XC 70 / 2.5t Intake valve issues

Just picked our Cross Country up from the shop where they replaced a pile o
valves. Our concern was the check engine light. Apparently there is a
bulletin on this - carbon build up, which seems strange as we put good fuel
in it. It's an 04 with under 25k on the clock. Anyone else?

 

That would take the cake ,are you sure the fuel is ok as thats a new car not
even run in and why replace the valves ,it doesn't make sense sorry .I would
be very suspicious of the fuel .

 

In 1986 or so BMW had a recall for the same thing. The fix was to remove
the intake manifold and shoot walnut shells under high pressure into the
intake side of the head.

The shells were soft enough that they would not damage the cylinders, or the
rings.

There was also Techron added to the tank and the owner was instructed to run
the tank almost to empty, then pour the provided additional can of techron
in before refilling the car next time.

I think that following sites have some good information to try to avoid
issues like this:

http://www.toptiergas.com/deposit_control.html
http://www.gm.com/automotive/fueleconomy/detergent_update_081705.html
http://www.sigma.org/meetings/handouts/TOPTIERslides.pdf

 

Thanks for the links. Interesting reading. We use 80% + Chevron and the rest
Shell. They indicated that Shell was evil. I've never had (or heard of) a
bad Shell issue before. We had switched from Premium to Midgrade at their
requests due to a starting issue. Valve scoring and carbon deposits. At 23k,
it doesn't seem to make sense. The service dept said it was definately a
fuel issue, not a problem with the car. (Tho they warranteed the repair
$2400 @ warranty cost) Obviously, I wouldn't want to pay this (or worse) out
of our pocket down the road. If all I need to do to prevent further issues
is to by only Chevron as was suggested, then so be it. Combined with the
starting issue we had I wonder if there was a connection or if the fuel was
the cause. . Tho, I don't have any reason to distrust the dealer. It would
be nice to understand this issue. I should have them send me a copy of they
service bulletin. I also read on Brickboard that a person had an 05, same
mileage etc that the dealer told them the wrong valves were installed at the
factory. The last Volvo ran 300k with no internal engine repair.Weird at
best.

This is an excerpt from the gm site.
Where can TOP TIER Detergent Gasoline be purchased?
The following marketers have met the TOP TIER Detergent Gasoline standards
and are offering this product in all octane grades and in all their
respective marketing areas:

a.. Chevron
b.. QuikTrip
c.. ConocoPhillips (Conoco, Phillips 66, and 76 brands)
d.. Shell
e.. Entec Stations
f.. MFA Oil Company (Break Time stores)
g.. Kwik Trip, Inc. (Kwik Trip / Kwik Star)
h.. The Somerset Refinery, Inc. (Somerset Oil)

 

Chevron is the only fuel I know of that has Techron, a super fuel
additive for keeping the valves clean. Also, to keep the valves clean
one needs to drive the car for over 20 minutes and at highway speeds.
If you have an oil temperature gauge you will see why the 20 minutes is
important. It takes at least 15 minutes to warm the oil up. A 20
minutes the oil has been running at temperature for a few minutes. We
are lucky because everything is at least 20 minutes from our home. I
have been using minimarket gas and haven't had any problems in by '01
XC70 with 69,000 miles on it.

 

What ever happened to Mobil's ad stating to "Drive your engine clean"?
Absolutely right about oil warm-up. Short drives just don't get the oil
hot enough to "flash" off the water condensed in the pan after
startup...a prime contributor to sludge in the oil pan. Enough moisture
in the crankcase over a long enough period of time creates a colloidal
suspension whereby the contents of the pan turn into a jelly-like, grey
muck that literally has to be removed by dropping the pan. So much for
the pristine 25,000 mile, ten year old Cadillac that was only used by an
old lady to go to the pharmacist five blocks away.

 

"........................................................"

Like these pictures?
http://tegger.com/hondafaq/sludge/index.html