Scanner to Help with diagnosing LHM?

about 4500 altitude.

the Van runs great other than the Limp mode. After I restart, I have good power going up the hills here in Sandy Utah. LM kicks in after one or two hills.

lndlyb4 said:

Could be. What do you think of doing a boost pressure test?

Click to expand...

Well, if you have a real-time monitor (like the ScanGauge) or someone riding shotgun to read the iCarsoft, you could try a variety of things:

(a) yes, you could do a static smoke test... cap and pressurize (to 20 psi above ambient) the mess and see where it leaks (if it does). Without smoke you could at least put a pressure gauge on it, pressurize the tubing (like a drain-pipe leak-down test) and see how well it holds it.

(b) you could try driving *gently* ... try to not exceed various pressures (24 psi MAP, 26 psi MAP, etc) until you find if/when it reliably drops out. Flat hiways at 60 mph, 65 mph, 70 mph are also good ways to test pressure levels.
When my resonator was slightly cracked, i could maintain 60 mph, but at 65 mph (or 60 on an incline) it would lose it (27 psi).

(c) along with the "gently", see if it gets more "fragile" as it warms up. That could be "something plastic" getting that itty bit more flexible, or even the intercooler finally warming up enough to expand a crack.

good luck
--dick

I got under the van to take a look at the turbo resonator to see if the seam had split. There was quite a bit of grease, soot, etc on it and the surrounding area I cleaned the whole area, then drove up and down the Wasatch mountains to see if it was oozing any oil. I deliberately made it go into LM just to make sure I was putting enough pressure in there and getting it hot enough. It went into limp several times, (I restarted several times.) then I came down the mountain and checked for a split seem. I couldn't see any obvious fluid coming out (could only see/feel) the bottom and sides). I will continue to test this and give it some more drive time to try to determine if its a split seam on the resonator. From what you all have said here, it seems to be a common failure. Thanks for sticking with me on this.

The Dorman turbo resonator is only $30 on Amazon. May as well replace it and see what happens.

Also, the intercooler outer house ($47) and the easy sensors (Intake Air Temperature Sensor $23 and O2 sensor $85) as you diagnose the problem. These items typically need to be replaced anyway and there's always the chance that one of them will be the problem (or that you'll discover the problem as you're working on these things).

My last ambiguous error code dilemma lead me to replace some of these things, and even though it turned out to be something unrelated, it's good to have them all new and dependable.

Keith, at Green Diesel Engineering, knows all about interpreting these error codes and is willing to help me diagnose things. I highly recommend getting one of their "tunes" because it will make your Sprinter perform much better, and also because their help is invaluable.

For anyone who followed this thread, it ended up being the resonator. The back side of it had separated a bit on the seam. If you're new to doing your own repairs, this is a pretty easy change-out. Not too hard to do.