2001 Pontiac Montana, 2550 miles, Supertech 10W30

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Originally Posted By: Coogles
I hate the GM 60*V6 with a passion.


+1

My 2000 Montana caused me such grief. Obviously a head gasket leak once but then again again a few years later. If was just this I might be ok but the car had problem after problem. Terrible for me and for sure not good for GM.
 
Originally Posted By: Onmo'Eegusee
Thanks, Bill. I didnt put ARX in it to get rid of the coolant specifically, just to do general cleanup. I will see what happens.


And I should have also said that make sure you use a oil WITHOUT sodium as a add.

Will make your life a lot easier trying to do UOAs after a coolant leak...
 
Originally Posted By: Onmo'Eegusee
I checked the compression in this not long after I did the repair. It was around 175psi across the board. Is it possible it has a direct coolant to oil leak in the HG?


Yup
Sometimes they (head gasket)crack along a coolant passage and spray coolant directly under the intake manifold. The seal around the cylinder can be just fine.
 
Originally Posted By: oilmaven
I bought a 2008 Impala with the 3.5L V6 Flex-Fuel. From what I understand, this engine has some improvements over the 3.1, 3.4 and 3.8L engines...particularly the coolant routing and associated gasket issues that GM claims should avoid any problems. At 34,000 miles, the engine is quiet (no piston knock...know what you mean here...very common in the 3.1L particularly) with good power and highway mileage from 30-34 mpg. I know I took a chance on this car but I couldn't deal with any more 7-8 hour stints in the Yaris (although dead reliable and 40mpg). I admit I caved and bought the extended warranty out of concerns regarding anything GM. So far I love the car...comfortable and economical. I'm changing the PP 5W30 at 5,000 mile intervals.


GMs "high value" engines (the 3.5L and 3.9L WITH variable valve timing) are totally different designs compared to the 60 degree V-6s). The first gen 3.5L though did not have the external coolant crossover, but had revised intake gaskets. With the new ones, it's physically impossible to get an intake manifold water leak because the intakes have no water going through them.
 
Originally Posted By: Rabbler
Originally Posted By: Onmo'Eegusee
I checked the compression in this not long after I did the repair. It was around 175psi across the board. Is it possible it has a direct coolant to oil leak in the HG?


Yup
Sometimes they (head gasket)crack along a coolant passage and spray coolant directly under the intake manifold. The seal around the cylinder can be just fine.

Hmm, I have no idea how I would test this, if it in fact still has a problem. If its just leaking into the engine then it could be either a LIM or this.
 
What's crazy is that GM totally ruined the motor with the updates they did in '94, at least from a reliability standpoint. Those old 2.8 and 3.1 Gen1 60*V6's were no powerhouses, but they were at least reliable.
 
Originally Posted By: Bill in Utah
Originally Posted By: Onmo'Eegusee
Thanks, Bill. I didnt put ARX in it to get rid of the coolant specifically, just to do general cleanup. I will see what happens.


And I should have also said that make sure you use a oil WITHOUT sodium as a add.

Will make your life a lot easier trying to do UOAs after a coolant leak...


Doesn't the Supertech have sodium in it? Definitely switch to a sodium free oil and do a couple of short changes before sampling again.
 
The WPP Supertech does not but the Mobil stuff does.

What does your bottle look like? If it looks like a Mobil 5000 bottle (or exxon) then it has sodium in it.

Unless they changed the mix?

Valvoline, GTX, and Mobil does have it 100% certain.
 
Originally Posted By: JohnBrowning
It will crack the block but no gurantee it will penetrate depends on where it hits. My 44 magnum can crack a Chevy small block!

If you want to make sure best get a 600-900 grain 50BMG round and then you will know it will penatrate 100%!LOL

I always like to run a quart of MMO after a coolant leak and Ihave found it works great to get rid of the left over stuff fromt he leak as long as the leak was not going on for a long long time. Seafoam also works good to get rid of coolant and water traces in the block. The Auto_rx is more of the answere to getting rid of sludge that was the result of a long term coolant leak it as far as I am aware is not going to grab hold of the coolant or the water that is in the system it is just going to work ont he sludge. If the leak is still on going then even ARX will not work to clean it!

What type of external coolant leak do you have that you can not stop? I have never heard of or seen an external leak that was not easy to get under control? They make test strips that can detect combustion by products in the coolant since you have an external leak still you can not go by the consumption because it might all be going outside of the engine. If the repair internaly was done properly then their should not be any combustion byproducts in the coolant.


As far as the GM 60°V6's are concerned they always have been junk! Even with the updates to them they remain a cheap design that is just dreadful when compared to all of the other modern V6's used by most automotive companies. Compare GM's 60°V6's to Nissian VQ engine or the Buick 3.8 or Toyota's current V6's or Audi's etc.........No matter how you slice it they are outdated low grade crudely built junk! It is a price point engine in every way. I used to have a bunch of failed pistons on my desk as paper weights and candy dish's when I worked at GM. I can honestly say that the piston in a Brig's and stratton lawnmower is not only better design but is built to higher levels of quality control and with better materials that is the sad part. If someone sent me pistons like the Mahl built pistons that GM use's in the 60°V6 for a rebuild on any engine I would reject them right away. Those engines have had piston issues, rod bearing issues, intake gasket issues, oil drive unit,lifter issues you name it! I have never seen an engine with more problems stay on in production for so long with so few upgrades. GM went so far as to claim that rod knock was not considered a durability issue based on their 3 year 36,000 mile validation testing!!! Here in Michigan the knocking of a 60°V6 is so common that no one even pays it any attention!LOL


The Buicks arent any better when it comes to coolant leaks grrr
 
Wow, if true for the 10W30 grade as well then my numbers could be way off. Might be worth it to have my 10W30 run...hmm. Does anyone think anything of potassium? It dropped from 60 to 20. In the inital report it was half the sodium number and now it is 3%.
 
Dexcool has lots of potassium but I'm not sure about G-05. The fact potassium is low is possibly a good sign. I'd switch over to something that safely doesn't have sodium like Penzoil and run a couple of short OCI's and then check again. If you want other options for oils without sodium call Blackstone, thcy can probably tell you what other options are. They specifically recommend not using oils with sodium if you are going to have any questions about a coolant leak.
 
Yeah, and I was reading the G05 has silicates (Si) and Dexcool is supposed to have almost none. Si did go up..but.. I also had the thing open to dirt or whatever else of course when I was doing the repair. The fact lead went up makes me think it IS actually just dirt. It could all be coincidence.
 
This can be boiled down to the contaminates still being in the oil from the inital repair.

You need to RELAX and lower your anxiety.

The stuff won't just disappear from your engine. Give it a couple oil changes and you will be fine.

By the the number you have in your report, they are too low to be a leak, they are just residual numbers.

Just chnage the oil WITH ANY OIL and the nmbers will eventually fall to near nothing.

But for cripes sake, RELAX and stop FREAKING OUT.
 
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