I bought my z a few months ago with a slightly noisy lifter on tickover but other wise all fine.

Last week it was getting louder and since I hadn't changed the oil since I bought it I thought it best to do it then.

After changing the oil the lifter got really loud and the car started running lumpy on tickover but fine when driving (although the lifter has become a loudish knocking even when driving it.

Checked the ECU for codes... code 55, nothing wrong although there is some pre ignition on accelleration.

Yeasterday I decided to phone a trusted trader who deals with zx's and price up relpacing the lifter, gaskets, and anything else I may as well do while I am in there pulling my motor apart and at the end of the conversation he said "have you tried putting 20/50 oil in it just to see what it does"?.

As a long shot I did just that today.... and, engine running sweet and no knocking.

Don't know now weather to change the lifter that was causing the trouble or just carry on using good old 20/50 as my car seems to like it :biggrin:

Before you go changing the lifter, have a search through this site at other threads that concern tapping. When I first purchased my car, I had the same problem. I took the car to a 'specialist'??? who recommended lifter replacements. £1000+ later, car was lovelly and quiet for about thirty miles and the tapping came back. Approaching the specialist for some kind of compensation didn't work, so I took the motor to a race specialist who identified that it was more likely to be an internal oil feed port feeding the lifter rather than the lifter itself. When I overhauled the engine, all the oil lines where cleaned out at high pressure. On rebuild, no tapping. Food for thought mate, it could be an expensive way of diagnosing your problem. As I've said mate, have a look at previous threads. Good luck.

Try an Engine Oil flush i have used it ages ago and it worked a treat.

(CLICK ME)

 

Far cheaper alternative that if works saves you a truck load and if it doesnt puts you like £30 out of pocket no biggie! Also as you said earlier a slightly thicker oil should do the job to lube them back up properly

My thoughts exactly and I am very thankful to the specialist guy I contacted for giving me the idea, he could easilly have sold me about 700 quids worth of stuff rather than give me good food for thought... thats why I still use him after all these years.

(It was the Z center by the way)... always helpful to me and never tries to sell me something I dont need.

In the end I think 2 oil changes in one week was what it needed as there was probably a bit of crap in an oil feed like you said.