I think (fingers crossed) ive found the cause of my smoking at idle issue.........i dropped the oil out of her yesterday and it was as thin as weasel p*ss!!!. it was castrol edge 5w40 fully synthetic and has been in for approx 1800 miles but when it drained it did look or feel any thicker than brake fluid!, and thats no exaggeration, and had appeared to have completely broken down.

 

refilled her with 10/40 semi and fitted a new filter, drove home (approx 12 miles) and left her idling on the turbotimer for about 4 minutes........and no smoke :) , whereas the night before it was billowing out :(!!!.

 

going by the state of the castrol that came out i would never use it again.

my car used to smoke a lot on idle and then i changed oil to castrol edge 5w40 fully synthetic and now it smokes just a bit and only till it gets to full temp

Had same once, put in Millers 10-60 , that sorted it.

isnt 5w a bit thin? i use 10W50 from opie oils.

 

dan.:biggrin:

5w/10w is the Cold temp thickness the Last number is the Max Temp Number ..

 

sure of it

can the wrong oil really cause car to smoke mine also does it

this is interesting, guess the oil must have broken down which is unusual for castrol. this happened to my mates celica on the track at japfest though, but he was using cheap oil.

Here are a few good reads on oil, from our very own member and trader Oilman

 

http://300zx.co.uk/forums/showthread.php?34815-Oil-Advice-and-Recommendations&highlight=

 

http://300zx.co.uk/forums/showthread.php?122188-Oil-advice-for-a-modded-300ZX&highlight=

Same again tonight, got home after a good high speed run and she sat idling for 5 mins on the turbotimer and no hint of smoke from either exhaust so changing the oil has cured it.i can honestly say I habe never seen oil as thin as the castrol that came out of it, especially only after 1800 miles!.

Done some digging on the net and it appears that castrol edge does break down quite quickly as the additives shear due to load and heat and a w40 will drop to like a w20 after 1500-2000 miles!.From what I can gather it isnt even a true fully synthetic, just a synthetic blend with a shedload of additives.i am sure that someone will correct me if im wrong, and I know all engines are different and maybe on a newer engine with tighter tolerances etc it would be fine,but mine really didnt like it at all and a lot of people on a range of forums appear to habe had the same problem with it breaking down very quickly and causing a burning/smoke issue that has stopped as soon as theoil was changed.

Fuchs pros is a truly synthetic oil and all i use on the cars now i started using it first when i use to race a zx6r and found it gave me a power gain of 8hp its that good :)

i always use the 10/50w :)

An oil with a 5 should only be used if the ambdient temp is never going to rise above 4degrees c for reference i dont even know why they sell it in this country to be honest as its not suitable

toyota started using it in all there cars from factory couple of years ago but when customers complained about oil consumption warranty was to change it back to 10/40 then they all complained about loosing 3-5 mpg so i shall let you all draw your own conclusions on that one ;)

In motor racing I have always used a veg based oil eg. Shell M or Castral R . You must first treat the oil by warming the engine up to running temp and then letting the engine cool down, then warm the engine up to running temp again before the start on the starting grid. At the end of the day drain the sump oil out and dump because this oil will oxerdise if left in motor to long .[go off or turn to goo if there is methernol used as a fuel] The engine has to be moderfide to use this oil by enlarging the oil ways by 20% this oil will lubricate at a lot lower oil pressure than normal and I never had a engine blow useing these oils.:thumbup1: