bboysteele

alunserjr, do you have a 5AT or a 6MT? Wonder if this is only seen on AT cars.

Thrillhouse

I'll be sure to update after my track day next tuesday. For the record I'm still completely stock, only TSB performed is the rear axle squeak. 6MT, original oil from the factory.

It would sure be nice if this wasn't an issue, but I think I'll still take a pesticide sprayer full of water with me to hose down the oil cooler between runs if I start having problems.

alunserjr

Mine is a 6MT, stock, dealer oil, only update is new muffler for the rattle issue. No other TSBs. No indicator lights come on when experiencing the rev limit. The dealer has indicated there is no code to read unless a check light comes on. It may not be all G37s - but if its not - I sure would like to know why - or even what is causing the limit exactly.

G37RacerX - was your VDC on and did it kick in at any time? If so, do you recall if it was before or after the rev limit?

DanMardik

iTrader: (7)

Looking forward to hearing your feedback.

04STi208G37

iTrader: (2)

I do not see an oil cooler in front of my radiator. I do see a power steering fluid cooler in front of my radiator. I think I did see an oil/coolant heat exchanger ,sandwich type, while changing my oil filter.

Also, I would not imagine that this car would need an external oil cooler the way a turbo charged car would since there is no turbocharger to cook the oil. Oil works well at 240 degrees.

I have not seen the problem , but I have only autoX'ed the car. I have done some spirited highway driving in 4th gear. I like that gear for thick commutes.

alunserjr

I haven't changed the oil myself yet and thought the cooler in the front was for the oil. Thanks for the info. I have attached the exploded diagram of the oil cooler. I can't tell where it actually runs just from the picture - or what is cooling the oil.

04STi208G37

iTrader: (2)

It's a sandwich exchanger. I had one on my STi. It's the tuna can size thing right next to the oil filter. item 1 in your attachment. The oil flows around inside of it as does the engine coolant. That's what the fittings are for. It is not really a cooler. It's more of a heater. Coolant heats much faster than oil. It helps bring the oil temp up more quickly and it does keep the oil temp closer to the coolant temp.

I am attaching a view of the Power Steering hydraulic line diagram. I think the cooler you see in front of the radiator is labeled 11.

I added an external oil cooler to my Sti using kit. Even without a kit it's not that hard to do and there's plenty of room in the G Grill area for one but I really can't fathom it needing one. There must be another reason for this issue. I am guessing.

notalk

To the OP, I noticed you are now posting this as a definite design flaw on other forums. You believe it is oil temp related. But, this is nothing but a guess on your part.

If you really want to know why the ECU is reducing the red-line cutoff, you need to learn what factors are programed into the computer to cause the reduced red-line cutoff. Then, you will have your universe of possibilities, and you can analyze them one by one.

P.S. I have a guess very different than yours. Mine, like yours, is nothing but a guess.

04STi208G37

iTrader: (2)

+ 1. Besides the above, I reiterate my estimation that the oil temp in this car is just not going to reach horrible temps even after several laps. Endurance racing maybe but the cooling system seems well built and it has not been an issue on earlier models. I am going to guess Detonation or some sort of valve train electronics issue.

G37RacerX

It was on in the beginning, kicked in a few times and then I switched it off, didn't really get the tail kicked out liked planned (blind corners) and then noticed the new rev limit...

bboysteele

No issues with my car today after driving in the mountains. Took my car up to 8000-8500 rpm by accident and that was towards the end of the run. Car was at about 4-5k during the cruising times. No issue with rev limiting at all.

alunserjr

Notalk, the oil temp was the best guess (yes it is a guess at this point without actual data) by an Infiniti dealer - service manager - near the track I was on - with all the track info I provided here. Is it truly oil temp? I don't know. If it is, then maybe the oil temp setting is too low - again admittedly just a guess at this point. However, oil temp or intrusive VDC or something else - the fact that others are experiencing this issue in this forum, leads me to believe it is not a part failure as much as by design and computer controlled since it returns to normal. It seems statistically improbable that the people that experienced the cutoff have the only cars with this issue. When I first experienced this issue I could not find any info about it on the Internet. I am posting on other forums to give this higher visibility in the hope that someone might now exactly what the issue - and fix - might be.

alunserjr

Notalk, I believe the other forum you are referring to is www.6mt.net. I added a reply indicating my previous comment as a "design issue" is just my opinion and I'm still looking for an answer to the issue.

notalk

My guess, like 04STi208G37, is that it has something to do with the VVEL software. That's why I previously asked what TSB's you had performed. Many owners do not notice the knocking when they turn off their engine either because they park outside or they don't turn off the radio before turning the car off. (An old habit, as race car drivers always let the car idle before shutting off to listen for any "odd" noises.) In either case, there's enough outside noise to prevent hearing the knocking. (And, you don't hear the knocking until the engine is fully warmed up and the valve timing is now out of whack.) The updated software also makes the car run smoother at high rpm's, possibly allowing the computer to read the acceptability of the valves opening/closing at speeds higher than the reduced cut-off. Again, just a thought.

P.S. The VVEL TSB is not like the rear axle chirp or muffler, where the dealer needs to hear/experience the problem before performing the TSB. The dealer only needs to determine a lower number software version. This is done by plugging in the OBD reading computer and reading the software version. If not the most current, the dealer updates. That's it. No mechanical parts replaced or attended to.

P.P.S. This is, most likely, not a "design defect". It appears to be a design to limit rpm's when something is out of the ordinary. It is not likely that high temperature would be out of the ordinary. It is more likely that something like prior generation VVEL software, or some other software, might lead to an out of ordinary circumstance resulting in the reduced red-line limit. In that case, this would not be design defect, but, rather, a design protection. The difference is whether someone would rather the ability to pull more than 6,200 rpm on a track day (even if it meant blowing up their engine) or protecting their engine from self destruction.

alunserjr

After each session of running HPDE I stopped my car and left it running with the hood up for about 10 minutes to cool down (using wheel chocks). I didn't notice any tapping or unusual noises at those times. However, I am scheduled to take my car in for an oil change, and a noisy clutch - when engaged, this Thursday and will ask to check if the VVEL TSB needs to be applied.

I understand the protection that the cut-back offers and do prefer that over engine failure, its just that by comparison, other products/cars running on the same days didn't have to cut-back. I would rather there be no problem or cut-back. Which makes me think that if there isn't a real problem, then the protection mechanism is too aggressive.

Does anyone who has experienced this issue know if their car has the VVEL TSB?