XC 70 / 2.5t Intake valve issues

[encat]

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?

 

[John Robertson]

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 .

 

[Steve (archive)]

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

 

[encat]

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)

 

[Stephen Henning]

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

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.

 

[..................................................]

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.

 

[Michael Pardee]

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

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