Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Iain]

Ok team, after doing my rocker gasket and o rings,i fired it up and all is well...
I then opened the oil filler cap, how much pressure should there be when you lift the cap
Some, a lot or none?
i.e what differences do you hear?

I know with an old Carlton i had,which had blocked breathers,there was so much back pressure in the engine that the oil was being forced out the filler cap...
I assume my breathers are blocked(must be the metal pipe,just cleaned out the rubber hoses) as i got a slight 'push up' of the cap when opened...not severely but a bit

Can anyone confirm please?

[tunnie]

should be hardly any pressure, check the thin pipe which runs from the front drivers side of the cam cover to the throttle body, this often gets blocked. Don't bother cleaning it, they are only about £0.70 new from a dealer!

Also follow AA's guide on throttle body cleaning 

[PhilRich]

should be hardly any pressure, check the thin pipe which runs from the front drivers side of the cam cover to the throttle body, this often gets blocked. Don't bother cleaning it, they are only about £0.70 new from a dealer!Also follow AA's guide on throttle body cleaning 

Don't be ridiculous tunnie  , you're talking to a Scotsman! These people know the value of everything & waste nothing!
Anyway, Iain has already said he's cleaned both rubber pipes on the cam cover
You do get a 'bit' of a push when you remove the cap Iain, but nothing worth mentioning really as tunnie says. I think checking the large crankcase breather is worthwhile mate, as mine was full of crud when checked & causing more of a 'shove' than a push!!!

[Iain]

A true Scotsman! I even wake up in the middle of the night to make sure i haven't lost any sleep!

70p is nearly a quid! jeezo!

 

I'm thinking it the metal pipe as you say Phil,i'll phone for a gasket in the morning 

[PhilRich]

A true Scotsman! I even wake up in the middle of the night to make sure i haven't lost any sleep!

70p is nearly a quid! jeezo!

 

I'm thinking it the metal pipe as you say Phil,i'll phone for a gasket in the morning 

Good Lad
The youth of today eh? Tsk Tsk

[Abiton]

Forgive me if this is lack of understanding, but if the metal breather pipe is partially blocked, wouldn't that lead to less pressure coming through from the cranckase to the camcover?

More pressure in the crankcase where it's trying to escape from, but less in the camcover where its being sucked from by the rubber hoses.  :-/

Assuming the perceived excess pressure is at idle, surely one or other of the points that the small rubber breather hose attaches to is partially/fully blocked?

[shane1000]

did'nt you know that copper wire was invented by two scotsman arguing over a penny ? were talking 70 of them here ... thats nearly a full roll !! lol

[PhilRich]

Forgive me if this is lack of understanding, but if the metal breather pipe is partially blocked, wouldn't that lead to less pressure coming through from the cranckase to the camcover?

More pressure in the crankcase where it's trying to escape from, but less in the camcover where its being sucked from by the rubber hoses.  :-/

Assuming the perceived excess pressure is at idle, surely one or other of the points that the small rubber breather hose attaches to is partially/fully blocked?

I always thought reducing the bore decreased the volume but increased the pressure

[Iain]

I once dropped 50p, bent down to pick it up, and it hit me on the back of the head!!!

[Iain]

The pressure cant get out so it backs up into the engine, creating back pressure........ i think

[Abiton]

Easy enough to test my theory about the small breather:

With engine running at idle disconnect camcover end of rubber hose, expect a bit of a blow out of camcover stub if port is clear.

Then check that the free end of the hose is sucking nicely; if so the port at the TB end is clear.

Of course there's no harm whatever in cleaning out the metal breather, but I don't think you'll see less pressure in the camcover as a result, just less crankcase pressure, which is all good.   

[Iain]

Just ordered the gasket from the dealer,do it tomorrow so i'll post my findings!

[Iain]

Actually i think i will take off the rubber pipes aswell and do them again too...
I did them but i just used a rag...now i got a tin of carb cleaner, so i'll soak a rag and pull them through!

My cam cover gasket change went well... no leaks (so far,touches wood)
 

[john6177]

replaced all 3 on mine last year. couldnt salvage them. perished due to previous owner following vauxhall servicing to letter (every 5k now). large rear crumbled in my hand. cost me £15.00 + vat from vx for all three. that was in england though. made a difference, advise anyone to check them.

[mark.adams]

Isn't there a bit of pressure out of the oil filler cap from blow-by past the pistons?