RS-Chevy-SS

Hey guys is this way too hot? What temp does this represent?

Apeiron

That's around 240 degrees. I wouldn't want to see it getting that high more than only very occasionally, and certainly never any higher.

RS-Chevy-SS

Well you see i just took that pic about 10 mins ago and it regularly does that..But then again the A/C Was on and its currently 116 degrees outside...This was in stop and go traffic what do you think?

Apeiron

I'd like to see it a lot closer to a consistent 220 in a situation like that.

Keep in mind though that the factory gauges aren't especially accurate, so it could be anywhere from maybe 220 to 260.

RS-Chevy-SS

Would one of those heat guns pointed at the top radiator hose be accurate?

Apeiron

Only at telling you the temperature of the outside of the hose.

RS-Chevy-SS

Would the inside coolant actually be a lot different?

bilms01

put a thermometer in the coolant through the cap, that should be pretty accurate

IROCWPB

no it shouldn't be, the radiator's job is to cool off the coolant. the only thing that matters is the temps of the fluid inside the engine, the temperature sensors are installed where they are for a reason, so they make direct contact with the fluid INSIDE the engine, not while it's cooling off in the radiator. sheesh

VenomX-87

Don't trust the OEM guage because 50% of the time they will be wrong, They are ONLY a rough guide.

To make shure you are not over heating tho pick up a normal mech temp guage (more acurate for youre $$$) then temp install it under youre hood (mine is next to my battery) put the probe in a water passage (normaly in intake or head) then run the car and see what that guage reads then compare it to the OEM (in dash) guage.
If the mech guage is reading over 230'F start by changing the T'stat to a 180'F (evan if you got one and it is new they can still be faulty) then you can either put a lower temp switch (turns fan on) in the passenger head stock is around 238'F I think way to hot IMO (Im running a 190'F) or install a manual switch for the fan so you can turn it on when needed.

Make shure all the fins on the radiator are in good shape and not squashed and blocking the air from passing through also try flushing the cooling system.

bilms01

The top of the radiator is where the coolant returnt to the radiator from the engine BEFORE it is cooled. Yes it is more accurate than most guages. I have compared that to a scantool and found it within just a few degrees of what the sensors tell the ECM. For his purposes of checking the guage anything within 10 degrees is very accurate.

Apeiron

Not in a cross-flow radiator. The coolant has already made one pass through the top core by the time it gets to the filler neck. Close enough in temperature, though.

bilms01

That's true I agree completely, and I do understand that, but if you are standing in front of the car with a thermometer in the radiator there is more than likely little or no airflow across the rad fins cooling at that point cooling will only be minimal. Of course the GM way is to use a temperature stick on the thermostat housing. More often than not a thermometer in the radiator as accurate as you can get short of doing what Venom suggests and buying a quality guage.

I guess I didn't word my last post as accurate as I should have.

Apeiron

GM specifies measuring the temperature of the thermostat housing as a safety measure. Opening the radiator cap while the system is hot is a bad idea.

AUSSIROC

iTrader: (1)

Guys,
I switched from a 195F-ish thermostat what was in it when i bought the car, to a 160F thermostat a couple of days ago. The operating temp on the guage has remained the same with both thermostats...
I was expecting a drop in operating temps for the coolant due to the thermostat opening sooner, and i have both fans turn on nice and early (about 70F or so approx)..

Is the 100F temp showing up on the guage (before AND after 'stat swap) normal? (It is winter down here still so its pretty cool mostly).

?? ??

Cheers!

5678TA

240?!?!?!?!?! JEEZ.. i never let my motor go past 200.. hell,i dont like to see it past 180..

dennisbernal91z

iTrader: (2)

My motor runs at 165* all day, I thought that was ideal, but then I did a little research and asked some guys who own 1000+ HP cars and turns out that you WANT your car to be around 180-190 all the time. This is the temperature that oil lubricates the best and makes the motor take on less wear. Do some research, its true. So i am swapping out my 165 thermo and temp switch for a 180 pieces. That will make the motor run in its prime temp. And stay there.

Oh I run stock rad, stock water pump, stock dual fans that all work well. No need for exotic BeCool parts or anything like that. Just stock stuff, that acctually isn't broken is all you need. Oh and run an air dam people.

I have them wired with Painless kits. Super easy and motor runs at whatever temp I want it to run. Even when its 95+F out.

KYLE87

iTrader: (5)

Its funny you posted this because I just started to have the same problem. Mine used to sit right on the 220 line and if If the a/c was on it set a line under that, well now its starting to always sit where yours is in the picture and if the a/c is on it sits on or a little below the 220, I personally dont like my car running that hot, if you figure anything out let me know, Id like to get it a little cooler withut doing the fan switch mod.

Kyle

jimdutro

iTrader: (1)

My dual fan `88 Iroc ran as hot as the gauge in the photo until I made a few changes. Replaced the thermostat with a 170 and drilled 4 1/8 bypass holes in the perimeter of it, installed a 185 on 170 off fan switch, used 30% anti freeze to 70% distilled water and added 1 bottle of water wetter. Replaced radiator cap, checked and repaired both air dams and cleaned out the area between the radiator and condenser. My car rarely exceeds 200 on these hot days.

dennisbernal91z

iTrader: (2)

Nice. You preach what I do.

Just get it running with stock parts, and you will not over heat. People seem to think that the more $ they spend (al. rad.) the cooler their car will run, when its just not the case.

nightmare

Only problem is that GM stealerships think that 240° is a normal operating temperature for these cars. I had this problem a few times, and once I changed to a 4 core radiator and a 180° t-stat, it stopped happening. My car rarely sees 160°, though, and most of the time, it stays right above 100°.

dennisbernal91z

iTrader: (2)

WHAT!!!! 100*!

nightmare: How long have you been doing this? 100* is WAY WAY WAY too low for your motor to be running at. OMG. your oil, if it in fast normal, is MUCH to thick down there to fully lube your motor. You are not going to seize up or anything, but you are putting a TON more wear on that motor than you should.

You should be running IDEALLY at 190*, all day long. You wanna get up to 190 as fast as possible and you wanna make your car stay there as consistently as possible. I have never in my life or years on TGO or reading magazines or books or manuals ever herd of running a car at 100*.

Who told you to do that!?

nightmare

Well, it's not at 100°, it's more like in between the 100° mark and the second line. Now, I understand that the cooler an engine runs, the more difficult it is to pump the oil through the plumbing. That's why I've got a high flow oil pump, and I'm not using conventional heavy weight oil.

The guy that I got the engine from told me the cooler the better. He's a racer, has been racing for 20+ years, and always runs his cars like this. He says that he's never had a problem with running them cooler than "normal," even in his everyday drivers. I trust what he says.

dennisbernal91z

iTrader: (2)

Well if you read formal pubished info on the subject you will see otherwise.

I was running my car it 165 and was told my friend who owns a repair shop and owns a 69 autocross car, as well as his pride and joy 1000+ hp 72 chevelle, "to optimize power and longevity your motor wants its oil to be at 190-195. I looked into it further and it is true.

I DEFINETLY go with what he says, as well as auto manufacturing engineers. 100* is just too cold.

Oh and to address your point that you have a high flow pump, thats fine. But now imagine if you have a high flow pump and properly heated oil, you will have even better coverage and supply. You are hindering your oil with your low temp and then trying to band-aid the problem with a high flow pump. Don't you see that your point of running a high flow pump proves the point that you are hurting your performance? Also you are wasting power. It is as clear as day that when oil is thicker your motor has to do more work to move it. No questions asked. So why would you want to keep it as dense as possible? To hurt your HP and TQ as much as possible?

I don't see the point. AT ALL.

In summary you are running your car at 100* to benefit nothing and to hurt everything....

Makes no sense at all. Advice to everyone, just get your stock stuff clean and running well (wiring, coolant, relays and sensors), and you don't even have to run cool thermos. I have a 180 in mine and my second fan turns on at 185. I rarely have my second fan turn on solely due to the fact that everything else is running 100%. Simple. The guys that engineered the stock stuff where not retards, the stuff works.

nightmare

"... So why would you want to keep it as dense as possible? To hurt your HP and TQ as much as possible?

I don't see the point. AT ALL.

In summary you are running your car at 100* to benefit nothing and to hurt everything.... "

Well, are we still talking about the same thing here? The pour point of the oil I use is well, well below the operating temperature of the vehicle. Basically, a temperature guage is there to show you the temperature of the WATER that is running through the engine. Granted, oil is also used to provide a heat barrier from the friction caused by the rotating masses, but I also don't live in an area where the temperatures freeze. "Most petroleum oils have pour points in the range of -15 to -35 degrees F. That means that their borderline pumping temperature is, at best, around -15 degrees F and probably closer to 5 to 10 degrees F."* Now, with that in mind, running an engine at 100°, which I don't, is still way hotter than the pour point.

*http://www.autoeducation.com/autosho...l-change-5.htm

Apeiron

Oil temperature will normally be well above the coolant temperature, so there's no problem there.

dennisbernal91z

iTrader: (2)

That might be true. But it certainly isn't in my car. My oil stays around 120 or so. I have good oil pressure and can drive it for a long time like that. EVENTUALLY, it gets to say 150, but I tend to be where I am headed by then. And if I am on the highway, it will drop significanly. While the temp gauge stays at 180-185 around town and drops to 165 on the highway. Granted I don't check my oil temp all that much. I wouldn't want it to be 100* or less with the car running all the time.

Apeiron

How do you get your oil to run that cold?

dennisbernal91z

iTrader: (2)

I dunno. I have an autometer gauge and sensor in the block, and it reads from 100-250 I think.

I run a 7 quart oil pan, so there is a TON of oil in the motor. Then I run a PCV and a breather and thats it. No oil cooler or anything. I know the gauge is getting oil to it, since I have my oil pressure T-ed right off or the same port and that works like a charm. The motor has less than 2000 miles on it. ummm.... Thats it. Appart from that, i run a stock cooling system that hovers around 180-185 all day long. Ummm, I have a K&N oil filter and a T-56 behind my motor. Not sure what else might effect the oil being the temp it is.

sofakingdom

iTrader: (1)

They think that, BECAUSE IT'S TRUE.

If you investigate the stock fan switch for these cars, you'll discover that it TURNS THE FAN ON at about 235°. That means, in the factory's opinion, the engine DOES NOT EVEN NEED COOLING until it reaches 235°. Furthermore, the factory fan switch shuts the fan off at about 215°, so in the factory's opinion, the engine ceases to need any firther cooling once the temp has been reduced to 215°.

Got it? Not that the factory knows anything about how their cars are supposed to work, or anything radical like that; but it helps to at least know what they built before assuming that it's not doing what it's supposed to be doing.

240° IS NOT "overheating".

One of these cars, when working right, will sit and idle all day long with the air off; and the temp will climb right on up to where your gauge is, the fan will turn on, the gauge will come down to a little below the 220° mark, and the fan will shut off; the temp will climb to right about where that gauge is, the fan will turn on, the gauge will come down to a little below the 220° mark, and the fan will shut off; and so forth, until the car runs out of gas.

In other words, IT IS PERFECTLY NORMAL for the gauge to read what yours is showing, at times.

With the air on, it will act differently. The fan will run continuously; and the temp will simply reach some equilibrium point determined by how much heat the AC is managing to remove from the pass compartment and put into the condenser, which of course heats up the air that then has to cool the radiator, which in turn raises the coolant temp because it's now being cooled by hotter air. Up to the point that the AC is designed to work up to (about 105° or so ambient) it will not exceed about what your gauge is showing.

So, I'm not really seeing any cause for concern there, just because that gauge is showing what it's showing.

dennisbernal91z

iTrader: (2)

True. Only reason I don't run that hot, and keep my car around 185* is cuz 2 reasons.

1) Not a single thing is stock on my car.
2) People with more experience have recommended that temp for a motor like mine.

With that said. I feel less like I should be posting about this topic since it is mainly about a stock cars running temp.


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