vq35

driver side valve cover off fuel rail and lower intake off - best way to access valve covers ONLY way to access KNOCK SENSOR KNOCK SENSOR AND DIRTY GUTS EXPOSED Will post more later but NO MORE LEAK for now - boy, this was more babysitting than brain surgery .........Prayed the last and 3rd time I went back in .....it helped, matter of fact, I thank God for this .....

I am getting pass gasket from dealer and i will post pix going in ...... no time to dive back in now but will post results asap also, I initially just put the silicone on the corners (all four) but the second round, i was a little more liberal with it although still not covering the whole of the head. That had an affect on the initial leak, although it might have been the more thorough cleaning of the surface, as it stopped leaking in the corner, I am now inclined to cover the whole area (lightly but more thoroughly) once I get the new gasket .... the other thing is that the drivers side has no leaks although I only cleaned it and put new gasket in - no leak at all but also no silicone, so inclined to redo that before it ends up leaking also ....

ok folks so here are the results went back to the valve cover and took it off - new gasket I put in got torn on its way out so luckily i had the old gasket....thoroughly cleaned the valve cover with brake cleaner ...... applied a little bit of silicone to the gasket grooves next cleaned the head thoroughly and ensured it was smooth and clean slapped everything together and old leak area cured but now leaking in the centre.....pretty frustrated will go to dealer tomorrow to get a new gasket and new cover bolts and redo everything for the third time - any suggestions welcome and encouraged .....tricks tips etc much appreciated - driverside is leak free from first round of cleaning and replacing gasket (without silicone) ......

yeah ..... sadistic but yeah ..... really enjoyed it though

that I did when I first went in - but the big issue was when it was put back together and I saw the smoke, it was ACTUALLY dripping from the valve cover gasket as the engine was running i thought it was just in need of burning off, but upon further inspection with a light, you could actually see the dripping of oil onto the mani.... @!*% was pretty scary and i am scared it might be something else, but your point seems the most logical as i did not clean the exposed head and something must have also went in ..... wow, this at least reduced my 'lap' times going in from 3 to 1.5 hours ...... I am going in tonight

have break cleaner thank god on a frkn sunday ....... hope this solves the problem, but now that it has leaked, does this mean I have to re use my old gaskets (which I have saved), could they have been damaged I wonder ....anyway, will post results hey thanks for the guidance slinger......

I cleaned the valve cover - didnt do anything as I did with the intake plenum/manifold (light sanding of residue), but the actual head I just covered with a rag while I replaced the gaskets on the cover .....I dont know, may have dropped some specs of dirt but nothing I could see.... what should I do because this sounds like I am going back in and taking a small shower with the fuel rail?? once I take the valve cover off, what like just wipe it down some more>>>>????

Howdy folks heres a little update on my little nightmare..... started with a repeating knock sensor code, after trying everything else, decided to take the plunge ....literally, as this thing is under the fuel rail fast forward a few hours and all new gaskets (including valve cover since i was there) came back out and went for a spin. SMOKE, lotsa smoke.....looked and oil was dripping onto passenger side manifold followed tightening sequence on the fsm ...... frustrated, went back in but had access to the valve cover without removing fuel rail and retightened thinking I didnt tighten it enough...same leak, same smoke any special procedure with valve cover/gaskets??? any direction appreciated ps the gasket fits into a groove in the valve/rocker cover, would it not show if it was not placed properly, I was pretty thorough .....

So anyone know if you need a reflash if all 4 o2 sensors are changed??

ok sounds good still have exhaust leak to tackle though and replacement of o2 sensors = reflash at dealer?? guy at service said that as long as there are no 02 sensor codes, there 'should' be no problems.........

Ok so here is the update to this and I will repost questions. I did not get to the knock sensor because the fuel rail was in the way and I was not sure about its removal. I re used old gaskets which seemed intact and wear free. Now I bought the following to go back in and conquer the knock sensor replacement. 12 rubber rings (upper and lower) for the actual fuel injectors, once off 4 o rings on the way to the pressure regulator and damper (new engine oil on hand) 4 poly insulators that the rail sits on 6 injector clips and since I am down there, will do the valve cover gasket also and all the way back up to throttle body did the sequence for tighteing last round but not torqued to spec (yes, I guessed!) this time will use torque wrench knock sensor WILL NOT be oe though as they are around $50-100 aftermarket (anyone bought knock sensor aftermarket???) any information on performance or experience with aftermarket KS?? appreciated couple of questions 1 the maxima maf i replaced about 1.5-2 yrs ago but am worried it might go again, any experience with aftermarket MAF?? 2 if there are no codes or issues with the o2 sensors, can I simply replace all four, I have a leak on the top portion of the cat so I got all the exhaust gaskets (aftermarket cat back exhaust is pretty new) and since I am there, wanted to change the o2 sensors without the dealer reflash ...is this possible??? 3 how do I check the voltages for all the sensors?? where can I get the spec/parameters of peak voltage for the sensors in the engine?? what tool do I need?? 4 when I remove the fuel rail (will remove the fuel pump fuse and use as much fuel as is in the system, the car shuts off then this will decrease the amount of fuel that will shoot into my eyes...anyone have any tips for this particular situation, will there be damage fro the spilled fuel on sensors parts etc? thanks folks I dont care until I get my power back, I will keep at it, one way or another last question, I scanned repeatedly after cycling the car and the knock sensor code keeps coming back 0325, so this means either the physical sensor is broken or the harness is damaged, are these things common as the mechanic went that far and actually reached the knock sensor (so could have damaged or broken the knock sensor) but the worse scenario is the harness, as I would have no idea how to check or fix it, any insights appreciated on inspecting and potentially fixing a broken harness¨????!!!!! thanks

late reply - kinda not related but running Xterra 17" w 275 60 17 - just enough I'd say....nice pix in this thread

Ok so managed to change the pcv and grommet - could not get past fuel rail but noticed there were 2 rubber insulators (they were just disregarded) that the bracket holding the fuel regulator and fuel damper sit on. I placed them in their proper places and there seems to be an improvement to my surge (upon accelerating). Does anyone know if the misalignment of the regulator and damper will have an affect on acceleration..........

managed to get at the pcv and the rear thermostat was what started this whole process (rear coolant leak) - then towncivilian pointed out the grommet that the pcv goes into (waiting for the dealer to stock it) my main problem is the fuel rail/lines, does anyone have a step by step of this??? the rail is in the way of the knock sensor and I need some guidance to re/re the fuel rail and what I will need to replace when I do so?? any more grommets or similar ?? once I have the rail off, should I have them cleaned and by whom? any help appreciated

LoL.... I was picturing that very scenario but rationalized my way out of it by calling meself a BIG OLE SISSY ..... that got me all angry and rev'd up ..... then it turned to I just dont want to do it anymore after reading your post. Thanks for the heads up though!

wicked and my apologies for the multi site post - thanks and please disregard the other this looks like one step lower than I thought, so this does mean taking the fuel rail off....... thats a little more ......is it at all possible to NOT mess with the rail?? what are the steps to rail removal - if straight forward, then I feel confident going at it??!! any suggestions appreciated

Anyone have a picture of lower intake manifold off showing the location of the knock sensor?

Aside from the last rear right bracket, it was pretty straight forward albeit LONG and awkward. My intention was to redo the gaskets/spark plugs (that a local shop claims they did). I have finally reached my destination which was to redo everything the shop did to ensure proper torq and sequence for everything AND look into the new codes that developed after they messed with it. (knock sensor/purge valve plus the previous intake timing sensor codes - bought new purge valve and intake timing sensor but wanted to see what the deal is on the knock sensor at $300 - maybe it was not placed back properly etc) So now that the lower intake is off and I am staring at the head and fuel rail. No sign of the pcv valve (which they failed to change) nor the knock sensor .........can anyone point this out please via picture or fsm and how exactly to extract them...... thanks

was wondering if anyone had pictures of the vacuum lines to check for leaks also may have plenum/intake gasket leak - what would be the symptoms? thanks for any help

just had a leak between firewall and engine - big $$ at dealership so took it to a local - they decided to tackle it from the top which meant they had to take off the the plenum top and bottom. I asked them to include spark plugs and pcv valve while down there and they did stop the coolant leak - pcv was not changed but cleaned and with aftermarket gaskets, they sealed it back up. the truck is throwing knock sensor and vacuum cut bypass valve codes and I dont know what to think - there is also the older intake timing sensor code which has had no affect on performance symptoms are as follows 1 idle is fine but once underway, there is a hesitation and when the power comes on it is NOT smooth or as powerful as normal 2 it sounds like there is some sort of vacuum leak whenever you give it gas - you can actually hear it when in higher gears and depress the gas since the vacuum cut bypass valve works directly to provide vacuum for the intake, could this be because they put in the wrong gasket or a faulty one?? also, I have yet to take it in for the recall for the related gas cap area - could this be related and triggered by this? what do you think and has anyone experienced similar symptoms??? you guys have any related pix - thanks for any help

OK oK - how would this work exactly, I mean the longer runners, what step by step should I take and has this been tried .......?????

Intake and exhaust already done - the heat shields made me do it and now well worth it! Sound is incredible but seat of pants says minimal gains!! The auto pathfinders make 265 of torq compared to my 240!!!! 25 is a big number for me dude and combined with the intake/exhaust that should amount to a significant .... increase in 0-60 and the low end of course. From what I understand, there is an electronic control unit in the tranny that I obviously do not have in my 5spd pathy. Anyway, I was thinking that maybe I could bypass this and make it mechanical somehow..........maybe opening full blast when I reach a certain rpm......again, any thoughts/experience would be appreciated!!!!!

I hear ya and thank you for the reply but this happens (apparently) because they get loose - so you can erase that problem by using locktite to hold them in place. The problem for me is that I am down on torque and want to get some sort of stock/oem type of upgrade and this seems the most realistic and do able. I am actually surprised that NO ONE seems to have attempted this........any help/insight would be greatly appreciated .......

Ok so I replaced my digital clock with that of the qx4 and the back light is on and it is working on and off (just as with my digital clock AND I cannot seem to rotate the arms to adjust the time) - so instead of fixing mine, I took the qx4 one and is soldering the solution for this as well?? Has anyone experienced problems with their QX4 clock and what did you do other than replace the whole thing!!??? Any help would be appreciated. The next question is that I want to install the power valves from the auto r50s - mine is a 5spd and only coughs up 240torq whereas the auto 3.5 loses 10 hp only to produce 265torq!!! I understand that the function is electronically controlled by the auto tranny (as the revs go up, more torq is produced) and mine probably has 250torq MAX - WITH an intake and exhaust (all tuning up to date) - no way I am gonna cough up $1200 PLUS labour for cams from 4x4 altho it REALLY seems tempting!!! Any help would be greatly appreciated.

Question - body redone, rust obliterated, rear susp redone, NOW everything is boring and I am twitchin for some STREET action (dont go past cottage, sorry folks) plus more power. Mine is a stick 3.5 = 240 ft of torq - I want POWER VALVES (yes yes locktite) and from what I have gathered, the opening/closing function is electronically controlled by the god damn AUTOMATIC tranny. So would there be a way is the question ......... I mean it is the same engine otherwise - has this been done/attempted ........ or is it theoretically possible and how ???? Please refrain from telling me that anything is possible provided I have the loot! I understand this clearly and do NOT have unlimited funds so I want to get a used engine and do it meself. I have an intake and cat back exhaust and there is a hot cam at 4X4 for $1200 (which happens to be the cost of a used 3.5 .....INSTALLED) Anyway, help would be appreciated - as a newby, I posed this question a year or 2 ago and maybe I didnt pose it properly, but I have a feeling that this is possible, somebody please confirm that I can install power valves....... please do not respond to the following if not interested .... Thank you Next is items I no longer want/need 1 4X16 inch stock wheels with no tires (plus DIY paint materials - sandpaper, flat black, primer etc) with NO issues $300 FINAL 2 4+1 16 inch stock rims (all with Michelin tires) and 4 tires at 40-50% plus steel spare with tire at 60% tread $400 FINAL 3 4 Bridgestone Blizzak tires at 75-80% tread remaining (awesome IMHO!!!) WITH RUST FREE steel wheels in silver $500 FINAL OR everything for $1100 FINAL LOCAL PICK UP IN TORONTO (CENTRAL) OR reasonable alternative