alunserjr

I took my G37S to 3 High Performance Driving Sessions (HPDE) on 3 different days. On each day I had power loss from the engine with no check indicators in the car. Its almost like the rev limiter moves to 6200 rpm. Spoke to a service manager that thought it might be engine oil temps. Has anyone else experienced this?

More detailed info below:

HPDE May Day 1 - weather: overcast, high about 75
Four 20-minute sessions, with as much as 1.5 hours between sessions. sessions 1 and 2, no issues, towards the end of session 3 car does not feel as strong. Session 4 the engine cuts out completely at about 6200 rpm - can't go over 6200 - thought it was because I only had 1/4 tank of gas and
suspected air was being picked up in the fuel line in the turns.

HPDE July Day 1 - weather: sunny, high about 94 in afternoon, morning around 80.
Four 30-minute sessions, 30-minutes between sessions.
Session 1 - no issues, session 2- no issues but engine doesn't feel as strong, temps now about 90, session 3 - after 20 minutes can't go over 6200 rpm, session-4 after 10 minutes engine cuts at 6200 rpm.

HPDE July Day 2 - weather: sunny, high about 90 in afternoon, morning around 75.
Three 25-minute sessions, session 1 and 2 separated by 1.5 hours, session 2 and 3 separated by 3-hours. Temps between 85 and 95. Session 1 no issues. Session 2 after 25 minutes engine limited to 6200 rpm. Session 3, after 20-minutes limited to 6200 rpm.

Between all sessions, hood up on car for cool down.

After issue on HPDE July Day 1, I recalled a forum entry that discussed issues with air filters and loss of power, found local dealer that day and bought 2-filters, discussed issue with service manager (who was very interested) and spent time looking up information on the service computer. He indicated it "may" be oil temp. Documentation he was viewing indicated G37 is first to get an oil temp sensor and if temps at certain level the engine will be cut back. I installed the filters after July Day 1 - and as you can see above - it did not fix the issue. I have discussed this with others and some suggestions: racing oil (however, won't do anything (or much) for temps), Water Wetter Super Coolant (might work), Synthetic Oil (not recommended by dealer until after 10k miles - but again - won't reduce temps much). Something to keep in mind - all other cars running faced the same weather/temps. I discussed this with the others in my group and no other cars (about 20) during the HPDE had this issue, such as: Suburu, Toyota, Porcshe, Vette, Mitsu, BMW, Nissan, Audi and a 2007 G35S sedan. If this is truly an oil temp issue - it must be set to trigger at a very low temp. But really, the oil temp being the source of the problem is speculation until proven some how. Anyone else come across the lower rev limit during HPDE or other times??

Some other info: On all runs water temp indicator remained below 1/2 way mark - close to normal. July runs full tank of gas 92-93 octane day one, second day when at 1/2 tank filled with 100 octane. Octane level didn't make a difference. At no time was tank less than 1/2 full. Oil at full mark 5-30W.

UPDATE - and save time on reading through all the posts: I installed a Stillen Oil Cooler and that solved the problem. It never happened again after the oil cooler was installed.

alunserjr

Would anyone know how I can provie its oil temp in this case? I don't want to go through the hassle of installing a 2nd oil cooler just to find out it doesn't make a difference.

KAHBOOM

iTrader: (4)

How old was your oil?
You might think about setting up a video camera to get documentation. Howeverf the fact that it occurs during track duty may give Infiniti an out on any warranty issue.

alunserjr

Oil had about 1500 miles on it. I can probably get it to do it for the dealer by running around on public roads in 2nd and 3rd - high rpms for 20 minutes or so. Not sure. I am hoping the dealer will come back with: here are the things that can cause the computer to cut back on RPMs without a check engine light. And maybe I can start there. I'm also hoping that with time more people will be taking their G37's to track days and finding out if they experience the same thing or not. I would really like to know if this is a design issue, or just something wrong with my car.

04STi208G37

iTrader: (2)

vdc. on ...or off? VDC will cut power in turns when slip is detected. It must be be turned off each time the car is started at a track day or autoX. I am sure you already know this but ....just in case.

alunserjr

VDC was on but the cutoff was happening mostly on the straights - when I was hitting the higher rpm. I turned VDC off once I noticed the cutoff on the straights and the engine still cut back to 6200 on the straights.

bboysteele

hmm...I wonder if this is a heating issue. I haven't tracked my car yet so I have not experienced this. When one of these management systems comes out then it could give you an idea of what the problem could be such as temps.

Thrillhouse

I'm very interested in this as I have a track day scheduled for August 12th. I'll be running 30min sessions though which may make things worse. I wonder if I should take a water tank to hose down the oil pan after each session?

Just curious, but do you have a front plate? That could block some of the airflow to the radiators.

Blackjack

iTrader: (3)

You need to check the specs on the endline for the...rotary...girder...


















I'm retarded.

alunserjr

I'm curious how your track day goes on Aug 12th. How many 30-minute sessions will you be doing? My car is completely stock. If it isn't heat related, another suspect is the VDC. If you experience the rpm cutback, you might want to try a session without the VDC from the very beginning.

Thrillhouse

It should be about 6 or 7 30min sessions, VDC will be off at all times. It steps in too early in my opinion.

DanMardik

iTrader: (7)

keep us posted.

alunserjr

If you don't experience the problem, maybe (as a favor) on the next to last session you could run with the VDC on to see if it kicks in.

mikelr

iTrader: (1)

Just did a track day at Watkins Glen yesterday and experienced the same thing.
I could get about 4-5 laps before the rev limit would drop or the engine would not pull at higher rpms. I could tell by the induction howl (or lack of) that even know I had the pedal to the floor on corner exit, the ecu was not opening the throttles.
After letting the car cool down it would be back to normal. It's possible that it's oil temp related, I also thought it might be related to heat soak and detination but oil temp seems more plausable.
I'm not going to pursuit a fix, I was just banging around with it to see how it performed on track while my dedicated track car is under repair. Other than the power dropping out after a couple laps the car wasn't too bad considering it has stock suspension and street tires.

G37RacerX

I also experienced the same power loss yesterday after some very spirited driving uphill through some tight twisters, (god was it ever fun!). Temps in the upper 70's, elevation about 5000 feet, humidity was low. Took maybe 10 to 15 minutes for the engine to start limiting revs. I thought it was about 6500 cut off, could be wrong, definitely not going to redline @ 7500. After parking and coming back after a hike, everything was back to normal...