I have a 1991 190E 2.6 175K It sat for a year or so and I just revived it. I took it home did cap, rotor, wires, fresh oil and filter etc. It fired right up and ran great. (I have owned it for over 12 years but my son has used it for the last 6) On my test drive I was sitting at a stop light and heard the engine "Tapping" I pulled over and the "tapping" was gone when I opened the hood. It seems it is smooth and quiet in Park or Neutral but starts to sing when in gear. Any time I am stopped it "taps" and if I shift into N or P stops regardless of engine temp. I checked the trans and it took a quart to bring it up to the proper level. I have noticed it does not shift perfectly until it has run for a few minutes.

I have some deteriorated vacuum lines but everything else looks good and at 30MPH and above still runs outstandingly well and is getting 24.5-26 MPG combination city highway (I drive it 120 miles per day) I was thinking maybe a transmission/torque converter issue. My son had a heater core failure and overheated it but it does not overheat or use any coolant at this time.

I thought I would solicit some ideas from the group before I do a trans fluid & filter change so I don't feel like an idiot if it doesn't help and someone here had seen the problem before. I have searched and searched and cant find any posts that help me.

ANY ideas appreciated.

Thanks

__________________
Charlie

Current Family Stable

'87 260E -My former daily driver looking for a head
'92 500 SEL -Sundays and Holidays
'90 190E 2.6 -Current Daily
'84 VW Scirocco 38MPG!!! 225K Looking for an engine
'91 VW Rabbit Cabriolet
'91 VW Corrado G60
'82 VW Rabbit Pickup - Perfect Classic Truck
'95 S10 Long bed
'05 Jag X-Type
'16 BMW 425i convertible
'16 BMW 320i sedan

'93 VW Passat Wagon - RIP
'09 VW Passat Wagon - RIP
'95 VW Passat -RIP