Long Term Carbon Deposits

Back in a Bowtie · May 16, 2019

How’s everyone’s intakes doing? I’m approaching 80k miles and weighing doing a mechanical cleaning. I think a Crc or Seafoam is out of the question as I had a cat issue when I did it at 30k and haven’t done it since. Trucks running fine. Share any deposit pics you might have with mileage.

Paintor · May 16, 2019

If you don’t see the oil in your plastic intake tube (between air filter box and throttle body) from the valve cover breather hoses, you are fine.

You can pop that off pretty quick to see if your truck has been eating oil coming from valve cover hoses. Causes detonation, poor fuel economy, carbon deposits on valves and heads.

Centex14 · May 23, 2019

Here are some of my intake valves at a 130k miles with no catch can. After seeing these I'm even less concerned about running a catch can.

Jacoby · May 23, 2019

2 hours ago, Centex14 said:

After seeing these I'm even less concerned about running a catch can.

Those look like shit.

Centex14 · May 24, 2019

Looks aren't everything. Truck still gets great mileage, doesn't burn oil, doesn't knock, tuner didn't see any issues in the logs, plugs look good. I see no reason to put a can on. I can spend that money elsewhere.

UnlimitedMatt · May 24, 2019

2 hours ago, Centex14 said:

Looks aren't everything. Truck still gets great mileage, doesn't burn oil, doesn't knock, tuner didn't see any issues in the logs, plugs look good. I see no reason to put a can on. I can spend that money elsewhere.

Fair enough. But think about how much better it *could* be if your values were clean...

3tspapat · May 24, 2019

Looks aren't everything. That is why the world is full of ugly people still.

Jacoby · May 24, 2019

3 hours ago, Centex14 said:

Looks aren't everything. Truck still gets great mileage, doesn't burn oil, doesn't knock, tuner didn't see any issues in the logs, plugs look good. I see no reason to put a can on. I can spend that money elsewhere.

Putting a can on at 130k miles is about as pointless as those pictures u posted. A catch can is a preventative measure not a cure

JONBLARC7 · May 24, 2019

Show me a picture of a valve with 130k miles with a catch can the whole life of the motor. I bet it looks just as bad.

Mike GMC · May 24, 2019

While I agree those pics don't look good, I would have imagined much worse at that mileage with no can. The valves on my 08 CTS looked much worse at less than half that mileage. I did a mechanical cleaning and added a can. At 110k miles the valves looked slightly better than those pictured, but MUCH better than they did at 60k when I cleaned them and added the can. At 60k, mine looked like the horror story picture you see posted as an add for cans.

Centex14 · May 24, 2019

Forced induction is a different story and I'll agree those need a can. Naturally aspirated it's no where near as important as the internet makes it out to be. But you do you. I wasn't worried about it before and I'm most certainly not worried about it now.

Centex14 · May 24, 2019

3 hours ago, Jacoby said:

Putting a can on at 130k miles is about as pointless as those pictures u posted. A catch can is a preventative measure not a cure

OP asked about long term carbon deposits. I have pictures of my valves at a 130k miles which is long term. Pretty certain that's the point of this thread.

Edited May 24, 2019 by Centex14

davester · May 24, 2019

Well, my '04 Sierra w LQ4, when I changed the knock sensors at 120k miles, the bottom of the intake manifold was filled with oil (as in, while removing it, it tilted a bit and oil spilled out, and then I carefully dumped the rest of the oil in the manifold in a bucket), and the intake ports were coated with carbon.

Jacoby · May 24, 2019

1 hour ago, Centex14 said:

OP asked about long term carbon deposits. I have pictures of my valves at a 130k miles which is long term. Pretty certain that's the point of this thread.

Yes he did and your pics provided more than enough proof that a catch can is needed. So I say thank you

Doublebase · May 24, 2019

Those valves don't look reassuring to me. And 130,000 miles? I mean, I thought 130,000 miles wasn't supposed to be high mileage anymore? Those valves look like something I'd expect to see from a carbureted motor at 130,000 miles, from someone who never changed the oil and beat the tar out of it.