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1996 Eldorado
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8 Posts
Discussion Starter #1
I purchased a 96 Eldorado recently with only 25,000 miles on it. It was owned by an elderly couple who passed away sometime back and I purchased it through their son. Besides needing a blower motor and tires, the car is in great shape. When I brought it home, I made sure that I flushed the coolant and replaced it with the dexcool and the GM pellets as required, and changed the oil. I started doing some research recently when I was having trouble with the blower motor, and I came across several articles and forums discussing head gasket issues. What I have read makes me wonder if hanging on to this car is a bad idea, but I like it. I do know, that I don't have the stash of cash to repair it if the head bolts pull. Now is there anything I can do extra besides maintenance to help it's longevity? Are the odds that great that it will fail? Certain mileage when and if it fails? Any advise is greatly appreciated. I do like to drive it a little hard too because it is a fun car.
 

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2002 ETC
2002 ETC Crimson pearl
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36 Posts
GM doesn't recommend those pellets anymore. Most of use including myself do not use them. There is a ton of great information and very knowledgeable people on this site. Start reading.
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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18,864 Posts
the problem with a 24 year old car with only 25K miles
is that EVERYTHING - except gas and oil - is probably original -
ALL fluids SHOULD be replaced - particularly the BRAKE FLUID -

the head gaskets MIGHT fail the next time you drive it -
OR - they MIGHT last another 500,000 miles without an issue -
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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66,972 Posts
Yup - "longevity" is like any other motor vehicle on earth. It might blow up tomorrow morning or not until 2050.

The use of the coolant supplement tablets as part of normal coolant maintenance was discontinued in 2006. The service manuals and radiator cover stickers were never updated. The coolant tablets caused small passage and purge line blockages, leading to overheat events. and MANY "head gasket" false alarms.

You need to study all the stickies, marked with a push pin, in any forum of interest - timeless info.

While you're at it, study this, written by a CF member who was a GM/Cadillac Northstar Powertrain engineer. Applies primarily to the pre-2000 Northstar System, but is good info for ANY Northstar engine owner.

 

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1996 Eldorado
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8 Posts
Discussion Starter #5
Excellent, thank you guys. Do you recommend I flush the coolant again, this time without the tablets, or wait until its next interval?
 

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Registered
Too many...
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878 Posts
Get rid of the Dexcool, just a matter of time before it turns to sludge, absolutely no need for it. As far as longevity, my '99 has 220k hard miles on it but still enjoys frequent WOT runs, purrs like a kitten. Headgasket failure, head bolts failing - whatever you want to call it - is only a matter of time. My time was around 150k. Went with the Huhn inserts and haven't looked back. YMMV.
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,242 Posts
Excellent, thank you guys. Do you recommend I flush the coolant again, this time without the tablets, or wait until its next interval?
Just wait until the next time you service the coolant.

As for longevity, the '99's seemed to be the worst for HG failure followed by the '98's.
Click "View Results" on the survey from this forum in the link below.


P.S.
Nothing wrong with Dex-Cool. It plays no part in HG failures.
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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18,864 Posts
Get rid of the Dexcool, just a matter of time before it turns to sludge, absolutely no need for it. As far as longevity, my '99 has 220k hard miles on it but still enjoys frequent WOT runs, purrs like a kitten. Headgasket failure, head bolts failing - whatever you want to call it - is only a matter of time. My time was around 150k. Went with the Huhn inserts and haven't looked back. YMMV.
============================
Get rid of the Dexcool, just a matter of time before it turns to sludge, absolutely no need for it.
absolutely NOTHING WRONG with DexCool -
and NEVER EVER heard of it "turning to sludge" -
 

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2000 Eldorado ETC
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6 Posts
I have a 2000 Eldorado ETC that I bought in 2014 for 4k w/54k. The car is a pleasure to drive and enjoy it immensely. This is the 1st Cadillac I've owned and it was 14 yrs old when I got it, thru the advice and reading on this forum I did all the maintenance, ie fluid changes, vacuum lines, crankshaft/camshaft sensors, spark plugs/boots, all coolant lines, all power steering lines, intake gaskets and plenum, water pump and drive assy, thermostat, fuel filter, new brake pads, new tires and a host of other things. I now have 95k on the car, it uses 1/2 qt of syn oil in 3k mi, I would be disappointed if it didn't use any. I don't baby the car and on occasion do the WOT, use top tier gas and don't use any additives in the eng or gas tank. I need to replace the front struts sometime in the near future, but other than that she purrs like a kitten. Now having said all this I do carry the cars title in the car in case of the dreaded head bolt failure when far away from home that I might get rid of it for something else!
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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66,972 Posts
Absolutely NOTHING wrong with (the mid-2000s reformulated) DEX-COOL. Just as with any other coolant, change it religiously at or before its recommended time.

DEX-COOL sludge ???? Never did, never has. The discontinued sealant tablets, maybe. Here's 4 year old 50/50 DEX-COOL out of my STS - see any "sludge" ??? What's in there right now looks exactly the same.

2 quarts coolant 3.jpg
 

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1996 Eldorado
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8 Posts
Discussion Starter #11
Well..I definitely feel more at ease that I'll get some time out of it. I appreciate the replys guys. Reading through the surveys, it is interesting that 97 to 99 seem to be the poor souls
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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66,972 Posts
If you really dig deep into the stickies in Seville, Deville, and Engines, Northstar (all marked with a push pin) you'll eventually run across the discussions on engine block metallurgy and casting procedures that had several changes through the mid-late 90s. Way back when, AJXTCMAN (an inactive member and Cadillac Dealership Shop Tech), posted a slew of pictures of porosities, ash pits and voids in some Northstar block head bolt holes.
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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66,972 Posts
I wouldn't lose sleep over the remote possibility of cylinder block head bolt hole thread failure - which causes loss of bolt clamping pressure leading to exhaust gas past the fire rings which erodes the soft gasket material.

Your 1996 is more likely to need chassis suspension, cam. cam follower, and timing gear inspection for worn parts.

That flat tappet style engine needs the extra protection offered by the 10W-30 fleet and marine oils, with their extra anti-scuff additive packages. Your engine was designed and built almost 25 years ago - since then the EPA has mandated lowering the zinc and phosphorus (anti-scuff) levels in later engine oil formulations. Not good for the older engines.

Now you can embark on the ZDDP oil wars. Always fun and filled with falsehoods, fancy, fact, and hearsay. Note how the levels have dropped since your engine was specified for oil usage ...........We're now into SN (Plus) ...........

ZDDP levels.jpg
 

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1996 Eldorado
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8 Posts
Discussion Starter #15
Oh I'm familiar with oil debates on the Harley Davidson forums lol. I did use the recommended 10w 30 dino, but whatc10w 30 do you recommend?
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
Joined
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86,242 Posts
I run Rotella T5 10W30 in my '69 Road Runner. Should work pretty well in your '96 Eldo as well.
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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66,972 Posts
Yup ^ ^ ^

Pennzoil, Chevron, Gulf, Quaker State, Shell - all make "HD" 10W-30 conventional and blend fleet and marine engine oils.

I see by your other thread reply that you're back from the past. Welcome !!! same 1996 Eldorado that was "owned by Grandma" ?

 

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Registered
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20 Posts
I purchased a 96 Eldorado recently with only 25,000 miles on it. It was owned by an elderly couple who passed away sometime back and I purchased it through their son. Besides needing a blower motor and tires, the car is in great shape. When I brought it home, I made sure that I flushed the coolant and replaced it with the dexcool and the GM pellets as required, and changed the oil. I started doing some research recently when I was having trouble with the blower motor, and I came across several articles and forums discussing head gasket issues. What I have read makes me wonder if hanging on to this car is a bad idea, but I like it. I do know, that I don't have the stash of cash to repair it if the head bolts pull. Now is there anything I can do extra besides maintenance to help it's longevity? Are the odds that great that it will fail? Certain mileage when and if it fails? Any advise is greatly appreciated. I do like to drive it a little hard too because it is a fun car.
I had a 97 Deville with the Northstar V8. I'm presuming the Eldorado has the same engine. But, the head gasket failed and it was a big deal to get it fixed. It took a week. With deep dealer discounts, I still shelled out $1,300 and that was back years ago. Once it was fixed, the car lasted for 200K, as I recall. There is a video somewhere - maybe on YouTube - showing the woefully inadequate bolts with very fine threads. They simply stripped out.

So, in a nutshell, mine failed. It was fixed. The repair was solid. I didn't have any additional problems thereafter and I drove the car hard for 200K miles. You asked when it happened. I'm thinking around 75K but I can't swear to that. My recollection from other owners was that there wasn't really an average time. It was all over the place.

Something else I read - apparently there are a bunch of these cars of this era with this problem that are in sterling condition and are very affordable. BUT, that soon-to-fail engine is what is killing the price. No one wants the bill which I think I read is $4,000 (?) - someone should confirm that - to fix the head gaskets.

Good luck!
 
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