element114401

iTrader: (1)

I recently purchased a 1988 Camaro that has the 305 TBI and the five speed manual. Everything is stock except for a short throw shifter and a cat delete. I've been using this car as a daily driver since I got it (approx a week ago) and never had any problems with cooling until today.

Today we had our annual 4th Street Cruise (Waterloo, IA) where all the classics parade around downtown. I noticed a burning smell from my car after a couple laps (approx 30 min) of stop-go traffic. The outside temp was about 85 I'd say, sunny without much wind. I pulled off and popped my hood to find the coolant boiling out of the overflow container.

I understand that in these conditions it's not unusual for my car to react this way, but the whole time this was happening the temp gauge in the dash was reading spot on middle, which would be normal operating temperature.

So obviously something isn't working correctly. I need to know whether the gauge itself is bad, or if there's some sending unit that needs to be replaced. Also when I start the car, as its turning over the temp gauge pegs itself all the way to the top then returns back down to normal after the engine starts. I'm new to this Forum as well as the world of Camaros, so any help at all would be greatly appreciated. Thanks in advance!

blaznhot

iTrader: (1)

If it pegs all the way over and then back your sensor is bad. I had the same problem with my oil pressure guage. Autozone!

Fionnla

I think Blaznhot is right about the Temp sending unit. On the driver side of the engine to the front under the exhaust manifold.
I had the same problem when I had the TBI and the fan was not kicking on when it supposed to. On a hot day at home start it up and let it run for a while and get hot, run it up to around 2000 rpm's a couple of time then idle and see if the fan kicks on. If it does then change the themostat. In Iowa heat and cold , you can use a 180 degrees. That what I use. You can get a themostat at Autozone that has a couple of real small hole tapped into the themo housing. If it still gets real hot, then check the top and bottom radiator hoses and see if they are closing up. If that doesn't work, maybe take it to a shop and get the radiator and engine flushed out.
Hope this helps you some. Good luck from Illinois.

element114401

iTrader: (1)

I appreciate all your help! I can't really say for sure because I've only been paying close attention for the last couple of days, but it seems that the fan runs all the time, whenever the key is in the on position. I just went out and started it up from sitting outside all night and the fan kicked on right away. Is this because of the temp sending unit being messed up, or is this something else entirely? Maybe the thermostat?

Fionnla

Hey it's me again. Sounds like the person that had your ride before you had problems with the electric fan control and wired the fan up direct so that it runs all the time. That is usually is ok except you live in Iowa and the winter can get pretty cold and it will take a lot longer for the engine to warm up. So the fan is not the problem with the over heating. I would start with the radiator hoses and a new thermostat. A good radiator and engine flush won't hurt if you haven't done it. Also check the timing and insure that it's correct.
When I had the new engine installed, I installed dual fans and used a Painless Wiring electric fan Relay Contro Kit PT#30102, from Summit Racing. It kicks on at 200 degrees and kicks off at 185 defrees. It works fine.
There is some good threads on this site from the Cooling Section that can give you some good tips.
PS. Sending you an Attachment of the Engine Electronic Diagram for the 305 TBI (L03). May help you in the future. Good Luck.

4playta

Temp gauge might be right but your radiator cap might be bad.

element114401

iTrader: (1)

I need to know if its the "coolant temperature sender" or the "coolant temperature sensor" that is bad. Can anyone enlighten me?

Pukka

The coolant temperature SENSOR feeds data to the ECM - it does not connect in any way to the temp guage on the instrument cluster.

element114401

iTrader: (1)

So I need a new "coolant temperature sender", correct?

Pukka

If you want to get an accurate reading on yout instrument cluster - then a new sender and/or guage is what you need.

Problem is your car should not be overheating if the fan is running all the time. Assuming you're air dam is in one piece, there is no debris between the condenser and radiator, and you are certain your head gasket is holding up, If I were you I'd drain and flush the cooling system, replace the water pump, T-stat, and radiator cap. You could probably get all the necessary parts for about $60 and do the job in a day.

Your car shouldn't overheat at this point - keep us posted.

element114401

iTrader: (1)

I'm on a really tight budget right now so I'm taking small steps, one at a time. I bought a new coolant temperature sender at CarQuest but I haven't replaced it yet, simply due to a lack of time. Am I also right in assuming that I need to dump the coolant in order to install the temp sender?

I donno if the overheating is normal or not. It was a hot, sunny day in nothing but stop-go traffic. My dad's 69 Camaro with the 350 was running extremely hot as well.

Pukka

I've never replaced the sender before - but if its anything like the sensor or T-stat you won't need to dump the coolant. You will most likely lose some when you remove the sender.

I live in GA where it gets quite hot and humid - the only time my car overheated when I was stuck in traffic was when the fan temp switch failed and the fan never started. If your fan is running constantly your engine temp should never get higher than 210-220 degrees, in fact it should be cooler. The temp guage on the cluster is not very accurate. If you can get a scanner you can check the coolant temp sensor readings from the ECM.

element114401

iTrader: (1)

The sender is kinda low on the block; between the first and second spark plug (if I remember right) on the driver's side, so I donno how much coolant will dump out of that hole when the sender is pulled out. I'm sure the whole system needs flushed but right now I can't afford it, and the daily driving I do with it doesn't get the coolant too hot anyway.

DSGx

Excuse me for not reading the entire thread, but if its any help , i had some issue with my coolant boiling in the plastic coolant tank , the problem was my radiator cap, i bought one from autozone(about 3 bucks) and problem solved, rad caps are like t-tats, once they go bad they will not free the pressure in the system and the result is coolant boiling nextdoor.

henryd3

iTrader: (128)

Im with DSGx, none of the overheating is being caused by the sender(s) or sensor(s). If your fans are running your problem is with your radiator function, and replacing the cap is your first, best, and cheapest possible solution. Good luck

ASE doc

Just a bit of info. The boiling point of water increases about 3 degrees with every pound of pressure. 16 psi increases boiling point about 48 degrees. A cap that doesnt hold pressure allows coolant to boil as low as 212 depending on mixture. Your fan running constantly can be caused by a fault in your ECM temp sender circuit. The spiking of your temp gauge may be caused by an electrical issue, other than the sender. If you can test the cap, do it. If not, I would replace the cap anyway. Its cheap and likely the culprit. Connect a scanner and watch data. If coolant temp on data reads way off, replace ECT sensor (ECM temp sensor, just below thermostat housing). If gauge reads normally, dont bother with sending unit. Hope this helps. Also, coolant is cheap also and regular coolant flushes are good insurance against system failure.

element114401

iTrader: (1)

Thanks for everyone's help. It is greatly appreciated! I will probably replace the cap for ***** and giggles since it seems to be so cheap, and an easy place to start. I would also like my gauge to read right, hence why I'm changing out the temp sender. Problem is that it's pretty well seized into the block, and with my tools and expertise, I am not able to change it out. I was reading around and it seems that since the gauge spikes as the engine is turning over, there might be a short in the wire that's grounding out. I will try to trace that wire back and post any results. I will probably replace the temp sensor as well, just so I will know that's not the problem. Again, thanks everyone for the help.

Ikerman7000

I have a 1992 RS that I just purchased with the 305. It only has 52k and was well taken care of. I notice my car does the same thing. It seems to run warm in my opinion. At times sitting it can climb up to what I assume it 240 the last notch before getting into the red on the temp gauge. My fan does come on and cool it down but I thought 235-240 seemed high. As soon as I start driving it gets back down to 220-225 or so. After reading alot of the posts it just seems alot of these cars run this way. Is that the normal operating temp or is mine running hot also?

Thanks for the help

henryd3

iTrader: (128)

That sounds kinda high to me. I've got the 5.0 TBI with single fan and have had issues and ended up replacing aging radiator, leaky WP , but still have stock AC Delco fan switch. 135,000 miles and in 100 degree heat it gets up almost to 220 on my temp gauge( no idea of accuracy), fan kicks on and stays on til it's back around 190. When cruising it stays around 180 or so . Maybe I'm incredibly lucky and really hoping I haven't jinxed it by saying that. Hows your rad and cap?

Ikerman7000

I changed the rad cap last night based on alot of the threads I have seen. I also put a bottle of Water Wetter by Redline in the radiator. I had it out this morning and is seemed to really do the trick. I am still curious though what is the exact measurment of the temp on that 1/3rd line. The last one before 260. I may have just been reading it wrong. Good thing is, today it did not get much over 200 even when I was sitting at lights. Thanks for the help and I would recommend the Water Wetter to anyone with slight heat issues.

henryd3

iTrader: (128)

Great. Stay cool!

CamaroLove45

I have a question...,
My car(92 camaro rs 3.1) will idle at normal temp then after about 10-20 mins of just ideling the temp will rise to 200-230,the fan is on and the problem is my radiator cap is cool slighty warm but not much but the hoses going into radiator are hot.. Does anybody know what the problem would be..i have a few things in mind but want to find the cheapest route

quaddirt1

i have a 1984 trans am with 305. my temp switch keeps burning out. i put napa brand fs110 and fs 113. and several differant switch.not working. i live in ca. and need to work right. to smog please help.mr quaddirt1