A couple a days ago I went to see some cars which are for sale. Not interested in buying paricular just for fun. But I saw an Astra GTE 16V which had very poor bodywork,made in 1990, but the owner said it had replaced engine, and this one had only 50000 miles on clock. At first it didn't look genuine to me, but when he started it I was amazed to hear it so quet from the engine department, especialy from top. He said, though, that it had some thicker oil 15w-40 or more.
Now, to my question. I have 102 000 miles redtop from 1988. It doesn't burn any oil, but leakes some from the sump- approx.1 lit per 5000 mile. For Opel/Vaux Fully Synth 5w-40 I think it is pretty good . So, my engine is fine, BUT the thing is - it is MUCH louder then his. It is from the top of the engine that I noticed that.Not that it is of any councern for me, but I was wondering what is the cause for this? Is this hydraulic lifters(mine does not tapp on cold start), or "valve train" or he is just running a thicker oil? What is your experience on this?