overheating 95sts

:welcome:
Possible causes:
1. Loose water pump belt tensioner.
2. Surge tank cap not sealing or not installed properly.
3. Purge line (water pump to surge tank) pluged.
4. Bad thermostat
5. Blown head gasket

improper antifreeze mixture. Low coolant level.

Thanks Ranger!

The guy I bought it from said that he changed the surge tank because it was leaking at the bottom and he replaced the cap. He let it sit idle for about 3hrs (so he says) without the a/c on and it did not overheat. If the coolant and water mixture isn't right, could that also be a factor?

anothereldoowner I just saw your post

What is the proper mixture? Answer in liters, onces, or gallons if you will.

the first thing to check on an overheating problem, is to check/replace the cap on the overflow tank.
if it is not sealing properly, you will overheat every time.
it is worth spending the 10 bucks or so to just replace it and see what the results are.

kevin

ZO95STS said:

What is the proper mixture? Answer in liters, onces, or gallons if you will.

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The proper mixture is 50/50. Not sure about capacity. Somewhere around 2 gallons.

I just bought a 98 eldorado and the first day the temp came almost to the last line before hot in traffic without the ac and the temp ousdie was only 70 deg. It did go back and forth from the mid line to the line beefore hot several times in 15-20 minutes. I called the dealer and he said it is common for it to move around without ac on as when it gets between the mid and hot line the fan comes on and cools it down. Im just not used to having a temp gage move around so much or run normally past the mid mark. The car typically runs just past mid line so I thought changing therostat and coolant might help. It didnt so Im done worrying about it.

I hear everyone quoting temperatures of their northstar coolant. Where do you get this temperature info? My gage just has lines. Also what years had my exact engne transmission combination?

What does "Service Ride Control" mean? How do you service it?

Hey Z095sts, Look to see if your cooling fans are kicking in. On mine there are two, One for normal riding, and the second kicks in just in case the first one doesn't do the job.

Service ride control, means there is something wrong with the ride control. Check connections at the suspension. What codes are there? I had an issue with that also. But it seemed to fix itself. I also had a ABS issue, The rear right tire connection was loose. It looked to be in there, but on further examination, i found that it was not "locked" into place. Out just enough to look in, yet throw a trouble code..

Need to know the codes..........there are many sensors on that system.

To get the codes, with your ignition on and the engine running, press and hold the OFF and WARMER buttons on your climate control until all of your displays light up. The OBD will go through its tests and display codes in the format of a letter followed by 3 numbers. Testing is done when it reads "PCM?". Post your codes when you get them.

Dougtune, 95 and older cars were equipped with OBD1 and were able to display coolant temp in a digital readout under the speedometer. There is a way to get that readout in some OBD2 caddys, but you have to go into the OBD system and make an override. This topic was recently discussed here: http://cadillacforums.com/forums/showthread.php?t=55326

Thanks for the info I'll check it out.
Another question. Where is the thermostat located?

Follow the hose from the bottom of the radiator to the water pump. The thermostat is under that housing where the hose is connected to the water pump.

dougtune said:

I hear everyone quoting temperatures of their northstar coolant. Where do you get this temperature info? My gage just has lines. Also what years had my exact engne transmission combination?

Click to expand...

The Devilles have a digital tempurature readout.

I found the thermostat housing thanks. Who ever had this car before me took
the darn thermostat out! I put a new one in. What is the normal operating temperature? I have a digital read out.

Normal operating temp has a fairly large range depending on different things. Between 199 and 225 is normal. Mine runs 199-205 while driving. If it sits and idles, the temp will creep up. Idling on really hot days, the temp will crest over 220. Your fans come on at 225. If everything is doing its job optimally, your temp shouldn't get much higher than that. I believe the North* considers itself overheating somewhere above 250.

If I were you, Id have a mechanic check it for blown head gasket right away, and if its blown, take back to that guy and demand your money back.

My Caddy is running normal. Praise God!!!!
I'm changing the water pump anyway. I had a guy go to the auction to find this car for me. The vin # came back clean but I have no idea as to how long this car has been sitting. So I'm doing preventive maintenance. What is the tool that you use to pull the wierdest looking water pump I've ever seen out of its housing?