Are you talking about the coolant line that runs through the intake. The S4 guys have been running it for years with no issues. Think about it. When the car sits over night its not like the coolant is warm on cold starts everything is cold.
So we had to open the IM again to check out a misfire but I was disappointed to see how quickly the carbon builds up. These 2 photos were taken after maybe 5 mins of engine run time - car hasn’t even come off the lift.
oh yes. carbon will collect quick.
that’s amazing…5 minutes of carbon
shows you that it’s probably about the same at 25,000 miles as it is at 5,000 miles, so all the people whose butt dyno say they noticed the car losing top end when they’re 15-25 thousand miles after a cleaning are full of shit.
This also shows that the car is probably performing very similarly at 5,000 miles after a cleaning as it is 25,000 miles after, thus it’s not that big of a deal.
I think what actually happened was that the valves spun around when the car was running and is now showing you what was on the back of the stem when you did the cleaning. This is just the stuff that didn’t get cleaned because you couldn’t see it.
Karma bump for you. Great point. When you look at the carbon clump you can tell thats a seasoned collection. Carbon will build up at low speed idle conditions and cold start issues.
While it can build up quickly it wont have clumps for a while
to be fair, the carbon was still soft and could be relatively easily cleaned. we’ll see what the car feels like once it’s on the road again.
While checking out the engine codes we were having a problem with bank 2: the left intake cam sensor, oil pressure switch, and coil packs
Look what we found - torn insulation behind the T14h 14-pin brown connector routing wires to ECU2. Don’t know exactly when this occurred, but the connector is located behind the IM below the oil filter. My mechanic thinks excess heat or hot oil may have contributed.
http://i.imgur.com/2k1UiGXh.jpg
http://i.imgur.com/x0oXsJnh.jpg
http://i.imgur.com/84swyiLh.jpg
http://i.imgur.com/SG081iSh.jpg
We are searching for another connector to solder and re-pin. Arrrrgh!
looks like a rodent had a chew
i love that last picture
Right, looks like fancy art
That looked horrible. What caused that.
I have no idea of the cause. The insulation was dried out and brittle at the point of failure, but we may have exacerbated the problem when we took out the engine/harness. My mechanic ended up just soldering the wires directly and wrapping with extra head shielding. fingers crossed.
http://i.imgur.com/j8LIWYc.jpg
The engine is back in and the car put together. It seems to run smoothly, with no misfires, but I have a few more issues to shake out. we’ll try to do a final checkout after I drive it for a few hours.
The engine is back in and the car is running perfectly!
Well, except for a gear shift sensor that isn’t detecting the “P” position unless I give it an extra shove. For completeness sake, here is a link to an issue we had with the intake manifold installation - there was a bracket that was interfering with the flap operation. http://audirevolution.net/forum/index.php?topic=3790.msg109446#msg109446
and a pic
http://audirevolution.net/forum/index.php?topic=3790.msg109446#msg109446
It all looks good. I posted a picture of the install without the bracket. It is much cleaner