[Healeys] Oil Change Frequency

[Oudesluys]

That may only be so on some modern cars, but not all. Plenty of EU and 
Japanese cars that have a system that can be cleaned out, however 
sometimes you do have to take some trouble to find out how though. This 
is usually conveniently overlooked by the service dealers (similar to 
forgetting to change the fuel filter and still charging you for it). Not 
cleaning the PVC hardly ever leads to trouble though (at least in EU), 
even after very high milages. Sometimes extra oil consumption can occur 
in extreme cases.
On older cars, and that is were our interrest is, the crankcase 
breathing system can always be serviced by rinsing in petrol, burning 
using a blow torch, using compressed air, replacing a filter, cleaning 
or replacing a rubber valve etc. Often there is no servicing neccesary 
at all as on many occasions it  is a straight connection from either 
crankcase or valvecover  to plenum or intake manifold with only some 
fairly crude device in the block or valve cover to prevent oil droplets 
to enter the system.
Sludging in EU was a problem about15-20years ago, when unleaded petrol 
was introduced, but has not been an issue for a long time since.
Kees Oudesluijs

> The only maintenance for the PCV system on the cars I work on is 
> Changing the oil.
> The systems are engineered into the design of the engine and have no 
> serviceable parts.  Assuming the owner changes the oil, they don't 
> need service.  Extend the oil change intervals too far and the system 
> gets clogged from burnt oil vapors which build up and plug the entire 
> system.  When this happens, the entire system has to be changed.  In 
> extreme cases, the oil pan has to come off to clean the passages 
> inside the block.
>
> The change over from leaded gas happened in 1975, sludging is a 
> problem that cropped up in the last 3-5 years.  Sludging is not 
> related to leaded gas in the least.  Last I heard it was more of a 
> cold weather issue, than a warm weather issue............. 
> Rick