Sitting in a Sig alert yesterday on the 101N. Some Trailer had flipped over and vacation stuff was all over the freeway. I was on the uphill side of a hill and behind a Yellow Z01. We were just inching along....literally.

I watched the temp gage first at 227° F. It stayed around there for quite some time and then it had enough. Temp started creeping up 1-2 degrees at a time every five minutes or so.

At 237° I called Central Coaster, no answer.

when it got to 245° I tried to pull over but no one was moving very fast and I couldn't get over if I tried.

At 250° I started to panic and almost killed the motor in the middle of the lanes.

Just then the traffic moved a hair and I got a bit of forward motion, maybe 100 feet at ~5mph. The temp dropped pretty quick. Then then traffic really started going forward and all was ok.

Just sitting or idling the motors cooling system is ok, but that part about inching forward half a car link at a time, uphill, in 100°+ temps really put the cooling system to the test.

My question, after 20 minutes of reading, is, Where is the threshold? Where do I need to absolutely kill the motor and let it cool off? or did I surpass that yesterday?

 

I think the absolute limit is 260 but I wouldn't chance it.
I'm not sure what year your car is or if you have aluminum heads but
aluminum heads don't like high temps.

I'd flush the cooling system or have it done and put a couple of bottles of Water Wetter (available at Auto Zone) in it.
Also clean all the stuff out between your radiator and AC condenser by removing the radiator shroud and vacuuming the stuff out or just get the stuff out somehow.

It gets hot here in TX too so I feel for you!

 

use a manual fan switch,very easy and quick!

 

I know with mine, if you turn on the AC, the fans will turn on.

I would be sure that the radiator is clean and there are no blockages for air flow.

You have one upside... iron heads and block will deal with heat better than iron/aluminum or all aluminum...

Do you run Mobil 1? If not, I would change the oil... that is quite hot...

 

The Flushing and new water pump and hoses are on the ToDo list for sure. I don't have an unlimited amount to spend on that car so I fix what breaks first. So I agree with you on that one. I plan to pull out the radiator and have it boiled out when I address that whole system. At that time I should be able to get all that stuff out from the front.

I have an '84

 

I'm not one to add too much to the design. I'd rather find out whey something is not working right and address it that way. They designed most of it correctly, just 23 years later things aren't working like they were when new.

Of course, parts changing will fix that huh?

 

What was the oil temp?

Mine I would turn off at 250° coolant and/or 300° oil temp. It's possible to go higher but unless I was racing for money, I would not go there.

Are you sure the water pump is bad? When I got my car the cooling system was in poor shape. I used the Prestone super flush and also flushed it with a garden hose hooked in. I drained it at the block with the knock sensor and replaced the 'stat. I cleaned the radiator surfaces as there were many bugs but I did not take the shroud off to clean in there yet. My car is still running cool and there are other things to work on. Many people find a large amount of debris in there witch could be your trouble. It's odd the fan didn't cool it. I would suspect a poor fan motor or debris in, on, or around, the radiator.

 

That is the perfect approach to take. Too many people want to add this or that, or change the way something works (thinking they are smarter than the engineers). It didn’t overheat when it left the factory. (Although some people will always think they ran too hot). 210-230 are perfectly normal temps under the conditions you described. Once moving again, they should drop back to around 193-197.

I would not let it get over 250 though, before shutting it down. Then find out what part of the system is not functioning properly. I believe the factory manual states to shut it down at 260.

 

Most of those quick oil change places can do the cooling system flush for you. Or you could do it yourself without removing the radiator.
You just use the Prestone quick flush or something like that.

If you have the fan in front of the condenser (auxiliary boost fan) you can replace the cooling fan temp sensor with a lower temp one that turns on the fan quicker/lower temp. I have the 200 on/185 off in my car.
You could also have your chip in your ECM reprogrammed or replace it so your main fan comes on sooner.

I'd just check for crap in between the radiator/AC condenser first. (free fix)
Then do the radiator flush soon.

 

The Oil temp was ~197-210

I don't think the water pump is bad, I just replace it once the system is cracked open. It is a cheap part and 23 years old.........change it.

I think the stuff between the radiator is the culprit. A flush is sort of short sighted, crack it all open and clean it all out.

 

Hmm oddly low oil temp for that high of coolant temp for that long.

 

well, really, not that long. Only 20 minutes or so. You think the oil should have heated up that quick?

I've noticed that the oil on my car stays at 80psi and the temps are half an hour slower than coolant at the least.

In other words. The oil temps are always 10-20° cooler than the oil and only after an hour or so of running will the oil get close to the coolant temps.

Freeway=210° coolant temps and 190° Oil temps.

 

Im pretty sure, if your oil psi stays at 80, you have an open circuit. The plug may be loose at the sender. I read this on here, but I have not looked into it.

 

Damn, you can't get away with anything with you guys

Yes the psi will fluctuate. A) when it is just starting up and B) when the oil level is low it will drop in PSI when I put on the brakes and stop at a quick rate.

So, I should have said........ "98% of the time it stays at 80psi"

 

that would indicate a failing oil pressure sensor.

The oil didn't get that hot? hm... I would have expected much more heat in the oil than that. I wonder if your temp sensor wigged out.

I agree, do a full cooling system service - remove the radiator, clean everything, replace hoses, waterpump, etc...

What I don't know - does the L83 use that wacky "oil heater" that the L98 used? It's the oil filter housing, and it has coolant routed through it. The coolant will pass via hoses to the housing and then back into the block via a fitting. Make sure the hoses there are good, too. Including the metal lines. Disclaimer: this is assuming the L83 has such a cooling system.