: Hot Hot Hot !!!!



MUGSANDLUKE
08-17-06, 04:01 PM
:( :confused: Desperate for an answer. I have a Deville DHS year 2000 with 75,000 miles. The springtime brought a new problem - the engine is overheating under any load at all. The temp guage jumps up in large increments while cruising at a steady pace for no reason at all. I found that with the A/C off the problem seems to dissappear and the temp guage stays dead center as it did when the car was first purchased. The dealer has changed the thermostat unit in its entirety, the water pump, the belt and has checked everything that can be checked. They say they now think the radiator may be clogged and they are going to change that too.:bang2: I wonder if it might be an electrical screw up that is causing the problem. The fans come on at the right temp, the computer lets me know that it's running hot and shuts the A/C off when the temp rises. It then tells me to idle the engine since its too hot to run and the oil light comes on with a message to change the oil. The dash looks like a Christmas tree when all the lights and messages are on. I'm stuck!:rant2:

Does anyone have any suggestions as to where this problem is located? I cannot drive the car anywhere without the fear of overheating.:mad:

Help Help Help Hot Hot Hot !!!!!!:mob:

Ranger
08-17-06, 04:45 PM
Have you checked for a plugged purge line?

dkozloski
08-17-06, 05:24 PM
Does it boil and spit out water? The gauging system may be lying to you.

EDBSO
08-17-06, 07:58 PM
The gauging system may be lying to you.

switch out the temperature sending unit.

Do the fans turn on to high as it heats up over 226 or something like that?

codewize
08-17-06, 09:48 PM
I love Christmas :bigroll:

Sorry I just had to.

MUGSANDLUKE
08-18-06, 12:03 PM
Thanks for the replys guys! The lines have been checked for plugs and are OK. The flow rate is very high and is operating as it should. There is a new water pump and new thermostat assembly. The coolant does boil out so the guage is not lying. The dealer says the temp went beyond 260 and the engine was running hot as the guage indicated. They will be installing the new radiator today. Any other suggestions would be appreciated but we have no other answers right now.

MUGSANDLUKE
08-18-06, 12:06 PM
PS - I love Christmas too but not while pulling over to the side of the highway with coolant running out and smoke billowing from the engine compartment. Hard to think of jolly old St Nick when you're thinking of jolly old tow truck driver.

dkozloski
08-18-06, 12:32 PM
If the radiator doesn't do the job the next step is a cylinder air pressure test for a blown head gasket. I just thought I'd make your day for you.

MUGSANDLUKE
08-18-06, 12:38 PM
Swell! Thanks! I feel much better now! I'll keep you posted as it goes along. Fortunately I have the extended warranty in place. All it costs me is aggrivation and time. At least I have another vehicle to use. I have a 1998 Lincoln Navigator that I bought new in 98. It now has 289,000 miles on the original engine and tranny and it runs like new. I tow a 6,000 lb boat and trailer all summer each year as well. What have I done to deserve this Caddy headache? I hope it gets resolved because I love to drive this car.
Frustrated!

MUGSANDLUKE
08-21-06, 08:08 PM
Oh Well! The radiator change did not help. Still runs hot. On to the next step whatever that is. The guys are still working on what to do next. The saga continues!

blb
08-22-06, 09:15 AM
What have I done to deserve this Caddy headache? I hope it gets resolved because I love to drive this car.
Frustrated!

Ah, welcome to the 'Northstar Headgasket Heartache', unfortunately very common on these engines. Figure on a $3000 to $4000 repair bill if the leakdown test confirms a failed headgasket, more if the dealer does the job.
These cars are fun to drive, but can be a nightmare to own.

dkozloski
08-22-06, 09:40 AM
The next step is a cylinder leak test with compressed air applied to the spark plug holes and look for air coming out the coolant cap.

JimHare
08-22-06, 12:13 PM
Ah, welcome to the 'Northstar Headgasket Heartache', unfortunately very common on these engines. Figure on a $3000 to $4000 repair bill if the leakdown test confirms a failed headgasket, more if the dealer does the job.
These cars are fun to drive, but can be a nightmare to own.

Won't add much to the discussion, but I have to respectfully disagree with your use of the words "very common" in the above post. HG failures are not "common" on the Northstars, they're just well publicized here on the forum, and the Northstar is no different than any other all-aluminum engine when it comes to the probability of a failure of this particular weak link in the system.

90+% of all failures can be traced to a lack of coolant maintenance which causes the corrosion that erodes the HG material. This is NOT to say that the occasional 'newer' car doesn't have a HG failure, but the statistics are straightforward. There are probably about 7-9 million Northstars still on the road in various cars from 1993 to 2007. Perhaps 2% have had HG failures. I was talking to a relatively high volume dealership about a month ago, and asked the service manager what he thought about it. He said he's seen about 10,000 Caddys go through his shop in the last decade or so, and less than 30 HG replacements, as far as he can remember. And most of them were on cars with over 100K on the clock.

The big noise when a Northstar fails is due to 1) the high cost of the repair - partly because of high dealer rates, partly because of the complexity of the engine itself, and 2) Caddy owners will squawk at a HG failure more commonly than the typical car owner - and that's not necessarily a bad thing.

This, and any other online forum, can not be used as a gauge for determining failure rates of any particular system, simply because people who have had failures gravitate to these forums. I've stated it elsewhere, you can't judge the noise on here as indicative of the general population, any more than you can by going to a hospital and saying "jeeze, everyone in this town is ill..."

blb
08-22-06, 01:08 PM
......the Northstar is no different than any other all-aluminum engine when it comes to the probability of a failure of this particular weak link in the system.

Sorry, the above statement is just not true. Compare the GM Northstar to the GM LS1 / LS6, etc. where a headgasket failure is almost unheard of.

The junkyards around here a great selection of nice looking Northstar equipped Caddys with bad headgaskets that people have junked because the cost to fix is more than the car is worth. One yard uses a '96 Deville without a trunk lid as a parts chaser because it can run awhile before it goes into limp home mode because of the lack of coolant. It has become the laughing stock of the yard. Ayone who thinks the Northstar headgasket issue is a rarity just needs to take a look in a junkyard or talk to a wholesaler and they will quickly discover why resale values are so low.

JimHare
08-22-06, 03:42 PM
Sorry, the above statement is just not true. Compare the GM Northstar to the GM LS1 / LS6, etc. where a headgasket failure is almost unheard of.

Ok, but a different head bolt design, too. Perhaps lessons were learned from the early Northstar?



The junkyards around here a great selection of nice looking Northstar equipped Caddys with bad headgaskets that people have junked because the cost to fix is more than the car is worth. One yard uses a '96 Deville without a trunk lid as a parts chaser because it can run awhile before it goes into limp home mode because of the lack of coolant. It has become the laughing stock of the yard. Ayone who thinks the Northstar headgasket issue is a rarity just needs to take a look in a junkyard or talk to a wholesaler and they will quickly discover why resale values are so low.

I still maintain that for every Northstar in a junkyard due to HG failure there are a hundred of the same vintage on the road. Hell, around here, you can't trip without falling over a 90's Deville, Seville or Eldorado. I was talking to a guy the other day with a 94 Eldo, he showed 215K on the clock and said the car still ran like snot...

Anecdotal evidence just isn't conclusive - you need to look at the total numbers.

And re your 96 Deville parts chaser - it may be the laughing stock of the yard, but they aren't using an LS1 engine, are they???

Perhaps we can just agree to disagree - it's more a matter of semantics anyway.

HITMONEY
08-22-06, 04:05 PM
Dollars to doughnuts its a head gasket.

:(

blb
08-22-06, 05:49 PM
.

90+% of all failures can be traced to a lack of coolant maintenance
"

....another unsubstantiated, unproven statistic! All of the coolant maintenance in the world won't prevent the headbolt threads from being pulled out of the porous aluminum block. Timeserts are specified for the repair precisely because of this issue. The change to the more coarse headbolt thread around model year 2000 was supposed to address this issue but the headgasket/block thread issues continue through at least model year 2002.

I guess the quote above will make some owners feel more secure if they believe that those with headgasket failures only have themselves or previous owners lack of maintenance to blame.

blb
08-22-06, 05:59 PM
And re your 96 Deville parts chaser - it may be the laughing stock of the yard, but they aren't using an LS1 engine, are they???


Ughhhhh.....no.......'96 Devilles are FWD and use the Northstar. The LS1 was used in GM RWD platforms such as '98 through '02 GM F bodies (Camaro/Firebird) and late 90's Corvettes through the early 00's until the LS6 began being used. (same basic design as the LS1 with some improvements)

blb
08-22-06, 06:03 PM
Dollars to doughnuts its a head gasket.

:(

Unfortunately, for MUGSANDLUKE, the facts are really starting to point in that direction. Sounds like they eliminated all the easy potential causes.

JimHare
08-23-06, 11:50 AM
Ughhhhh.....no.......'96 Devilles are FWD and use the Northstar. The LS1 was used in GM RWD platforms such as '98 through '02 GM F bodies (Camaro/Firebird) and late 90's Corvettes through the early 00's until the LS6 began being used. (same basic design as the LS1 with some improvements)

What I meant was that the junk yard ISN'T using an LS1-Engined car as their parts chaser - they're using a "junker" that will run back and forth for 50 miles without any cooling.

I am fully aware that the 96 Deville is FWD with the Northstar. I am also fully aware that the LS1 and LSx engines are used in GM RWD vehicles.

MUGSANDLUKE
08-25-06, 12:45 PM
Well guys, here's the update as of today. The leak test showed no leak anywhere, anyhow, anyway. The head gasket appears to be 100% ok according to the shop. I know you won't believe this, as I am having trouble believing it myself, but the shop guys are telling me all their tests led to a bad radiator cap. It was releasing fluid at 15 lbs or less and once the fluid went down at all, the air in the system caused the overheat situation. They have installed a new GM OEM 18lb cap, and have driven it for three days without any incidence of overheating. I am picking it up today to give it my own acid test and drive it hard. I will let all of you know the outcome in a day or two. Wouldn't it be crazy if that's the answer after all the replacements, radiator, pump, thermostat etc. We'll see. GM has a notice about bad radiator caps in their system, but it just sounds too simple to me. I still lean toward the H.G. problem but it can't be found to be defective after all the tests were done. Any more ideas guys? Wish me luck after I pick it up. I'll call everyone from the side of the road while the smoke billows up out of the engine compartment and I boil over as well.

dkozloski
08-25-06, 01:41 PM
Even the blind hog finds an acorn once in a while.

Cadillacboy
08-25-06, 04:07 PM
As I recall, bad caps lead to some amount of loss of coolant for a certain amount of time .I wouldn't be confused with it .Anyway I am happy for you , nothing seems wrong .

Ranger
08-25-06, 06:51 PM
You are leaning towards HG's because you have a bad case of internetformitis. Happens to us all. When the purge line nipple on the surge tank developed a hairline crack on my '97, I never noticed the ever so small leak as it evaporated before it dripped, til one day I got the Check Coolant message. My heart sank as I was sure it was a HG.

Elmer Fudd
08-25-06, 10:20 PM
Super good news mugs.... hate you had to spend al that $$$, but look on the bright side. Now you ahve a virtually new cooling system :)

MUGSANDLUKE
08-26-06, 11:51 AM
Time to fish or cut bait! The radiator cap easy fix did not work. The engine comes out this week for a head gasket change and they are going to send the heads out to be re-worked as long as they are off the engine. There is a slim chance that the insurance guys may opt to put in a new engine instead but we have to wait and see this week. It has finally come to this after all the time, cost and agrivation. If the next repair doesn't work there will be nowhere to turn. I'll let you all know after the repairs are done. Thanks to all of you for hanging in there through all of this nonsense.

MUGSANDLUKE
08-26-06, 11:59 AM
Just one last point for advice that I would like to have. What is the general opinion as to whether or not a new engine is a better way to go than the head gasket repair and associated repairs done at the same time? Am I better off with rebuilding the existing engine and head gaskets etc., or am I taking a chance of also having problems with a new engine? It may come down to a decision. If the engine has to be swapped out, can a 300 HP version from a DTS be installed in place of the 275 HP N* that's in the DHS now? Just asking for some food for thought here in my desperation.

Ranger
08-26-06, 04:14 PM
No, you can't swap engine models. 300 hp uses a 3.71 final drive and the 275 hp uses a 3.11 not to mention different PCM's.

Are you talking about a brand new motor or a junk yard replacement. If you are talking about a junk yard replacement, you are trading the devil you know for the devil you don't. There is almost never a need to rework the heads. Just be sure that the block is Timeserted and the repair should last forever if done properly.

zonie77
08-26-06, 06:19 PM
No, you can't swap engine models. 300 hp uses a 3.71 final drive and the 275 hp uses a 3.11 not to mention different PCM's.

Are you talking about a brand new motor or a junk yard replacement. If you are talking about a junk yard replacement, you are trading the devil you know for the devil you don't. There is almost never a need to rework the heads. Just be sure that the block is Timeserted and the repair should last forever if done properly.



DITTO

mmayer
08-28-06, 03:25 AM
I am having almost all the same symptoms with my 98 STS as mugsandluke is having although my troubleshooting might be a little different since I replaced the radiator and cooling fans 5 months ago. Not because of an overheating problem, but I did the engine mount and the car had 115k on it. Recently the car ran hot and I found a bad t-stat. Now it has not ran that hot again but it still runs up to about 5/8 on the temp guage and I am getting a little coolant boil off on the surge tank. Today I am going to order a surge tank hose, water pump, belt and tensioner. Any advice, I am getting tired of draining this coolant!

STS-in-Nottingham
08-28-06, 05:06 AM
Replace the surge tank cap also.
If the cap is not holding it's pressure, the engine will overheat.
With any luck, this may be the problem,
So change the cap first before spending money on a new pump etc..

mmayer
08-28-06, 12:52 PM
I replaced the cap with a GM one. I called today to order the parts and the parts guy asked me if I also wanted the housing or just the pump. I called the service writer at the dealership I used to go to and he said it would probably be a good idea. What's everyone else think? The car has 125k and I have suspected for some time there was someplace air was getting in the cooling system. Could that be an indication of a bad housing?

MUGSANDLUKE
08-28-06, 03:43 PM
I only hope you don't have to go through the same routine I have been involved with for some time now. If you read back through the messages here you will find that I have had everythying replaced except the air in the tires and I still have an overheat problem. We are now at the end of the experimental road and have come down to the realization that the heads have to come off and new gaskets put in, with Timeserts for the bolts. If this doesn't work it's going to be a real bad scene at the repair shop.

Maybe you'll be luckier than I have been and yours will be fixed with a simple cap and housing change. I'll keep my fingers crossed for you. Just let us know how it turns out and I'll do the same. I'm getting very tired of not having this car on the road. My other vehicle, Lincoln Navigator, runs fine at 285,000 miles but costs big dollars in fuel use. I bought the Caddy to get away from the gas guzzling but it's been in the shop more than in my garage. It's a great car to drive when it runs OK. I'm hoping this will be the end of my nightmare and hopefully yours will get resolved quickly. I'll let you know how it goes.
Frustrated........................
Steve

STS-in-Nottingham
08-28-06, 03:58 PM
Can you smell exhaust fumes in your surge tank?

Take the cap off and have a good sniff!!

mmayer
08-28-06, 04:16 PM
I do not smell exhaust fumes from the surge tank and there is no bubbling upon cold startup. Three weeks ago I did an oil analysis and it showed up negative for glycol in the oil. Tomorrow I am going to a "five gas analysis" and if that shows up negative I am going to go ahead with the water pump. Any other ideas please let me know. Thanks.

Ranger
08-28-06, 05:10 PM
The water pump will not cause it to overheat as long as it is turning. When they fail, it is usaully a leak. Save your money if it is not leaking. Check the purge line & thermostat.

MUGSANDLUKE
09-03-06, 06:19 PM
Still waiting for my car. the engine is not out yet and therefore no news about the head gasket. Just keeping you all up to date with my nightmare.:thepan:

MUGSANDLUKE
09-03-06, 06:23 PM
didn't know there was a right hand drive version of the Caddy. Very cool! Hope you are having better luck than I am. (just read back throught the comments in this thread).

Aboslutely fascinated by the fact that you're driving a right hand verison of that Caddy in the U.K. Best of luck!

STS-in-Nottingham
09-03-06, 06:46 PM
didn't know there was a right hand drive version of the Caddy. Very cool! Hope you are having better luck than I am. (just read back throught the comments in this thread).

Aboslutely fascinated by the fact that you're driving a right hand verison of that Caddy in the U.K. Best of luck!


They were sold between 1998 and 2001 in the UK, not many were sold due to poor promotion,
The only advert I ever saw at the time was in a golfing magazine!!
Cadillac are back in the UK in the form of CTS and the slightly smaller BLS which is in fact a Saab,

Also, all other American cars are available in the UK via specialist car dealers.

dkozloski
09-04-06, 12:28 AM
The only thing better than a right hand drive would be a student driver version with dual controls.

MUGSANDLUKE
09-04-06, 10:25 AM
Excellent! I may have to come over just to see it and try driving it around town. Thanks for the reply. Have you had any problems with the car? Hope not. They are great vehicles as long as you can find someone capable of working on the N* engines. I am still fighting with the overheat problem but I have my fingers crossed that they will fix it this time by pulling the engine and replacing the heads or the whole thing once and for all. Speak to you again soon.