What does the waste gate do?

[EArmsF350]

I have 4 codes showing on my truck. Waste gate malfunction P1690 and Wastegate control valve performance(wastegate fail steady state test)P1249, P0640 Air intake heater, and finally P1670 No electronic feedback signal detected. I'm not sure what the wastegate does but I obviously want it to work properly. How do I test the air intake heater. Should it get warm when the glow plugs are warming. Can I feel it getting warm. Or should I just try replacing the relay. I have power on 3 of the posts on the relay when the key is on but the 4th post never gets juice. No electronic feedback signal, I have no clue. Any input out there?

[dray8165]

First, your air intake heater is the device in the front of the x shaped pipe in front of the turbo. It only comes on in below zero weather, and its only purpose is to reduce smoking in those conditions. It is controlled by the relay next to your glow plug relay. Several places sell plugs to delete this device because it is considered unneccessary and blocks air flow through the intake. Unless you live on the border of Canada - I wouldn't pursue fixing it.

The wastegate is a protection device on the turbo that prevents overboost. It is set to allow venting of the exhaust during periods where the turbo output exceeds some preset number - usually 24-30 in the 7.3's. You may have gotten an overboost situation that set off the codes. Are you running any programmers?

[EArmsF350]

No, I'm not running any programmers. I just bought this truck 45 days ago and haven't driven it much. I need to repair the transmission before driving it too much. I made the dealership take it to a mechanic to scan the truck before buying it to see what came up. Those codes came up which I mentioned on the original thread. The mechanic said the PO had something in it becuse it had been pluggged into a port on the drivers floorboard next to the E-brake. He said if the screw was gone, which it was, he said someone probably had some sort of chip in it. The truck is exceptionally clean for 211,000 miles. Just some minor blems that need attention. When it was 10 degrees out when I bought the truck, I started it without it being plugged in and it started but it was real rough until it warmed up, so maybe a GP or all of them are bad. The GP solenoid is working but when I remembered that code about the AIH I thought maybe solenoid for it was out or the heater itself was bad. Anyway, I had the mechanic clear the codes before driving it 10 hours home and the only codes that came back are P1249 Wastegate control valve performance and P0741 TC clutch system performance/stuck.