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Exhaust VVT not retarding/ not working

Posted:
Wed Jan 15, 2014 6:23 am
by JMlegacy
So I changed my head and got the car hooked up only to notice it bogging over 4000 rpm. I did a datalog and saw IAM being cut to 0.6 even with no apparent knocking. Then I decided to log my AVCS behavior.
Turns out my left exhaust VVT is not retarding.
I swapped it for another one and the same problem.
HELP!
Re: Exhaust VVT not advancing/ not working

Posted:
Wed Jan 15, 2014 7:35 am
by bigBADbenny
What's the history of the car? As regards oil & bearings especially.
The issue can be caused by clogging of the oil lines, the banjo filter, solenoid body (where the line meets the body) the solenoid itself, and the cam gear can sludge up or become jammed with particles.
So start with the easy items and proceed from there.
Iirc debris in the cam gear had a specific behavior, the gear would advance and stay advanced till key off.
That thread was by underdog on LGT.
If the solenoid is non operational also check the wiring to see if the connection is good.
Also have you tried swapping the L&R solenoids, and cleaning them before reinstalling?
Get a 9v battery and actuate the solenoid whilst spraying it out.
At this time you can flush the solenoid body as well.
Re: Exhaust VVT not advancing/ not working

Posted:
Wed Jan 15, 2014 9:47 am
by JMlegacy
OK. Will check those things.
I spun a bearing, yes!
What i've done so far:
Removed the VVT, applied 12V to it and it did actuate. I tested the current on the connection it self, it varied from 6V when idle to 14V when revved.
I'm not sure but i'm thinking oil banjo is clogged
And sometimes my car hesitates when moving off. Usually i can let it idle and it moves with me as i drive out, now it sometimes giving me this back and forth feeling as if it is going to stall
Wonder if that;s the cam gear sludging up?
Also, could this sludge break a timing belt???
Re: Exhaust VVT not advancing/ not working

Posted:
Wed Jan 15, 2014 10:29 am
by bigBADbenny
From what I've read, the key banjo filter for preFL is at the rear of the Rhs head/block area.
There may be more along the oil lines eg at the solenoids and iirc inbetween the timing belt cover and the block.
I'd suggest a thorough search of your cars factory service manual.
Have you tried an aggressive oil flush/es?
Eg with wynns, UEC or kiks method with cheap heavy mineral and a big dose of ATF.
Some even put in a dose of kero, 5minute drive then drop it.
Don't forget to strain the used flush for evidence.
I'm postFL: replacing the OCV did the trick and I'm doing 3x delvac mx 5k OCI's before returning to full synthetic.
Delvac is high detergent for hopefully a long term flush effect.
Another member is facing a similar preFL avcs issue atm, iirc.
Use my forum search link below with VVT, OCV, avcs etc added as the key words.
Re: Exhaust VVT not advancing/ not working

Posted:
Wed Jan 15, 2014 12:14 pm
by JMlegacy
What Is preFL? What is FL?
Re: Exhaust VVT not advancing/ not working

Posted:
Wed Jan 15, 2014 1:01 pm
by bigBADbenny
face lift,
prefl = 2l = dual avcs = inlet & exh
postfl =2.5l =single avcs = inlet only
Re: Exhaust VVT not advancing/ not working

Posted:
Thu Jan 16, 2014 1:39 am
by JMlegacy
Thanks. I'm hoping it's not the cam gear. Really hate doing the timing belt
Re: Exhaust VVT not retarding/ not working

Posted:
Thu Jan 16, 2014 10:21 am
by JMlegacy
If the banjo is blocked, would that affect both exhaust OCV or can it only affect one?
Also, are the OCV interchangeable?
Re: Exhaust VVT not retarding/ not working

Posted:
Thu Jan 16, 2014 10:54 am
by bigBADbenny
The oil line just runs at engine oil pressure but afaik low actual flow.
So it can get clogged up.
In your FSM there should be a schematic showing oil flow direction yo help you track the blockage if any.
Re: Exhaust VVT not retarding/ not working

Posted:
Thu Jan 16, 2014 11:42 am
by dr20t
Banjo filter sounds blocked. This has other more severe consequences if you don't fix it too (blown turbo inevitable)
Need to pull TMIC, inlet pipe off turbo and airbox to get to it
Re: Exhaust VVT not retarding/ not working

Posted:
Thu Jan 16, 2014 12:48 pm
by bigBADbenny
Indeed the rear banjo clog can starve the turbo.
So check out where all the banjos are either by starting at the rear and following the lines all the way around, or by checking the oil line schematic in the FSM or try the opposed forces site: link below

Re: Exhaust VVT not retarding/ not working

Posted:
Thu Jan 16, 2014 1:02 pm
by bigBADbenny
http://opposedforces.com/parts/legacy/e ... tration_1/So I just went to my parts link in my sig, backtracked through the site looking at EDM 2L turbo legacies.
The page above shows the avcs oil lines on a EDM 2L Gt: looks like single (inlet only) avcs, but at least it show the correct location of the rear banjo. You'll have to research what model on that site is closest to yours. Can anyone help?
Re: Exhaust VVT not retarding/ not working

Posted:
Thu Jan 16, 2014 1:16 pm
by dr20t
Banjo bolts are in exactly the same position as the 2.5 turbo for inlet, and mirrored for exhaust (on underside)
Exhaust manifold may have to come off to get to it (I can't remember how far the stock headers protrude with the heat shields as mine has after market headers and to get to mine I'd definitely need to take headers off)
You will have to check for yourself by looking under the car. If you can see the bolts then generally you can get to them
Mick
Re: Exhaust VVT not retarding/ not working

Posted:
Thu Jan 16, 2014 1:44 pm
by bigBADbenny
http://forums.nasioc.com/forums/showthr ... ?t=2392133Interesting post showing the oil holes on the cam shafts.
I'd always wondered how the oil got from the OCV's to the cam gears.

Also further down a pic of the OEM OCV mani, the complex passages can get sludged, thus the rec to flush first.
Re: Exhaust VVT not retarding/ not working

Posted:
Thu Jan 16, 2014 4:01 pm
by JMlegacy
I wont make it to the shop before Saturday. Sounds like I should park my car and take a taxi!
Thanks for the information everyone.
Posted a pic below for future reference.
Item #27, #29
