Ok guys got a question on a damn foriegn car.

Girl I am seeing drives a 2004 Audi A4 with about 45000 on the clock.

She keeps getting the check engine light. It is intermittent and not on all the time. It has been very hot over the last few days here and we seem to notice the light is more frequently on when driving in extremly hot conditions. For example it was not on this morning when it was about 65 but did come on this afternoon when we peaked at about 102.

Also...it is an automatic with a digital readout on the dash indicating the gear your in. Normally only one (the gear you are in) is lit up at a time. Lately though they have all lit up and been flashing. The manual indicates this means a transmission issue and that it has gone into failsafe mode. This also is intermittent and again seems related to the heat as this week has been really hot and this is when it started.

The coolant bottle clearly shows the coolant level BELOW the min line but far from empty. Could the LOW coolant level be causing all this havoc because there is not enough to keep the system, including the transmission cool when the temps are extreme?

Took the car to autozone and used the code reader and it came up blank. tried it several times 12 to be exact in every key position including running and never once got a code even though the check engine light was on.

She just got the car from her son in a 3 way car swap deal so he could buy a new one. the oil was changed and supposedly the car was gone over AT the dealership just 5 weeks ago. The car has a 10000 mile bumper to bumper so she made an appointment but just thought I would check with the brain trust on here and see if anyone had any ideas.

I don't know a lot about the mechanics of cars but can read and understand. My simplistic mind tells me that the low coolant level is causing all these issues....

Thoughts please.

Thanks

My thoughts are that when German cars start flashing weird lights and doing odd things...run for the hills (if your the guy supposed to fix it) or dump the car like a hot potato.

Sorry...not much help. I've just had a couple bad experiences with them- dealership is the way to go, IMO. They're wired and programmed in such a way that it's next to impossible to figure anything out without ALL the factory books.

EDIT: I just re-read your question about the coolant. My guess is that although it's possible the coolant is low enough to trip a sensor, if there's coolant in the overflow bottle at all, the "working" parts of the cooling system are filled, and thus not the cause of the problem.

On the pic shows the coolant bottle in question. I always thought you put coolant in the radiator and excess or boil over or whatever went into th overflow bottle. Now I don't see where the damn radiator is on this car, even though I assume it is in the front I just can't get to it. Which is why my concern for the coolant bottle. Are there generally min and max fill lines on overflow bottles?

Thanks again for the help.

It is, I believe, a slightly different system, where you can only add coolant to the plastic tank. I can't really tell you what the differences between the two are, but if the cap on the plastic tank is a threaded pressure cap, that'll be where you add the coolant.

Knowing the Germans, it wouldn't surprise me if it needs some sort of fancy coolant, too- I'd look in the book before dumping anything in.

Well for some reason the pic I posted above "red ex'd" so here it is again. It is a plastic threaded cap and does require some special coolant with "G12" in it. Regular coolant $12/gallon, special G12 coolant $25/gallon and only available at the dealership.

There should be some kind of indicator as to the level on it. That is not an overflow bottle, it is part of the sealed system.
Hate to say it, but check engine on, and no codes to read, I would be concerned about the ECM diagnostic circuits. When they read the codes, did it say there were no codes, or couldn't communicate with the ECM? Other things make me wonder if the ECM got spiked sometime... BTW, I despise Audis... used to have to work on those tricked out VWs...which is all they are, same for Porches, glorified VWs....

I used the code reader myself. Plugged it in, all the lights came on, hit the "read button", it appeared to be functioning through the various readings and after about 15-20 seconds flashed 0000 with no codes showing up.

She loves the car but I am quickly starting to hate it. Again lucky it has the 100000 bumper to bumper.

Many of the european vehicles need specific to that vehicle software in the reader, or it wont communicate. OBD2 has some features that are universal to all models though. Because it seems to be temperature related, I would suspect a fuel delivery code caused by the temperature. The open/closed fuel is very much temp related.

When it comes to Audis, Aaron- just take it to the dealership and let them sort it out. They aren't great DIY cars. Personally, I really, really detest them. Great engineering, decent mechanicals, wired by lego and assembled by elves. We have three of them in the neighborhood, and have jumped or towed all of them at least once in the last few years.

Update

Took the car into the local VW dealership as I guess they handle warranty stuff for Audi also. The car is out of the regular warranty but does have some fancy extended warranty through Audi. Bad news is only an Audi dealership can perform work under that warranty and the nearest one is about 35 miles, so got to make another appt.

Service writer was very nice though. said the coolant was low and added enough to make it right. Said he was the service writer for it last time also and knows it was full when it left leaving him to assume a coolant system leak. Said the transmission is definitly having issues as it has gone into limp mode again. He pulled up the history on the car and found it has had several electrical gremlins in the past that have been fixed. So my guess is not repaired properly or mis diagnosed.

We'll see when it gets into the shop.