Hi i'll keep this as short and precise as possible, but please bare with me as i am new to audi vehicles and have been reading my life aeay the past few days trying to solve these issues im having.

1) my coolant temp light is on (in red), its driving me up the wall because i've flushed it and filled it (using G12 and distilled... I've read numerous articles on the procedure and am without a doubt positive i did that correct) my car DOES NOT overheat A/C works good and heat does too, i DONT have any leaks, and yesterday i went to get a new sensor ( o-ring and clip)( cost me 50$ ) replaced that and the light is still on ... So that is one of my concerns however my biggest concern is

2) my engine oil pressure light is on ( and was already on when i bought the car) i get the 3 beeps and when i push my button on the dash its the first sign that shows. I'll be going to get a new sensor today 8/1/15 (however im not convinced as the rest of my family is that thats all it needs) now the oil is fine not dark at all and i use 5w-40 motor 1 (I believe thats it) (eventually i will transfer to the rotella or purple that most audi owners rave on but the man i bought my car from says this will due, he owns 3 others so am i wrong to trust him ) i live in PA just fyi. The gauge continues to just read between the 150 and 250 mark (always has since ive gotten it) i have NOT done an oil change yet (ive only had the car for 4days) though im really eager to and probably will flush as well ( ive read up on the sea foam crave) but all in all im worried , it doesnt leak at all, could use a good rinse off though i know that means nothing, i know its not good to drive so i dont (barely)... The car makes no noises not a crank not a screech, nothing, it sounds just as any car sounds starts up fine drives fine turns off fine drives pretty smooth and all. (Timing belt was replaced if that matters)


I thank anyone who takes their time in reading and helping me honestly i do! And please as i said bare with me this is my first audi I've previously been a jeep lover im trying something completely new!

 

I just bought my 1st Audi a couple weeks ago, too. 2001 A4 1.8T Quattro, AWM, 146K mi, from the original owner. So, I know next to nothing about these cars.

That said... How many miles does yours have on it? Did your seller give you maintenance records? If he owned three, perhaps he had an Audi/VW specialist mechanic/shop servicing it. You should find one, if not that same shop, and have them look at it. My local shop did a thorough exam (their "pre-purchase inspection," only for me it was POST purchase, oops) and they charged me just $120. The first shop I went to quoted me $200, meh, so I went to the other, which also has a good rep.

Good thinking by not driving it, yeah. Try pulling the coils and checking for oil in the spark plug housings and around the coils (mine had dirty oil two inches up the coils, a sign of a gasket leak). Pull the plugs and check for sludge build-up on the plug bottoms. See if there is wet oil on them. Remove and look under the oil cap for lots of sticky sludge build-up on the underside of the cap. And did you check the size and type of oil filter?

If your oil level does not appear low on the dipstick, you might have a clogged pickup tube screen inside the oil pan.

When I bought my car, the seller had just gotten a neighborhood shop to do an oil change (I had that receipt from him along with all records), and they used the smallest size filter (as opposed to the Mann 940/25 I use now). When I emptied the oil after I bought the car, it was fairly black and did not look like freshly changed oil should look.

My car didn't have an oil warning light on, so, I could run the car to test my oil pressure. I connected an OTC mechanical gauge to the filter housing (yours doesn't have a test port so you'd use the pressure sender port), idled the car, let it warm to 175 degrees (about 80C I think), and checked pressure and got it at 25 PSI at idle. Then revved it to 2000 RPM, and got 65 PSI. On the high side at that, but I'm still working on that. Might be a bad pump.

Insofar as flushing, I did not want to use Seafoam or any "special" flush. Read/heard from enough others who said ATF works best, as it dissolves sludge better. Seafoam will loosen the sludge, but it doesn't do as well at actually dissolving it, so you end up with glops of sludge trying to make its way through the oiling system, possibly blocking things and potentially creating worse problems than before.

Just to give mine a low-level treatment, I drained the oil, put on a proper filter, filled it and the car with 3/4 qt of Dexron ATF (store brand Dexron) combined with 3.5 qts of Rotella T6, ran it on idle for about an hour and a half. Then let it sit overnight, idled it again for an hour the next day. Then changed the oil/filter to 100% T6. I'll change it again after 1K miles to Motul 502 505 spec.

When you use ATF to flush the engine, make sure not to rev the engine and not to use more than a quart of ATF, or else you risk killing your seals. Just use 3/4 qt or so, let it idle so the detergent-laden oil flows through the oil galleys, passages, and pickup.

Once I drained that oil/ATF mixture, I filled with new oil, w/new filter, and then idled it again for an hour an a half to bring it to 80C, and revved it to record the new pressure. Not much difference, but mine wasn't very low to begin with. I believe the specs are around (ideally) 30-35 PSI at idle, 45-60 at 2000 RPM, and 60-75 at 3000 RPM.

See if you can find someone with a VCDS (vag-com diagnostics) who might help you with an auto-scan, and see what fault codes pop up. No need to run the car, just turn the ignition to "on" position without cranking it. I just bought my own vag-com for about $275 shipped from ross-tech.com. It's pretty cool. It might tell you a little about your coolant issue. If you don't have your own, the specialist shop will.

But yeah, if you have an Audi/VW specialist nearby, you may want to make that your first stop.

But I'm a new owner, so hopefully other owners can chime in with some suggestions. Maybe you can provide the mileage info and do those checks of the coils, plugs, and oil cap.