overheating 94?????

[rbjb99]

Hey again, here is another problem with this POS,
Is it normal for the temp on these things to run at around the "N" mark on the guage???
I can watch it fluctuate from the tpo of the N to the bottom of the N, I live in vegas so it is hot but every time i drive it i think it is going to blow up. I know it is too hot because the ac cuts out.
I pulled the thermostat and it works, and it had 88c stamped on it.
When i check the radiator it is always full, but the overflow isn't.
Is it the pump going bad or gone bad?
Probably is, but i am just hoping it isn't because of the job i am in for if it is.
Any ideas??

Thanks
Rod

 

[Slo-Sho]

Are the fans running? Has the ECT ever been replaced? ATX or MTX fan assembly?

<small>[ June 04, 2003, 12:46 PM: Message edited by: SLO-SHO ]</small>

 

[screaminsho]

Maybe stupid to ask but what is the mix ratio on the coolant?

 

[HopefulSHO]

If your fan is coming on and going off normally and consistantly I wouldn't be worried about it. My radiator fan comes on consistantly at the N on the gauge. These dashboard gauges are not the most consistant things, for sure.
I think your A/C cutting out is a different matter altogether.

Does your engine temp go down after you've been driving on the highway for a bit?

Oya, 50/50 mix of distilled water and coolant.

<small>[ June 04, 2003, 01:55 PM: Message edited by: HopefulSHO ]</small>

 

[rbjb99]

OK, Fans do come on ok, don't know what the ECT is, car is an atx, coolant mix is 50/50, when driving on the FW the temp guage sometimes goes down and sometimes it wont.... Wierd!
Won't the computer shut the ac off if it gets too hot? I heard that somewhere, don't know if it is right.
I just replaced the engine with a clean 60K miler a couple of months ago, i just don't want to cook it thats thats why i'm a bit worried here.

 

[projectSHO89]

screaminsho:
Maybe stupid to ask but what is the mix ratio on the coolant?

Coolant mix will NOT cause a change in temp readings. Water cools great anyway (it also corrodes the system when used by itself, so be advised that corrosion protection and pump lubrication are also important).

No, the computer won't shut off the A/C on higher operating temps. The ECT is the Engine Coolant Temp sensor that tells the computer what the temp of the engine is. There is a separate sensor for the guage.

Before assuming that there is a cooling system fault, you have to take an accurate measurement of the actual system. You will either need to install an accurate aftermarket guage or use a non-contact IR thermometer to test it. FWIW, Sears has one on sale this week for around $50.

Steve

 

[yamahaSHO]

projectSHO89:
Coolant mix will NOT cause a change in temp readings

Actually, heat transfer is not the same between water and anti-freeze. That is why they make products like "water-wetter"

 

[projectSHO89]

Indeed. That was not the point that I was trying to make.

According to the Water Wetter site, plain water is twice as efficient as 50/50 in transferring heat anyway.

Some are misinformed that it is the other way around and that the coolant mix will cause a noticeable change in the displayed/indicated operating temperature.

Anyone who wants to see Water Wetter's info can go here: http://www.redlineoil.com/redlineoil/wwti.htm

Water Wetter includes corrosion inhibitors and lubricants for the health of the system, plus surfactants to reduce surface tension so that the water gets into smaller places at or near the molecular level.

Ethylene glycol is used first and foremost to lower the freezing and and raise boiling points of the coolant. It is a compromise between heat transfer efficiency and the realities of the environments to which the motor will be exposed.

Steve

<small>[ June 05, 2003, 10:20 AM: Message edited by: projectSHO89 ]</small>

 

[Markus]

projectSHO89:

No, the computer won't shut off the A/C on higher operating temps.
Steve

Actually the computer will shut off the compressor when coolant temperature gets to high. Not only do the Helm manuals state this, but I have experienced it twice.

 

[projectSHO89]

Perhaps I should have been more specific that the computer would not shut off the AC while the coolant temp is still within operating range temps.

Overtemp, by definition, is outside of the operating temp range.

Steve

 

[rbjb99]

Ok, I sat the car in the driveway with the motor running and the ac off,once the gauge reached the "M" the fans came on then a minute or so later they went off, then they did their thing (went on and off) and kept it at about the same temp. (M)
THEN!! when i turned the ac on, that is when the temp shot up, the both fans stayed on but it went up to about the N mark, then came back down again when i turned it off.
Whats up with that?

Thanks
Rod

 

[projectSHO89]

When you run the AC, not only is there a greater load on the engine, the airflow through the radiator has already passed through the condensor coil. As air passes through the condensor, it extracts heat from that coil causing the temp of the air flowing through the radiator to be appreciably hotter. The hotter air is not able to transfer as much thermal energy from the radiator as before, causing the increase in operating temp as indicated on your dash guage.

As long as the system is pressurized, the cooling system can easily withstand operating temps of 225F or so with no problems. It's tough on the system, though.

My suggestion would be to flush the system with a good cleaner, empty all the coolant out, fill it with 80% distilled water, 20% ethylene glycol, and a dose of water wetter.

Steve