1999 deville northstar - weird problem, not sure whats going on

[TheRoger]

Is there any merit to the theory of changing the thermostat for one a little bit lower temp?

[rockfangd]

No. It is best with what it was designed for. Plain and simple

[TheRoger]

It's a done deal fellas. I replaced plugs only fixed her right up. They weren't badly fouled but a little carbon on some and some of the usual grey/tan sediment. Didn't look a mess but did the trick. Also discovered that both wheel sensors were unplugged in the rear so fixed that up and now not a single code showing after clearing. Always had abs trac light since I purchased 3-4 months ago. Guy said his mechanic told him it was a bad sensor lol I never bothered investigating because it's winter here and trac is a pain in the a when it snows actually. Car had mc increased power

Side note. I noticed when I was doing the WOT that when the trac light is on you lose first gear. Soon as I cleared her up it came back. This used to happen on my 96 as I recall. At that time I had no knowledge of working on cars or I would have still had it

[Cadillac Jim]

New plugs are always a good idea when you pull them on a Northstar for any reason. The come with a special anti-seize thraedlock and anti-arcing insulator lube already applied, and pre-gapped. And, on a FWD car, the rear ones are a bear to get to unless you drop the cradle, which is a bit much for a plug change.

Since they are pre-gapped, I always checked the gap, and if it wasn't right, I threw away the plug because it had been dropped.

The "huge" gap on a couple of plugs was probably due to losing the platinum pad, then rapid erosion on the rest.

Once, long, long ago and far, far away, I was looking at a house with a real estate person in the wintertime; her car had no heat. I asked her about that, and she said that her mechanic told her that her HVAC blower was shot and she needed a new one. When we got back to the office, I asked to look at her fuses, and, saw that the 30 A blower motor fuse had been pulled. I got another from my car's emergency parts supply and put it in for her; end of problem.

[KHE]

The dielectric lube is pre-applied to the wires at the factory. Do not add any additional dielectric lube. There is no anti-seize coating on the plugs and do not under any circumstances apply anti-seize lubricant to the threads - it will cause the plug to be at a tighter actual torque vs. the torque spec.

The plug threads are plated with a zinc plating to resist corrosion.

[Cadillac Jim]

The threadlock on the plug threads isn't a lube, although, of course, if you do find an anti-size *lube* somewhere, don't use it on plug threads; in general, it's a bad idea to use any lube on threads for a torque-sensitive application, and spark plugs in aluminum heads are definitely very torque-sensitive.

Sorry, I thought that I recalled that there was a coating on the insulators as well as the threads of new OEM AC/Delco double-platinum plugs for Northstars.

The last time I did a lot of that was on my Quad 4 HO, which recommended compounds on the threads and insulators in the FSM. And, I found that the dealer techs rarely tightened these plugs *and* seated the boots on them - these inline 4's used two coils bolted to a cam cover that had the plug boots integrated into the assembly, and seating all four boots was not a click-in installation. I re-checked the plugs every time it was at a dealer and only once did I find all the plugs at the right torque and all the boots properly seated. I had the car for seven years, trading it in for a 1997 Cadillac.