PCV Valve on an Alloytec

[SammyD]

Hi,
I've had my VZ Berlina for about 3 weeks now and so far I'm pretty happy with it except for a couple of niggles (even worse because I'm a qualified mechanic)

First one is a lot of whine in first from the 4 speed auto although I'll live with this as it's done 87,000km and it's just wear in the gear set. I'm going to get the trans serviced soon anyway as I think the service intervals on the trans and spark plugs are a crock. I pulled out the 2 plugs I could get to without taking the plenum off (a $100 gasket?!?!) and they have a lot bigger gap than 1.1mm and the earth electrode looks like it's been bent towards the centre.

The second problem and more annoying because I'm convinced it's an easy fix is that when the car is cold, there is a pulsing induction noise that sounds very plasticky (is that a word?) As the car warms up, the noise reduces in volume. If the car is left for a while once it is warm and then re-started, the noise is even quieter (I believe from heat transfer going from the engine to a plastic part). I removed the engine covers and drove the car today and the noise was not as loud as normal, possibly because the covers actually channel the noise towards the firewall. The noise changes with the rpm of the motor and is easiest heard at about 33-50% throttle but it is at a much lower rate than the engine speed. I'd say that it pulses at about 2 or 3 times a second up to 4 or 5 times a second depending on the rpm.

If anyone knows where the pcv valve is on the 175 (the pipe i found doesn't have a valve in it and feeds from the lh roccker cover to the intake) or has any suggestions, I'd be most grateful.

P.S. Sorry about the "war and peace" length post but it's easier than responding to a lot of questions.

 

[80shovelead]

Hi SammyD, welcome to jc
in regards to the PCV valve, does it sound erratic in operation? the location i believe is on the LH side up near the intake manifold, but im not sure if its the same between the 175 and 190 motors though

 

[HUMBLZ]

what is the purpose of this pcv valve?

 

[SammyD]

what is the purpose of this pcv valve?

It feeds oil fumes from the motor back through the intake to be burnt. It's to help reduce emissions.

 

[SammyD]

Hi,
I've had my VZ Berlina for about 3 weeks now and so far I'm pretty happy with it except for a couple of niggles (even worse because I'm a qualified mechanic)

First one is a lot of whine in first from the 4 speed auto although I'll live with this as it's done 87,000km and it's just wear in the gear set. I'm going to get the trans serviced soon anyway as I think the service intervals on the trans and spark plugs are a crock. I pulled out the 2 plugs I could get to without taking the plenum off (a $100 gasket?!?!) and they have a lot bigger gap than 1.1mm and the earth electrode looks like it's been bent towards the centre.

The second problem and more annoying because I'm convinced it's an easy fix is that when the car is cold, there is a pulsing induction noise that sounds very plasticky (is that a word?) As the car warms up, the noise reduces in volume. If the car is left for a while once it is warm and then re-started, the noise is even quieter (I believe from heat transfer going from the engine to a plastic part). I removed the engine covers and drove the car today and the noise was not as loud as normal, possibly because the covers actually channel the noise towards the firewall. The noise changes with the rpm of the motor and is easiest heard at about 33-50% throttle but it is at a much lower rate than the engine speed. I'd say that it pulses at about 2 or 3 times a second up to 4 or 5 times a second depending on the rpm.

If anyone knows where the pcv valve is on the 175 (the pipe i found doesn't have a valve in it and feeds from the lh roccker cover to the intake) or has any suggestions, I'd be most grateful.

P.S. Sorry about the "war and peace" length post but it's easier than responding to a lot of questions.

UPDATE : Apparently the PCV valve isn't replaceable by itself, you have to buy a rocker cover kit that's $180. I think I'll be giving that a miss.

The good news is that I got the 2 gaskets for the plenum and spark plugs this morning. The guy at the dealer did them for me at trade (gotta be lucky some time ) so the whole lot only cost me $82. Does anyone know if there is a specific torque for the plenum bolts? Being alloy, I would suspect that there is.

Sammy

 

[andyman]

UPDATE : Apparently the PCV valve isn't replaceable by itself, you have to buy a rocker cover kit that's $180. I think I'll be giving that a miss.

The good news is that I got the 2 gaskets for the plenum and spark plugs this morning. The guy at the dealer did them for me at trade (gotta be lucky some time ) so the whole lot only cost me $82. Does anyone know if there is a specific torque for the plenum bolts? Being alloy, I would suspect that there is.

Sammy

even if you remove the valve cover and blow the pcv out with brake clean to make sure the little ball in side in moving freely. then you just need a valve cover gasket.

also that noise, you speak of, is that the sort of inconsitant low pitch ticking noise when cold? thats the normal sort of noise from those. nothing to worry about. it either a little piston noise from being slightly oval when cold. or the hydraulic lash adjusters not being fully pressurised with oil when dead cold. i believe the noise is little more from the latter.

how much is the plenum gaskets seperate? id just tighten them up firm but not mega tight - its only alloy, theres a holden techline notice at the moment showing what happens if you over tighten the sump bolt, either crack around the thread or splitting the case, same goes with the plugs only about 20-25nm i believe.

let us know how you go with the plugs, im only at 80,000 and i estimate it will be roughly 3 years before i get to 105,000 when there due by the book.

cheers andrew

 

[SammyD]

even if you remove the valve cover and blow the pcv out with brake clean to make sure the little ball in side in moving freely. then you just need a valve cover gasket.

also that noise, you speak of, is that the sort of inconsitant low pitch ticking noise when cold? thats the normal sort of noise from those. nothing to worry about. it either a little piston noise from being slightly oval when cold. or the hydraulic lash adjusters not being fully pressurised with oil when dead cold. i believe the noise is little more from the latter.

how much is the plenum gaskets seperate? id just tighten them up firm but not mega tight - its only alloy, theres a holden techline notice at the moment showing what happens if you over tighten the sump bolt, either crack around the thread or splitting the case, same goes with the plugs only about 20-25nm i believe.

let us know how you go with the plugs, im only at 80,000 and i estimate it will be roughly 3 years before i get to 105,000 when there due by the book.

cheers andrew

Just finished doing the job. Took about 90 minutes including cleaning the manifold and plenum and cleaning up the throttle body a bit. The old plugs were noticably worn but all showed even deposits, just the usual burnt fuel crap, no oiling The plenum bolts were ridiculously loose, like hand tight plus a half a turn. The new gaskets ($35.80 for the pair) are made of metal with a silicon type ring around the ports, a much better idea that the crap paper-type that was on there. At a guess I'd say that all the harness connectors were designed in Germany too, going by the over-engineering.
An interesting result from all the messing around is that I think the economy is slightly better cruising at 60 which I out down to the manifold gasket rather than the plugs. I'm still glad I did them early once I compared them to the new ones, lots of wear.
As for the noise, it's got me stumped. If it were piston slap, I'd expect to be able to hear or feel it on over-run. The noise doesn't seem to generate any form of vibration. I'm going to rip the wheels off tomorrow to check the front brakes so I might take a close look at the exhaust.
At least I've almost done all the servicing stuff I want to do, even after only having the car for 4 weeks. I just hope that if something breaks it happens within the next 2 months.

Sammy

 

[andyman]

At least I've almost done all the servicing stuff I want to do, even after only having the car for 4 weeks. I just hope that if something breaks it happens within the next 2 months.

Sammy

no worries, i might find myself doing plugs very soon than. i wouldnt be to concerened about thing breaking, ive seen some hard things happen to the cars at work and the swollow it up (literally lol - water) and keep on going

 

[FnomnaVZ]

even if you remove the valve cover and blow the pcv out with brake clean to make sure the little ball in side in moving freely. then you just need a valve cover gasket.

Is the PCV on the rocker cover in this pic?
http://forums.justcommodores.com.au...175kw-motor-vz-intake-manifold-assebly-91.jpg
The "PCV fresh air tube(3)" - one end goes to the big inlet tubing just before the throttle - and the other end into the rocker cover - and is that where the PCV is?

I have oil in that small tube which seems to have been putting oil into the big intake pipe (the pipe between the MAF and throttle). Does that mean the PCV isn't working? Or is it because someone put the big corrugated pipe (next to the MAF) back to front? (like in this pic the left and right ends were swapped
File:Alloytec V6 engine of a 2006 Holden VZ Commodore SVZ 01.jpg - Wikimedia Commons
which meant the big end was on the small MAF end, leaving a gap when the clamps are done up! - I've now fixed that bit.)

Which way does the oil vapour flow in the PCV system and that pipe that hooks into the throttle intake? Judging by the name 'fresh air tube' I'd think the tube is taking in fresh air to the rocker cover?

 

[vangara]

Hello All

the pics attached to this post - the one taken from repair manual i guess, could some one please tell me what kind of repair manual was that???? i have a chevy lumina ltz which i guess is is rebadged calais vz, and i desperately want a repair manual, can i buy it online? appriciate any help.