right continuing on from out tappy engined track z, we have removed the rocker covers to have a look at the lifters, now, we have found the head on the high compression side of the engine to have lifters which we can press down on, and on the other side the lifters dont compress by hand.

 

now we turned the engine over to build oil pressure here is what we found......

 

the "normal" compression head on the drivers side the oil comes up through the lifters and lubricates the camshafts normally..(?)

 

on the higher compression side (passenger side) you can here the lifters tap but more importantly there is little to no oil being forced thrugh the lifters to lubricate the camshafts!!

 

is this due to gummed up lifters (seems like all of them!!) or have we got a possible blockage in the oilway leading to the head...

if so what can we do to clear the blockage??

 

 

i keep seeing references to a check valve pressed into the block under the head

 

shown here under orifice check valve http://www.300zx-twinturbo.com/s.manual/lc/004.gif

sorry i am using my bros computer and posted under his username!!!! its me hellraiser

 

its our car so its relevant anyway lol

 

 

the manual says there is an orifice check ball in the system.

Now from what I can see the oil is pumped through the block up past the second head bolt ( intake camshaft front so second bolt in) through the head to the lifters, we have no oil being pumped up trough the bolt hole as we took it out to see.

Nobody :-( jeff,jimmer,mark...... Anybody ?

Ok you have described the cause of why camshaft sometimes seize and stop the cambelt allowing the bottom pulley to pull the teeth off the belt, have seen this so many time over the years, usually the front camshaft journel / bearing is trashed as a consequence.

 

In the past to help owners out we have just change the head complete with cams etc and rebuilt and all is fine again, so the problem is with in the head lubrication galleries, so what I am saying is you have a potential seized camshaft about to happen!! the noisy lifters on that side do appear from what you describe as oil starvation, needs more investigation before more damage is done.

 

Jeff TT

Thanks jeff, we really suspect its the galley that feeds the lifters with the check valve in it as the intake camshaft is still recieving oil to the pulley and flowing it through the cam, we have poured some paraffin down the bolt hole too the check valve to let it soak to see if any sludge will dissolve overnight , we have poured oil over the cam shafts on that side to help lubricate the cams too while we turn it over to check flow, we will report back tomorrow if it has worked in unsiezing the valve. If it does work we will drain the oil straight away and fill with fresh to get rid of the paraffin.

If it does not work we will swap the head as you have advised, thank you for your help :-)

sorry i am using my bros computer and posted under his username!!!! its me hellraiser

 

its our car so its relevant anyway lol

 

the manual says there is an orifice check ball in the system.

 

Crikey, your bro has made 7 posts in 9 years! 1 of them was just made from you :lol:

LOL @ the username! Labia minorum!

LOL @ the username! Labia minorum!

A double entrendre he used to work in a lab but also likes lab.. Well you get the idea lol

I get it and I haven't got a degree in vaginaplasty! haha

UPDATE :-( no luck still no oil flow to the lifters, we are now stripping off the head! We have only driven this once in anger lol

Hi Gaz, what did you do in the end to resolve the oil starvation issue?

Hi Gaz, what did you do in the end to resolve the oil starvation issue?

Sorry only just see this! It was a blocked check valve in the oil gallery in the block. I used a needle and paraffin. I then applied vacuum via a tube and drew the oil through the valve. once the head was off to unblock it. All is well with it now.

Edited September 27, 201411 yr by hellraiser