hi there,

any of you guys changed your valve stem oil seals without removing the heads?? how much of a job is it??, is there anyone not too far from north wales who can help me with them or i can bring the zed to them,

 

any help greatly appreceated, :dance:

 

dewi thomas

Very big job this and is best done with unit

out of car! Baggins :bow: will tel you more, tell us the

symptoms of the smoke that makes you think

it stem seals?

 

Allan

hi there,

any of you guys changed your valve stem oil seals without removing the heads?? how much of a job is it??, is there anyone not too far from north wales who can help me with them or i can bring the zed to them,

 

any help greatly appreceated, :dance:

 

dewi thomas

 

Dewi what ye done now

 

You can only change them with heads off as valves have to be removed first, after engine has been removed. One of the symptoms of stem leakage is under de-acceleration the engine will smoke the most, not sitting at the lights when they mostly smoke. Tubs,PCV Valves, breathers, old oil, rings, guides are all causes of the dredded blue smoke. Speak to are man Phil @C&S Woods you know he can sort it.

 

Are you still getting smoke after your tubs were changed last year?

I think its a head off job. Apparenlty you can take the heads off with the engine still in.

The unit has to come out of the car and the heads removed

if you try to do it in the car with the heads on you will have

24 valves inside the cylinder block when you try to take the springs

and collets off! :headvswal

oh dear this does sound like a big job :confused:

 

ok then when coming down a hill or deaccelarating i get no smoke but just after deaccel when i put my foot down to start off again i get a nice puff of blue smoke!!

 

i dissconected my breathers to prove it wasnt them and it still smoked when i started off after accel

 

which only leaves one thing i think valve stem oil seals hope im right!!

 

i have read the nissan manual and it says it can be done with the heads on!!

 

i think i better do a compression test before i go any further what do you think??

 

what is the appropriate cost of doing these seals heads off ect??

£1000+ very simular to cost of tubbys.

good indicator of stem seals is smokeing

on startup after overnight lay up.

the oil seeps through the seal into

the piston. sorry for the bad news comp

test will tell you but you may not loose

much pressure and may not be ovious.

each seal has to be coxed out by soaking

heads in hot oil bath to aid removal,there is also 24

of the buggers!

Sorry hot oil is for guilds no seals, its late im going to bed!

Engine out job mate if you want to do the job properly

you *can* do valve stem oil leals on some cars without removing the heads. iv got some tools iv made up to do mercs in situ. never tried it on a zed tho.

 

basically you need to get the cyl up to tdc on the compression stroke, pressurise the cyl with a compressor, then you can compress the valve springs & remove the colletts & springs - hey presto stem seals out!!

 

it will depend on if you can make up a tool to compress the valve springs really. may work out quicker just to pull the damn engine & remove the heads :D

yeah im quite sure i can make a spring compressor in work no problem and i even have a spare engine to practise on, the only thing that is worrying me really is doing the cambelt as i have to remove the cams to get to the seals!!

you *can* do valve stem oil leals on some cars without removing the heads. iv got some tools iv made up to do mercs in situ. never tried it on a zed tho.

 

basically you need to get the cyl up to tdc on the compression stroke, pressurise the cyl with a compressor, then you can compress the valve springs & remove the colletts & springs - hey presto stem seals out!!

 

it will depend on if you can make up a tool to compress the valve springs really. may work out quicker just to pull the damn engine & remove the heads :D

 

You are right Paul, as i have done a few myself,Not on zeds though...

I learned this from a american chevy magazine while i was working on a V8 chevy small block.

Apparently if you use compressed air the valve will refuse to be pushed down due to the amount of high pressure in the cylinder bore.... :)

yeah im quite sure i can make a spring compressor in work no problem and i even have a spare engine to practise on, the only thing that is worrying me really is doing the cambelt as i have to remove the cams to get to the seals!!

Cambelt is the easy Part.... :duffer:

You are right Paul

 

I know ;) :D

Am I missing something here, why can't you remove the cylinder heads without removing the engine?? :confused:

 

 

 

Richard

Am I missing something here, why can't you remove the cylinder heads without removing the engine?? :confused:

 

 

 

Richard

For a start you will have to remove the turbos and exhaust manifolds which you can only do if the engine is Out....make's life alot easier... :)

have you actually done the stem seal test???

 

car up to running temp

drive car in second to about 3500 - 4000 or higher if you want

then leave car in gear and come right off the gas

let car decel. to about 2500 -2000

then boot it ..... and look in rear view mirror smoke ?????

 

running the motor up like that causes some pressure build up in the bottom end this then pushes the oil past the old hard stem seals down the guides and into the cylinder hence the smoke when you boot it its the oil getting burnt off.

 

there will be a nice cloud of blue smoke if there knackered

 

cvh fords do it the heat from the motor slowly hardens the seals untill they seal no more also crap oil can do this...

Draper do a tool for this job i dont know how good they are?