Author Topic: 97 Deville Issues (Read 3147 times)

waterzap · « **on:** January 14, 2013, 12:13:24 AM »

In the process of getting rid of my 2000 Grand Marquis with around 140,000 miles on it. Great car, and overall have been happy with it. Had some issues, cracked intake manifold, front suspension, but all that has been fixed.

So went to look at a nice 97 Deville with around 40,000 miles on it. Always garaged, older lady drove it, first owner. Services always performed by the dealer. I checked the instrument codes, nothing came up. Oil looked fine, and they said they dont know about any oil usage.

Air suspension seems to work fine, compressor just came on once briefly before we started the car, so probably no leaks. Tires are less than a year old (Michelin). Car has been here all its life, not a spec of rust. Small scrape on the one side, maybe an inch long where the lady scraped the garage.

Test drove the car, and runs great. Fast, quiet, comfortable. Have read about some of the Northstar issues, just wondering with such low miles and good maintenance, what else should I look at? Are they very expensive to maintain?

The one issue the car does have, and the owner was honest, is that there is an electrical leak somewhere. Apparently the battery is new (Optima Red Top), and the alternator checks out. So something is draining the battery, so much that the car wont start after sitting for a week. Havent bought the car yet, but I can always disconnect the battery if I dont drive the car, and later see if I can find the short. I have a Power Probe short finder which might help. Any comments?

Dave Shepherd · « **Reply #1 on:** January 14, 2013, 11:30:33 AM »

The biggest issue with these cars is the great performing N'Star engine but plagued by oil leaks and oil consumption, Dex Cool should have been changed once already, same for the trans.

Eric DeVirgilis CLC# 8621 · « **Reply #2 on:** January 14, 2013, 11:31:29 AM »

...and head gaskets...

waterzap · « **Reply #3 on:** January 14, 2013, 01:46:10 PM »

Coolant was probably changed. They said the Cadillac dealer used to call up the lady to tell her to bring in the car for services. I cant believe they would not have done any and every service they could find.

Eric DeVirgilis CLC# 8621 · « **Reply #4 on:** January 14, 2013, 02:11:19 PM »

Sad part is even with coolant servicing, the head bolts still stretch resulting in gasket failure. No way around it. You can check the car till you're blue in the face and the gaskets can just fail just like flipping a toggle switch. Luck seems to have been with you on your '87 so maybe it'll continue. I wouldn't necessarily be afraid of it - provided the car is as mint as you say it is. I'd far rather deal with correcting mechanicals than cosmetics any time. Just be prepared, if the gaskets do fail, you're looking at a $2,000 bill or more. The good news is that once they're done properly with the updated kit, it should never be an issue again.

How much is this car anyway?

waterzap · « **Reply #5 on:** January 14, 2013, 03:05:25 PM »

, the intake manifold did fail on the 87. Not a big deal. Was pulling into a parking lot, saw the smoke under the hood, coolant spraying on the exhaust. Shut down the engine right away. Didnt overheat, coolant reservoir was still half full.

Got some more coolant, made sure the bottle was full. Had the car towed to the shop. $550 later, new intake manifold and new valve cover gaskets. There was no coolant in the oil, but changed that anyway. Drove the car 350 miles this last weekend. Didnt miss a beat. Got around 26 mpg, easily doing 70. After all the scary stories about the manifold, it really wasnt that terrible. The new one should last quite a while.

76eldo · « **Reply #6 on:** January 14, 2013, 03:11:14 PM »

Electrical drains are a pain.
I had one on my 99 Eldo and I think it may have been the trunk light switch.
My pull down failed a while ago and I set it up to stay in one position, closed, so the trunk shuts like an ordinary car.

It may have been too tightly closing, allowing the light to come on. You would have to see the switch for this to make sense.

In the personal program choices, there is a choice to select storage mode which eliminates some draw when he car is sitting. On my car it's explained in the manual.

40,000 pampered miles? If the price is right I would not hesitate.

These are great cars and although some experience head gasket issues, it's not all of them.
The head bolts don't stretch. The problem is that the aluminum threads actually pull out on the ones that go bad. That's why when they repair the engine, new thread inserts are installed. That's what fails. Been there, done it with my 99.

If you like it, buy it!

Brian

76eldo · « **Reply #7 on:** January 14, 2013, 03:14:03 PM »

DO check carefully for oil leak from the pan and block.
If its really wet under there which I doubt if its a garaged car (you would see oil stains) do not buy it.

Brian

waterzap · « **Reply #8 on:** January 14, 2013, 03:22:17 PM »

Thanks. Didnt see any oil stains. Asked them about it, and they also dont know of any, or oil usage. Would the information panel have shown anything like overheating ever?

Said "No Error Codes" or something like that. They were surprised you could even get the error messages :-) Car has been in this family since new and they didnt know the car could do that.

Eric DeVirgilis CLC# 8621 · « **Reply #9 on:** January 14, 2013, 06:58:47 PM »

Regarding the head bolts, the information given to me was that the head bolts would stretch resulting in head gasket failure.

Of the two N* head gasket failures I've dealt with, neither required new thread inserts which I understand is required in the vast majority of cases. Regardless of the cause, it's highly advisable that a N* under consideration be pressure tested and/or the coolant be tested for the presence of hydrocarbons (preferably).

Guidematic · « **Reply #10 on:** January 15, 2013, 10:29:59 AM »

The oil leak issues from between the upper and lower crank case was largely resolved. The engines built in 1993-1994 were the most susceptible.

However high oil consumption is an issue that plagued them all, right from the get go. But GM never recognised it as a problem, they just changed their oil consumption guidelines.

However, incorrectly checking the oil level can lead to higher consumption as well. The engine must have been shut off for 20 minutes so that the oil in the upper engine can properly drain back to the pan. If this is not done, a false reading will result. Adding an extra quart will result in excessive fogging in the crankcase, which is then burned off either through the PCV system, or by excessive wetting of the cylinders. Once the engine finds the correct level, then it will stop.

Mike

waterzap · « **Reply #11 on:** January 15, 2013, 12:00:06 PM »

Interesting, thanks

Quote from: Guidematic on January 15, 2013, 10:29:59 AM

The oil leak issues from between the upper and lower crank case was largely resolved. The engines built in 1993-1994 were the most susceptible.

However high oil consumption is an issue that plagued them all, right from the get go. But GM never recognised it as a problem, they just changed their oil consumption guidelines.

However, incorrectly checking the oil level can lead to higher consumption as well. The engine must have been shut off for 20 minutes so that the oil in the upper engine can properly drain back to the pan. If this is not done, a false reading will result. Adding an extra quart will result in excessive fogging in the crankcase, which is then burned off either through the PCV system, or by excessive wetting of the cylinders. Once the engine finds the correct level, then it will stop.

Mike

waterzap · « **Reply #12 on:** January 28, 2013, 01:28:24 PM »

So took the car out this weekend. Checked the coolant, and that looked great. Still will change it in the next few weeks. Just stay with Dexcool and change it out often?
Changed the oil. Very clean underneath too. Maybe wiped one stray drop of oil, but that was it.
Think it needs a new battery though. People said that the car â€œleaksâ€ electricity at night. I think the battery is just getting old. Around 5 years, hasnâ€™t been driven much. At night when I drive and tap the brakes, I can see the headlights dim every so slightly.
The DIC shows that the alternator puts out around 14 V. Battery migth just not keep a charge well anymore. With low mileage cars I have always had to replace the battery / and / or alternator. They just dont last sitting around.

This car has an Optima Red top battery. Never had good luck with the red tops. I think I went through three in a year when I had a Corvette. The Yellow top worked great. Red top not so much.

Eric DeVirgilis CLC# 8621 · « **Reply #13 on:** January 28, 2013, 02:28:27 PM »

Dexcool is said to be horrendous for internal corrosion protection. Suggest replacing with a Dexcool-compatible coolant.

A failing battery could easily result in the symptoms as described.

Looking forward to more pics when you get the chance.

waterzap · « **Reply #14 on:** January 28, 2013, 03:25:40 PM »

Which one is Dexcool compatable? Things like Prestone Long Life?
I can always just flush it out with water. 2 or 3 flushes should clear everything out to put new coolant in

Eric DeVirgilis CLC# 8621 · « **Reply #15 on:** January 28, 2013, 05:11:57 PM »

I usually just have a local Monro shop perform that service for ~$50.00. Much better % of coolant replacement than can be typically accomplished by the individual.

Most coolants today are compatible with both Dexcool and traditional- check the label. Prestone is probably as good as any.

*Have been told you should never use regular coolant on a car that had Dexcool in. Others may wish to elaborate.

caddyman20 · « **Reply #16 on:** February 01, 2013, 05:45:16 AM »

I need to look in my shop manual to fully recomend this but I'm pretty sure it says its ok to add the GM anti-freeze supplement stop leak pills to the antifreeze just like you have to do with the 4.1 powered caddys. I'll do this when I do a complete coolant change.. Not sure if it helps or not but I've currently got 4 nothstars running in my fleet and one of them has 245K on it and I've only had head gasket issues with one of them. And they're 96 and 97s so they're right in the bad years. I've got a 85 Eldo that I've had for years and never had any coolant leaks on that so I figure if the pills work for that problem child maybe it would help the northstar.. And for the record I've had excellent luck with the 4.1 and the northstar.. They're both great engines in my mind.

Eric DeVirgilis CLC# 8621 · « **Reply #17 on:** February 01, 2013, 08:59:23 AM »

Engine Coolant Suppliment is not recommended on the Northstar.

waterzap · « **Reply #18 on:** February 04, 2013, 10:54:15 AM »

Well, I donâ€™t think it was an electrical issue. Measured the current draw with everything off, and it was very low. 0.005 Amps or something.
Then checked the voltage drop on the negative. Also very low.

The belt was squealing, so changed that. Ran better, but still noisy. After that changed out the tensioner and idler pulley. Runs great now. Charges well, and no noises.
The tensioner and / or belt was so noisy I was scared of waking the neighbors.

Just going to replace the belt and tensioner on the water pump side too. Cheap insurance

What did you do / not do with the high mileage Northstars ?

David King (kz78hy) · « **Reply #19 on:** February 04, 2013, 12:02:49 PM »

When you change the coolant, make sure to ad in the sealing pellets. In the service manual, it describes how to do this. Unfortunately, the easy way is the wrong way. Remove the air intake box to expose the lower radiator hose, remove the hose and put the pellets in there so they are drawn into the block.

These pellets are very important in this engine design, not using them is the cause for many of the failures attributed to the northstar engine.

David