Bad oil temp sensor
 

Well it seems as though I have a bad Oil Temp sensor. Would ignoring this harm the car? I just got an oil change thinking it would solve the fluctuating temperature readings I've been getting. Still keeps jumping from 215F to 203 back to 215F once in awhile.

Thanks
-Steve

Mine does the same thing. It will be at 195 one minute and 165 the next. I've been meaning to take it in but haven't had a chance yet. Have you had any luck getting yours fixed?

Yeah I've been so busy I haven't had a chance, But luckily I'll be taking it tomorrow morning.

Why would it jumping back and forth automatically make the sensor bad? Sorry this might be a newbie question...but just by reading this post, it seems that oil temp jumping back and forth may a few degrees here and there is normal...mine does the same thing...like 242 to 233...

I assume this is some kind of a narrow band sensor, that does not detect small-ish changes, so it only ticks when there is a significant change...when the fan motors starts to run, lesser loads on the car, oil circulation starts to move.

I have a PLX oil temp meter on my other car, and it does change rather quickly...but I assume that the PLX sensor is more sensitive since it changes in 1 degree intervals...but the time it goes from 130C to 110C when I stop gunning the car, is about the same time my AMG oil temps drop...albeit in the AMG, it does not do it 1 degree at a time, but rather in big jumps.

Mine works fine. It does intervals of 2.

I'm not sure I would consider mine subtle drops in temperature. First of all, it was 105F in Dallas today and after 15 miles of highway driving between 50-75mph my oil temp never got above 199F. Heck at one point I saw it go from 199F to 190F to 172F in a matter of seconds. That's not normal in my mind, especially since 177F (80C) is when the manual suggests you can finally let loose :zoom:. I could understand a drop like that if it was 40F outside, but at 105F that just seems odd.

Any word from the shop yet PistolWhipC63?

Just dropped it off this morning they need to keep it over night so the amg tech can take a better look at it, But mine is doing exactly what you have described.

I live in Houston and I never got below 200F when it's fully warmed up. My average in 90F is 215-225, 100F=220F+. That means there's definitely something wrong, lol. Good luck fixing it.

Yeah it's the fact that it will randomly dip below minimum operating temp that concerns me!

Hopefully he won't put too many miles on it tonight while he's out drifting it with his buddies:naughty: j/k

Good luck with the fix, definitely not normal--I only drive my car in the AMG screen and I'm always watching the temps, I've never seen my temp drop like that.
Keep us posted:y

i'm in dallas as well and that doesn't sound normal at all... unless your car has an aftermarket thermostat or something... after the car is fully warmed up, it's near impossible to see it get back below 200...

i also always drive on the AMG screen.

So I was driving home last night and decided to take a video of the temperature fluctuations I've been witnessing. Keep in mind that at this point in the video I had been driving the car for at least 15 miles at highway speeds and it was almost 100 degrees outside. I know its a little choppy but it should get the point across.

http://youtu.be/hvgiE1YWjaM

That's exactly what happens, But the dealer supposedly said they couldn't reproduce the problem and that it was due to the extra air going in or something outrageous. They said if anything was wrong the cel would turn on. Maybe you'll have better luck at your dealer Buds.

:eek: that's crazy... i've never seen it do that before.

i know that the oil temp is a hot topic right now cause of the heat but i dont even pay attention to any of them anymore. they just dont work right.

for example my last car was always spot on the outside temp. the c63 has been up to 15 degrees off on any given day. and dont get me started on the oil temp gauge. mine is showing up to 255 all the time. and a low of 215. and really im not doing much different on my driving to obtain either of them.

its just mercedes cutting corners on a c class.

i don't know about cutting corners... i think the majority of the c63s out there have a working one... both 09 and 2010 i had worked the same. temps were similar...

and if i'm not mistaken, none of the c class models have an oil temp gauge... just the amg

i think at 176 or 177 the numbers stop blinking... after that point as long as your car is still on, i find it very unlikely for it to ever go back down seeing as how it's known how hot these engines get already...

Buds did it right... taking a video.. i would show that to the service advisor or email it to them

For those of you with the problem put a P- and the mileage you currently have. For those of you without the problem put OK- and the mileage you have.

For example mine is P- 10,000 Miles.

Ok-40028 miles
2008 Owned the car since 4/08.
I do have a problem with the sunroof if anyone can help me?

OK - ~42000 miles (2009)
OK - ~23000 miles (2010)

edit - i guessed completely wrong on the miles for the 2010

P-43,500 (2008)

Okay so I just got my car back after spending 3 days at the Dealer while they tried to fix this problem (as well as perform Service A)... At first they tried an SNC (Software update) on the instrument cluster and thought that had solved the problem, but quickly realized that the oil temp was acting the same. Apparently there is a TSB for this however I could not find a copy of it. Since the software update did not work, they decided to replace the oil temp sensor completely (under warranty of course).

I just picked up my car and I can say that on my 12 mile drive back to work (almost all highway) the new sensor seems to be working a lot better. It's certainly not perfect and did have a few dramatic temperature swings, but it was definitely more stable than it was. At highway speeds it stayed up around 195-206 fairly consistently. I'll be curious to see how long this lasts and will certainly report back on here if anything changes.

Buds,

Any updates? Did the new sensor work? My digital oil temp display is completely messed up at the moment. It's almost always fluctuating. Not the biggest deal, though, as the mechanical display always shows good temps.

I have this problem and was wondering if the car throws any timing? When i run my car decently hard my temps don't go much higher than 221 could this be a good thing?

WELP the new sensor seemed to stabilize things a bit (not completely tho), especially once I reach the 177F mark HOWEVER I just returned from lunch and my digital display wasn't reading the oil temp AT ALL, it just showed --- !

When I turned the car off after the 2 minute drive back to the office for lunch the fans stayed on long after the car was off (which considering its a nice 88 degrees outside today and it never did that when it was 110 out is concerning to me). Looks like I'll be heading back to the dealer and most likely switching to a different dealership all together, my impressions of my current dealer keep getting lower.

When I run hard I've never seen my temps get above 212... I guess in theory cooler temps are better but I'm not sure how much I believe my readout at this point in time.