: Keys to long lasting N*'s



N0DIH
11-09-06, 01:02 AM
A friend of mine just picked up a 96 Deville (Concours? not sure yet.....) for $1400 in good shape. Engine purrs nicely.

What are the key things to do to a N* to keep it running good for a long long time? Car has 140K now...

chazglenn3
11-09-06, 02:16 AM
Change the coolant when due, if not earlier. The '96 uses Dex-Cool 5yr/150,00mi coolant. It should have been changed twice by now.

dp102288
11-09-06, 09:11 AM
But if the green stuff is in there, change every two years.

Check all the fluids. Any that looks burnt or old should be changed.

Check any wires, the spark plugs, etc... You say the car runs good so that shouldn't reveal any problems, but its better to know.

Ranger
11-09-06, 11:41 AM
If the trans fluid has not been changed, it's due. NO FLUSH!

N0DIH
11-09-06, 01:26 PM
You can't buy non ext life coolant anymore. I looked, not there anymore...

Thanks! We will get coolant and trans fluid changed ASAP...

fpmesiIII
11-09-06, 03:23 PM
is it true that transfluid should last the lifetime of the vehicle?

N0DIH
11-09-06, 03:25 PM
No, I would never do that. Most trans rebuilders recommend 30K mile changes. 60K is to me the LONGEST you should ever go.

Too much of the additives in the oil burn off / evaporate over time, they need to be replentished.

Ranger
11-09-06, 06:23 PM
GM says yes if you're not driving under "severe" conditions listed in the owners manual. Personally I do mine at 100K.

chazglenn3
11-09-06, 10:21 PM
My local Autozone still sells regular green coolant. Bought a couple of gallons the other day for my wife's Explorer and my '87 Supra.

N0DIH
11-10-06, 12:13 AM
Ahh, but look closer, color is meaningless. I haven't seen any coolant in the last 2 years that isn't the extended life type. I would be very surprised if it was actually NOT the low phosphate formula. Considering all cars sold since the mid 90's have come with it factory, and a majority of the cars on the road are 90's and up, NOT to have only that available. Like SM spec oil. Just go and try to buy SL or older oils at your local store. Hard to find. OEM's drive things hard this way.

fpmesiIII
11-10-06, 03:14 PM
GM says yes if you're not driving under "severe" conditions listed in the owners manual. Personally I do mine at 100K.

what do they mean by "severe" conditions?

Ranger
11-10-06, 03:47 PM
Towing, dusty conditions, taxi service. It's in the owners manual.

nigelb
11-10-06, 04:46 PM
looking after a N* is not really any different from looking after any modern design engine.
check your fluids regularly and change them when the service book tells you. use the best quality service parts you can get.
check the DIC often for codes and repair any problems as they arise.
the coolant seems to be a major issue, the approved DexCool and similar are silicate free. this seems to be the key to help avoid corrosion. regular use of the coolant pellets/bars leaks is also important.
if you buy a used car one of your first chores should be to change the coolant, in fact i reckon it should be the first chore.
apparently mixing the older style coolant with DexCool can have a negative effect on the corrosion inhibitors.
my '86 volvo 740 uses silicate free coolant, that motor has got in excess of 300k miles on it and still runs great.

GreenMachine
11-10-06, 06:28 PM
Also say high performance operation Ranger....I think anyone with a Northstar is guilty of that one :)

Cadillacboy
11-10-06, 06:39 PM
High performance operation but aren't Nstars meant to be driven that way ? People here say don't baby it but anyway from what I infer those cars are so smart and protect themselves against anything that can be dangerous .
Sometimes I can't help but think why Nstar don't have an iron cast instead .May be we might have less performance but more reliable engine at least eliminate and minimize head gasket problems

GreenMachine
11-10-06, 11:36 PM
High performance operation but aren't Nstars meant to be driven that way ? People here say don't baby it but anyway from what I infer those cars are so smart and protect themselves against anything that can be dangerous .
Sometimes I can't help but think why Nstar don't have an iron cast instead .May be we might have less performance but more reliable engine at least eliminate and minimize head gasket problems

You'll have to change most fluids, in anycar, more often, when you "hot rod" it. For the most part it appears head gaskets are from not changing the coolant out, I can't help but wonder why they have not implemented a "tracker" that counts downs the days, and mileage, that you've been on the same coolant just like the EOLI, you simply reset it at coolant change. I think if your car started up and was hounding you about "change coolant soon" we might have less head gasket issues, most of it comes from uses vehicles that simply slipped through the cracks that a single owner or lease vehicle for service might have missed.

Despite the few head gasket issues (considering the northstar was featured in the 90's in the Eldorado (Base and ETC) Seville (SLS/STS) and Deville (Base/de' Elegance-DHS-/Concours-DTS). Also consider that the Deville has lead from the mid-90s in the Full size Luxury Sedan market, and then how many of these fine cars are still on the road, and you can see that its a pretty damn good engine.

We rarely see post 2000 caddys with head gasket issues (may see more now that the coolant changes are coming up) but generally speaking your seeing cars that 7,8,9+ years old and the only thing wrong is a headgasket.

It wouldn't be to bad of a problem if it weren't for that fact that you had to take the engine out to change them....something the switch to RWD might have changed. Also consider that most of the time its the exhaust gas getting into the coolant and you might imaging it could be the higher compression ratio of the pre-2000's that are contributing.

dp102288
11-12-06, 09:40 AM
Is constant high speed driving a severe condition? :rofl:

So I should get the Tranny fluid changed at around 100k even under ideal conditions? Sure, why not...