: Head Gasket Questions



Bberger
05-27-12, 09:43 PM
2001 DTS ~110K, original owner

Okay, experienced a little overheating... the gauge went to the next mark past 12 where it has always been rock steady at 12 o'clock. Inspecting the cap (original) I noticed it was brittle and cracked so I put on a new 18 lb. cap and the temperature stayed at 12 o'clock. But... after cooling and restarting I noticed it missed a bit. I cleared up quickly but I also noticed a few wisps of steamy smoke out the rear view mirror, arg! The oil is clean. The coolant is clean. For temporary measure I put a 7 lb cap on it to try and buy some time.

I've read a bunch of threads and want to get this right.

I appears that you go with inserts and new bolts (Huhn seems to be the best for inserts) or Studs (Carroll Custom), is this right?

Secondly, can this be done in situ or does the motor have to come out? If it has to come out and you have access to a lift is it easier out the top or drop the cradle?

And lastly, for now, about how much time should I allow? I know this is hard to answer, does anyone have the dealer allotted time? I'm just trying to get a ballpark.

I know I will have more questions as I dig deeper and want to thank again the community here. Over the years I have done the dreaded mode door (thanks to Sub it was only a 4 hour job!) blower fan, steering rack, wheel bearing, strut bearing and intake plenum.

I really like this car and and just sick the HG decided to start leaking.

-Brian

Submariner409
05-27-12, 09:58 PM
Read through the 4 or 5 threads immediately preceding this one !!! Then read the threads up in the sticky section ^^^ - it's all answered in here several times within the last two weeks.

Put the 18# cap back on it - lower pressure in the cooling system = lower boiling point. The low pressure cap accomplishes nothing and may, in fact, complicate matters.

GM dealer or independent shop - studs or NS300 inserts - two to four days depending on mechanic load.............DIY - your call.

Ranger
05-27-12, 10:02 PM
I appears that you go with inserts and new bolts (Huhn seems to be the best for inserts) or Studs (Carroll Custom), is this right?

Correct.


Secondly, can this be done in situ or does the motor have to come out? If it has to come out and you have access to a lift is it easier out the top or drop the cradle?

It has been done in the car, but is a LOT harder. Out the bottom (drop the cradle) is considered the easiest by those who have done it.


And lastly, for now, about how much time should I allow? I know this is hard to answer, does anyone have the dealer allotted time? I'm just trying to get a ballpark.

I don't know what the dealer time is, but it is not a weekend project. Several people who have done it and are now doing it will chime in with more info.

bill buttermore
05-28-12, 12:31 AM
I am currently installing studs to repair leaking head gaskets as well as sealing a crankcase leak in my '98 DeVille. The work is documented in the thread "DIY Northstar Head Gasket......" on this forum. There is no getting around the fact that this is time-consuming and expensive work. I will probably end up spending close to $2K not counting labor to complete my repairs. Removing and installing the engine is a big job, and drilling and tapping the block for studs or inserts requires careful, skilled effort. Although all jobs may not, my engine required machine shop work to bring the head gasket sealing surfaces within flatness specifications. It may be possible for a skilled Do-It-Yourselfer to replace the head gaskets and fix the block for about $1000 out of pocket and about a month or two of "project" time working a few hours per day. Special tools costing hundreds of dollars are required for drilling the block, for removing the rear seal, for installing the rear seal, and installing the water pump. If you are not experienced in working with engines, I would not recommend you start with the Northstar. As others have advised, take a couple of hours to read through the threads by Faded Crest, Joe Tahoe, Eyewonder, as well as my thread. You will see firsthand why it can cost so much or take so much time to make these repairs.

Bberger
05-31-12, 10:42 AM
Thanks for the responses. I have read hours and hours (yours too Bill), I just need to recap to make sure I understand. You can see in the threads where I documented some of the repairs I've done I tend to think things through a lot first and then share what I learn in a concise manner.

http://www.cadillacforums.com/forums/cadillac-tech-tips/209163-2000-deville-blower-fan-replacement.html

I will have the support of 20+ year Ferrari/Lamborghini/Alfa/Maserati/Ducati mechanic as well as an engineer/machinist/fabricator who also has a red hat from the Southern California Timing Association. He is also a current class record holder at Bonneville. So while I may struggle to top off the halogen fluid I have replaced a bad muffler bearing or two! (grin)

I have spoken with Norm Huhn since posting, he was very helpful and my engineer friend likes his solution over Time-Serts product, though he does think studs would be better for a racing oriented solution.

Bill leads me to the next few questions.

While we are there anything else other than:
-Replace water pump
-Replace rear main seal
-Replace split block gasket

I would think you also need new:
-Cam cover gaskets?
-Timing Cover Gasket?
-?

Saturday I am going to remove the plugs and inspect the cylinders to try and find out which cylinder/gasket is leaking. I doubt both failed at the same time. If... IF the front bank went, I wonder if it may be easier to repair that in place and buy my self a little time before removing the engine and repairing the rear bank. Thoughts?

And thanks again,

-Brian

RippyPartsDept
05-31-12, 11:34 AM
my suggestion: replace as much as you can afford to ... that way you'll know that you did as much as possible

that said, i wouldn't get into the lower end unless it was leaking badly (leaving drops of oil)

----------

we do replace the valve cover gaskets and the spark plug o-rings and the timing cover gasket when doing head gasket jobs

also the cross over tube gaskets (four of them - two of each type)

bill buttermore
05-31-12, 12:46 PM
It is usually cheaper to buy a conversion gasket set for the bottom of an engine, but not so for the N*. That's because you don't re-seal the case or the pan with gaskets, but just use grey RTV silicone. (see p 24 of my thread) Certainly, you will need the cam cover and front cover gaskets. Somewhere in both my thread and I think, in Faded Crest's thread you will find parts lists.

JoeTahoe
06-01-12, 10:22 AM
My first choice would be northstar performance shure grip studs and Jake is shipping studs as I type second choice would be norms. Jake and a few members remove from the top. I have done two with northstar performance studs and both went flawlessly and are still doing great. I have only dropped the whole cradle and thats the way I am always going to do it.

Bberger
06-01-12, 10:37 AM
Thanks Bill, thanks Joe.

Doing all the research I just about fell off my chair when I saw the price of the main seal install tool! The water pump tool is not too bad at ~$20. I wonder if the local auto part stores rent the seal tool...hmmm....

JoeTahoe
06-01-12, 11:31 AM
you dont need the removal tool and check ebay for the install tool

bill buttermore
06-01-12, 11:36 AM
Thanks Bill, thanks Joe.

Doing all the research I just about fell off my chair when I saw the price of the main seal install tool! The water pump tool is not too bad at ~$20. I wonder if the local auto part stores rent the seal tool...hmmm....

No one rents them that I have heard about. Check e-bay for used ones. I got mine for a low- low $150. On this 98, I will probably use the tool for the cartridge seal to install a regular lip seal. The 15-yr-old lip seal in mine had not failed. My leak was coming from a failed case seal. For newer cars like yours, you need the removal tool (about $25), then the sealant spreader (about $75), and the press ($150). Like you say, helps to be sitting down, or doing more than one N* job.

JoeTahoe
06-01-12, 01:41 PM
I have done a 2001 ESC and a 99 STS with no removal tool but I did do half case seals. The install tool is a must

89falcon
06-02-12, 06:27 PM
Thanks for the responses. I have read hours and hours (yours too Bill), I just need to recap to make sure I understand. You can see in the threads where I documented some of the repairs I've done I tend to think things through a lot first and then share what I learn in a concise manner.

http://www.cadillacforums.com/forums/cadillac-tech-tips/209163-2000-deville-blower-fan-replacement.html

I will have the support of 20+ year Ferrari/Lamborghini/Alfa/Maserati/Ducati mechanic as well as an engineer/machinist/fabricator who also has a red hat from the Southern California Timing Association. He is also a current class record holder at Bonneville. So while I may struggle to top off the halogen fluid I have replaced a bad muffler bearing or two! (grin)

I have spoken with Norm Huhn since posting, he was very helpful and my engineer friend likes his solution over Time-Serts product, though he does think studs would be better for a racing oriented solution.

Bill leads me to the next few questions.

While we are there anything else other than:
-Replace water pump
-Replace rear main seal
-Replace split block gasket

I would think you also need new:
-Cam cover gaskets?
-Timing Cover Gasket?
-?

Saturday I am going to remove the plugs and inspect the cylinders to try and find out which cylinder/gasket is leaking. I doubt both failed at the same time. If... IF the front bank went, I wonder if it may be easier to repair that in place and buy my self a little time before removing the engine and repairing the rear bank. Thoughts?

And thanks again,

-Brian

I think a good number of gaskets start leaking before finally failing catastrophically, so both banks could be leaking, with one hard broke. I'm pretty sure that's what happened in my case....the car needed occasional coolant re-fills.....then I started blowing parts of the cooling system once a month....hose here and there....heating core....radiator....and would start to overheat after about 30 minutes......then "hard starts" in the morning (was letting the kids drive it to school....only a 3 mile trip).

Faded Crest
06-02-12, 07:10 PM
When I pulled my heads off I discovered that both head gaskets had failed, albeit one was worse than the other.

eyewonder
06-03-12, 07:47 PM
How much time to DIY the head gaskets?

I believe that Chris @ Rippy said the techs there usually figure 20-30 hrs labor. And that's with all the equipment, lifts, cradles, tools, parts, gaskets, etc on hand, AND THE EXPERIENCE.

It took me almost a week of after-work time to just get the cradle out, as I ran into problems separating the steering gear intermediate shaft. Other folks seemed to just breeze thru that issue.

And at most stages, I had to stop & figure out how to get things apart, without breaking them. And like the others here who are in the process, I'm taking bunches of pictures - not for bragging rights, but so that I stand a chance of getting it back together, correctly. Once again, that experience thing (if you have it) really makes things go faster.

It makes a difference what your time constraints are. Is this your main transportation, or someone else's, and does it needs to be back running quickly? That puts the pressure on you. In my case, this is a non-time-critical project, so it has been a slow thing, for me.

So ..... IF you had all the tools & lifts etc ready, and the work space, and IF you had all the parts, and IF it really was only the head gaskets, and IF you took a week off of regular work to devote only to the car, and there were no hangups, you might be able to do it. But remember, this comes from an old slow-poke. You might really find it easier than I have. So, there was my free advise, and I hope it was worth what you paid for it.

And last, don't let me discourage you. It sounds like you are making an informed decision, whichever way you choose. Good luck

Cheers,
Steve

RippyPartsDept
06-04-12, 10:05 PM
Book time is about 20-30 we do it in 16 and only charge about that much. If you ad a lower reseal that adds some time but for a HG job it's in and out and back in within 2 days