02SE6MT

hey guys, so i did a thread a while back here basically about a misfire i had on one cylinder which turned out to be a bad valve job. they reworked them and the engine idles smooth and the valvetrain is quiet enough not to worry me. I did mention i had the P0021 code before i tore apart the timing to find it was spot on. After reinstalling the timing and head that was reworked, the only problem im having now is the P0021 code and its very sluggish, also feels like the pedal is being "jiggled" if you will under acceleration, its power delivery is jerky almost and feels like it hits a wall at 4k but will continue to rev freely .
I have the fsm and have followed it and all of my sensors ohm out (cam/crank) and bank 2 IVT solenoid is getting the right voltages. So I took it to a friends shop today (with a nice scanner) and took it around the block while monitoring the IVT solenoid position in % and it was always at 0 for both banks under all driving conditions, it never moved. We tried multiple times to reset the code and drive it but not for one second would the %'s change. So we took the Solenoids off to verify that they were engaging, where i found the rear (or bank 1) VTC was stuck and not actuating. This would normally throw a p0011 .... I cleaned them up and got it unstuck and put 12 volts to it and it looked as it was actuating freely in comparison to the 2nd banks solenoid (which is the one i expected to be stuck).
With them actuating freely i put them back on and took it out while monitoring the IVT solenoid %'s, where i found they both registered numbers from 2% to 42%, but never went above 42%. However the car still feels like its hitting a wall at 4k rpm, and still throws the P0021 code and then shuts off the VTC all together.

Sorry about the length i just try to make it to where you kind of have an idea of the troubleshooting so far, i usually do my fair share of surfing before i post. Any ideas or insight i really appreciate. Its only that one code, i almost wish there were more so i knew a direction to go in.

02SE6MT

i wouldnt say its running terrible, it revs freely all the way up... the intake sounds like the vtc is not working before the code comes up and the engines power seams way flat, no pushing you back in the seat. harness power to the connector is good and the solenoid moves with power... im thinking i may take it to Nissan and see what their diagnosis is. this may get interesting. i had cat problems before where the front bank (2) precat failed and clogged the cat so i had the main downstream cat replaced but i haven't separated it since. Im going to do that before the dealership trip. I'm just not sure if P0021 is even closely related..

02SE6MT

so i took off the main cat but couldnt get it separated cus one of the bolts stripped and i dont have a cutting wheel. ive tried a torch to heat it up and tons of wd40. I drove the car with just precats on and an 02 disconnected and the car ran a little better but still slow, after the trip I had a pending p0021... any ideas?

Scottwax

iTrader: (8)

Have you blown out both solenoids with compressed air? Have you checked the grounds for both solenoids (they ground on the top of the timing cover on the radiator side). Make sure the oil level isn't below the add line, that will also affect solenoid operation. Could also be with the head work something got in the oil passages. Make sure the camshaft position sensors are working properly as well, they can also affect how the solenoids work.

02SE6MT

I have checked the grounds and voltages coming through the harness after checking that the solenoids actuated via 12v power. I have only checked that the cam sensors with a voltmeter, has anyone else done this and by any chance have readings? the manual says anything but 0 or ∞. ill grab the readings and give exact numbers to post, but when i did it they were not at 0 or ∞. Whats getting me is it happened before i tore the timing apart to see that its spot on so i dont think its timing, which is what im resorting to because everything else seems to be checking out....

does anyone have previous insight and had to replace the VTC solenoids? maybe while they were still actuating?

Scottwax

iTrader: (8)

If you had headwork done, it could be there is something clogging the passages where the solenoids bolt on to the head.

02SE6MT

ill check that out, we thought that may be the case but i messed up a couple bolt holes on the back head and had about three quarts of oil on the ground in a matter of seconds. Ill check the front (bank 2) head since that is the one giving me the code. Do you think compressed air would hurt anything while its attached to the engine? Thanks for the replies

Scottwax

iTrader: (8)

Not sure if blowing compressed air down through the oil passages in the head is a good idea or not, guess it depends on what might be in there.

02SE6MT

is there any chance the bank 1 solenoid (the one that was stuck) could be causing the CEL for bank 2 (the p0021)? Because when i took it off and put voltage across it it clicked but didnt move. With some cleaning and disassembling i got it to freely actuate with voltage. But if it is the one that was stuck it should be throwing a p0011 if anything right?

02SE6MT

cant decide whether im going to trade it in or not, id hate to solely for the reason of how much ive put into it from week 1 (MAF and alt), to axles, clutch, tranny, motor mounts... i could go on ... with gas as it is and being in Texas im lookin at something with 2 wheels, and dirt friendly I just cant trade my max in for another 4 wheeled vehicle... too much invested

02SE6MT

im going to try and find some solenoids. I have a bad clatter when about half throttle and up at low rpms. i hate getting used elect components, especially vtc's but i have been breaking bank putting it back together. Cold front came through and rained the day i was gonna go look at the bike, figured that may have been a sign I was sketchy about it anyways, granted the 72mpg was enticing. anyways thanks for the replies, sorry i didnt have a camera to snag some shots. my friend got some but theyre limited

02SE6MT

so i went and got a camera phone at the least, figured id show some pics of the blown engine :

Scottwax

iTrader: (8)

Lunched that engine pretty good. :eek3:

spock

iTrader: (5)

Wow. That block is now only worth it's weight in aluminum!

02SE6MT

Which surprisingly is not much. I have been quoted anywhere from $0.08 per lb to $0.15/lb. Which hardly makes up for the gas driving out there

02SE6MT

ok guys so i got 2 new IVT solenoids and swapped 2 cam and a crank sensor from a running max and i still have mediocre power and still get the p0021 code. Both banks look to be getting oil to the solenoids. When it idles after warming up i can see the oil pressure light flicker and it goes away when i touch the throttle. i dunno if that could be a bad oil pump causing these probs... I did use the intake sprockets from the last motor. Does anyone know if blowing a motor might seize those up? Im am lost and about to drop more money an an entirely new motor. ANY help is greatly appreciated. its been since november and im about to catch it on fire

Scottwax

iTrader: (8)

Low oil pressure certainly can cause problems at the top end of the engine. Usually caused by a failing oil pump, or excessive rod/crank clearances.

02SE6MT

i hope that new engines oil pump isnt bad... it certainly could cause funky vtc action.

02SE6MT

would a tiny amount gasket sealer sucked up to the oil pump screen (i removed it when i saw it) cause low oil pressure? Im just at my wits end and its going on a year without the car because of this.

02SE6MT

bought a used 06 with a carfax certified 74k miles. it was an auto so i had to do some swapping of upper oil pans and engine mounts, drive shaft brace, fuel rails etc. but it runs great, i used to have clatter from the vts on start with the last engine and this one is quiet every time.
If anyone needs any parts from a 03 vq (entire engine) that i got to see the cylinders and looks like its in great shape let me know.
I also have a harness for an 06 max and some misc fuel rails/manifold/mounts/plenum blah blah. It runs, runs great but has low oil press i believe is causing malfunctions with the VTCs and id love to swap out the oil pump and redo the timing cover with all new orings, i just dont have the space or time.