actionS4

Here's a cut out of my post from a week ago...

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First, I drove the car about 400km yesterday morning - drove very calmly until near the end when I got to open highway that I know really well and let loose for a couple of minutes (200+kph). During this time, my oil temp increased from ~95C (203F) (where it has been for the first 45000km on the car) to ~115C (239F). I wasn't too concerned about this, but it was the first time that I noticed any really significant change in my oil temp (outside temp 20C). About 10 minutes later, I got to my destination & parked it for a few hours then went out for a little run with my brother in car - drove pretty hard (but not over 170) for about 30min with oil temp staying around 110 whole time. Parked again for a couple of hours, then on way back home (the 400km), drove normally, but oil temp still steady at ~105/110. I know that these oil temps are not necessarily too high, my only question is: Is this a sign of something else that's going wrong? Specifically, why didn't the oil return to the same operating temperature that it's been at for the first 45000km? BTW, just had my oil changed last week.
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It's now a week later, and it still almost always runs at or above 105, often at 110, and occasionally at 115 - especially if I'm pushing it at all.

I've been told by the service advisor that they put in conventional 5W-30 (Castrol), which is what they have always used. I doubt that anybody here is very surprised, but the advisor doesn't know what normal operating temperature is supposed to be - nor does he know what might cause this temperature change - nor does he even know if this is something that should be looked into further.

Any ideas here? Has the oil just broken down, and I need another change? Partially blocked oil filter? Not enough oil? Too much oil? (it almost looks like too much on the dipstick, but it's so hard to read that I can't really tell) Oil pump problem? Some part is overheating and the oil is actually getting hotter? A sensor? Or nothing to worry about?

PS: My coolant temp hasn't changed at all - still steady at 90 where it's always been. And I'm still 100% stock above the wheels, so it isn't mod related either.

Thanks.

Nogaro Baller

Do an oil change.. change the type of oil... and maybe change the weight.

S4_Cinci (I S'edTFA)

Less valvetrain noise as well!

P. Bauer

I recently switched back to Mobil 1 0W40 and it's back to what I consider normal.

actionS4

I've always had the standard 5W30 that the various Audi dealers have put in because I didn't know enough at the time to ask for anything different. Even this time, I did drive it for a week after the oil change with the temp still at 95 - it wasn't until that day that I drove moderately hard that it climbed up and then stayed up. I think I have driven my car hard enough in the past that I would have had this happen if it's normal, but maybe not - should I just get another oil change and go on with life? (yes, I will get a better quality oil) Or should I be concerned about something else right now?

S4_Cinci (I S'edTFA)

or a buildup of dirt or something that is fouling the heat transfer on your radiator or intercoolers. Could try spraying the radiator fins with a garden hose. I do this every few washes, but I wouldn't try using a pressure washer - could be too much!

S4_Cinci (I S'edTFA)

for about 2-3 minutes when I'm driving home at night (i.e., it'll read say 65 F when it's really about 80 F, and then it gradually climbs to the correct temp during the first part of my drive home). I had another car that would do that as well. Another item to put on my (Audi's)long list of "things to fix". Could be something akin to what your oil temp sensor is doing - minor sensor malfunction.

actionS4

1) I just need an oil change - either the oil has broken down, or perhaps there's a circulation problem - partially blocked filter, or maybe a pump going bad?

2) There's something in there that is actually overheating.

I say this because of the change in temperature that I'm seeing - it used to be really constant at 95 - but now I'm seeing an increase from 105 to almost 115 just from accelerating in traffic - like from 120km/h up to 150 to pass someone - it's not just consistently reading 110C.

I also know that I'm pretty n00b at this - that's what I get for leasing my last 2 cars - ignorance - worked fine for me too, until now when I really care. Thanks for the help.

S4_Cinci (I S'edTFA)

almost never goes above 200 F during the winter; runs about 215 during summer months, but it will increase to about 225 when I'm on the highway at about 70 mph. It drops right back down to 215 or so when I exit and drive 45-50 mph.

If anything was happening to your dino oil, it would be that the lighter fraction has boiled off and it is now slightly thicker, but you would notice the lower level. If it's still a golden color, it's not breaking down due to excess heat. Then again, they could have put something other than 5w-30 in there (as you say they might not know exactly what they used or something to that effect).

The only reasons I can come up with for a relatively sudden difference is either bad sensor data (sending unit) or some sort of reduction in cooling efficiency such as dirt on radiator. Anyone else care to chime in? Either way, it doesn't sound like a drastic high oil temp situation yet...

actionS4

The first thing I did was take a road trip and drive it across the Midwest in 90F weather, and later in Sept, down through Cali and across Death Valley - over 100F - didn't have any big increases at those times - often driving 8 hrs a day - not necessarily all that hard, but definitely pushing hard enough at times, if I could find good roads. I'm not ruling out a seasonal thing now, but I just don't think that would account for all of the 10-20% difference that I'm seeing (I know, you said small degree too).

Anyway, I think I'll just get my oil changed for now and keep an eye on it, since it's not running too hot yet. One of my main reasons for posting was to check that it's not an early warning sign that my turbos are running a bit hot or something like that. Thx for the input.