First Symptoms: Car heating up in normal driving.

What I know: New air dam, new water pump, 180 stat, almost new radiator...no leaks anywhere, no bubbles in coolant. Both fans work (I've seen them turn at the same time) but when I do the ALDL paperclip trick, only the drivers side turns on. When the AC is on, the drivers side fan is on.

First question: My gauge reads 235 yet my diagnostic software is seeing ~220 from the ECM. Do the ECM and the gauge get their signal from the same sensor? If not, is it common for the one for the gauge to just rerad higher instead of going out completely?

Second question: Could it possibly be that my primary fan motor is going out? It's spinning, but possibly not fast enough?

Third question: Considering it only started in the past few weeks and the radiator is fairly new and has been flushed I doubt it is the radiator, but...where can I get a bigger radiator decently priced? I think stock is 1 core? Do they make a 3 core that will fit right in?



Thanks in advance. I'm open to any suggestions.

 

they use 2 diff sensors at diff places on the engine.


could be... but HIGHLY unlikely.



they make some badass alum radiators... athough the generic alum ones are cheaper, and almost bolt right in....


but i dont think any of thoes are your prob...

for the 18th time billy.... GET A NEW RADIATOR CAP!

 

The radiator cap seems brand new Travis. I'll go buy another tomorrow, but still.

 

Could the car be so low that the air dam is not grabbing enough air to feed the monster???

If it is a loss of flow from the air dam and being so low it also may be sucking hotter air than normal into the engine.

Matt

Not sure how a cap would help it run cooler or a bad one make it run hott.

 

Are the side air dams behind the front nose cover installed?
Is there some "ram air set up" that is blocking radiator air flow?
The factory radiator is very decent piece.
It certainly could be a new cap.
Get the GM one from a dealer, not after market. The aftermarket caps don't last very long.

 

I would look close at the fans again.... When the fans kick on they don't kick on at the same temp. One should kick on first somewhere at about 208 ( by memory ) and the other should kick on up to about 231. The temp gauge is operated off a sensor in the left cylinder head. The coolant temp for the PCM is in front of the intake below the T'stat and is usually most acurate and the secondary cooling fan temp swith is in the rt rear cylinder head. .. The connector on the secondary cooling fan switch ( below the exhaust manifold ) is common to fry, corrode or just turn crispy.

A fairly new radiator is meaning like a few months or is it like a few years... Was it brand new ? A modine ? It's should be a max cool core design which should be fine if it is working correctly. I decided to drive my bird the last few days and it's been 105 to 108 with no prob's.... 1990 model, with A/C and extra ponies....

 

Going along with the "how new is new?" idea on the radiator... was it pulled out recently? Some f-bodies have been known to accumulate crap between the a/c condensor and radiator that blocks air flow.

Something that helps cooling a bit, and also makes it easier to avoid air bubbles, is to drill some tiny holes along the edge of your thermostat. It's an old hot rodder trick to prevent an air pocket from forming underneath the thermostat, which would prevent the t-stat from opening when it should. According to my gauge, I drop about 5-10 degrees just from those little holes.

I'll attach a sketch i whipped up a while ago... doing this certainly couldn't hurt, and you might as well test the new thermo out again in a pan of boiling water...

 

I run a 195 thermostat and I run about 180 on the highway according to the gauge in the car. Seems to me if I cut holes in the thing it couldn't hurt. What is the advantage though of running much cooler? There has to be a limit at which you can run too cool and the engine not operate as efficiently.

 

you are right. no cooler than 180*. running any cooler than that, and cylinder wall wear is accelerated.