Hi all,

Me and a friend just finished rebuilding his 2.8 V6 (ALG). New cylinder block/pistons, reconditioned the heads, replaced all seals and bearings. New DMF, clutch and timing assembly, etc. etc. Anyway, the engine's back in the car, with everything hooked up and we're running into some issues here.

#1: The engine doesn't seem to run quite right. When starting from cold, it runs at ~800rpm initially, before dropping back to ~650rpm after warming up. Initially, it's hard to notice, but it idles somewhat irregulary. After the idle drops to ~650rpm it's more noticable by the exhaust note and engine shakes somewhat. So far we've:

• Replaced all vacuum hoses,
• Checked all electrical connections,
• Measured the coil & spark wire resistances. Both seem to be well within spec.
• Checked the spark plugs, they don't show any obvious signs of malfunction or misfires
• Replaced the O2 sensors, to no avail.

There's no CEL on the dash, oil pressure and compression are excellent. Cooling temp sensors were replaced last year. By now, I'd like to get an OBD reading on the car, but more on that later.

#2: The steering pump keeps making a nasty whirring noise. We've followed the procedure to bleed the system (steering back and forth on jacks), and it eventually stopped making noise, and bubbles stopped showing up in the reservoir. Next day, we fired it back up, and the noise came back shorty after (not immediately). Proceeded with the bleeding procedure until all noise disappeared again, only to have the noise return on the next startup. We've been through this five or six times by now. Is it possible that the system is pulling in air somewhere, or does it just take an ungodly amount of time to bleed the system?

#3: We can't seem to get a reading on our ODB scanners. Granted, we're using off-brand, generic scanners, but all of these have always worked fine for me on any vehicle, some VW's among them. Things we've checked:

• Disconnected the radio and ABS module, having read that these might cause issues. Still no connection.
• Tested connections for pins 4 and 16. They provide GND and +12V as they should. Scanner connects to phone, but not to ECU.
• Measured connections between Pin 7 (K-Line) and the chassis, as well as the battery to see if there's any unwanted connections. Results are as follows:

• Voltage between K-Line and chassis is 2.0V. My meter is quite slow however, so this might just be how it interprets the digital signal? (Alike to PWM on LED's) Not sure on this however.
• Resistance between K-Line and chassis is 14kOhm. Battery was disconnected for this, and the next measurement.
• Resistance between K-Line and battery + terminal is 18~19kOhm.

Worth noting here is that we've never been able to get a connection to the ECU through generic OBD scanners. We've borrowed a copy of Würth WOW Diagnostics in the past which was able to get readings, but we no longer have access to this system. We don't have direct access to a VAGCOM, so haven't tested that yet.

Any help is appreciated!