Much as I thought! I have never used them. My thoughts have always been, if the additives are any good the oil manufacturers will stick em in anyway.
jamesmartin
Well-Known Member
but some like zinc were removed when they moved to cats quite useful for cam followers that arent rollers
...just like lead removal meant valve seat recession started up again! A step forward means more work to counteract the effects of the progress. So does that mean changing oil more frequently will counteract the removal of zinc or do you need to find a zinc-rich additive? (Never knew that about the zinc.) None of my Discos have a cat. Can I still find oils done to the old formulas with zinc in them? Or am I overthinking this?
jamesmartin
Well-Known Member
yes and yes you can or add it, theres an extreme pressure point with the cam and flat topped tappet,
That makes sense about the flat topped tappet, although it is kind of counter intuitive. I change the oil every 5k normally anyway, but I'll have a look out for the zinc additive and also determine which of mine will need it, apart from the V8 which I take it is a definite. cheers for the info!
jamesmartin
Well-Known Member
oil changes are important ,the most notable thing with those that hadnt was white bearing material eroded of the shell bearings
Cheers mate!
James, what is your view on engine flushes or flushing oil?
I don't use them and an old mate of mine who had been a mechanic for years told me that for a petrol engine you may as well put a gallon of diesel oil in it as it had a higher detergent level and was cheaper, and then to run it around for a coupla hundred miles. No idea really on that one.
jamesmartin
Well-Known Member
the old castrol oil that was recommended wasnt detergent enough,id just use a high detergent oil and regular changes no flushes
Nice to know that I've been doing the right thing, whether by chance or not, doen't matter.!
I'm running Rotella 15W-40, which has higher ZDDP levels. I change it every 3k miles, but have about 2k until my next change is due. I'll plan to run one of the crankcase cleaners for 50 miles before the change. If it doesn't quiet down, I'll start thinking about rebuilding.
Thanks for all of the input everyone - much appreciated.
Thanks for all of the input everyone - much appreciated.
If it is just a lifter, you may well be able to find it by using a mechanics stethoscope while it is running then trying each one with a set of feeler gauges, although that might not work very well as the gap is only taken up once the lifter fills with oil. I have had this before and once the engine got hot and the oil got thinner, the lifter started working. This is quite common. Quite simply the lifter is opening the valve late and closing it early as thr oil isn't pressurising it and pushing it towards the valve. Just struck me, could a shim have come out somehow?
Anyway, have a look at this which tells you quite a lot.
https://www.pistonheads.com/gassing/topic.asp?h=0&f=66&t=1779074
Anyway, have a look at this which tells you quite a lot.
https://www.pistonheads.com/gassing/topic.asp?h=0&f=66&t=1779074
