Truth about dexcool, pellets and the 3.4 intake leak

My wifes has a 99 Alero with a 3.4L engine and about 46K miles. We bought it used so I have no clue if the dexcool had ever been changed so today I took it into the dealer thinking 5 years or 150K and this
is its fifth year. I asked if they would put the pellets in and they said they had never heard of putting pellets in this particular car. Only the 3800 which had a throttle body problem. He told me they would do it if I wanted them to but it would be at the customers request. He then began to explain what the pellets were for and cautioned me that it could clog my heater core etc... if used excessively. He said since I bought the car used I probably shouldn't put any pellets in because the provious owner probably had it done already.
I took him over to the car and showed him the traces where my intake leaks slightly on both ends (left and right). They are not wet, more like moist traces that are visible to me and i'm in no way a mechanic. He said the pellets would do nothing for this and that I needed to have the intake manifold gasket changed. $850 was the quote.
What do you guys think? Should I have the dexcool flushed and changed with a couple of pellets added and hope everything turns out ok or should I save and save until I can afford to have the intake gasket replaced?
PS... He also said he could see that the head gasket on the back bank will need to be replaced eventually. Again, slight moisture but never anything on the driveway and i've only added more dexcool one or two times in the 3 years we've had the car.
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Soapm wrote:

Wife's 3.4L Impala had a little bit of wetness and I had to add once or twice. After a while it started to smell like antifreeze so we took it to replace the intake gasket on the extended warranty, I would say get it fixed now before it gets worse.
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Soapm wrote:

There is no point in using the pellets on this engine line. They were never really intended for use in these engines. There may be some added from the factory initially, but I've never used any on this particular line of engines.
> I took him over to the car and showed him the traces where my intake

He's right. By the time you see the slight leaking on the outside, it's already leaking internally.

Save for the intake, and instead of changing the dexcool right now, change your oil instead. That's more important. The 3.4 engines are also getting a bit of a reputation for rear head gaskets failing. They split at the outer perimeter and you get an external coolant leak. They do not seem to leak internally, the intake gasket manages to do that all by itself.
Ian
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Let me add to this here. The 2.8/3.1/3.4 engine family in both FWD & RWD versions is known for external leaking at the cylinder head gaskets. All have intake gasket sealing issues, regardless of generation. Charles
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Charles Bendig wrote:

And thats the frustrating part, how many years will it take for the issue to be fixed, the 2.8 was introduced around 20 years ago. I mean its still not as bad an an import with having to replace the timing belt but still it shouldn't take 20 years to fix a common problem.
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Thanks for all the responses. I guess in short I won't be getting the new wheels for my Buick anytime soon. Might be for the best, I was nosing around ebay for prices and noticed I can probably get a set of 15" at a great price if i'm patient. However I have a couple of questions below.

I'm confused, after reading about the 3.4L intake problem I started googling and there were several sites reccommending this. I realize after talking to the guy at the dealership that GM would never use pellets and call it a fix they could back because 1) changing the head gasket brings in more revenue and is more of a sure repair and 2) I agree that the use of a stop leak is a hit or miss, shaddy tree mechanic, get by type of measure and not a "fix". However, one site said GM recommended it in bulletin 00-06-02-004. I didn't want to pay any site to see the actual bulletin but can someone tell me if GM really said this is the fix or was this bulletin mis-quoted?

This is where i get lost, I maybe added coolant 1 or 2 times in 3 years. That doesn't seem like much with the extreme temp changes we have in Denver. Do you really think it could be leaking internally? Can't you usually smell a sweet smell on the oil filler cap when this happens?

I took your advice here and had my oil changed even though it was just changed about 1.5K miles ago. I ordered one of the test kits from the site John Horner posted (thanks John). My plan is since it will take 2 or 3 weeks to get the kit, we will mostly dive this car untill the kit arrives then we will send in a sample. I guess that will tell us if we need to spend the $850 or not. Does this sound like a good plan?

So if this is the case, it is not as urgent as getting the intake changed. If I have to get the intake changed do you think it is smart to go ahead and have the head gasket changed at the same time? That is what the dealership was alluding to...
Thanks Ian and all...

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Soapm wrote:

We don't change components because they "bring in more revenue".....we change them because we know that it will fix the problem and fix it right. The GM stop-leak was never intended to actually fix big coolant leaks that need repairing, it was intended stop minor seepage that might occur. Having said that, it won't hurt an engine to install a couple of pellets, but you can't fill up half the cooling system with the stuff and not expect bad things to happen.

This bulletin has nothing to do with the pellets, doesn't even mention them. I guess that site either doesn't know what they are talking about, or misquoted the bulletin number.
> This is where i get lost, I maybe added coolant 1 or 2 times in 3

Extreme temp changes mean nothing. Coolant is not like oil where it gets "used up". You should never need to fill up coolant on a regular basis. And no, these intake gaskets tend to leak so slowly at first, that you get no creamy scum build-up on the filler cap. But you will notice a brown scum starting to coat everything inside the engine.
> I took your advice here and had my oil changed even though it was just

Sounds reasonable.

Well, let's put it this way....it's only another couple of hours labour, and the cost of the head gasket in order to complete the entire job. If you do the intake (and it really needs the head gasket) and you don't do the head gasket.....and then the head gasket really fails and needs to be done....you will be re-doing and re-buying all of the intake gasket stuff again. But make sure the head gasket is really leaking, not just showing minor signs of seepage. They will go a long time with that seepage and cause no harm. Dexcool does that, it likes to kinda ooze out everywhere.
Ian
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The big problem with these intake manifold gasket leaks is that often coolant is also getting into the engine's oil. That is a very bad think. You can have a sample of your used motor oil checked for $20 to see if it is happening to your vehicle yet. http://www.blackstone-labs.com/ is one of several places which will send you a free sample container to do the test.
John
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