VQ35 reaches a new league of oil loss
05-15-2007, 04:55 AM
#41
Originally Posted by soonerfan
welcome to the club...look at your tailpipes and the inside will be all black from the burning oil
05-15-2007, 05:22 AM
#42
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Join Date: Feb 2006
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A bit of an update on this...
Well, not really, but interesting: No smoke.
After work yesterday, I took the car for a ride and ran six or seven runs to 6500 RPM in first gear. First two after the engine was cold. Then I cruised on the high way for about 10 miles, and at the light off the exit, I took of in first, still nothing. Then the last few tests were downshifts into second, again running it up to 6500 RPM. Not a single sign of smoke. Oil was filled up at the last gas fill up, and since then I'm at 35 miles, and can't notice any loss. Now normally, it would be ludacris to look for oil loss after 35 miles, but in my case, 35 miles is 12.15% of the mileage last observed as sufficient for a 1 quart loss, and that mileage was driven tamely. This 35 miles was ripping the RPMS up to near redline on multiple runs.
I will continue to monitor this, however, I can't help but to wonder (hope mostly) if the oil loss is not mileage based, but rather time based, as it would make more sense seeing as how the current observation was only 22 hours, approximately 1 day, after oil fill up, and the previous observation was approximately 13 days after oil fill up. Render the testing runs irrelevant, and then I would only be looking for a 7.6% loss, which would be unnoticeable. A time-dependent oil loss would suggest more of a leak than a burning problem, so I'm keeping my hopes high. Tomorrow I am going to change the oil, as the oil that's in there is pretty black (probably due to running on only 3 quarts for so long), and that will give me a fresh start to begin testing exactly what my oil loss is.
Any suggestions?
Well, not really, but interesting: No smoke.
After work yesterday, I took the car for a ride and ran six or seven runs to 6500 RPM in first gear. First two after the engine was cold. Then I cruised on the high way for about 10 miles, and at the light off the exit, I took of in first, still nothing. Then the last few tests were downshifts into second, again running it up to 6500 RPM. Not a single sign of smoke. Oil was filled up at the last gas fill up, and since then I'm at 35 miles, and can't notice any loss. Now normally, it would be ludacris to look for oil loss after 35 miles, but in my case, 35 miles is 12.15% of the mileage last observed as sufficient for a 1 quart loss, and that mileage was driven tamely. This 35 miles was ripping the RPMS up to near redline on multiple runs.
I will continue to monitor this, however, I can't help but to wonder (hope mostly) if the oil loss is not mileage based, but rather time based, as it would make more sense seeing as how the current observation was only 22 hours, approximately 1 day, after oil fill up, and the previous observation was approximately 13 days after oil fill up. Render the testing runs irrelevant, and then I would only be looking for a 7.6% loss, which would be unnoticeable. A time-dependent oil loss would suggest more of a leak than a burning problem, so I'm keeping my hopes high. Tomorrow I am going to change the oil, as the oil that's in there is pretty black (probably due to running on only 3 quarts for so long), and that will give me a fresh start to begin testing exactly what my oil loss is.
Any suggestions?
05-15-2007, 06:54 AM
#43
Originally Posted by 7_places
Has anyone considered a VQ35 to VQ30 swap?
Hahaha
Why would ya wanna do that. You might as well tear it apart and replace rings if you're gonna take the engine out. step your game up, not doWn.
05-15-2007, 10:32 AM
#44
Originally Posted by Epacy
I don't see how this can be entirely correct. Normal soot and discharge from the engine will make your tailpipes black.
mine have thick black deposits inside the ends of the pipes.
05-15-2007, 02:57 PM
#46
Originally Posted by nismology
Rings and displacement aside the VQ35 is a flat out superior motor, IMO.
I'd love to know what makes the VQ35 superior (displacement aside).
And you can't say "rings aside" since it is a reliability issue - and reliability is one of the hallmarks of a "great engine."
05-15-2007, 03:00 PM
#47
Originally Posted by irish44j
please expand on this....Aside from the power difference (which you put "aside" since it is due to displacement), the VQ30 is a much smoother running engine with far less problems. Personally, I also prefer cable throttle to the lame DBW setup.
I'd love to know what makes the VQ35 superior (displacement aside).
And you can't say "rings aside" since it is a reliability issue - and reliability is one of the hallmarks of a "great engine."
I'd love to know what makes the VQ35 superior (displacement aside).
And you can't say "rings aside" since it is a reliability issue - and reliability is one of the hallmarks of a "great engine."
pros - more power
cons - bad rings
VQ30
pros - good rings
cons - less power
the engines are both smooth and yes the DBW sucks.
and the 35 has a better intake system (manifold, etc)
05-15-2007, 03:45 PM
#48
Originally Posted by irish44j
the VQ30 is a much smoother running engine
with far less problems.
Personally, I also prefer cable throttle to the lame DBW setup.
I'd love to know what makes the VQ35 superior (displacement aside).
Let's start with the heads. Lighter valvetrain = springs don't have to be as stiff = less valvetrain losses. Longer spark plug allows for larger water jacket around the exhaust valves = superior knock suppression allowing for more timing advance. Larger intake valves and greater port cross-section area = superior flow. Also the cams come backcut on the preload side which serves to reduce friction. And there's this minor, unimportant technology they call VTC which helps the VQ35 have one of the highest torque/liter numbers of any naturally aspirated Nissan motor.
Now the bottom end. Lighter pistons/pins with a shorter piston skirt and rod bearing caps secured by bolts reduced reciprocating mass and preserved the free-revving nature of previous VQ's. Piston oil squirters and revised coolant passages in the block improve thermal control of the internals. OEM oil cooler. The oil pump is also a VAST improvement over the 3.0's pump which becomes unreliable north of 7200 RPM. The 3.5's pump can sustain greater RPM despite having to supply oil to the squirters and VTC sprockets. Revised timing chain and sprocket teeth design allows the chain to operate more quietly than the 3.0's.
I'm sure i'm forgetting some other things.
And you can't say "rings aside" since it is a reliability issue - and reliability is one of the hallmarks of a "great engine."
05-15-2007, 04:27 PM
#49
Senior Member
Join Date: May 2004
Location: Vancouver, BC
Posts: 933
It seems to me that the "majority" of VQ35s don't use oil, so what is actually going on here with the ones that do use oil? Has it been determined for sure that the oil consumption is in fact caused by the rings? Oil control or a compression ring(s) or both? What has been the bore condition on teardown? Any common factors, such as.... is it more prevalent with autos or manuals, operation, mods, oil used, maintenance practices, additives?? SID? etc, etc. It appears to me that so far we still don't know the ACTUAL root cause.
05-15-2007, 04:35 PM
#50
Originally Posted by P. Samson
It seems to me that the "majority" of VQ35s don't use oil, so what is actually going on here with the ones that do use oil? Has it been determined for sure that the oil consumption is in fact caused by the rings? Oil control or a compression ring(s) or both? What has been the bore condition on teardown? Any common factors, such as.... is it more prevalent with autos or manuals, operation, mods, oil used, maintenance practices, additives?? SID? etc, etc. It appears to me that so far we still don't know the ACTUAL root cause.
i dont feel like providing proof AGAIN since i have many times
05-15-2007, 04:37 PM
#51
not true..my 02 is running rich as hell..headers and c/b and doesnt burn any oil. even at WOT in any gear no white smoke is seen..if your stock with no mods then i can see the buildup in the tailpipe...
Originally Posted by soonerfan
welcome to the club...look at your tailpipes and the inside will be all black from the burning oil
05-15-2007, 04:42 PM
#52
Originally Posted by HotshotVQ35
not true..my 02 is running rich as hell..headers and c/b and doesnt burn any oil. even at WOT in any gear no white smoke is seen..if your stock with no mods then i can see the buildup in the tailpipe...
05-15-2007, 04:45 PM
#53
you would know better than me. it sucks that you have to deal with this. i bought my car new and ran dino oil till 10K and synthetic since. i hope nissan steps up to the plate for you...although it seem not gonna happen. good luck with the rebuild!
Originally Posted by soonerfan
i know the difference between "normal buildup" and what my tips look like now.
05-15-2007, 04:57 PM
#54
Originally Posted by nismology
That has to do with rod/stroke ratio, not inferior design or build quality.
Originally Posted by nismology
That's your opinion; you have a right to think so. But the VQ35's system isn't all that bad. Sure there's the lack of a direct mechanical connection to the throttle plate, but the VQ35's ECU (32 bit) processes sensor signals faster than the previous 3.0 ECU's, so it's not as bad as one would think. Some have calculated the DBW lag and it's 1/4 of a second from throttle input to confirmed throttle plate action. Imperceptible to most people. The elimination of the conventional vacuum-actuated ASCD and IACV assemblies is a plus in my book as well.
Originally Posted by nismology
Hmmm...where to begin....
Let's start with the heads. Lighter valvetrain = springs don't have to be as stiff = less valvetrain losses. Longer spark plug allows for larger water jacket around the exhaust valves = superior knock suppression allowing for more timing advance. Larger intake valves and greater port cross-section area = superior flow. Also the cams come backcut on the preload side which serves to reduce friction. And there's this minor, unimportant technology they call VTC which helps the VQ35 have one of the highest torque/liter numbers of any naturally aspirated Nissan motor.
Now the bottom end. Lighter pistons/pins with a shorter piston skirt and rod bearing caps secured by bolts reduced reciprocating mass and preserved the free-revving nature of previous VQ's. Piston oil squirters and revised coolant passages in the block improve thermal control of the internals. OEM oil cooler. The oil pump is also a VAST improvement over the 3.0's pump which becomes unreliable north of 7200 RPM. The 3.5's pump can sustain greater RPM despite having to supply oil to the squirters and VTC sprockets. Revised timing chain and sprocket teeth design allows the chain to operate more quietly than the 3.0's.
I'm sure i'm forgetting some other things.
Let's start with the heads. Lighter valvetrain = springs don't have to be as stiff = less valvetrain losses. Longer spark plug allows for larger water jacket around the exhaust valves = superior knock suppression allowing for more timing advance. Larger intake valves and greater port cross-section area = superior flow. Also the cams come backcut on the preload side which serves to reduce friction. And there's this minor, unimportant technology they call VTC which helps the VQ35 have one of the highest torque/liter numbers of any naturally aspirated Nissan motor.
Now the bottom end. Lighter pistons/pins with a shorter piston skirt and rod bearing caps secured by bolts reduced reciprocating mass and preserved the free-revving nature of previous VQ's. Piston oil squirters and revised coolant passages in the block improve thermal control of the internals. OEM oil cooler. The oil pump is also a VAST improvement over the 3.0's pump which becomes unreliable north of 7200 RPM. The 3.5's pump can sustain greater RPM despite having to supply oil to the squirters and VTC sprockets. Revised timing chain and sprocket teeth design allows the chain to operate more quietly than the 3.0's.
I'm sure i'm forgetting some other things.
I'm well aware of the differeces in the engine (sorry you wasted your time trying to sound so smart) - but the bottom line is that they are all academic if the engine isn't running correctly. Nobody is arguing that a newer engine isn't going to have (gasp!) newer technology.
Originally Posted by nismology
If you want to ignore everything i just posted in terms of improvements over the 3.0 and want to focus on the rings, that's fine.
Don't get so damn defensive. My original post was little more than a wisecrack. Did I accidentally say "I hate Skylines" or something??
oh...
Originally Posted by nismology
helps the VQ35 have one of the highest torque/liter numbers of any naturally aspirated Nissan motor.
.....the VQ30DE-K in the maxima has peak 72.3 ft-lbs of torque per liter.
obviously the torque curves differ, but just sayin'......
05-15-2007, 05:05 PM
#57
Originally Posted by irish44j
shouldn't you be driving a Chevy, Mr. NASCAR? 
shouldnt you be driving a honda, mr F1?
despite the problems i have had...i still like my 02 better than my 00.
05-15-2007, 05:21 PM
#60
Originally Posted by irish44j
I didn't say there wasn't a reason behind it, I was simply stating it as a "plus" of the VQ30.
Didn't say the DBW was "bad" per se. Simply stated my opinion of preference, that's all. Certain 3.5 drivers in this thread who previously have had 3.0's have voiced similar opinions. And you act like I haven't driven quite a few VQ35-powered Nissans....
I'm well aware of the differeces in the engine (sorry you wasted your time trying to sound so smart) - but the bottom line is that they are all academic if the engine isn't running correctly. Nobody is arguing that a newer engine isn't going to have (gasp!) newer technology.
let's not blow things out of proportion here. Nobody here said anything about the 3.5 not being a fine motor.
but "best engines" are the sum of all their parts - including their problems. It's pretty obvious that the VQ35 has more "significant" problems than the VQ30.
Don't get so damn defensive. My original post was little more than a wisecrack. Did I accidentally say "I hate Skylines" or something??
yup, the VQ35 in the maxima has peak 70.3 ft-lbs of torque per liter.
.....the VQ30DE-K in the maxima has peak 72.3 ft-lbs of torque per liter.
obviously the torque curves differ, but just sayin'......
.....the VQ30DE-K in the maxima has peak 72.3 ft-lbs of torque per liter.
obviously the torque curves differ, but just sayin'......
Friends?
05-15-2007, 06:16 PM
#69
Member
Join Date: Sep 2006
Location: berkeley, ca
Posts: 107
seems to me that soonerfan might have difficulty expressing and communicating with other adults. Maybe his insecurity and immaturity stems from something in his childhood... dunno
that what i want to be, 30's something in diapers, and of course i don't mean that literally, unless soonerfan can verify this.
that what i want to be, 30's something in diapers, and of course i don't mean that literally, unless soonerfan can verify this.
05-15-2007, 06:26 PM
#70
Originally Posted by zenjia 03merlot
seems to me that soonerfan might have difficulty expressing and communicating with other adults. Maybe his insecurity and immaturity stems from something in his childhood... dunno
that what i want to be, 30's something in diapers, and of course i don't mean that literally, unless soonerfan can verify this.
that what i want to be, 30's something in diapers, and of course i don't mean that literally, unless soonerfan can verify this.
05-15-2007, 06:28 PM
#71
Originally Posted by zenjia 03merlot
seems to me that soonerfan might have difficulty expressing and communicating with other adults. Maybe his insecurity and immaturity stems from something in his childhood... dunno
that what i want to be, 30's something in diapers, and of course i don't mean that literally, unless soonerfan can verify this.
that what i want to be, 30's something in diapers, and of course i don't mean that literally, unless soonerfan can verify this.
05-15-2007, 06:30 PM
#72
Originally Posted by P. Samson
Soonerfan.........I've gone through the papertrail re the HOC. I must have missed your proof on the rings as the root cause. Care to allude me?
dealership trying every other fix to no avail
NNA saying it was bad rings
pics of torn down VQs with bad rings
plenty of experience and research with this issue
05-15-2007, 07:39 PM
#74
HaHaHaHa!!!!
Originally Posted by soonerfan
failed leakdown test
dealership trying every other fix to no avail
NNA saying it was bad rings
pics of torn down VQs with bad rings
plenty of experience and research with this issue
dealership trying every other fix to no avail
NNA saying it was bad rings
pics of torn down VQs with bad rings
plenty of experience and research with this issue
Listen doesent the benifit of having a 6 speed with a 3.5 engine over your previous 3.0 get negated by all of the weight of having to keep cases of oil in your trunk?
05-15-2007, 08:15 PM
#75
Originally Posted by Kevon1
Yes Sooner we hear you. But can you prove it??? LMAO Listen doesent the benifit of having a 6 speed with a 3.5 engine over your previous 3.0 get negated by all of the weight of having to keep cases of oil in your trunk?
Listen doesent the benifit of having a 6 speed with a 3.5 engine over your previous 3.0 get negated by all of the weight of having to keep cases of oil in your trunk?
05-16-2007, 01:28 AM
#76
Originally Posted by '02_EMILBUS
Hahaha
Why would ya wanna do that. You might as well tear it apart and replace rings if you're gonna take the engine out. step your game up, not doWn.
Why would ya wanna do that. You might as well tear it apart and replace rings if you're gonna take the engine out. step your game up, not doWn.
I'm not hating on the VQ35 but I guarantee you when Nissan finally retires it the last year it's made should be the best VQ35 you could get. I just hope the new VQ37 doesn't burn oil. Now that's a swap to look forward to just gotta wait till someone wrecks their G37 coupe.
05-16-2007, 01:36 AM
#77
Originally Posted by Kevon1
Yes Sooner we hear you. But can you prove it??? LMAO Listen doesent the benifit of having a 6 speed with a 3.5 engine over your previous 3.0 get negated by all of the weight of having to keep cases of oil in your trunk?
Listen doesent the benifit of having a 6 speed with a 3.5 engine over your previous 3.0 get negated by all of the weight of having to keep cases of oil in your trunk?
I better shut up before my 3.0 starts smoking.
05-16-2007, 02:39 AM
#78
Nightmare = Reality
Join Date: Nov 2005
Location: Waterford, MI
Posts: 718
Originally Posted by Kevon1
Yes Sooner we hear you. But can you prove it??? LMAO Listen doesent the benifit of having a 6 speed with a 3.5 engine over your previous 3.0 get negated by all of the weight of having to keep cases of oil in your trunk?
Listen doesent the benifit of having a 6 speed with a 3.5 engine over your previous 3.0 get negated by all of the weight of having to keep cases of oil in your trunk?
05-16-2007, 05:24 AM
#79
Member
Join Date: Apr 2005
Posts: 36
Originally Posted by Rydicule
So I found out recently I'm burning oil like many other people on the board. My 02 SE 6 speed has 83k miles on it, so I figured this was normal. I'm currently running full synthetic and bought a 5 quart jug to keep in the trunk to top off the oil on each fill up. The first time I noticed the oil issue was when, about 1500 miles after my last oil change (and first switch to synthetic after an auto-RX phase), the oil wouldn't even show on the dipstick. It ended up taking 2 quarts to top off. My initial reaction to this was that the place I had the oil changed didn't completely fill it (I always change the oil, except when it's -9 degrees outside). Well, I got gas last night and went to top the oil off to find that after driving 288 miles, it was down about a quart, or slightly less, perhaps .9 or .85 quarts.
No, I didn't type that wrong, two hundred and eighty miles, 1 quart of oil. Oil has never collected below the car while parked, and I have never, even running the car to 6k rpms, seen smoke coming anywhere from the car, front or back. Where in sam hell is all the oil going? I know I'm not the first to consume oil, but at a rate like this? People burn far less than this and report seeing smoke... if it was leaking, wouldn't it collect somewhere??
The only thing I can think of is that it's leaking, but only while driving. Does anyone else have any input on this? All I can think to do right now is throw in cheap dino oil and keep topping it off. Any ideas or suggestions welcomed. Flame me and post a link if this has been discussed before, I don't care, I just want an answer.
No, I didn't type that wrong, two hundred and eighty miles, 1 quart of oil. Oil has never collected below the car while parked, and I have never, even running the car to 6k rpms, seen smoke coming anywhere from the car, front or back. Where in sam hell is all the oil going? I know I'm not the first to consume oil, but at a rate like this? People burn far less than this and report seeing smoke... if it was leaking, wouldn't it collect somewhere??
The only thing I can think of is that it's leaking, but only while driving. Does anyone else have any input on this? All I can think to do right now is throw in cheap dino oil and keep topping it off
. Any ideas or suggestions welcomed. Flame me and post a link if this has been discussed before, I don't care, I just want an answer.Someone recommended changing the PCV valve which I did about 2500 miles ago....so far so good. No oil lose. I do think there is a point of no return i.e. once you start losing a ton of oil, changing the PCV will not help.
Just my 2 cents
05-16-2007, 08:47 AM
#80
Originally Posted by 7_places
I know the VQ30 has a stronger bottom end for boosting than the VQ35
and if you eliminate the pre-cats your hp isn't far from the VQ35 anyway.
Plus think about this, 2001 the VQ30 was at it's best after undergoing years of refinement.
I'm not hating on the VQ35
but I guarantee you when Nissan finally retires it the last year it's made should be the best VQ35 you could get.
This is type of mindless post i was referring to, Irish.