Cain1152

Hi my names Cain I have a 2003 Audi Allroad with about 137K, I'm leaking oil from the front by the oil filter and smokes from the passenger side back if I drive it. I'm also missing coolant idk if it's burning or leaking to be honest something smells off from the exhaust. Any idea on what it is would be great. Headgasket? Random seal?

transman

My best advice before spending any money would be to pull the spark plugs and put a pressure tester on the cooling system. let the tester sit for a while. Continue maintaining the pressure around 15psi. Check down in the spark plug holes to see if you see coolant filling up the combustion chamber. If you see the cylinder with standing liquid in it, then it would be best to remove the engine and put it on a stand for repairs. If you do not feel comfortable getting that involved with the repair, do your research and find the reputable independent shop in your area that can tackle a job like this and stand behind it.

The other test that could be easier for you is to go to autozone and rent the block tester, and fluid, and use it on your coolant recovery tank, and see if there are combustion gases present while the vehicle is running. This test is 100% effective, and is my preliminary check when I suspect a vehicle with a blown head gasket.


As for the oil leak, it is probably the least of your concerns right now if you have coolant disappearing.

Good luck and hope this helps, Connor.

Cain1152

Ok I'll try the block tester, now if it is would that be a head gasket? I would be fine with pulling the motor at some point I only worry about keeping the timing right, and if it gets pulled I'll just replace gaskets and that should find the oil leak. I bought a beater for the time just to not drive it so not to rush myself

transman

The block tester is a blue liquid that turns yellow when it comes in contact with combustion gases. You can test it by holding it to your tailpipe, to see what color to look for. Then dump the fluid out and put fresh fluid in and try it on your expansion tank.


No the thing is, if the head gasket is leaking, it is because the head has warpage. Metal head gaskets RARELY leak without head having been warped.

At work, once I take a head off, I use a straight edge to measure the warpage, to see if the head is machinable. A safe amount of runout is like 0.002" in the center. Anything more than that needs to be machined. It most likely cant be machined if its something like 0.020"+ which is unlikely it will be that warped, unless its a straight 6 motor like a volvo or bmw. Every time I do a head gasket due to coolant leaking in the combustion chamber, I get it machined unless it is too warped, then I replace the head.

If you take the heads off, even if you dont have a straight edge, take the heads to your local machine shop, and have them check out the heads, and clean them and put new valve seals in, and if it needs to be resurfaced then have it done. Ask the machinist to measure the runout before you leave the heads with him. Ask his opinion about it being too far warped or if its able to be machined back into spec.

Cain1152

Hmm ok, that all sounds expensive but what I would expect, so if the test comes back and nothing could it just be leaking out somewhere? And how much do you think new heads cost in range, or to be machined if possible. It throws a generic code for missing gasses or something. I can't thank you enough for the information I'm not used to these engines and looking at it seems a little overwhelming at first

MrKid

IMHO, I would not machine a warped head on anything but a pushrod engine. Even then, it would need to be very minimal warping.
You can probably find used, bare heads fairly cheap. Some guys swap over to 2.8 heads, so you have a second option while searching.

PaperToast

before you go pulling heads, go over the motor and check the common coolant leak areas.
t-stat housing, connections to the radiator, motor, turbos

you oil leak is either valve covers and/or tensioner gaskets
both common spots to leak and fairly easy to diy