: 97 northstar still overheating



sdpj
09-30-05, 11:34 AM
well the car was given to me by my parents about 2 months ago when they drove to idaho to visit my family and i, and apparently blew a headgasket per dealer. well i changed the oil, it looked fine, flushed the line that goes into the surge tank across the motor, it wasnt plugged. drove it to town yesterday to get it registered and everything worked fine the 10 miles going 60, temp stayed at 212. got into town and it shot up and started steaming. stopped at a gas station and put some water in the surge tank to try and get home. got about a mile from home and pulled over b/c it flashed across the dash idle engine, wanted to stop and eat anyway. let it sit for about 45 min and drove the rest of the way home, still flashing idle engine, took it easy on her. not sure if it is a headgasket, hoping maybe something simple like a thermostat. also would it be something as simple as not having the right coolant mixture now that i had to top it off at a gas station. any help would be appreciated. thanks.

Ranger
09-30-05, 11:48 AM
Thermostat and water pump belt tensioner are certainly worth checking, but you would surely hope the dealer checked all the possibilities before diagnosing the head gaskets.

sdpj
09-30-05, 12:07 PM
i hope they did also. i hope they also didnt see my dad stuck between a rock and a hard place being 1200 miles from home with a broke car. it was just a chevy dealer, the closest cadillac dealer is 60 miles away in boise. my dad wont get screwed over by anyone so he just gave the car to me, got an 05 cadillac for my mom. by the way where is the water pump belt tensioner? thanks ranger.

Guyz1996deville
09-30-05, 01:13 PM
If you are looking into the motor from the front it will be on the driver side of the motor, right in the front. It will have (3) 10mm screw that hold the cover on. You should be able to see if there is a belt inside of there without taking the cover off.

jupiter57
09-30-05, 03:07 PM
Don't forget to check your "radiator" cap on the surge tank,(a weak cap will allow coolant to escape before temp gets to boiling, then a lack of coolant will cause overheating), the radiator itself for flow, and any and all hoses for even the tiniest pinhole can lead to eventual overheating. Another sore spot is the metal lines running behind the engine, they tend to rust if not properly serviced.

I would also replace any and all of the old hose clamps with screw on type clamps if they are still the originals.

Alway be sure you have the sealant tabs or powder in also, lower radiator hose, and always use a 50/50 mix of Dex-Cool & (distilled) water.

I bought a '97 with a dealer diagnosed "blown head gasket", tried everything until I discovered the radiator was clogged, probably from some non-standard sealant.

Also heard from another owner that when his '97 started overheating, he was told it was the head gaskets, upon further investigation, it was discovered that his pressure cap was weak, allowing coolant loss before the fans even kicked on! New pressure cap and presto, no more overheating.

The cooling systems in these Northstars are quite fickle after a few years, only by keeping everything up to "spec" can you avoid the enevitible(?) overheating. Most here say to not flush your system, but as with any vehicle, flushing will remove sediment and deposits that can clog up things, just be sure to thoroughly replace any tap water with distilled water ($0.59 gallon at Wal-Mart, 10 gallons is half the cost of one gallon of Dex-Cool)

Good Luck and be sure to keep us posted on the final outcome!

powerglide
09-30-05, 04:37 PM
Seems like lots of mechanics (especially dealers) automatically jump the gun and assume its the headgasket. I wonder how many junked N* out there thats actually just fine....proceed with caution!

Ranger
09-30-05, 05:12 PM
Don't forget to check the purge line. If it is plugged it will overheat.

sdpj
09-30-05, 05:25 PM
thanks, you guys are awesome. how could i tell if the radiator cap is bad, actually i assume you guys mean the purge tank cap. ranger, i have checked the purge line, that was one of the first things you told me to do, its good to go. also can i flush the radiator out myslef or do i need to take it somewhere. hopefully its something simple. ill see what i can do.

Eldyfig
09-30-05, 07:23 PM
I haven't seen anyone test a radiator cap. They are fairly inexpensive, just a few bucks. If you don't when it was last replaced, then get a new one.

If you suspect the radiator is partially plugged, you can flush it yourself. I would suggest using distilled water. Just flush the rad, not the engine. All you need to do is remove the bottom hose. Pour the water into the top radiator hose (the end you disconnected from the block). Let it drain out the bottom.

Ranger
09-30-05, 09:23 PM
thanks, you guys are awesome. how could i tell if the radiator cap is bad, actually i assume you guys mean the purge tank cap. ranger, i have checked the purge line, that was one of the first things you told me to do, its good to go. also can i flush the radiator out myslef or do i need to take it somewhere. hopefully its something simple. ill see what i can do.
Sorry, I forget what I told who to do :bonkers:.
Actually you can have the cap checked. Most shops have a hand held cooling system pump. They come with adapters to test the caps. I would doubt if anyone would even charge you for it.

Flushing it is simple. Just pull both radiator hoses, stick a garden hose in the upper, seal it with your hand and turn it on. Not a bad idea to reverse the flow. The more pressure and flow the better.

Eldyfig
10-01-05, 01:22 AM
I would doubt if anyone would even charge you for it.


I would hope not. It wouldn't be worth it.