SO my 04 A4 3.0 has 96k on her and just had the oil changed about 1k ago.

Anyways i was out driving the other day and hear this loud thud it sounded like a baseball hitting my car, anyways i went home and looked around found nothing and decided to check the oil for some reason. There was a light colored puss like stuff on the dipstick, i wiped it off and checked again this time there was less, did it again, and less yet. I checked the coolant it looked a little low but nothing strange in it. I thought it was just moisture in the tank from only driving short distances and not burning off the moisture build up. It's been about a week and I checked again, Coolant is a little lower yet, the oil level itself is pretty low, and there is still stuff on the dipstick. Nothing under the car is leaking, do you think this could be a blown head gasket with a very slow leak? What else should i look for?

 

i dont know about the noise, id write it off as a coincidence. the most common source of coolant leaks are the head gasket and the coolant temp sensor. with how slow its leaking id say coolant temp sensor would be a good place to start.

 

Thank you for helping where is that located?

 

whoops sorry i didnt mean coolant temp sensor! i meant coolant flange

honestly im not sure exactly where they are located, maybe somebody else can jump in on this one

 

the coolant flange is located in the rear section of the engine before you get to the firewall. You probably gotta get a small mirror if u want to visually inspect that area but if there is a leak i would imagine you would see some white crust around the area that is leaking. As for the coolant temp sensor thats a easy one to get too. http://www.a4mods.com/index.php?page...tml&category=5
Basically the flange is right under the sensor so thats the general area you should be looking at first. Also when was the last time u changed your oil?:

 

oil was changed by dealership about 1000 miles ago

 

when u turn ur car on do u ever have smoke come out of the exaust white smoke. Or see any white smoke coming from the engine on ce its warmed up. I know when my coolant flange was leaking i would see wisp of white smoke coming from the hood and passenger side of the car.

 

no, i don't see any abnormal exhaust colors