coolant temperature 1997 Northstar 275hp

[Michael kelly]

What is the "Normal" coolant temperature supposed to be on my 1997 Caddy Deville with a Northstar 275 HP. A repair shop service wrighter said it should be 195 -210 degrees, he said it shouldnt get over 210. The manual does not state the normal range. While driving on a warm day, (not extremely hot day) in traffic the reading went up to 218 tops and goes don after you start driving. Nothing on the dash said it was too hot but I am concerned as I am told dont ever let this engine have a cooling issue. Where would I get the spark plugs and wire for plugs at? any special brand? I dont mind paying extra for quality stuff.

[JohnnyG]

There are plenty of posts on this board that will address each of your questions in great detail, but just to get you headed in the right direction, I'll try to summarize for you.

Yes, the cooling system is extremely important on these cars, make sure all of the proper maintenance has been done and the outside of the radiator is clean. Make sure the electric fans are operating properly. Make sure the correct 50/50 mix of Dexcool and water is ALWAYS in your engine and that it is no more than 5 years old. I don't think you have a problem at this point.

Always use AC Delco spark plugs and wire sets from GM, never use aftermarket plugs or wires of any kind on this engine.

[hjb981]

The OEM spark plugs are AC Delco, platinum tipped, and have a 100000 mile service interval. They should not be gapped. One place to get them would be rockauto.com. On that site, you will find them as ACDELCO Part # 41950 (they are under the ignition menu). For wires, there is ACDELCO Part # 748J, which is the right length for your car. There are also other AC Delco wires listed for your vehicle, but that is a generic set, and the length of the wires are not exactly right (it is a bit cheaper, though). A have the same make and model you do, and bought these items last year. I got the more expensive wires with the right lengths. Call or email rockauto if you have any question - they are usually answering fast. Be sure to check out the pinned thread about rockauto discount codes, to get 5% off if you order from rockauto.

Is your reading of 218 degrees different from what you are used to, or have you not checked before? Read this thread:

http://caddyinfo.ipbhost.com/index.php?showtopic=31731

In it (post #9), I give a detailed overview of my car's operating temperature behavior. It is also a '97 DeVille 275 Hp, so it should be relevant to you. Other people give more information about their cars, so you should be able to get a pretty good idea from that thread. BodybyFisher gives a good overview in post #3.

If you have not done it, check your coolant level, just in case. It is always good to keep track of all your fluid levels.

One more thing: I think that the Northstar has an unusual construction with the thermostat on the engine coolant inlet rather than on the outlet, and that this has to do with protecting the engine from temperature shocks. Someone else please fill in here (I would be interested in learning more myself).

Hope it helps,

Jonas

[winterset]

Most important thing to do for a Northstar is to change the dexcool every 4 years. If you don't know the history of yours, than change it immediately.

[Ranger]

Nothing wrong with 218. My '97 (digidash) ran a consistent 205-215. Cooling fans do not even come on until 224.

[firefoot0315]

I'd check the thermostat. My car was running hot (225-235). The guys on here recommended swapping the thermostat, and now it runs between 200 and 210 in the Texas summer heat.