It Happened,the dreaded overheat!
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 16
Northstar Engines and System Technical Discussion Discussion, It Happened,the dreaded overheat! in Cadillac Engine Technical Discussion; I thought I would be able to drive it('99 Deville) for a while even though I was losing coolant. I ...
  1. #1
    Quadrasteer is offline Cadillac Owners Fanatic
    Join Date
    Jun 2004
    Posts
    167

    It Happened,the dreaded overheat!

    I thought I would be able to drive it('99 Deville) for a while even though I was losing coolant. I filled it every three days and all was fine. Until last night in the pouring rain on the Palisades Parkway, message came on that said engine overheat. Stuck, dead in the right hand lane. What happened to my limp home mode?? First it said idle engine, which I did. The temp went down slightly so I put her in gear and drove off. A few seconds later the overheat message came on and I shut it down. God I love GM cars!!

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    1996deVille is offline Cadillac Owners Member
    Join Date
    Feb 2005
    Posts
    74

    Re: It Happened,the dreaded overheat!

    Quad,

    If you'd gone just a few more miles you'd have gotten the "disposal mode" warning on your dash! This is calculated to go off at the point where the trade-in value of your vehicle reaches the cost of having to pull the body away from the car to replace $50 worth of head gaskets...

    Had I known the actual cost of keeping these cars running I'd have gone about the purchse much differently. Buy it at about 20K and trade it in just before 50K, or 2 years. My cost over time would have been less than the $$$ spent over the same time with an older car - my 14K used vehicle has cost me about 20K - I should've put the 6K in on the front end and gotten rid of the car at two years... my bad!

    Hope springs eternal - my '79 deVille did the same thing to me... I'm waiting for my dash to show, "fooled you twice..."

  4. #3
    BeelzeBob's Avatar
    BeelzeBob is offline I'm a Cadillac Fanatic!
    Join Date
    Dec 2002
    Location
    Fort Lauderdale, Florida
    Age
    49
    Posts
    9,577

    Re: It Happened,the dreaded overheat!

    You never got it hot enough to reach the limp home mode of operation. If you had just kept driving it would have gotten hotter and would have reverted to the limp home mode and it would/could have limped home.....

    Stopping like you did certainly put the least overheat stress on the engine but, given it's past history, stopping was kind of pointless. I would have kept driving it until the limp home mode engaged and then kept on limping it to a safe/convenient place.

  5. #4
    97BlueDeville's Avatar
    97BlueDeville is offline Cadillac Owners Member
    Automobile(s): 06' DTS
    Join Date
    Sep 2004
    Location
    Aurora, CO
    Age
    39
    Posts
    65

    Re: It Happened,the dreaded overheat!

    I must Say the Limp Home Mode got me off ther Hywy 2 times on my Headgasket problem.. Good design the limp home mode is.. BBob, it seems like the injectors go twice the duty cycle, err run very rich to help cool down the heads and engine, correct? I'm sure it also retards the timing, wont allow it to go over 2000 rpms or so. All these conditions help keep the motor as cool as possible...

    Clint

  6. #5
    maydog's Avatar
    maydog is offline Cadillac Owners Fanatic
    Join Date
    Jan 2003
    Location
    Minnesota
    Posts
    319

    Re: It Happened,the dreaded overheat!

    I would be a little hesitant to "limp home" on a headgasket overheat. Isn't it possible for coolant to get into the oil and start wreaking havoc on the bearings?

    Limp home did save me a tow when my wife's aurora's water pump belt broke. Its a nice feature, but I would not care to drive too far like that.

  7. #6
    BeelzeBob's Avatar
    BeelzeBob is offline I'm a Cadillac Fanatic!
    Join Date
    Dec 2002
    Location
    Fort Lauderdale, Florida
    Age
    49
    Posts
    9,577

    Re: It Happened,the dreaded overheat!

    No, I'm not suggesting "driving" it anywhere of any distance in limp home but getting off the freeway or to a safe spot is what it is designed for.

    The Northstar is not likely to put coolant into the oil even if a head gasket fails competely due to the design of the engine. There are no adjacent coolant/oil passages for crossleaks to occur.

    The limp home mode does several things. It activates when it sees temperatures in the cylinder head that are indicative of a dry cooling system that is boiling and exceding the threshold of a "wetted" engine. The system shuts down 4 the injectors on 4 cylinders allowing them to cool themselves by pumping air while the other 4 motivate the car. Then the cycle alternates and the other 4 cylinders pump air and cool while the resting cylinders run the car. The power is SIGNIFICANTLY reduced so the car will barely maintain 55 MPH even in the best of circumstances...but...it beats walking and/or destroying the engine. The 4 cylinders that are running are ruch to help reduct temps as much as possible and the spark is retarded significantly to prevent detonation. The idle speed control/idle air control automatically bumps the idle speed way up to prevent stallling and the cooling fans are help on max high to push as much air thru the engine compartment as possible. The oil assumes much of the cooling duties in the limp home mode so the oil should be changed immediately after a limp home mode event.

  8. #7
    weister42 is offline Cadillac Owners Enthusiast
    Automobile(s): 1998 Cadillac Deville Sedan
    Join Date
    Feb 2005
    Posts
    897

    Re: It Happened,the dreaded overheat!

    Just my curiousity, is the N* very expensive to replace the head gasket? When will it tend to blow/how to I prevent such a thing from happening?

  9. #8
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,331

    Re: It Happened,the dreaded overheat!

    About the only thing you can do to help prevent it is change the coolant every 4-5 years (Dex-Cool) and 2-3 years (green). Other than that, if it's gonna go, it's gonna go. I've heard $3000-$4000 to change them as the drive train has to be dropped and the block Timeserted.

  10. #9
    1996deVille is offline Cadillac Owners Member
    Join Date
    Feb 2005
    Posts
    74

    Re: It Happened,the dreaded overheat!

    Weister42,

    Good question, really... I've got 114K on my '96. The car is basically worth nothing at this point, even for trade-in value.

    So, if your car is in perfect shape, no dents, interior still looks new, you may find the value built back into the car if you drive it another 100K after a set of new head gaskets. But, while you have the body pulled away from the engine to get to the $100 worth of head gaskets, you have a rare opportunity to get to ALL of the problematic parts.

    I'd rebuild the A/C while you have access. $500, or so for parts. I'd replace the alternator at this point as well. Another $150, or so. Now'd be the time check the radiator and electric fans and replace as necessary. I'd do the blower motor at this point, as well, another $300, or so. Cabin filter could be done, too. You get the point...

    The tranny, well, your choice, but at 100K it is probably due for some work. The cost of that depends on what is needed to bring it back to a like new condition.

    I'm guessing I'd be spending around 2K on parts alone if I did ALL the work. If it is done for you, 6 to 7K. But, the drivetrain is ready for another 100K.

    My car has too many nagging electrical problems to make this all worth while - the jobs mentioned above would take quite awhile if you did them in your garage... and then when you factor in your time to do all of these things, well, there's the real cost...

    I made a very basic mistake when I bought my car. I should've put the 6K on the front end and driven the car for two years and traded back at about 50K. The best part of 100K on these cars is the first 50, not the last 50!

    My bad, I won't make this error again!

    Much sucess!

  11. #10
    growe3's Avatar
    growe3 is offline Cadillac Owners Enthusiast
    Automobile(s): 1993 STS and 2004 DTS
    Join Date
    Oct 2003
    Location
    Cameron Park, CA
    Posts
    564

    Re: It Happened,the dreaded overheat!

    Quote Originally Posted by weister42
    Just my curiousity, is the N* very expensive to replace the head gasket? When will it tend to blow/how to I prevent such a thing from happening?
    A dealership will charge about $4,000 to repair both headgaskets.

    The parts and usually replaced items, including the Timesert kit, will cost about $900. Labor is the big expense for this job.

    See the attached PDF for a look at the costs I put out for my 93' STS, yours would be very similar.

    -George
    Attached Files

  12. #11
    maydog's Avatar
    maydog is offline Cadillac Owners Fanatic
    Join Date
    Jan 2003
    Location
    Minnesota
    Posts
    319

    Re: It Happened,the dreaded overheat!

    I was quoted $2200, to do both headgaskets from a reputable Caddy dealership.

  13. #12
    growe3's Avatar
    growe3 is offline Cadillac Owners Enthusiast
    Automobile(s): 1993 STS and 2004 DTS
    Join Date
    Oct 2003
    Location
    Cameron Park, CA
    Posts
    564

    Re: It Happened,the dreaded overheat!

    Quote Originally Posted by maydog
    I was quoted $2200, to do both headgaskets from a reputable Caddy dealership.
    $2,200 is a very good price, if it includes Timeserting ALL twenty head bolt holes and the other common worn out items, including the usual oil pan seepage.

    At that price I may have elected to have mine done by a dealer, as it was no one even came close to that price; so I did both of my cars myself.

    -George

  14. #13
    dkdoob's Avatar
    dkdoob is offline Cadillac Owners Member
    Join Date
    Apr 2005
    Posts
    9

    Re: It Happened,the dreaded overheat!

    I had mine done on a 95' Eldo for $4,000 with new time-serts at a reputable Caddy dealership. 3500 miles later a rear bolt pulled out. And I paid $7000 for a new Northstar. Get a warranty in writing. I think I am headed to small claims court.

  15. #14
    maydog's Avatar
    maydog is offline Cadillac Owners Fanatic
    Join Date
    Jan 2003
    Location
    Minnesota
    Posts
    319

    Re: It Happened,the dreaded overheat!

    The $2200 was only a quote, but I called an independent shop and they quoted me $2300 for the same job. The book time on headgasket repair is 20 hours, so I figure 20 hours at $100 dollars an hour and $200 dollars in parts could be close.

    They may not have included the timserting in the quote? Timeserting may bring the total closer to $3000.

    I found a cheaper option, a salvage yard engine for $1500 and a local wrench to install for $300 - we will see how that goes

  16. #15
    Multi Caddi's Avatar
    Multi Caddi is offline Cadillac Owners Member
    Join Date
    Oct 2004
    Location
    Hampshire, UK
    Posts
    9

    Re: It Happened,the dreaded overheat!

    Over Heat ? but not headgasket ??
    Calling bbob + Other experts Can you assist ...99 STS 67K miles runs fine around town, temp guage is at "12oclock" normal but run it down the motorway at 80+ and the temperature suddenly goes up round to the red slow down to 60 and it cools down back to normal doesnt happen every time some times a motorway trip will be fine.

    When it did boil I pulled of the motorway stopped the engine and very slowly released the expansion cap at first not much happened then there was gurgling then hot water found its way to the expansion tank and bubbled up, i tightend the capslightly to prevent water loss but allowed steam to escape, after retightening the cap went back on the motorway, engine temp perfect, this currentl happens about every 2/3 journeys

    Starts and runs good, no oil in water, its clean , Oil is perfect, water pump an dthermostat replaced,radiator removed, endcaps removed passages cleaned, fans all operating, at the correctspeeds relay all ok !

    The exp cap is often leaking steam after a run, I supect that exhaust pressure is getting into the water jacket and over pressuring the system at high speed!
    Any Ideas ??
    I see the egr valve is located in the water crospipe have we ever had leaks in this area
    Thanks for all inputs

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting