I own a VW Golf V 1.6 FSI with 295k km on the meter. It has a BLP block.
Recently, the chain and all its components have been replaced. After that, there was loss of compression on one cylinder (cylinder 1). We checked the whole car and the ERG valve turned out to be defective, so that was repaired. When we tested the car again, 2 cylinders had a loss of compression (# 1 and 4). Started it again and then we had 1 cylinder (#1) with loss of compression.
We changed the springs on the cylinder in question, even though the old ones were still in good shape. Since then we haven’t been able to find a solution.
As a precaution, we’ve also cleaned the atomizer and replaced the 16 tappets, but to no avail.
As a last resort we changed the cylinder head and so that one is in good condition.
The throttle has been replaced with one from another car (also set up through VAG COM), but it makes no difference.
In the meantime, the catalyst has been checked as well and it’s in good shape.
The timing has been checked and turns out to be perfect; so it’s only the compression that isn’t working on all 4 cylinders. Spark plugs and ignition coils have all been replaced, but to no avail.
Who knows a solution for this problem?