[dtino]

Hey guys,
I got my 02 DTS when it had 82K on it. It always has heated up a little after a run across the interstate. City driving is ok, but on hot days and sometimes when the air is on she'll heat up. (only about one mark past normal, straight up.)
I have about 125K on her now and she still heats up a little. Is this a normal thing with these cars? The NS engine is a strange bird! That why I love my old 85 with its 4.1, 30 years old and still starts and runs great. I am starting my restore on the 85s body and hope to be done in a month or so. Let me know what you guys think about the 02 NS engine.
Thanks, Dave

 

[Submariner409]

Let me know what you guys think about the 02 NS engine.

I have one and I like it.

Have you studied the several sticky threads concerning Northstar cooling systems, fan operation and gauge operation - down in Engines, Northstar ? Have you read the Cadillac Technical Archive way up ^^^ in the top black bar ? - it's all about Northstars and was written by the engineers who developed the Northstar System (it's not just the engine........).

 

[Ranger]

Anything north of 12:00 is not "normal", though it appear it may be in your case. If yours has been running from 85-125K (without problems), I'd probably consider it normal.

GM made several improvements to the 2000+ Northstars. They are much better than the pre 2000's.

 

[MoistCabbage]

What do you mean by "one mark past normal"? One line, or a needles width or two?

Having the needle move a couple of width a past 12:00 in traffic/after high speed driving/wiyh the A/C on is perfectly fine.

Moving to the next line is another story.

 

[dtino]

Well guys, this car is making me worry. Here is the history on it: Last winter it would blow cold air at idle and heat back up once you start driving, come to a stop it would start blowing cold again. I had the system fully flushed out, 3 days later found a crack in rad. so now I have a new rad, new overflow, new w\p, and themstat. seem to be ok for a few weeks then one day after coming home (drove 30 miles) from work the gauge almost when into the red, I pulled over, turned off and sat til cool. started up drove maybe one city block and she when over again, stopped again. I checked both times and no boiling of blow out. got home and replace the senor and no more going red. but the gauge will still go up sometimes. sometimes to the next mark past 12:00, sometimes to the second mark past 12:00 but once the fan turns on she moves back to normal. did the exhust test and it stayed blue passing the test. but I see it starting to go past normal just going about 3 miles now, but again once fan turns on she goes down. I have checked the flow and all the hoses and they look to be running clear. Could the heater core be clogging up? I know that will be a job to replace. ant other advise that you can give on this? THANKS!!!

 

[Ranger]

A clogged heater core will not cause it to overheat.

Have you confirmed that the purge line is clear and flows coolant?
Did you do the block test right after an overheat episode?

 

[dtino]

yes, I confirmed the purge line is clear and has a good flow going. I did the block test after she cooled down. It seems like there is a lot of pressure in the system. I have let her sit over night and have opened the cap the next day and there is a lot pressure that is still in there. the coolant is not boiling or coming out the overflow tube.

 

[Ranger]

Pressure in a cooled down cooling system points to a HG. Probably in the early stages.
I'd do the test again as soon as you can after an overheat episode.

 

[dantemoravil]

The pressure on the morning is what I noticed on mine last spring. As well as the overheating after 9 miles.

 

[dtino]

Well can't figure it out, and I do think it is a H/G getting ready to go. I think I am going to trade her off Monday for a Lincoln MKZ. Already talked to the dealer and really don't want to put 2 or 3 more grand into this car. She still needs a cat, and power steering is leaking bad and it needs calibers. Time to let go.

 

[Submariner409]

Sorry to see the car get traded - and at 125,000 + the cat, power steering and brake calipers are normal maintenance for any car on earth - it takes time and bucks to keep a high mileage car on the road.

 

[bgbllbffr]

The pressure on the morning is what I noticed on mine last spring. As well as the overheating after 9 miles.

did you ever figure out what the problem was?