So, we have had some excessive heat here lately but my oil temps and coolant temps have no exceeded 215F. I drove to Austin and back Saturday to a car show and got stuck in traffic for a while (for freakin' ever). After a while my oil and coolant were at about 215F each and never went above that.

Then at idle my low oil pressure beep comes on and the car is at about 20psi and my idle is fluctuating at about 750-800RPM (lower than usual). It didn't stall but worried me. The car drove great otherwise, no power issues and of course at speed, water and oil temps dropped to 180F almost immediately.

This motor has about 15,000 on it and has seen GC 0W-30, Mobil 1 0W-40, and Rotella T6 5W40 for all of it's life and never an oil change longer than 3,000 miles and typically at 1500-2000 miles just because I am fanatical. The engine also had the BHR ignition installed when the engine was only a few weeks old and is on it's second set of plugs ( I change them yearly). I have changed the air filter twice, I have premixed every tank with JASO FD semi-synthetic 2 stroke and I run the SOHN injecting the same.

I have noticed that MY SOHN doesn't drink as much as it used too but also only work less than 2 miles from my house now too. I haven't worried too much because I premix 1oz/per gallon. When I changed teh plugs they didn't look great but had a nice oil residue on the threads which I assume is premix.

I may do a compression check just to see but I know my car very well after 112,000 miles and I just sense something is wrong. I don't drive her past 3500RPM's until oil temps are at 160F at least and she gets redlined every single day.

The only CEL I get is from my midpipe and for the lack of my air pump.

this has only happened twice, once after a hard day of canyon driving in hot weather and this past Saturday. Once the car cools down it idles fine. Thoughts?

 

you're worrying WAY too much ...

 

what is normal idle pressure ? Does it still get same pressure at higher rpm ?

 

Yeah everywhere else oil pressure seems the same but I did get a spike to 150PSI once which scared me. I dunno my previous two failures started with low idle/eventual stalling. I am wondering if they just don't rebuild them properly or skip steps.

 

If your temps crept up there over many minutes rather than jumping up there then it will be fine. Most likely your engine bay heat soaked to the point that the intake air was extremely hot where the ecu was pulling back power. I forget where but somewhere 180* or so intake temps the engine starts being unhappy. Your idle probably had nothing to do with your oil and coolant temps but all were related to high heat. You may have to change your oil a bit more often in extreme temps but aside from that it doesn't sound too alarming. If you car runs bad constantly now then I'd be concerned. Being in San Antonio in the summer you probably want to run a good 5 or 10W40 oil anyways.

 

Yeah it's only happened twice, once after a day of bashing during the state wide meet and now this time. I even recently sealed up my radiator even more and it helped lower my coolant temps about 10-15F. I am working on something to get extra air in through my empty factory oil cooler locations and I may lift the year of the hood just to see if it helps. Track sessions are limited so I should not see those temps but I would still like to be able to sit in traffic if I have too. I think I need to ditch the Koyo, some guys are staying under 200F in high heat track situations.

I run Rotella T6 5W-40 fully synthetic, before that I ran Mobil1 0W-40. both have tested well in UOA's but the Rotella had less fuel dilution so stayed with it. Plus it is cheaper which is a plus.

 

My idle oil pressure readings are generally 14-18psi. Maxing out at 75psi. However don't you have a custom oil cooling system?

 

Yeah I have a 28" Fluidyne oil cooler and the Mazmart RE-medy oil pressure kit.

 

again, you're thinking too much man ...

 

"worrying" was a more accurate description

I'd be more concerned if it starts becoming harder to start than the idling stuff

 

Yeah it hasn't started giving me trouble on hot starts yet. I guess I'll find out after the first track practice session.

 

possibly start shopping for a vented hood just in case?

 

I wish they made a functional vented hood that was not so aggressive using NACA ducts or something.

 

If you paint them they really don't look THAT aggressive.

 

Come get stuck in traffic in Phoenix for a while. I'm seeing 210-220+ while taking surface streets

 

I was seeing 230F or so during our statewide meet (whole day of aggressive driving) but I sealed up the air leaks around my radiator so temps have come down a bit. I do notice my oil temps drop way faster than my coolant temps once I pick up speed so the Fluidyne oil cooler I have kicks ***.

 

Here in CT on a humid hot day in the 90's in stop and go traffic it will run 230F water and 215-220F oil worst case if I can't move for some time. I've seen my oil pressure drop below 1 bar (14psi) due to the temp being so high. Then again I'm running a 50/50 mix and need to change that to a 60/40 or 70/30. Have to keep in mind I believe this is testing they've gone through for a hot environment before releasing the car.

Then again, they knew about the issues the engine would have no matter how much you followed their manual anyhow and still released that design also

I'm contemplating getting a better thermostat so the ports open up before 200F+ to start cooling earlier.

 

I tried running mostly distilled water and if it did not affect my temps at all versus the 50/50. now I am running distilled, 50/50, and water wetter. Next time I will just leave it at 50/50.

 

I get that in NYC too. I would say its "normal"

 

My whole family is from New York and Jersey, I used to spend summers there and it gets freakin' hot in the city. I am thinking there is a major problem with the way heat escapes the engine bay.

 

you think Rx-8 is bad?

try to look at FD's engine bay

 

Yeah I seem to remember many FD's dying of heat stroke back in the day.

 

After taking a spin in the RX8 on an 88 degree day around the block (grandpa'd it), I went to check my oil level after a 5 minute rest with the hood open. Freaking engine cover and strut bar burnt my palm. Heat soak for the win.

 

FD's stock system was barely enough for stock car.

biggest problem was TONS of ********* up the boost by 2-3 times the day they got their ride, then the Engine just go booom.

my honda fit's windshield washer cap burn my hand too :P

not as bad as RX-8 tho.

 

RG is right about the intake air temps and ecu.
Just keep an eye on it like you already do.
i re did my secondary radiator for just those type of times.
vented hood is only good when the car is setting still?
becareful with vented hood--has the possibility of making the coolant temps hotter.
OD