Jump to content
SAU Community

Recommended Posts

I'm in the process of rebuilding my 25. Just looking at my VCT oil feed, I stuck a pick into it and it only went in a max of 2mm deep. Is this normal, does the oil feed straight up into the gallery from the bottom of the block or does it 45deg into it?

Hopefully this makes sense, I want to make its not blocked because VCT wasn't working when the motor was last running.

post-84181-0-92728400-1367539826_thumb.jpg

Link to comment
https://www.sau.com.au/forums/topic/424564-rb25-vct-oil-feed/
Share on other sites

Think it works as a check valve so might just be bottoming out the check valve. Just blow some air through and see if you can feel it come out. If the engine is out that is. I think if you blow air into one of the ports where the filter goes and block the other 2 head feeds with your fingers then you should feel some air come out

  • 2 weeks later...

So I drilled feed with the top of the block facing down (I used a bit smaller than the hole size so it didn't cut any metal) and some oil dried up like jelly came out. The feed seems free now and I can get a pick in there but compressed air still doesn't come out of the feed.

I've tried blow air through various spots including both oil filter ports and the oil pump port but i get nothing from the front VCT feed!

Hi Guys,

Does anyone know where in the oil system does the VCT feed, feed oil from? i.e where does the feed tap into the rest of the system? if possible could you highlight it on a photo for me? Its hard for to now that the engine is partially built.

Yeah should be from the same feed as to the other head oil feeds.

oil pump --> Filter ---> main oil gallery ----> Head feeds

From memory anyway, I did sus it out when I had a bare block and some air and some cleaner spraying through it

can you track down a pic of the oil feed? if you can get a hold of a manual it will show it

I have the Nissan workshop manual but it doesn't detail the oil flow /path it just shows how to assemble oil pump etc.

Here's a photo of it

post-84181-0-96909000-1369099208_thumb.jpg

I got this from the oil control thread its for an RB26 though

post-84181-0-19310900-1369099313_thumb.jpg

How do you guys troubleshoot a blocked oil gallery - with drilling as a last resort as the block as it has already been cleaned and assembled...

  • 4 years later...
14 minutes ago, silencium said:

Sorry for digging up this old thread but I have kind of a similar problem.

Does anyone know if there is a check valve in the VCT oil feed or if it simply is a restrictor?

Thanks for the help

 

Why would there be a check valve?

How would that be useful?

Why do you think there is one?

why does it matter?

 

I vote my ass no check valve

That is very simple: When the engine is stopped, oil could flow back due to gravity, leaving air in the oil gallery. Next time the car gets started the air has to go out through the journal bearing before the oil follows.

I do not know how much the oil actually flows back, but it is definitely a bit, because otherwise oil pressure would be instant on the first engine cranks during start up. But it usually takes about one second till the oil pressure switch goes off.

Using a check valves in the block would make sense imho.

If one has a RB block laying around it could be checked with a thin wire.

Edited by silencium
typo

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Is the panel filter one that is oiled? Have you ever cleaned or touched the AFM?
    • So.... the K&N air box thingo was too big, ended up gifting it to a mate, well, by gifting it he actually supplied food and beer at the pub,  which was nice, as it will not sit on a shelf in the garage for the next 10 years I did trim up some of the existing stuff to neaten it all up and gave it some wrinkle paint, unfortunately it currently has a used and abused mish mash of different types of hose clamps, 4 big fat T bolt type (shit), and a few normal clamps of vairing sizes and brands, but..... only until the 6 constant tension black worm clamps that I ordered from EFI solutions turn up next week Currently the current hose clamps are triggering me hard, LOL Is this the final version, probably not, I really want just 2 silicone pieces, a straight bit of silicone from the filter to the MAF is easy and will happen as soon as I head into Just Jap tomorrow, the problematic part is a 30° silicone bend from the MAF to the TB that I can connect the engine breather from the head, I found that there are bulk head fittings for boat bilge pumps that should work, but until I can get a 30° silicone bend the alloy pipe, and the 11ty thousand hose clamps, are there for the foreseeable future 4 hose clamps are golden, 6 are grudgingly acceptable, the 8 currently holding it all together is just taking the piss    I've also ordered 60 more retaining wall blocks for the front yard, I mis-gonculated the height that was required to get above the base of the Photinia's (red robin's) that are the hedge behind the front fence, currently it is 2 blocks high, and about 1/2 a block short, so going 3 blocks high will be above the base of the red robin's, and allow some room for mulch
    • It is the stock air box with the panel filter. Everything else is stock except the exhaust at this point, as I also went back to the cleaned 270cc injectors. I will check the RPM when the IACV is unplugged and report back.
    • As MBS suggested if this is happening when the engine is cold you're going to want to remove the intake air regulator and verify resistance + that the shutter is physically opening and closing. At -20C should be fully open, 20C half open, over 60C fully closed. At 20C should be 70-80 ohms. For AAC valve testing using a Consult cable see if you can raise and lower the idle by commanding more or less AAC duty cycle. Hopefully it's pretty linear as well, shouldn't be like 30% AAC valve is barely idling and 40% is 1500 rpm.
    • Bloody apprentices! 🙄
×
×
  • Create New...