Backstory as follows: My car, which I call 'Liebchen', is a 1992 1.8 5 gear stick shift VW Golf with abut 110,000 original miles on her. Last November I replaced the clutch, flywheel, distributor cap/rotor, spark plugs and wire set and my mechanic installed the parts. Interestingly, the original clutch/flywheel lasted until about 2yrs ago (late 2014) whereupon I needed to replace it. I purchased the clutch/flywheel from the same auto part store I am now complaining of and had it installed by the same mechanic I speak of now. I have purchased a number of parts for Liebchen over the last 6 years or so from the same shop and trusted them implicitly - and following their advise - I have always bought the best parts I could because I want and need her to live long as VWs are known to do. Unfortunately, the best that I could buy for her then came with a 2 year warranty AND amazingly very shortly very shortly after warranty expiration the clutch went bad and needed replacement again. Stupidly, I purchased the clutch/flywheel and tune-up parts from the same auto shop which brings me to November 2016. This means that I have purchased two complete clutch kits and flywheels in four years; each of which I purchased from the same shop and had installed by the same mechanic.
Now I find the new clutch randomly failing to slip into gear whilst simultaneously making a back fire sound. The car makes a different slightly grinding noise, also randomly, when I shift gears. My mechanic assures me that all is well with the car but I have strong reason to believe otherwise particularly as the clutch is so high that I must strongly depress my foot to the floor to shift. After on-line research and browsing through the auto part store's own web-site I find that the clutch set sold to me by them is suitable for a variety of older VWs but not my make, model, or year. Further the flywheel, spark plugs and wire set also appear to be wrong for my car per the auto shop's own website. Hells BELLS is all I can say at this point and now I reach out to you good reader. I realize that you may tell me that I should have purchased the parts from VW but I didn't so such is life. But with that said I can assure you that the store from which I purchased the parts from is thought to have a sterling reputation and I know that they are widely used by the auto repair industry at large.
I have already spoken with the shop pointing out to them that this is the 2nd clutch et al that I have purchased from them in two years and alerting them to the fact that I am investigating the issue. No one in the shop can drive a stick shift so that I am unable to demonstrate to them the gear issues but the manager has acknowledged that the store may be responsible for my problems. I have told the store that I aim to check the issue out further and get back to them. Please give me your best thoughts on this matter. What think you? In short how would wrong parts affect the gear shift and why are the gear issues sporadic rather than constant? What clutch,flywheel, etc part number and manufacturer would best serve my car? Thanking you in advance I close by wishing you all the best.
PS: Rest assured that I am not your typical damsel in distress as I am tough as as alligator but I sure could use any help offered.