'05 Stealth Grey CTS-V, 19x8.5/10" CCW T140s with Toyo Proxes T1 Sports (summer), black Team Dynamics ProRace 1.2 wheels with 275/35-18 R-compounds (track), Hyperblack Rota Torques (winter), KW Variant3s, V2 front brakes, Hotchkis rear sway bar, EPS cam, TEA-ported 243 heads, FAST92 intake w/LS2 TB, JBA Camaro/G8 1-3/4" shorty headers w/JBA cat pipes, Corsa exhaust, UUC motor and tranny mounts, UUC shifter, MAPerformance trailing arms, Specter cradle bushings, etc...
My oil temp has been running up to 300 for a while but it's been really bad since we've been in the mid 90's for the whole month of June. I checked the voltage and it was running 250mv. I pulled off the bolt and sanded everything down and it went down to 110mv and after a 15 minute spirited drive my oil temp held steady at around 200*. I was hoping the voltage would of dropped a little more but it's fixed so I'm happy. I did not do the bolts on the back of the heads only the main ground on the the right side.
I've been putting this off for a while because I thought it was going to involve pulling the sensor, but this took all of 5 minutes. I feel like a dummy for not doing it sooner.
I would appreciate it that if you do this and it fixes your problem, please post so.
As I was changing my spark plugs, I found another ground. I had my coil packs off, otherwise I couldn't see it. It's on the back of the passenger side head right above the last plug.
So I finally put a star washer on the fender wall ground. I scratched some paint off, but need to get back in there and do a better job. As is, driving around town with AC and lights on temps were very steady at 222. It used to bounce around 5-10*.
Didn't pay attention to highway temps (this is when mine starts to climb) cuz I was focused on something else.
I'm getting closer every time I mess with it and will post up when I have more to add.
I'm going to check into this too.
I'm sure you guys in the yellow group noticed me at V Day during 1 session just puttering around at 50.
My oil temp had hit 302 and the alarm was going off so I put it into 5th and just cruised for 2 or 3 laps.
I don't think it was an issue with the sensor as the track temps were probably over 100 and I was winding 3rd into the rev limiter quite often.
I did manage to get it to drop during that session and once it sat for lunch it was fine the rest of the day.
I'm guessing the rain cooled the track down plus I was shifting into 4th before redline.
Still something I want to look at tho...
Here are pics of where the voltage is measured and the washer used to "fix" it.
Notice the probe is on the head of the bolt (not the cable terminal).
The voltage being measured (lights and A/C on) is the drop across the junction of the bolt (body ground) to the cable terminal after the washer was installed.
Damn, dopy me did it with the car off.
I'll check it again in a bit, but this is what I got.
Ok this is what I got with everything on.
CRAZY hot the next couple days. If I'm brave enough to go out, it should be a good test.
Turn on the A/C, and the lights for the "acid test".
Pretty interesting to see that much drop huh?
This is a major problem with the high tech electronic monitoring systems in autos.
Ground referenced (single ended) measurements can change when the ground reference is different as the PCM is using "frame ground" and the sensors are using "engine ground".
The sensor sends a variable 5 volt signal to the PCM which got offset almost 1/2 volt (in Reed's car) because of the bad contact.
Because of the low current the sensor draws, the biggest offset it could generate is minimal though its' ground.
To put is simpler, the voltage is correct coming out of the sensor.
The "ground reference" the PCM uses for measurement gets "tricked" by the bad connection into reading a false high (sensor output + offset).
Thanks for the tip! I was dinging all over place yesterday and for the past 5 years. I applied the fix about 20 minutes ago and IT WORKED! It seemed too simple a fix to actually work, but it did. Just before I applied it, my temps were hovering around 270 with out the ac and off the chart with the ac on. right after the fix, 218 without the ac and 224 with the ac. Its 94 in NYC and it's 69 in the car!
Next to FREE, I bet this is the cheapest fix for a problem with the V.
What battery voltage are you guys getting in the DIC? I'm still at low 13s with everything on.
Lowest is 12.8
Highest over 14.
Is my membership up for renewal?