kv6 oil leaks
 

why is it all my 3 kv6 powered cars have oil leaks, seems from rear seal area
but my one diesel 75 is as dry as a bone.
Same goes for old toyota hilux ute thats done 300,000km and still dry underneath!!
Is there a design fault here??

Have you cleared the crankcase breather pinhole in the camshaft covers recently Peter?

Simon

hi simon, took your advice and checked the breather holes out.
The large pipes were ok but the small one on the front rocker cover was
blocked up as when it was unplugged oil poured out.
The only one i cant get to is the rear one which is under the rear head passenger side.
It Ts of the front small pipe and has an inline one way valve.
All i know is the car seems to be running smoother by just cleaning the front one out.
re oil leaks, we shall see if it makes any difference!!

The breather hoses don't have any one-way valves Peter. You're probably looking at the vacuum feed to the brake servo there but your sentence seems to have lost some words.

I'm glad that you've noticed a difference. Did you manage to clear the small pin hole in the LH bank camshaft cover without removing it? The RH side requires removal of the plastic manifold chamber. :o Once done though, your engine should magically gain a few bhp!

Simon

As far as i know there are four breather holes on the rocker covers.
The two larger pipes (one near the vis and one on the front cover)
and two smaller pipe ones( one on front and one rear under the manifold passenger side which is the one i cant get to.
i would think maybe removing the battery box might be able to get to it but not sure.

Yes the rear one is a pain to get to. Trouble is, if you just poke the smaller holes clear then the debris ends up trapped between the gauze filters and the outlet holes, suction will then probably once again trap the debris and block the holes (unless twist drill perhaps). Only sure way is removing the cam covers and if you remove the upper inlet manifold to clear the restriction then you’re halfway there.

Regards

its got me why the larger pipe holes are quite big but the other two are like pin holes which are going to block up easily.
Wonder if they can be widened?

The most comprehensive description of the breather system I’ve seen is believe it or not in Haynes which basically states that the smaller pipes are for extraction of gases and the larger for air into the engine, but under full throttle all pipes are used for extraction.

I could imagine that when the engines were new blow-by gases were minimal but as they age perhaps slight enlargement could be beneficial.

Cam-caps blowing is often terminal, and here we have problems of water vapour freezing in the pipes or inlet manifold, so I’ve bothered to lift the cam covers.

Regards

Just for ease of understanding can anyone offer any photos of the pipes / joints / bits that are being referred to?

Or a previous thread with photos?

I'd look /search myself but I'm sitting outside a clothes shop changing room on my small screened phone while the wife tries on outfit numbers 3 4 and 5 .... I'm so bored!! :D :D

Tia

John

Some photos here from Reebs: https://the75andztclub.co.uk/forum/s...d.php?t=116751

Regards