Being I rarely get to see my mom's N*, and I will next week, what is a way to keep an eye out for her to ensure she doesn't have a head gasket going?

And, what is preventative maintenance on it to ensure it WON'T ever blow?

The car is a 97 Deville 275hp.

Thanks!!

I thought this was beaten to death...

Coolant loss with no visible leak, overheating going up hill or heavy accelleration,
missing when cold.

There is no way to prevent it from EVER happening. To put it off as long as possible do a coolant change regularly.:stirpot:

A 97 should have had a coolant change in 2002. 5yrs.

And don't forget the coolant tabs!

What exacdtly are the coolant tabs? I could never find them, and Im pretty sure the service dept didnt ever put them in my engine when they changed the coolant. I bet you they didnt. What exactly happens if you forget the tabs?

The tabs are a sealant (ginger root is one ingredient) that plugs nuisance leaks. It doesn't do anything for major leaks.

are you supposed to put them in each time the coolant is changed? if u dont can the head gasket be put at risk?

are you supposed to put them in each time the coolant is changed? if u dont can the head gasket be put at risk?

The coolant supplement required on Northstars is one of three products:

* Six of the GM Cooling System Supplement pellets (available at any GM dealership)

* Six of the Bar's Leaks HD Tablet Stop Leak tablets (Bar's part number HDC)

* Two tubes of Bar's Leaks Golden Seal Powder (Bar's part number G12BP)

One of these products should be installed to the radiator hose before refilling the system. They should never be installed in the surge tank. This should be done at every coolant drain and refill. For traditional antifreeze cars, 1995s and older, that means every 2 years or 30,000 miles. For cars with Dexcool coolant, 1996 and newer cars, that means every 5 years or 100,000 miles. It's very important to eliminate air from the cooling system, so I think it's also wise to check the vapor purge line every coolant change to ensure it flows freely.

Doesn't have anything to do with head gasket leaks. It's only for minor, low pressure leaks.

Well we did the plugs yesterday and 1 plug (#6) had some sparkly stuff on it that I have always identified as antifreeze.

Has anyone ever looked closely at the plugs when they changed them?

The car is running factory installed antifreeze, as per the 1997 FSM, no changes to antifreeze for 100K. It lists no changes for coolant until >150K.

The only thing we really don't have time for is throttle body cleaning. I would like to, but I don't have time.

Even if the FSM gave 150k the jugs and all the other literature I've seen say 5ys OR 1xx,xxx miles. That means it should have been changed.

I agree with Zonie. A '97 should have been changed 3 yrs. ago.

So why would Cadillac steer every 97 Deville owner wrong? Would they really risk it?

I don't buy that personally.

Although I do agree it should be changed, with all the years and years of GM doing maint schedules, I find it hard to believe that GM would post a schedule that has info in it that would comprimise the life of the car.

Katshot, what did you do with the limo's? Or did they get a commercial maint schedule that isn't posted in the FSM?

The first thing I would do is stop towing that airstream behind it.

^^Why'd you dig up a 2 week old thread to say that? Plus, that's a pic of a Fleetwood Brougham (I'm assuming a V4P car) which is rated to tow 7000lbs.

good thing i saw thism y 96 sts has water in it now, bad head gasket, so i remember to run dexcool after i am finished with the motor, that thought hadnt crossed my mind yet!!!

The tabs (or GoldenPowder) themselves do not prevent headgasket damage, but they MAY help prevent the leak that could lead to an episode or two of overheating, which COULD cook the headgasket.

The tabs (or GoldenPowder) themselves do not prevent headgasket damage,

I was under the impression that the additive tabs were used to mitigate the corrosive nature of coolant and prevent the steel inner part of the head gasket, as well as the entire coolant system from corroding, rusting, etc.

I was under the impression that the additive tabs were used to mitigate the corrosive nature of coolant and prevent the steel inner part of the head gasket, as well as the entire coolant system from corroding, rusting, etc.

Nope. The tabs are ground up walnut shells and ginger root. They expand to seal nuinsance leaks caused by casting porosities.

You were on the right track though: the coolant must be replaced every so often according to schedule, in order to prevent corosion. While it's cooling capacity does not degrade, the anticorrosive agents deplete.

I was under the impression that the additive tabs were used to mitigate the corrosive nature of coolant and prevent the steel inner part of the head gasket, as well as the entire coolant system from corroding, rusting, etc.

They do - kind of. If the coolant starts to corrode the headgasket, the barsleak sealant will get into the corroded area and help prevent it from spreading and worsening.

Head gaskets are under an intense amount of pressure. The tabs do nothing to prevent or cure a bad head gasket. NO addative can do that. Mtflight is correct.

So what if i have missing coolant and no overheating even going up the mountains on steep grades??

I saw the check coolant level a couple weeks ago, put in about a gallon of mixture. I just went to centennial wy to snowmobile and when i got back the check coolant level was on again. 1500 mile trip plus about 2 weeks of driving. The hill from centennial is about striaght up, no overheating, no message. I got the message when i got home.

Could the water pump leak like they do on the chevy pickup and im not seeing the leak?? When i got to the lodge something was smoking very faint, could have been from the snow up there at the lodge. This happened all three times. No overheating though. Could it leak out the waterpump and burn off somewhere??

The car is always garaged and have never seen any puddles. Have had the car just over a year now.

Yes, it could be leaking and burn off (evaporate). Have the cooling pressurized when cold and let it sit overnight. If there is a leak, it should show up.

Also you can send your old oil to a lab, which besides telling you how your oil and engine are getting along, will find even miniscule amounts of coolant in your oil and you can "head off" a problem (pun intended) before it gets bad.

www.blackstone-labs.com