foreignsoda

iTrader: (2)

I hardly post and only a few of you are familiar with my build. Check the garage for details.

The first oil change I noticed it was unusually black and gas-fouled, and noticed a little consumption as well. I was told this was normal for a built engine because the rings aren't 'fully' seated yet.

The next oil change I am losing large amounts of oil. In 3,000 miles I lost close to 2 quarts, oil is still black as ever and gas-fouled.

Same exact things on my next change, but I was more aware and added oil every other week or so keeping it at middle level.

I drive around 10k miles a year so I have only done 3 oil changes. 1 yr anniversary is coming up shortly here.

From what I have been told it sounds like the rings on my piston(s) have gone bad, or were improperly installed.

Last weekend, I did a compression test while I was swapping out my spark plugs..

134,146,140,135,137,145

Those numbers look fairly healthy. Now they should be off if I was losing compression because of a bad ring? I suppose a leak down test would tell that for sure.

Anything is possible, just looking for some insight.

thom000001

did you do a leakdown test when you did the compression test.

Built motors consume some oil but that is quite excessive.

tom

wannabuy350z

iTrader: (27)

good luck man, but that is alot of oil.

Nexx

iTrader: (41)

builtz motors by any chance? if not who built it?

350 Rookie

iTrader: (29)

What kinda of oil did you use on first start up. Its important to not use synthetic until first 5k or so miles so the rings can seat. Maybe this is the reason why you have consumption now. And if your compression is good, no need for leakdown. Leakdown is just to verify a faulty compression.

foreignsoda

iTrader: (2)

I did not perform the break-in on my car. I'm not sure what break-in steps he took. When I received the car I was told to just do normal oil changes/filter with synthetic. I don't think he mentioned that he used non-synthetic. I'll have to get in touch here shortly.....

UMW350Z

iTrader: (18)

That sounds like the smoking gun right there...good luck OP

How does that GT35r spool on a built motor? I may be going this route in the future with this same kit

rcdash

iTrader: (18)

Read this.

http://www.ntnoa.org/enginebreakin.htm

Is the car making power? A/F is ok? Not a misfiring cylinder causing fuel wash into one cylinder? Who built the engine and who performed the break in?

foreignsoda

iTrader: (2)

Car is making power, A/F is spot on. Motor runs beautifully to be honest.. purrs like a kitten.

Intense built the car and Jason (ProEFI) had the car for break-in/tuning purposes.

350 Rookie

iTrader: (29)

so how many miles on the new motor and so far at what mileages did you change the oil at?

INTENSEPOWER

iTrader: (208)

Joey,

Let me touch on some of the issues you're having. Built turbo motors will consume more oil than n/a motors (through the turbo). You're also running meth, which will result in more than normal oil loss. The compression is perfect and you haven't blown it up. Just keep an eye on the oil level every few days and you'll be fine. We've build 100's of built motors and they're built the same way every time -- very very carefully. I know you daily drive this car, and I've seen how hard you drive it. That being said, after 1 year of beating on it, your compression is still on point, and you haven't blown it up. I'd say that everything is a success.

Jason is on his way to Texas Supra 2K9 and I have advised him of your concerns. He will provide his take on this when he has time to stop and get into his laptop.

Thanks,
Darren

ToastZ

iTrader: (2)

Proper break-in takes around 3 normal oil changes on conventional dino oil I've always been told.

The instructions I received and followed for my built-motor was 6-9K miles on regular dino oil (castrol 10W-40), then switch to synthetic. During those initial 6K miles, my motor used around 1.0 Qt. every 3K miles. After it was fully broken in, the oil consumption is around 0.5 Qt. every 3K miles.

foreignsoda

iTrader: (2)

No worries Darren... I'm just concerned about the blackness of the oil and the smell of gas in the oil as well.

In no way am I calling anyone out..

rcdash

iTrader: (18)

Then as Intense stated, everything is probably fine. Better crankcase evacuation is another thing to look into as our stock PCV setup is poor for FI. Several threads on it but bottom line is get an open breather on there somewhere... Fuel vapors are part of the blow by gases that are supposed to be evacuated through the PCV system and you may be seeing this in your oil. You need to replumb the system to accomodate greater amounts of blowby - try to still allow fresh air ventilation to pull gas vapor out (but leave the heavier oil mist in). Someone needs to come out with a complete low cost kit for reworking the crankcase evacuation setup.

foreignsoda

iTrader: (2)

^definitely will look into it - thanks =)

INTENSEPOWER

iTrader: (208)

An interesting tidbit of technical news that I discovered today from a Nissan Master Tech: The 03-04 VQ35de in their n/a stock format go through roughly 1 qt every 1000 miles. If you're waiting to change your motor oil in 3000 miles, you're actually doing average or even better than stock n/a. Other factors to consider -- we build these motors pretty loose and I know Jason tuned your motor to run somewhat on the rich/safe side at ~10.8:1. Last, all motors are not equal. Even from the factory the same motor built in the same factory can have varying responses to stimuli. Again, my take on the health of your motor is that it is in good condition (not smoking, compression well within 10% range of each cylinder). Thanks to Raj for his input as well!

D

SlideFox

Me like Joey's car!!

FredB

Intensepower; what does factory oil consumption have to do with oil consumption in a built motor? why would running methanol cause an engine to consume more oil then regular?

I think if foreignsoda were to run a leak down test it would tell him what he needs to know,