I have “new to me” 2000 VW Passat GLX (station wagon). Intermittently at @ 30 mph it will make a thunk and momentarily “brake” as if it just hit a pot hole. I assume its transmission related, but what am I looking at to repair it?
Loose engine/transmission mounts might be the cause. The other possibility is suspension problems.
A competent mechanic should thoroughly inspect the underside of the car first. I hope it’s an easy to remedy problem.
Personally, I doubt if the problem is transmission-related.
I like Docnick’s theory about loose engine or transmission mounts, but there is another possibility that comes to mind…if this vehicle has Electronic Stability Control (anti-skid system).
Recently, Honda issued a large recall on ESC-equipped vehicles that were…guess what…suddenly and unexpectedly applying the brakes (briefly) while driving down the road. The cause of Honda’s problem is a malfunction of the ESC, and if Honda has identified this problem then it is possible other mfrs also have this problem, but have not yet identified it.
Offhand, I am somewhat doubtful that any VWs came equipped with ESC for the 2000 model year, but if this car has ESC, then this may be something to consider.
If an automatic, I’m thinking this is a transmission problem of some sort or another. Engine & transmission mounts are another possibility, but less likely.