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'05 CTS-V
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Discussion Starter #1
From the day I picked my car up about 2-1/2 weeks ago the oil temperature has seemed unusually high. I have real oil temp gauges (not factory dummy gauges) on both of my other cars, so I have a good idea of what normal oil temps should be.

I came here and learned that the high oil temperatures and the high temp warning when using the A/C is a relatively common problem. There are a number of threads that talk about people seeing temperatures that are too high as a result of the bad sensor/ground, but I haven't seen any mention of what one should be seeing once everything is fixed right. Obviously driving style, ambient temps, etc will play into this, but what would you guys consider "normal" oil temperature for cruising along at 75mph or so with air temps in the 80s? My Subaru runs 200-210°F on the highway spinning at ~4000rpm, and my Mustang will sit about 180°F (it's got an oil cooler, and the oil-stat is 180°, so that makes sense).

As for my CTS-V, after reading about the various sensor/display issues that people have had (particularly high oil temps with the A/C on), I took the car to the dealer last week to get the problem fixed. The service guys seemed to be very familiar with the A/C - high oil temp issue, and said they replaced a wiring harness to fix the problem. (The sheet just says it was a warranty repair, doesn't list the part number of the wiring harness or list a TSB number or anything like that.) I've driven the car a number of times in the past week, but only short jaunts that never got it warmed up.

Today, though, I drove about 90min or so round trip to go check on the Mustang at a body shop. Cruising along on 2-lane highways, cruise control on ~70mph, my (displayed) oil temps varied from 240° up to 280°ish, usually towards the bottom end of that band. Turning the A/C on and off still caused an immediate jump/drop in temperature - about 30 or 40° within a matter of 5 or 10sec. Clearly, whatever fix the dealer did wasn't enough. It's also clear that the response of the oil temp isn't normal, but it seems to like to come back to ~240°F. The fact that it keeps coming back to about that temp makes me wonder if that's an actual steady state temperature, or if that's still a bad reading. 240°F seems awfully high for an engine loping along at 2000rpm.
 

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I've been hitting 280's on a regular basis and when pounding through the gears getting onto a freeway I have hit 300 several times in the past few weeks :eek:

This should not be happening, right? The oil temp alarm went off each time it hit 300. A few weeks back the dealer replaced the oil temp sensor and refilled with oil (not sure what kind because they didn't document what weight/brand). They did this because the oil temp was reading "--".

What to do? I have LITTLE faith in the dealer at this point.
 

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I've been hitting 280's on a regular basis and when pounding through the gears getting onto a freeway I have hit 300 several times in the past few weeks :eek:

This should not be happening, right? The oil temp alarm went off each time it hit 300. A few weeks back the dealer replaced the oil temp sensor and refilled with oil (not sure what kind because they didn't document what weight/brand). They did this because the oil temp was reading "--".

What to do? I have LITTLE faith in the dealer at this point.
Those are temps to be seen at the track....not on the street, bring it to another dealer.
 

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'05 CTS-V
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Discussion Starter #9
I went back to the dealer today and showed them the '04 TSB that StealthV posted. Theoretically that's only for '04 cars, not my '05, and there's nothing in the Cadillac TIS about that fix being applicable to '05s (or newer). They're going to contact GM and see what they have to say about my problem not being fixed by the '05 TSB relating to correcting the bad ground.
 

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2005 CTS-V
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I went back to the dealer today and showed them the '04 TSB that StealthV posted. Theoretically that's only for '04 cars, not my '05, and there's nothing in the Cadillac TIS about that fix being applicable to '05s (or newer). They're going to contact GM and see what they have to say about my problem not being fixed by the '05 TSB relating to correcting the bad ground.
There are some other possibilities (in addition to the oil temperature sensor and the TSBs) on the oil temperature gauge troubleshooting chart contained in the 2005 Service Manual including, among other things, replacement of the Instrument Panel Cluster and tracing the related wiring harness.
 

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Supposedly when they "fixed" my broken oil temp sensor they rigged up some cheap looking wire splices in the engine bay, several inches from the block. I will take some pics of this ridiculous wire splicing job when I get home from work today. It may have something to do with this problem. You will shit yourself when you see the splice job they did, instead of replacing a harness (they were so vague on their description its scary).

BTW - My V is an early 04.
 

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'05 CTS-V
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Discussion Starter #12
There are some other possibilities (in addition to the oil temperature sensor and the TSBs) on the oil temperature gauge troubleshooting chart contained in the 2005 Service Manual including, among other things, replacement of the Instrument Panel Cluster and tracing the related wiring harness.
I just got my FSM set from Helm in the mail the other day, hadn't cracked it open yet to see what it has to say. The guy at the dealership was very helpful and interested in seeing this resolved, so I'll let them do their research and see what they come up with.
 

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BTW I hit 331 on the oil temp sensor on the way home from work, my driving wasn't too insane, but c'mon, 331? Its gotta be a display error. Taking in to dealer tomorrow morning.
 

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I'm not jackin' here if we still are talkin' oil am I???
I was wondering what pressures your all running. I never remember seeing 60lbs, now when the RPM's get up I get to 70! That seems real high to me. Any suggestions. I have two track days in a week. Oil level is good. Relatively new oil.
 

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Discussion Starter #16
I never remember seeing 60lbs, now when the RPM's get up I get to 70! That seems real high to me. Any suggestions. I have two track days in a week. Oil level is good. Relatively new oil.
I honestly haven't watched my oil pressure at high RPM to see where it peaks. However, the common thumbrule for ensuring you have "good" oil pressure is to have at least 10# for every 1000rpm. So if you're seeing 70# at 6000+rpm that seems good to me.
 

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I'm not jackin' here if we still are talkin' oil am I???
I was wondering what pressures your all running. I never remember seeing 60lbs, now when the RPM's get up I get to 70! That seems real high to me. Any suggestions. I have two track days in a week. Oil level is good. Relatively new oil.
I run 60lbs just driving down the highway...~2k so 70lbs shouldn't be too far off....I'd only start worrying if you start getting seepage around the filter from the pressure...but I don't think 70lbs would be enough to do it.
 

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Discussion Starter #19
I run 60lbs just driving down the highway...~2k
Really? Huh, now I'm curious what other people are running. I run about 40-42# or so cruising on the highway, which seemed perfectly reasonable to me. If other people are also running 60# at ~2krpm I have to wonder if my high oil temperature is for real. A bad bearing would cause low oil pressure and high oil temperature. Hmmm....

I'd only start worrying if you start getting seepage around the filter from the pressure...but I don't think 70lbs would be enough to do it.
My Subaru runs up around 100# when the oil is cold, and that's normal for that car, so you'd have to have some pretty serious pressure to have oil filter problems.
 

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Sorry to dig up an ancient thread, but i was curious as to what people paid to have their IPC reprogrammed under that service bulletin? Called the dealer and they want $130 to do it - call me crazy, but if a mfg finds out they made an error programming the gauge cluster, I expect them to cover the cost?
 
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