L36

iTrader: (4)

Id figure to ask this here because G35 forums are a joke and everyone tells you to pay a shop to do it.

So, 04 G35 coupe. VQ35DE. Prior to oil catch can burned a quart every 500 miles or so. With OCC, 1K miles per quart. Still, a lot of oil. Burns more oil if I engine brake so obviously the rings and or stem seals are letting oil through due to that vacuum during engine braking.

I did do a compression test and I got sub 190 PSI in all cylinders. I'm assuming its all the oil on the rings sealing everything but I did not do a wet test to confirm it.

I'm considering replacing the rings, might as well do stem seals since the heads will be off. Several questions are along the lines of what brand of rings should I get, should I get piston + ring combo? I’m assuming there is no need to replace the pistons...? Also, I don't need oversized rings; just get standard rings for 95.5mm bore size? The engine has 99K miles and it has been well maintained for what it seems though I don't know how it really looks on the inside until I crack it open...

Also, I heard HR head gaskets are better vs DE, should I use HR HG? Anything else I should do while inside? Not interested in doing cams or upgrades, this is one of those "are there any other defects I should take care of while I'm inside" questions. Planning to check timing tensioners and will do the water pump while there along with rear main seal etc. Though tensioners are not making any noise, but do get a loud rattle every time I change oil and do the first start up. Thinking it’s the main chain tensioner not holding up well enough when oil pressure is low...


Or, replace the engine and hope I don't get a crappy engine but used prices for a RWD VQ are just plain dumb. Planning to do all labor myself so saving a buck here...


Thoughts?

sergofast

iTrader: (22)

If I remember correctly the Revup oil pump is better than stock.

You will have to research this but I know on the max the valve covers are better on the later year FWD VQ....I dont know if that changes at all for the G RWD VQ. For the max it is the 04-05+ covers that are better than the 02-03 covers (they dont leak as easily).

I would do the tensioners and all the plastic guides....

If you are doing HR head gaskets you have to slightly modify the cooling passages. This allows better cooling at a higher RPM.

Although you said you dont want to do the upgrade on parts....ARP bolts would be a good addition if you hit higher RPMs and its perfect timing for cams, lightened flywheel and light weight pulley. Just a thought....

All of this being said...someone is going to mention just putting in a low mileage junker engine vs. a full rebuild. Although with a full rebuild you know what you have and its done right.

Crusher103

iTrader: (10)

^I agree, if you have the time and dont mind your car being down for sometime(like a week maybe 2) I would recommend a full rebuild with QUALITY parts only. The thing about it is what is your budget for rebuilding the motor looking like.

The HR headgasket can be used but unless you are seriously tracking the car it is unnecessary. Only a few people on this forum are running around with HR HG on their cars. Most people dont bother it is overkill.

Just rebuild a stronger motor. ARP bolts(rods,main,head), ACL bearings, Rev-up oil pump, new oem valve seals. Strip your block and head of everything and them checked and cleaned at a machine shop before throwing new parts in them, having the cylinder walls checked for damage is crucial, and rehone.

If you have the spare cash what you can do is buy a set of HR Valve springs(important with cams and high rev motor) and after you get your block back incase a set of HR pistons and a .040" cometic HG(compression ratio should shoot up to 11.4:1) a decent set of cams and you easily have an 300whp capable motor with tuning(Haltech PnP). Some food for thought.

Good luck.

sergofast

iTrader: (22)

Crusher. Don't mean to thread jack but what sort of gains do you think you would get without the haltech? I'm in the midst of a mild overhaul (replacing timing components on a replacement engine with 70k on the clock).

I too didn't plan on doing any major upgrades but I've got the "while I'm in there bug". That raised compression and HR valve springs seem real tempting but I'm not planning on swapping cams, doing a haltech or HR pistons...plus I've not even looked into if the hr pistons can work in a fwd configuration (no I haven't searched yet).

Mostly just bolt on was the main objective for this daily driver.

Paul

L36

iTrader: (4)

While I'd love to build a nice, strong NA motor; I'm currently budget constrained. I don't want to spend a lot of money and just want to fix my oil consumption issue.

Though considering HR oil pump as I've read much about it and its clearly superior to the DE pump.

Question I have is about the cam chain tensioners. I know these tensioners in my RWD VQ are same style as ones found in the 02-03 maxima VQ. From what I remember, you can't replace the black plastic guide, you have to get a whole new tensioner assembly? I know 04-08 FWD VQ have the white tensioner guides that can be removed and replaced without replacing entire $60 tensioner assembly.

I'm just trying to find a company that makes the rings for VQ that's trusted. Also, I need standard rings, no need to get oversized unless I make a bigger bore. Stock is 95.5mm?

Crusher103

iTrader: (10)

PM SurraTT. He is the one who works haltechs pretty good. But its a full standalone, so complete control over all engine functions, so possibilities are endless.

The HR pistons are a great cost effective upgrade if the motor is already a part. But with out cams, well for one you wont need valve springs, and its not that you wont get the power out of just the upped compression but you will not be able to get the full benefit of them. Tomei cams would be a good route something in the 260* duration, 11mm lift, and about 4* worth of overlap would be great for a NA street car. Anything over 11mm lift you will have to check your valve clearances.

Building a motor can get involved and expensive(right now what i have mentioned count on about $1500-2000 once all is said and done) so its something where you have to want it to actually do it. If its a while im here it would probably be better for you to not touch it because if you are taking those pistons out you want to take your block to the machine shop and get it honed and ready for new piston rings, then time and etc.

L36

iTrader: (4)

So my options not to touch it at all or do it only if I have the block honed for the new rings?

Crusher103

iTrader: (10)

HR oil pump WILL NOT fit on a DE block, only the Rev-up oil pump will work. Also the HR oil pump is not stronger than the DE pump. It is actually weaker than the Rev-up pump which is interesting. But its due to the improved balance and less vibrations of the VQ35HR made strengthening the oil pump pretty much pointless. It does flow more but it wont fit the DE block.

Just buy the whole tensioner assembly, seriously its like $50 and it will save you soo many headaches.

hopefully there is no damage to the block and you wont need oversized stuff, (I severely doubt there is any damage). And yes stock bore is 95.5mm.

There are some more knowledgeable people floating around here i hope they chime in pretty soon on what you can do that shouldn't make things more difficult, hopefully.

Crusher103

iTrader: (10)

Yes get the block honed for the rings. that's just to insure that your rings seal properly to go along with the break in procedure. It shouldn't cost too much and better safe than sorry, i learned that the hard way.

sergofast

iTrader: (22)

I agree with this completely. Sorry to slightly thread jack your question. Ill take the questions to another thread.

L36

iTrader: (4)

One more thing, if I hone the block should I worry about the bore increasing in size or this is so negligible that its pointless to worry about?

Crusher103

iTrader: (10)

As long as the block is not damaged, its negligible. Clean all the carbon off your pistons new rings and throw them back in. Stay OEM if your not upgrading anything. If you have to go aftermarket these companies make good stuff ACL, Mahle, JE, Hastings and NPR/Nippon.

Also are your running LT headers or test pipes? the G/Z have the same Cat blow out problem that the maximas do so i would ditch the cats IF they are still on the car. HFC if your state is ****, other wise test pipes.

And before you embark on the rebuilding journey have you tried the ATF trick? people usually pour a little bit of ATF down their spark plug tubes let it sit for a day or 2 then restart the car and it can sometimes reseal the rings. There will be some smoke be warned. Its worth a shot if you have not tried it.

Personally i would save about 3G and build. Tomei 272* 10.8mm lift, HR or JWT HD valve springs, new valve seals, HR pistons w/ cometic .40 HG, rev-up oil pump, ACL race bearings, new OEM waterpump. Run osiris for now and raise your redline to 7500rpm. Troll HR&G37 guys and be happy.

http://www.courtesyparts.com/

schmellyfart

iTrader: (46)

I've never heard of the ATF trick before. How does it reseal the rings?

Crusher103

iTrader: (10)

ATF is more detergent then it is actual oil. Basically you pour some in turn the motor over a couple of times so the compression forces it into the rings and your let it sit. that way It can eat way at some of the carbon build up around the rings and frees them up allowing them to move around the piston like they should. If the cylinder walls and piston rings are not damaged then they rings should be able to reseal. Sometimes it works sometimes it doesnt. Its on old trick V8 guys use.

L36

iTrader: (4)

I highly doubt that the rings are stuck. For one, I frequently engine brake so the vaccum from the braking would suck up the rings causing them to move around. Two, I dumped seafoam into the oil on numerous occasions.

I think this is a problem that can't be solved by detergents or placebo. I don't want to do this, but I have no choice.

I'll also throw in test pipes. I'm getting a cat code right now due to all that oil burning. In the mean time I'll be indexing part list. I just hope the engine is in good heath.

CMax03

iTrader: (3)

I personally think most orgers (not All) are consuming oil due to dry rotted valve stem seals...During my NWP spacer upgrade I noticed the dry intake tract from the TB to the Head port but the valve stems were wet only (with fresh oil)! I'll more than like try too replace mine on the car using the JWT valve spring tool...I'm going with Ferrea High temp valve seals.

Crusher103

iTrader: (10)

Correct. VQs rarely have valve seal problems. If it was this silly BMW like what i have sitting here with valve seal issues......

vipervadim

iTrader: (10)

Many times, 3.5L oil burning issues are caused by clogged precats. The exhaust gasses start to build up within the headers, they keep buiding up until they start choking back into the engine -> piston rings and valve stem seals both get hit as there is nowhere else for exhaust to seep through and wear away at the seals of those moving parts.

I ripped apart a few oil burner 3.5Ls; used one for headwork and noticed the destroyed blackened valve stem seals during head disassembly, superheavy carbon buildup around the valve seats, charred piston tops and toasted piston rings.

LOL @ silly BMW.. oh the M52s and Toyota 2JZs have those valves stem seal issues too.

CMax03

iTrader: (3)

I keep hearing this and it's hard to beleive that amount of reversion it would take to make this possible... I'll believe that when someone pulls a head and the cylinders and ports are full of precat debris....If it was true even one should have a oil pan full of precat debris as well as piston lands full of this gritty debris....The vendor used for the valve stem seal F@#Ked Up! and that's why I've seen 3 VQ35DE with leaking intake stem seals....If someone can get a video of this precat prediction, I'll love to see it! My intake valve stems where clean but wet...If the exhaust are leaking they'll be full of carbon build up as on anyother car out there!!! This dedris from the precat is Nonsense!!! Just like that other BS story about 00-01 SE 17" rims not being compatible with 6th Gen Front brake assy!!!

Crusher103

iTrader: (10)

True. But a VQ with out clogged cats will not have this issue is basically what i mean. The valve seals are not an issue because they are bad but other factors cause them to go bad. Jesus i would hate to do valve seals on a VQ, on a G/Z it wouldn't be as bad but on a maxima.

I'd rather work on a 2JZ with valve seal issue then any mentioned motor because man this BMW, ok its a N62B44: $50s in parts, $6000 in labor......you do this first: Then you do this: At the end of the day it leaves you like this: fcuked with no vaseline.

CMax03

iTrader: (3)

I've seen those same descriptions on engines that didn't have precats, especially if there is more than desired amount of oil gettng in the combustion chambers via the exhaust and/or intake valve stem seals...The lean burning engines and their extremely high operating temp is the cause of most of the seal hardening/crystalization (causing leakage) not precats particle reversion!

L36

iTrader: (4)

Guess ill post an update. I sold the car. Did not want to bother with it. Bought an 07 M35X. Staying in the VQ family.