Engine vibration issue


Apr 14, 2022
Rio Rancho, NM
05 golf TDI
I have been having a weird issue with my mk4 05 golf tdi BEW engine lately. When I am driving generally just before the car gets to the full operating temp, it will begin to shake violently and loose power like a bad misfire. It only does it while driving. This doesn't always happen but seems to be beginning to happen more frequently. The weird thing is, it will do this until I turn the car off and back on, either while coasting or stopped, then go away. The other thing is when it is doing this, if I put the car in neutral and rev the motor it runs fine but put it back in drive and the shaking continues. If I stop without turning it off while it’s doing this and let it idle in drive or in park it will have a very light vibration. I've read a lot about the cam lobe issues on the these engines but I am thinking this is not the issue as turning off and on the car shouldn't fix the problem. The vehicle threw one code which was for the MAS but on a day when the car had not shaked at all and had driven maybe 60 miles with no issues. I took it out and cleaned it and it did not look that dirty. Other things that steer me away from the cam is that there is no soot in the intake piping, no smoking, and doesn't shake when car is in neutral. I'm thinking it may be a sensor issue but don't want to just keep replacing them until I find the correct one. I've tried testing a few sensors like the MAF and cam positioning sensor but since the issue only happens when driving, I'm not getting any irregular readings. Things that I have done recently before the issue started was, changed the oil, air filter, replaced the oil pan as I got a crack and began getting a small leak (oil never got lower then the hash marks), fixed a leaking coolant tee just above the thermostat housing (now leaking slightly from the large radiator hose going the hoisting), changed the tandem pump due to it leaking, and pressure washed the engine from the leaking tandem pump. This was all done just before the issue started. When I pressure washed the engine, I did not start it for a day and let everything dry and tried to stay away from electronics. I've done this several times before on this vehicle with no issues.
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