can intake manifold gasket leak cause bad mileage?

wrote:
> I always change the radiator fluid once each year.Usually just before
> Wintertime.Years ago, some people used to change radiator fluid twice
> each year.For Summer time and Winter time.
> cuhulin
>
Irrelevant. If you're using Prestone, you're just putting in fresh
2-ethylhexaonic acid to keep dissolving gaskets every year.

I never have had any gasket problems (Knock on Wood) with the many old
clunkers I have owned over the years, since 1957, in 1957, that old car
was a secondhand car too.I don't remember which brand name of car it
was, it was about six years old when I bought it in 1957.I will keep on
using Prestone, Bar's Leaks too.
cuhulin

wrote:
> I never have had any gasket problems (Knock on Wood) with the many old
> clunkers I have owned over the years, since 1957, in 1957, that old car
> was a secondhand car too.I don't remember which brand name of car it
> was, it was about six years old when I bought it in 1957.I will keep on
> using Prestone, Bar's Leaks too.
> cuhulin
>

So if you'd always bought Borden milk, and then one day Borden started
selling milk substitute made from manufacturing waste instead of cow's
milk, you'd just keep buying Borden?


The whole point is that Prestone isn't Prestone anymore. I used it
exclusively from the 60's until the formula changed, but I don't use it
anymore. If you want to stick your fingers in your ears and shout
"LALALALALAICANTHEARYOU" go right ahead.

Vic Smith wrote:
> On Thu, 25 Feb 2010 09:32:48 -0600, Steve > wrote:
>
>> wrote:
>>> I never have had any gasket problems (Knock on Wood) with the many old
>>> clunkers I have owned over the years, since 1957, in 1957, that old car
>>> was a secondhand car too.I don't remember which brand name of car it
>>> was, it was about six years old when I bought it in 1957.I will keep on
>>> using Prestone, Bar's Leaks too.
>>> cuhulin
>>>
>> So if you'd always bought Borden milk, and then one day Borden started
>> selling milk substitute made from manufacturing waste instead of cow's
>> milk, you'd just keep buying Borden?
>>
>>
>> The whole point is that Prestone isn't Prestone anymore. I used it
>> exclusively from the 60's until the formula changed, but I don't use it
>> anymore. If you want to stick your fingers in your ears and shout
>> "LALALALALAICANTHEARYOU" go right ahead.
>>
>>
> What you said about the green Prestone being almost the same as
> Dexcool was news to me.
> What does that mean for eating gaskets, if that was a real problem
> with Dexcool?

I haven't found anything really definitive, and it will probably be hard
to do. DexCool was manufacturer supplied, and lots of its issues cropped
up under warranty. Prestone is aftermarket, and there's not nearly such
a good information gathering system on it. But it DOES contain 2-EHA,
the acid implicated in damaging (not really eating, just
plasticizing/weakening) intake manifold gaskets on GM cars. It may also
be prone to sludge formation in air, but its also possible that other
additives in the Prestone keep it from doing that.

Personally, I don't believe in anything that says its "ok for all makes
and models." That means its not really *right* for any make or model :-p

As for DexCool alternatives, Mopar/Ford/Zerex G-05 seems to be very safe
and effective, but that's also based on anecdotal evidence. Some
evidence exists that the "Asian vehicle" coolants (phosphated OAT
chemistry) might work well too, but you have to be careful because some
of *THEM* contain 2-EHA. G-05 does not. Another coolant that is often
recommended is Peak "Global Lifetime," but its somewhat hard to find and
often confused with their "long life" coolant, which is a different
chemistry and is also similar to DexCool. Lots of good debate (and
information buried in the debate..) can be found on the cooling system
fluids/additives section of the bobistheoilguy forums.

The other bottom-line fact is that DexCool seems to be just fine once GM
got all the requirements sorted out- it should only be used in cooling
systems where the overflow tank is pressurized and not with the more
common type where the overflow tank is open to air with only the
radiator being pressurized, and it should only be used with specific
types of gaskets if the gasket ever touches cooling passages. If those
conditions are met, people rarely seem to see an issue with it.