Distinct miss just above idle- 617 turbo - Page 2 - PeachParts Mercedes-Benz Forum

ROLLGUY · #1 08-21-2013, 02:08 PM

Years ago, my bro and I put a junkyard 617 turbo from an '80 SD in his '81 300D. It had a miss in it, but found out it had a dead cylinder, so that engine was sold. I since got the car from him, and put in a good (at least I thought) 617 turbo from an'84 300D parts car. The engine has a distinct miss just above idle, but it not felt when accelerating. The car has great power (just about as quick as my former '82 300CD), and accelerates smooth and quick. However, driving down the road (35-45 MPH), it has a miss that is worst at about the RPM that is just above idle. I have checked the compression (all at 300+), replaced the injectors with rebuilt units with Monark nozzles, adjusted the valves, but it still has an annoying miss. It is almost like there is something wrong with the trans or torque converter (out of balance), as that is the only common thing to both engines. The guy I got the parts car from (bad trans), said it ran smooth when he drove it. I thought of doing a leak down test, but figured there was no need, as all 5 have 300+ compression. Any ideas?