2006+ Northstar

[Luke]

I have been looking at some sites recently about head gaskets. Just recreational reading really. What I have noticed.... none list anything about doing head gaskets on 2006+ Northstars. They all talk about head gaskets, bolts, studs, etc on 1993-2005 Northstars.

I knew the 4.4L Supercharged version was redesigned without water jackets for sturdiness.... did they do this to all Northstars in 2006? Are 2006 models really more reliable in the head gasket department or are they a little too new yet to be showing such issues?

[JimD]

....I knew the 4.4L Supercharged version was redesigned without water jackets for sturdiness....

Say what? Where did you read that the 4.4L version was "air cooled"?

....or are they a little too new yet to be showing such issues?

That would be closer to the truth.

The Internet mythology/hearsay that the Northstar is only engine ever designed/built that has experienced gasket failure is one of my pet peeves. How long is a head gasket expected to / supposed to last?

The answer would be "forever" in the minds of 80% of the motoring public. An unrealistic expectation on the part of 'the key goes here' and 'the gas goes here' majority.

The answer would be "until they fail" for the remaining 20%.

[Cadillac Jim]

My 1986 Ford Escort with the 1.8 liter SOHC engine had a head gasket failure at about 50,000 miles. Ford fixed it under warranty and I forgot about it.

The 2006 model year is about five years out. Most HG failures happen at about seven years - five years for the coolant to go out of date, and another year or two for traces of the bad coolant to rot the threads of a head bolt, ususally the corner one on the left rear.

[Luke]

....I knew the 4.4L Supercharged version was redesigned without water jackets for sturdiness....

Say what? Where did you read that the 4.4L version was "air cooled"?

Haha, no, It's not air cooled. The Supercharged 4.4L does not have the open water jackets that completely surround the "floating" cylinders like conventional Northstars do. There is of course coolant. But, the block was redesigned to have water passages around the cylinders like most engines rather than the completely open water jackets. This makes the engine much more robust and sturdy to handle the extra pressure. Undoubtedly, it also makes head gasket retention much better.

Original open water jacket design:

http://www.caddyinfo.com/nsrepair2.jpg

STSv block, note the water passages:

http://www.d3cadillac.com/wp/wp-content/uploads/2010/06/STSV_Engine_001.jpg

[Luke]

My 1986 Ford Escort with the 1.8 liter SOHC engine had a head gasket failure at about 50,000 miles. Ford fixed it under warranty and I forgot about it.

The 2006 model year is about five years out. Most HG failures happen at about seven years - five years for the coolant to go out of date, and another year or two for traces of the bad coolant to rot the threads of a head bolt, ususally the corner one on the left rear.

At the risk of starting a war, I say, I use ONLY conventional green coolant and change yearly to avoid head gasket issues. No need to tell me how wrong I am, it won't change my mind.

[JimD]

My promise to the forum is:

I will not consume further bandwidth with my position on this perceived "issue". Enough is more than enough.

....The 2006 model year is about five years out. Most HG failures happen at about seven years

Seven years? Internet hearsay. Where can we find the engineering statistics to back that up?

.... - five years for the coolant to go out of date, and another year or two for traces of the bad coolant to rot the threads of a head bolt,

Explain to the world how 'bad coolant' can reach the threads of a head bolt without a gasket failure. Please.

....ususally the corner one on the left rear.

Engineering statistics?

Internet hearsay does not qualify.

[rockfangd]

....I knew the 4.4L Supercharged version was redesigned without water jackets for sturdiness....

Say what? Where did you read that the 4.4L version was "air cooled"?

Haha, no, It's not air cooled. The Supercharged 4.4L does not have the open water jackets that completely surround the "floating" cylinders like conventional Northstars do. There is of course coolant. But, the block was redesigned to have water passages around the cylinders like most engines rather than the completely open water jackets. This makes the engine much more robust and sturdy to handle the extra pressure. Undoubtedly, it also makes head gasket retention much better.

Original open water jacket design:

http://www.caddyinfo.com/nsrepair2.jpg

That is totally cool. Excellent pictures. It seems very open on the older design. Cadillac has improved but I am still upset as they have discontinued the northstar v8. After they improved it they ended it. Agan excellent post

STSv block, note the water passages:

http://www.d3cadillac.com/wp/wp-content/uploads/2010/06/STSV_Engine_001.jpg

[JimD]

At the risk of starting a war, I say, I use ONLY conventional green coolant and change yearly to avoid head gasket issues. No need to tell me how wrong I am, it won't change my mind.

Very little risk of starting a coolant war. And I have no interest in changing your mind.

But future forum readers deserve the opportunity to read something other than the "Don't confuse me with the facts" position. And arrive at an independent decision.

GM continues to factory-fill cooling systems with Dexcool since 1996 model years, and that is 16 years on my calendar.

Dexcool contains a corrosion inhibitor chemistry package that your "convention green coolant" might or might not contain. It's your money and your engine and your choice.

[Cadillac Jim]

My promise to the forum is:

I will not consume further bandwidth with my position on this perceived "issue". Enough is more than enough.

....The 2006 model year is about five years out. Most HG failures happen at about seven years

Seven years? Internet hearsay. Where can we find the engineering statistics to back that up?

.... - five years for the coolant to go out of date, and another year or two for traces of the bad coolant to rot the threads of a head bolt,

Explain to the world how 'bad coolant' can reach the threads of a head bolt without a gasket failure. Please.

....ususally the corner one on the left rear.

Engineering statistics?

Internet hearsay does not qualify.

"Explain to the world" seems a bit aggressive. Where's the Caddyinfo courtesy? And, no, I'm not going to take the time to go through Caddyino and other sources because you are belligerent. You want to *disprove* it, you do the data mining. And, yes, people *will* critique it. I made a simple observation and you want to play lawyer, well, *you* play lawyer. I'm here to help people. I don't have the time to devote to data-mining for the obvious and pointless arguments. Since *you* want the *proof* I'll leave it to you to go through the archives and collate the data to prove or *disprove* this generalization, or to start a survey topic, whatever your time and inclination leads you to do. If you want me to do it, I'll send you a time estimate and a billing rate, and if you agree to pay it we can talk. Otherwise, if you want data mining done, you do it. Frankly, you are stating something when you contradict anorther's post and demanding proof; perhaps you are the one with the burden of proof.

To answer your imperative challenge question, the seven-year observation, and the corner head bolt pulling, are both from years of observation here at Caddyinfo, with occasional forays on the "other" Cadillac forum. You do the searches; I don't' need to because I recall the posts.

There are always traces of head leakage, no matter what. Look at analyses of coolant for combustion by-products and they are never nonzero. Search Caddyinfo; I've seen such analysis reports. They go up by orders of magnitude when there is a bad head gasket, but they are always there. This "proves to the world" that there is no such thing as a perfect head gasket seal, or, should I say, it proves it to me.

Look at any head gasket and you will see that the rim seals around the bores are not repeated around the water jackets. They are nearly always repeated around the high-pressure oil passages but not often anywhere else except on some premium head gaskets. This is because coolant pressure of about 15 psi is tiny compared to cylinder compression pressures, but tiny, tiny traces of coolant do exit the water jacket through *all* gaskets that seal coolant in just about all engines. These traces find their way to oil drain passages, the lifter valley, the edges of the head - and the head bolt wells.

This gets us to the fact that the head bolt wells are sealed with chemical coatings and the threads are sealed and chemically locked, given them a lot of resistance to coolant damage, as we once heard from the guru. But, imagine a tiny fraction of a drop of acid coolant at the bottom of a head bolt well, where it is in contact with both a steel head bolt and the aluminum tops of the threads, spanning the tiny gap of sealant and thread-lock. For years. As the engine temperature cycles a few to several times a day and the head bolt tension increases and decreases, and tiny amounts of acid coolant condenses when the engine cools. Galvanic corrosion begins on the aluminum immediately when the coolant goes acid, and, after a couple of years, you have penetration of the aluminum-threadlock bond. Cracks in the threadlock keep the shortest electrolyte path at the threads.

I've seen only a few posts here about which head bolt pulled, but most of the time it's the driver's side rear. It was on my engine, too. I have heard here of one on the passenger side corner. I wouldn't hazard a guess why; I will leave that to others.

There are exceptions. I have heard of at least one engine - on a 1997 ETC - that had a head gasket failure when the car had proper coolant maintenance. I've heard of head gasket failures on lower mileage cars. Of all makes. But it's rare, particularly in the last ten or fifteen years.

For a good time, I've heard of one good way to test your coolant. Get a voltmeter, and, with a cold engine. put one terminal against the battery ground connector and dip the other into the coolant in the surge tank, being careful not to touch the probe to anything metal. If the voltmeter reads less than 0.5 Volts, your coolant is OK. If it reads more than 0.7 Volts, then the coolant is acid enough so that galvanic corrosion is underway.

I agree with Luke in the sense that using green coolant and flushing it yearly is OK. I've talked to mechanics recently that tell me that most of the water pump failures that they have seen on all makes are on cars that have red coolant; I believe them but, since *all* cars come with red coolant, well, you might expect that. And, running for a long time with low coolant, or running with less than 50-50 allows steam pockets to happen, and that breaks down the OAT corrosion inhibitor and sealant in red coolant but not the sodium silicate in green coolant, so failure to properly maintain red coolant gets you in trouble quicker than with green. On my car, though, I want red coolant and good maintenance, and a three-year coolant flush. But, it's the owner's choice.

[Luke]

This is my 7th Northstar. Every single one has had only green coolant while I have owned it. I have never had a head gasket failure. The thread was only started to ask if changes were made in the Northstar design in 2006+ cars. My last car, a 98 DeVille, I sold with 162,000 miles with very few problems of any kind ever. I only sold it because I found the DTS and got a REALLY good deal on it.

Northstar Performance will warranty their repairs for 5 years or 100,000 miles but ONLY if green coolant is used and changed every other year. I just see where so many people using the factory fill of Dexcool have head gasket failures with less than 100,000 miles. I on the other hand, have had good luck with green coolant so that is what I will stick with.

For anyone who is interested.... What looks like green coolant, Prestone, Supertech, etc, is no longer. It is green or yellow but is actually Dexcool. If it says it is extended use, it is Dexcool. True conventional green coolant is getting hard to find. I did find that Peak makes a coolant that says on the bottle that it is CONVENTIONAL GREEN coolant on the front label.

[BodybyFisher]

I am not going to get into this other that to say, don't make assumptions

That Northstar Performances insists upon using GREEN is no support for using GREEN. Northstar Performance has not been in business that long for ANYONE to have a track record on their performance, what has he done 200 to 300 blocks? Northstar Performance is a pimple on Timesert's azz in terms of track record.

The key to a successful head gasket repair is whether or not the block material is GOOD when its drilled. If it is, ANY FN insert, stud will work perfect regardless of whether you use GREEN OR DEXCOOL.

As far as going GREEN, you can go GREEN, ORANGE or any color you want as long as you change it before the corrosion protection is depleted. That you change your coolant every year it great. Good for you. But don't dump on DEXCOOL, it has and still performs well in millions of engines.

That you have had success is great but millions have had success with Dexcool.

That you have not had a head gasket problem is great, millions of owners don't have head gasket problem, but don't ASSUME its due to green

[mike5514]

My take on all this is the HG issue main cause is not bolts by themselves coming loose but by coolant leaking into bolts causing the failure as previously mentioned. The Northstar properly manufactured has a predicted life and will reach that if properly maintained. Heat is the killer of the northstar aluminum blocks and iron bolts do not work well together in extreme heat. Coolant tabs were recommended in the early years 2 tabs per coolant change, the proper method to use these tabs was to put them in the lower radiator hose. This was probably not done in most cases, I can only make a educated guess that most tabs were installed in the surge tank likely resulting in surge line blockage, causing overheating as documented on this forum. Proper maintenance procedures require that the overheating be taken care of before driving any further I assume that this was not always complied with.

The HG issue would not be such a big deal if the work could be done with engine in car and special serts not needed like with a small block chevy. As I mentioned in a previous post the repair cost are coming down, mechanics are becoming more knowledgeable and they are doing the repair in the car. This bodes well for the Nortstar going forward. This is a compelling reason not to junk your well kept Cadillac, and that you can buy one with a Hg issue as long as you know that going in.

Probably like me you don't like seeing our favorite car in the junk yard cant see the future but hopefully people will see the value in these cars and stop sending them there just because of a HG issue.Mike

[Texas Jim]

My 2006 is 5.5 years old with 107,865 miles on it.

So far so good.

I had the coolant changed back in the early summer at about 95.000 miles.

Also had the transmission fluid changed at the same time.

[BodybyFisher]

Now that surprises me Jim, but I know you are a risk taker,

[Texas Jim]

Now that surprises me Jim, but I know you are a risk taker,

What part surprises you??

[Cadillac Jim]

I've been having my transmission "serviced" every 30,000 to 40,000 miles since I bought the car, too. But, after all this time, I'm beginning to wonder if much of that is a scam, or at least wasted. I'm not just talking about the JiffyLube scandals in the news that we discussed on Caddyinfo a couple of years ago, either. I'm not talking about hearing about 4T80E transmissions going 200,000 miles and more without being serviced, either, although that certainly is something to think about, if you don't plan to keep the car on the road beyond 200,000 miles.

A few months ago I had the 4T80E on my 1997 ETC serviced, and asked for a flush using Dexron VI. They did it while I waited for that and other scheduled service items, and the car did not go out to another facility for any part of the servicing. It was all done in about an hour, which isn't enough time to do everything. Also, I didn't see a transmission flushing machine anywhere. I think they did a standard service, where they drain the fluid and drop the pan and clean the screen, and maybe change the transmission filter if it's serviceable at that level. Then they top off the fluid, check for leaks, and its ready. That leaves over half the fluid in the transmission, meaning that my fluid is a mixture of Dexron III and Dexron VI of undetermined composition. It's possible that the previous transmission service by a dealer, I believe in 2006, used Dexron VI in a flush (that's what dealers do with a transmission service, a flush) but GM did not discontinue licensing Dexron III until the end of 2006, so I don't really know.

I recently had my wife's Pontiac 4T45E serviced at an independent garage, and I asked that after the drop-the-pan-and-clean-the-screen service that they do a flush with Dexron VI. This car had never had a transmission service and has about 47,000 miles on it, so I figured that this was a really great idea. I found out when I picked up the car that they simply did the top-off with Dexron VI and did not flush the transmission, but at least they admitted to it. The next time, I'll do it at the dealer and get a Dexron VI flush for sure, and we will be set for the life of the car.

Coolant? Yes, this applies to coolant too, because if you don't have the cooling system reverse-flushed with the thermostat out, some old coolant remains in the car - about half, in fact. If the old coolant is beginning to go acid, replacing half of it with fresh 50-50 may give the system coolant that is good for one or two years at the most, not five. Ask a mechanic to flush your system, and he may think that's a waste of time and just nod and silently not do it. Pulling the thermostat and reverse-flushing a Nortstar cooling system is a lot of work.

[BodybyFisher]

Now that surprises me Jim, but I know you are a risk taker,

What part surprises you??

Me?, I'da changed it at 50K and 2.5 years but I have chicken feathers under my T-SHIRT....

[Texas Jim]

Now that surprises me Jim, but I know you are a risk taker,

What part surprises you??

Me?, I'da changed it at 50K and 2.5 years but I have chicken feathers under my T-SHIRT....

But....... I don't have any T-Shirts...so I had to wait... :lol:

[BodybyFisher]

[Texas Jim]

Dress slacks or khakis and white shirts.... uniform of the day...

.

.

[BodybyFisher]

Hey I hope you drive the Caddy with your eyes open!

[Texas Jim]

Hey I hope you drive the Caddy with your eyes open!

Most of the time...

Trying to look into the setting sun is rough...

At least I put on a shirt before she took the picture...

[Cadillac Jim]

Can you get a Northstar into one of those things?

[Texas Jim]

Can you get a Northstar into one of those things?

I wish.... :D

[Cadillac Jim]

These guys have a selection of Northstars that will really make your lawn mower go. You might want to consider a wheelie bar and some suspension and brake enhancements, but their sand car accessory line should help there too.

http://www.chrfab.com/Engines.htm