deml0

i observed the following today, and was wondering if they are cause for concern.

- when the car was first started (engine cold), the rpm initially shot up to about 1500 or 2000, the car (engine) shakes a bit, the rpm drops to about 1000, and the shaking stops.
- the engine, after about 20 minutes of normal driving, sounded like it was working harder than usual.
- BOTH fans were running under the hood, which contributed to a noticeably loud engine compartment.
- the ac was NOT running.
- the needle in the coolant temperature gauge was fairly far to the right (2 marks away from the far right end). it normally is somewhere in the middle. most of the time, it is between the 11:00 and 12:00 positions.
- the outside temperature is not high here in nyc (about 70 degrees).
- the engine coolant light on the dash was NOT on.
- the coolant level in the coolant reservoir was in between the min and max levels.
- the engine oil level on the dipstick was at the max mark. i added 2 quarts last week because i noticed it was at the min mark. it's strange ... the dipstick gives DIFFERENT readings sometimes, as if the oil was taking awhile to return to the oil pan. how long should i wait before taking a read?
- because of oil consumption, i find myself adding 2-3 quarts after about 5000 miles. is this normal? i do the oil changes every 8000 miles.

those are the symptoms/observations. is this an indication of engine overheating? my a8 just broke 100k miles. any help or suggestions would be appreciated. thanks in advance.

danny

jazbo123

In many vehicles the A/C is disabled if the engine overheats (not sure about the A8s however). The lack of a light is a puzzle.

deml0

the ac does work. i didn't turn it on, fearing it may contribute more to the problem. thanks.

ryalex

I am having the same problems at 55k miles on a 200 A8 (and only 2 weeks after buying the car). For the first few days it hovered at the large white line before H and the A/C would turn off. Last night the temp warning came on for the first time and I had to pull over and let it cool off (of course, being a t-stat problem the car only *thinks* it's overheating).

I took it to a local mechanic (not Audi dealer) to troubleshoot the radiator and they also concluded the thermostat. Unfortunately, it's a timing belt-off job, so it's silly not to do that too. The shop is doing it tomorrow for $590.

https://forums.audiworld.com/a8/msgs/120081.phtml

deml0

sounds similar to what i am experiencing. for me, with 100k+ miles, i might as well get the tb service done while i'm at it.

thanks for the info & hope it works out for you.

PaulW

The 5 valve motors have a history of this, and the 00's have a real history of them failing.

It's come up time and time again.

Good luck!

PaulW

When it's over heating, feel the upper hose and the lower hose.....one is going to be very hot, the other is not if the thermostat is failed.

That's how they fail on our cars.....they no longer open up versus failing open.

deml0

i was just reading up on the timing belt replacement procedure on audipages. excellent write-up! has anyone ever questioned why the thermostat is so DIFFICULT to get at? or can it be replaced without taking apart so many parts? man, would it suck if the thermostat fails right AFTER a timing belt change.

thanks, paul.

PaulW

Audipages shows a ABZ engine, you have a 5 valve motor, not the same

ryalex

Hey, let's make a car that requires $800 in dealer service to replace a $14 part that's normally easily accessible on any other car that isn't from Italy or Russia.