318ti.org forum - View Single Post - M44 Long Term Fuel Trim 20-25

FuelCell250 · 08-01-2015, 11:43 PM

In town it's getting about 18 mpg. Ouch. The car also needs to pass emissions in 3 weeks.

I couldn't see where any other vacuum leaks could be from, so I took it to a BMW specialist and they smoked the intake. Unfortunately I couldn't be around when they smoked it. They identified two possible leak sources:

- Vacuum lines from the fuel injectors
- A leak from a possible crack on the DISA valve

I replaced the vacuum lines from the fuel injectors, and no change. That leaves the DISA valve. It's about a $280 part, non-OEM. I can't see any cracks on it (I didn't remove it). Has anyone had experience with this part failing, or what the replacement procedure is? It looks like the lower intake manifold has to come out, which is a real pain.

08-01-2015, 11:43 PM	#8
FuelCell250 Junior Member Join Date: Apr 2015 Location: Boise, ID Posts: 19 iTrader: (0) Photo Gallery	In town it's getting about 18 mpg. Ouch. The car also needs to pass emissions in 3 weeks. I couldn't see where any other vacuum leaks could be from, so I took it to a BMW specialist and they smoked the intake. Unfortunately I couldn't be around when they smoked it. They identified two possible leak sources: - Vacuum lines from the fuel injectors - A leak from a possible crack on the DISA valve I replaced the vacuum lines from the fuel injectors, and no change. That leaves the DISA valve. It's about a $280 part, non-OEM. I can't see any cracks on it (I didn't remove it). Has anyone had experience with this part failing, or what the replacement procedure is? It looks like the lower intake manifold has to come out, which is a real pain.