Need help in diagnosing a motor problem in my 03 a4 quattro 1.8 turbo.

Asked by Jan 01, 2015 at 01:22 PM about the 2003 Audi A4 1.8T quattro Sedan AWD

Question type: Maintenance & Repair

One afternoon while checking the oil in my wife's 03 a4 Quattro 1.8 turbo I noticed that the water reseviour was full of dark fluid appearing to be engine oil. When I checked the oil there was barely any on the dip stick. I had high hopes that after allowing our daughter to use the car that she might have added oil to the wrong place. But unfornately there appears to be bigger problems at hand. Normally the car doesn't use any oil and as of now it still runs great, but after adding some oil to the engine and running it for a few minutes there is water in the engine oil as well. I done a compression test and all cylinders still have over a 170psi. Like I said the car still runs great but this oil exchange is not right. I'm wondering if someone else has maybe had the same problems and could give me some advice in witch direction I should go in diagnosing the problem. I would hate to pull the head and that not be the problem.

4 Answers


Look at the oil cooler first, second would be seal on the turbo. Your compression test looks good. My bet would be oil cooler leaking into the radiator.

KenF , thanks for the advice on the oil cooler. Any suggestions on where to look for a diagram of the motor components?


I'm not very familiar with your make of car, I'd try some of the specialized Audi forums around, they'll be able to give you specific information. Your symptoms are a classic sign of a leaky cooler, however. If you rev the engine and see bubbles in the radiator or in the reservoir, then you might want to look at an intake or head gasket. There is a type of test that can look for exhaust gas (spent carbon) in the radiator fluid as another proof of a bad head gasket, but I'd start with ruling out the oil cooler first.

1 of 1 people found this helpful.

go to the vw dealer and head to the parts counter. ask for a schematic of the oil cooler and they will print it and the part number sheets out for you for free.

Your Answer


Looking for a Used A4 in your area?

CarGurus has 12,349 nationwide A4 listings starting at $1,700.


Audi A4 Experts

  • #1
  • #2
    Tom Demyan
  • #3
View All

Related Models For Sale

Used BMW 3 Series
900 Great Deals out of 32,980 listings starting at $1,300
Used Audi A6
143 Great Deals out of 7,663 listings starting at $1,999
Used Audi S4
23 Great Deals out of 1,538 listings starting at $3,850
Used Mercedes-Benz C-Class
606 Great Deals out of 25,311 listings starting at $1,950
Used Audi A3
98 Great Deals out of 6,302 listings starting at $3,495
Used BMW 5 Series
387 Great Deals out of 15,995 listings starting at $1,650
Used Honda Accord
553 Great Deals out of 91,963 listings starting at $1,495
Used Ford Mustang
287 Great Deals out of 38,472 listings starting at $1,995
Used Audi A8
49 Great Deals out of 1,443 listings starting at $3,499
Used Mercedes-Benz E-Class
427 Great Deals out of 20,627 listings starting at $1,999
Used Volkswagen Jetta
403 Great Deals out of 28,090 listings starting at $1,650

Used Cars For Sale

2018 Audi A4 For Sale
5 Great Deals out of 6,271 listings starting at $29,000
2017 Audi A4 For Sale
30 Great Deals out of 903 listings starting at $19,000
2016 Audi A4 For Sale
12 Great Deals out of 217 listings starting at $17,320
2015 Audi A4 For Sale
34 Great Deals out of 925 listings starting at $14,399
2014 Audi A4 For Sale
20 Great Deals out of 670 listings starting at $13,900

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.