Hope to put an end to oil consumption
03-20-2011, 04:45 AM
#81
Thanks guys. This solution would most likely work but the only thing I wish I did different is to try to ensure that the air flow from the pcv system doesnt reverse due to the greater restrictions possibly on the intake manifold side with reducers catch can and added pcv. I did eat little to no oil up until it threw up. I had been eating a quart every 400 and I would say before the crap threw up I as eating 1/4 quart every 1000 miles. Still there is a possibility this contributed to the blown issue although unlikely because my engine was acting like a wh*re before and after that mod. actually felt a tad better after the mod. When I get the new engine my intentions are not to install this mod or a catch can at least at first cuz I have high hopes for an engine that doesnt have this issue preferably out of a 04 and I will be installing headers at the same time.
03-20-2011, 05:57 AM
#82
on the up side your motor will not use any more oil...
I saw on CL here that there are used VQ35De's for sale for under a grand with low miles.
If it was me I'd use it as an excuse to build it up a bit
I saw on CL here that there are used VQ35De's for sale for under a grand with low miles.
If it was me I'd use it as an excuse to build it up a bit
03-20-2011, 06:20 AM
#83
mn is a little far from me lol
03-20-2011, 10:29 PM
#85
The shop manager told me that he had heard of this problem in the past with that engine but with Nissan Maxima's. To get a monster sized engine that big under the hood of a Maxima, they have to turn it and tilt it back towards the driver. This causes the badly designed valve cover to trap oil, get clogged over time, and burn it excessively...in these circumstances.
.
.
http://townhall-talk.edmunds.com/direct/view/.f1c12a1/0
NismoAce could have been on the right track...
04-01-2011, 09:17 AM
#86
http://townhall-talk.edmunds.com/direct/view/.f1c12a1/0
NismoAce could have been on the right track...
NismoAce could have been on the right track...
NismoAce, do you have the parts (ie hose-size) for the write-up?
04-01-2011, 10:50 AM
#87
The6spdMax,
If you decide to try this, please keep us updated on the results. If you do try, can you also tell us about the condition of you engine now so we can get an idea of before and after and see how much this method helps?
If you decide to try this, please keep us updated on the results. If you do try, can you also tell us about the condition of you engine now so we can get an idea of before and after and see how much this method helps?
04-02-2011, 10:19 AM
#89
I do not have the hose sizes. I never truely finished it before scrapping this idea due to my blown engine. Not sure if it was to blame doubt it but if someone wants to try it just keep that in mind. If my 04 engine im throwing in also eats oil, For sure I will continue this project if not I am not doing this.
I completely agree with you on this and im sure if contributes to why they eat oil. But why some and not all? I have removed both valve covers after the car has sit over night and it is obvious that there was a drainage issue on bank 1's head.
Last edited by NmexMAX; 04-02-2011 at 12:41 PM.
04-21-2011, 08:47 AM
#91
Join Date: Feb 2011
Location: New Jersey
Posts: 19
Can this be caused by the faulty Cats that Nissan was using during the 2001-2005 year? I read that the cats were failing and creating a dust like material that would be sucked up by the engine? the Sentra's and Altima's had these issues
05-02-2011, 09:32 AM
#94
Join Date: Feb 2011
Location: New Jersey
Posts: 19
I'm not talking abuot a clogged cat...i'm talking about a disintergrating cat, which seems prone on nissan's cars from the early 2000's. It seems that the cats are disntergrating prematurely, and the fine particles are getting sucked back up into the engine, which in turn is scratching the cylinder walls, which then lets oil past the piston seals...causing more and more oil consumption.
05-10-2011, 12:37 PM
#95
Supporting Maxima.org Member
Join Date: May 2002
Location: Atlanta
Posts: 1,815
I can't even begin to describe how bad adding a second PCV valve to the front bank is. But I will try 
Please look at the diagram below carefully.
When the engine is at WOT the second "Inline" PCV valve the OP added will operate as it should allowing overpressure back to the IM and even then it may not function at 100%.
But under most other throttle positions it will remain closed and will most likely effect the operation of the original PCV as they're spring loaded. (Please note the removed "Fresh Air" arrows.)
The ECU is designed to take into account for the air that travels into the front bank valve cover, figure 8~12% depending on load. With the second PCV valve added none of this air enters the valve/rocker covers and it all goes to the intake. This gets exasperated the higher the RPMs go until the valve opens and or the ECU is in open loop, in which case there should be enough pressure to at least partially open BOTH PCV’s. It’s almost like letting un-metered air into the engine which causes the motor to run lean. The ECU’s fuel and timing maps have no idea what was modified. There will also be a vacuum created in the rocker cover at lower throttle which is why he stated early on the hose was collapsing, even though he was using non-automotive water line.
I’m not saying the OP didn’t have a problem before he did this but it certainly accelerated the demise of the engine. I can see moving the valve to the higher port. I can even see re-routing the lines so the valve is on the front bank. But do not ever add a second valve to the system. When you also take into account the extended idling he might as well have taken a .50 cal to the motor. This is a case of having the best of intentions but a lack of knowledge. I don't mean to come off rude but as I was reading this for the 1st time today I was not at all surprised to find out the motor blew. Actually I was expecting it with every post I read.
If people are looking at this thread for catch can ideas like I was your best bet is to put in two, one in between the PCV and the IM and the other between the front cover upper hose and the intake port before the TB. This should go a long way to helping keep the IM & TB cleaner.
I only hope people read this far before trying this themselves.
Please look at the diagram below carefully.
When the engine is at WOT the second "Inline" PCV valve the OP added will operate as it should allowing overpressure back to the IM and even then it may not function at 100%.
But under most other throttle positions it will remain closed and will most likely effect the operation of the original PCV as they're spring loaded. (Please note the removed "Fresh Air" arrows.)
The ECU is designed to take into account for the air that travels into the front bank valve cover, figure 8~12% depending on load. With the second PCV valve added none of this air enters the valve/rocker covers and it all goes to the intake. This gets exasperated the higher the RPMs go until the valve opens and or the ECU is in open loop, in which case there should be enough pressure to at least partially open BOTH PCV’s. It’s almost like letting un-metered air into the engine which causes the motor to run lean. The ECU’s fuel and timing maps have no idea what was modified. There will also be a vacuum created in the rocker cover at lower throttle which is why he stated early on the hose was collapsing, even though he was using non-automotive water line.
I’m not saying the OP didn’t have a problem before he did this but it certainly accelerated the demise of the engine. I can see moving the valve to the higher port. I can even see re-routing the lines so the valve is on the front bank. But do not ever add a second valve to the system. When you also take into account the extended idling he might as well have taken a .50 cal to the motor. This is a case of having the best of intentions but a lack of knowledge. I don't mean to come off rude but as I was reading this for the 1st time today I was not at all surprised to find out the motor blew. Actually I was expecting it with every post I read.
If people are looking at this thread for catch can ideas like I was your best bet is to put in two, one in between the PCV and the IM and the other between the front cover upper hose and the intake port before the TB. This should go a long way to helping keep the IM & TB cleaner.
I only hope people read this far before trying this themselves.
Last edited by MaximaMan77; 05-10-2011 at 12:41 PM.
07-17-2011, 07:44 AM
#96
Newbie - Just Registered
Join Date: Jul 2011
Location: miami
Posts: 4
NismoAce writes:
ORIGINAL POST STARTS LIKE THIS: "The oil that is getting sucked up from the rear valve cover will be dropped into front valve train that appears to be ok with draining the oil back into the oil pan so the suction out of the front valve cover should be oil free.
Bringing back to life my own thread.
So yesterday I took off the lower oil pan, both valve covers, and both cam solenoids (whatever there called). I also replaced the ignition coil lower halfs (the wire kinda). I had my good old air compressor with nozel handy and blew air into passages as well as cleaned up the optical rings for the cam position sensors. I got a lot of nasty crap out from the lil holes. BTW be careful cuz some of these passages end up right where you are blowing and you will end up with a face full of oil just like I did. I also cleaned up the oil pickup screen. This is all after running her with some atf in the oil. That stuff works wonders. I also cleaned out the solenoids.
I am unsure of any change in oil consumption but the car is running smoother. I still have an akward tick coming from her but I have yet to notice a misfire. The car doesnt feel as strong as it once did but who knows.
Now My Answers and questions:
I did not read all your responses, however, on a G35, like mine (Manuals only) the engine sits straighter than on Maxima (Front drive), so the valve train must be having little less oil, but if so both sides will be equal.
The valve covers holes to the PCV are sitting quite high above the oil puddle, so its hard to see how the oil will get there without draining back the way it entered, thru same holes.
If that would have been the case Nissan would have replace all valve covers years ago, its cheaper than replace engines.!
There must be more to this than just a little oil sitting in the valve pan!
Lets find out with more communications. (mine has only 32,350 miles, I drive it under 4000 RPM and still drinks oil).
ORIGINAL POST STARTS LIKE THIS: "The oil that is getting sucked up from the rear valve cover will be dropped into front valve train that appears to be ok with draining the oil back into the oil pan so the suction out of the front valve cover should be oil free.
Bringing back to life my own thread.
So yesterday I took off the lower oil pan, both valve covers, and both cam solenoids (whatever there called). I also replaced the ignition coil lower halfs (the wire kinda). I had my good old air compressor with nozel handy and blew air into passages as well as cleaned up the optical rings for the cam position sensors. I got a lot of nasty crap out from the lil holes. BTW be careful cuz some of these passages end up right where you are blowing and you will end up with a face full of oil just like I did. I also cleaned up the oil pickup screen. This is all after running her with some atf in the oil. That stuff works wonders. I also cleaned out the solenoids.
I am unsure of any change in oil consumption but the car is running smoother. I still have an akward tick coming from her but I have yet to notice a misfire. The car doesnt feel as strong as it once did but who knows.
Now My Answers and questions:
I did not read all your responses, however, on a G35, like mine (Manuals only) the engine sits straighter than on Maxima (Front drive), so the valve train must be having little less oil, but if so both sides will be equal.
The valve covers holes to the PCV are sitting quite high above the oil puddle, so its hard to see how the oil will get there without draining back the way it entered, thru same holes.
If that would have been the case Nissan would have replace all valve covers years ago, its cheaper than replace engines.!
There must be more to this than just a little oil sitting in the valve pan!
Lets find out with more communications. (mine has only 32,350 miles, I drive it under 4000 RPM and still drinks oil).
Last edited by WECHSLERL; 07-17-2011 at 07:47 AM.
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