the cap and looks like it will start overflowing if i start up the engine. Is that normal?

GASGZLR

Next time your car is running as soon as it gets a tad over 220 the fan should kick on. When it gets this hot, go pop the hood and make sure the fan is coming on. When the A/C lever is in the on position the fan should come on and STAY on until you move it. It should not cycle on and off. My car did the same thing it would get hot when I stopped all of a sudden. I noticed it was getting hot so I pulled over and did this test and sure enough my fan motor was on it's way out and it was all fried up from being so old.

jconrad

The coolant up to the top of the fill neck is normal. After the car has reached around 200º, the thermostat opens up and then the coolant from the rad starts flowing to the block. It is not uncommon for the level to start to get lower after the thermostat is open.
You are definetely having a fan related problem, the next step is to identify if it is the motor, sensor, and/or wiring that is causing it.
Have you let the car get to over 225º to see if the fan comes on automatically? Also check below the passenger head to make sure the plug is still attatched to the coolant fan switch. (between #4-#6 plug, I believe) If all that checks out and the fan still is not coming on, try giving the fan motor 12v directly, to see if it comes on. If it does, then there is a wiring/relay problem. If the fan still does not come on, then it is the motor.
Process of elimination.
Let us know how it turns out

meeklay812

I just let it idle till it got to around 240 and the fan never kicked on. When i turn my AC on, it goes intil i turn it off. I dont understand where to check to see if the plug is attached to the coolant fan switch? The fan gets power, just doesnt turn on when it gets hot? Whats goin on here....

jconrad

Passenger side head. Under the manifold, under....you'll probably have a better time seeing it if you are under the car.
There is a plug going into the block that is for the knock sensor, and the one above that, is the one for the coolant fan switch.
If it is plugged in, see if it is loose. That could be the indication of a bad connection. Take the plug off and inspect the wire for damage. I have seen the wire running to that switch roasted from the manifold before, so really look at it good.
If all of this proves unsucessful, then you will have to talk to one of the electrical wizards of this site, such as Trickster.
Good Luck

meeklay812

I cannot find that fan switch anywhere. If im looking from the top at the passenger side, it should be towards the back plugged into the block?? I see all the plugs from the distributor but other then that nothin. Is it above or below the spark plug wires? I searched on the boards and see its between head #4 and #6, how are they numbered? 1 and 5 start from the rear of the head of the block?

Benm109

It's located in between the last two spark plugs on the passenger side. You probably going to have to feel around for it because it is very hard to see from the top. If you can get the car on a lift it is really easy to see.

jconrad

driver's side: 1,3,5,7
pass side: 2,4,6,8

--------------------
2 4 6 8 rear of block >
--------------------
.....^
CTS plug is here

Easier to see from underneath car.....

meeklay812

Well i went out and got my coolant drained and it looked like diareah. They had to do it 3 times to get it totally clean, so i dont know if they helps the problem at all? They also said to get a new thermostat. Im going to do that tomorrow and then work on the fan. I drive this car only in the spring/summer so what thermostat should i get? Thanks for all the help

TA

iTrader: (1)

If you can find a 170 degree thermostat, go with that, otherwise a 180 will work. I'm assuming its not highly modified. An old trick is to also remove your radiator and fill it with lime-away, and let it sit for a few days. When you drain it and wash it out, it will be nice and shiny inside, all the crud will be history.

...but it sounds like your thermal switch is dead, if the AC turns the fan on, it is getting voltage and it works. It might also be the wiring. My GTA had the wire burned onto the exhaust manifold when I got it.

Good Luck
Troy
So Cal

meeklay812

IS there any certain brand preferred? Be cool, Mr. Gasket, hypertech? And should i get a "high flow" thermostat?

jconrad

1- Just buy any brand 170-180º thermostat (Stant probably the cheapest) and drill a few tiny holes in it to prevent air pockets from building up in your cooling system.
2- Buy a new Coolant Fan Switch. They make them aftermarket that make the fan come on at a lower temp, so your car runs cooler.
Lemme see if I can find the site someone gave me....
http://www.madvet.com/shop?frame=3.138.944
I think this is it. They sell one that comes on at 200 and off at 185º. For like $12 or so.
Most aftermarkets are around $45-50.
3- If your coolant looked that bad, then it would be a good idea to flush the whole system out, the radiator, the block, and turn your heat on when you do it so it flushes the heater core too.
Most automotive shops have coolant flushing machines to do this.
But you can have the same results by doing it at home, just got to try to be neat and not make a big mess.
4- I am not sure how much mechanical experience you have, (no offense meant) you mentioned 'they' drained your radiator...who are 'they'? If it is indeed a shop or tech that you trust, then they can probably swap out that CTS for you in no time, being as though they most likely have a lift and/or jackstands.
5- If it is at a shop, then they may be able to use a digital thermometer like I use to see if there is any hot spots (restrictions) in the radiator itself; warranting replacement.
6- Oh yeah, make sure you always run a 50/50 mix of antifreeze and water. Too much of either one can cause corrosion in the radiator.
Good Luck and keep us posted.

meeklay812

I got the 180* t/stat. Im waiting for the engine to cool down. For installation, i just take off the two bolts where the upper radiator hose go to, take off the gasket and switch the stat? Is that it or is it more complicated then that?

jconrad

Thermostat is probably one of the easiest things you can do. But it can also be a messy pain in the neck if not done correctly. Try and drain down the radiator a little before loosening the hose clamp. After the hose is off, then remove the bolts to the thermostat housing. Scrape off any gasket material left on the intake and water neck (thermostat housing). You did drill a few holes in the thermostat like I suggested, right? A couple 1/8" holdes will do nicely. OK, now plop the thermostat into the intake (spring side down). Get the gasket (and I always use some RTV on both sides of gasket and the threads of the bolts, just to make sure), put it on. (Let RTV setup for a few minutes) Put bolts back in and torque down to spec. (21-30 ft.lbs.)
If you don't have a torque wrench, it's just a little past "ugh" tight. Be careful not to overtorque the bolts, or you could strip out the threads of your aluminum intake. Let sit for about an hour to make sure the RTV is dried. Then put your hose back on, tighten the clamp. A good way to make sure the hose clamp is tight enough is to try to twist the hose with your hand. If you can move the hose around, then the clamp is not tight enough.

BTW, what are you going to do about the Fan issue that you have? Changing the thermostat is not going to fix a bad Coolant Fan Switch, or roasted wire.

meeklay812

Thanks, that clears up a lot of questions on installation. Can you just take off the housing and not the hose? I plan on installing a new fan switch some time next weekend....

jconrad

Yes, you can do it that way, but I find it easier to clean up the thermostat housing with out the hose attatched.

jmd88iroc-z

My car was running the same way with me.
All I did was put a 180 deg. thermostat, a 200* on - 176* off Hypertech fan switch from Jeg's (switch comes with a new connector).
After this, I can set at a light all day and the temp stays around 190* or so. You can reach this switch from behind the passengers side motor support under the car (might as well change those spark plugs while you're under there, if you haven't already). It's a little tight under there. Just take your time and use some high heat teflon on the threads and don't cross thread it (if I remember right, the brass threads are pretty fine, so be careful).
Like has already been mentioned above, make sure your whole system has been flushed and cleaned properly.
Hope this helps! Let us know

ZROC86

My car has been doing the same thing lately also. My fan doesn't come on when the AC is turned on though. I havn't checked anything yet and I have a 160* stat. Should I bump it up to a 170* or 180*? This thread has been helpfull on what I should do. Thanks guys! Didn't mean to ***** your thread in anyway if I did.

jconrad

ZROC,
As far as I see, this is a forum for people to help each other. I don't think anyone of us would consider your inout, or questions obtrusive.
If you already have the 160, then don't worry about changing it. BTW, is your car TBI or TPI? Just wondering, as there are some differences in their setup.
I would do a search, specific on fans not working, and if no results are found, then seek out Trickster or maybe Vader. From what I have seen, these guys have ALOT of experience with these electronic controls, such as ECM's, relays, wiring, etc.
(No offense meant to anyone else)

Meeklay,
Keep us posted on how everything goes with the thermostat and Coolant Fan Switch.

meeklay812

I was going to put in the stat today, but i got called into work. I was thinkin, should i do this on flat groud or does it not make a difference? And is the tstat in the housing?? Is it screwed in or do i just pull it out??

DJXero

The RPM surging is an indicator that you are low on freon, and should charge it. My z28 had the same problem/ Neither fan came on at all, and the rpm's surged when I turned on the A/C. Try charging your freon system and see if the fans kick back on. I don't know why it happened, but your situation is very similar to my own. I hope it works for you too.

meeklay812

never heard of freon, what is that??

Trickster

That is the gas used in your car's A/C system to provide that nice cooling effect on those hot summer days. In the newer cars they use R134A for a refrigerant gas.

meeklay812

Can you refill that yourself or should you go somewhere to get that done?

Trickster

Yes, you can do it yourself by buying these small cans of refrigerant that they sell at wal-marts and most auto parts stores. Although it has been discontinued at some places. If you do find some, be sure that it is "NOT" R134A refrigerant. The systems in our cars can not use that stuff without a modification to the A/C system and they do not mix well together. If you are unsure of how to do it, take it to a good reliable shop and have them do it. They can also test the system for any leaks you might have in it.

jconrad

Meeklay,
You stated that the fan comes on with the A/C on, and stays on until you turn the A/C off, right? Does your A/C get cool after a few minutes of running, or does it stay luke-warm?

More to the point; Your fan is not coming on with your A/C off, so you most likely have a problem with that Coolant Fan Switch. Follow the link I shared, and get that switch. That should be #1 on your list of things to do.

Oh yeah, the thermostat just pulls out of the intake after you get the housing off.

meeklay812

I think i may have found the fan switch. At the bottom of the block, its a little white cap with a what wire going into it. Just one wire....

jconrad

Correct that it is a single wire, but it could either be the knock sensor or the coolant fan switch.
The knock sensor comes out of the block, just above the oil pan. The knock sensor has a similar plug, but it's base is a larger diameter. Like 2-2.5" around. It screws into the block with a small, almost 3/8" size thread.
The coolant fan switch is a little farther up on the head, closer to the spark plugs then oil pan. The outside diameter of this sensor is smaller than the knock, probably 1" around. It has a Hexagon shape made onto it so you can remove it with a wrench/socket. The threads on this sensor are closer to 1/2".
Hope this helps.

red90bird

you said the coolant looked terrible so you changed it, I have no doubt that will help, however I wonder why nobody has suggested that you check and see how bad you really are over heating (in other words does the gauge work?)
just a thought

jconrad

Look waaaay up close to the top of the thread, my friend

meeklay812

I finally found the time to put in the t/stat! It stays under the (1/4) mark at all times when driving and at a stop, it does better, but still climbs up there...When i have the A/C on at a stop, the car stays below the (1/4) mark so its definately that fan switch. Now i just have to find that little thing, Im on the right track! Thanks for all the help

jconrad

Just a few more tips for you. The fan switch is in the head, not the block. When you do find it, before you take it out, make sure to drain the cooling system first. There should be a drain on your radiator, down near the bottom, on the passenger side.
The size you need to remove the switch should be 13/16". A wrench will probably work best. If you only have metric tools, then you can use a 21mm.

*EDIT*
Oh yeah, be sure to disconnect the battery before doing any electrical work on your car, trust me

meeklay812

I put the new fan switch in and the fans didnt kick in the first time but they do now......It fixed the problem, THANKS ALOT GUYS!!!! I apprechiate it, Now on to installing my B&M Megashifter! ~ Matt