Surging turbo

6speedsd · May 1, 2014

Hrmm...the day I checked IAT readings it was 65 degrees and raining outside. But I was reading high 80's to low 90's while driving.

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HeavyAssault · May 1, 2014

Could be the reading was from the intake manifold. I'd have to hook up my AE to verify what I'm able to read. I currently use the Insight CTS which reads the MAF sensor IAT. In the past I used the AeroForce OBD II gauge that reads both IAT sensors.

6speedsd · May 11, 2014

Well the vgt solenoid isn't the culprit. Swapped in a known good one with no change (thanks again Charlie!). Did the vgt relearn as well...seemed to get worse after I did that. I pulled the IAT today and it's not clogged at all, but gave it a quick cleaning anyways. MAP hose is clear as is the fitting.

I need to get good data when it's working correctly so I can compare and figure out if it's a sensor issue, but this thing is so sporadic that it's near impossible to get that data! Anyone with a little spare time be willing to record some data off theirs for me to compare?

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WILD_PHIL · Jul 6, 2014

Got a question for you knowledgeable on this subject. Working on a truck right now that had a high pitch squealing from the turbo. I pulled the turbo to clean the veins and solenoid. Veins were dirty but looked OK. I think there is something wrong with the solenoid. While the truck was running we can unhook the solenoid and the squealing stops immediately. Hook it up and it starts again. I have cleaned the veins and the solenoid. Just looking for any other advice before I reinstall this. Do these solenoids go bad? Anything to check or clean? If not I'm going to replace the one rings on the solenoid and reinstall this.

mint-6oh · Jul 6, 2014

You sure squeling noise was from turbo and not cracked Inlet pipe? Changing vane position (like when you unplug solenoid) can change back pressure and the noise from a cracked pipe.

WILD_PHIL · Jul 6, 2014

That's exactly what we thought at first but the pipes look good. Truck has 250k miles on it and is bone stock. Any pointers on checking the pipes?

fordfreak4life · Jul 6, 2014

Check the bellows for soot

WILD_PHIL · Jul 6, 2014

When you are at a stop it's squealing but when you take off it stops and won't start again until rpms come back to idle. They said it didn't drive funny and showed no signs of an issue other than the noise.