My engine likes chocolate milk.

[Kyle H]

My oil and coolant have been flirting for a while, tonight they decided they wanted to make chocolate milkshake babies.



What's your vote? Head Gasket, oil cooler, or other?

[biketsai]

Does the winner get a prize?

[b5andm3]

HG

lol.

[rocky.ca]

hg most likely.

[Kyle H]

After searching a bit, I'm starting to get the idea that it's my oil cooler....

the first and most obvious place to look is the oil cooler. It's the most common place for oil and coolant to mix in our cars. They're not too pricey, or too difficult to replace either.

Besides something being seriously wrong (cracked block or head) the other place they could mix is at the head gasket. Unless you overheated the hell out of it, I doubt that's the issue.

Oil in the coolant could also be the result of a bad oil cooler... Not to mention that if the head gasket were bad enough to allow oil into the coolant, I'm pretty sure you would be burning oil as well.

Is there any way to check and see whether it's the oil cooler vs. headgasket? Compression test?

[njm23]

yes, do a compression test.. see what the results are, the cooler doesn't affect compression where a HG will..unless im wrong and somehow the oil cooler has an affect...

[speedydragon]

off topic here...you moved to san diego? if I recall correctly, you used to live in Redding right?

[Kyle H]

off topic here...you moved to san diego? if I recall correctly, you used to live in Redding right?

yup. moved to san diego for school... luckily I'm only a mile from a trolley stop and i normally ride my bike to school anyways


you familiar with redding?

[Poopie]

i'm leaning towards oil cooler. I've seen that more then a blown head gasket on a stock turbo car. compression check is they way to easiest diagnosis.

[speedydragon]

yup. moved to san diego for school... luckily I'm only a mile from a trolley stop and i normally ride my bike to school anyways


you familiar with redding?

nicee. I was suppose to be attending UCSD or UCI right now, but with the lack of aid and parental asistance (mom would only agree to pay 10% of my tuition, and she makes way too much for me to wualify for any aid or grants), I ended up going to community college. I'm a freshmen in college, so it was pretty much impossible for me to cough up nearly 25k :|. I've been to Lake Shasta to wakeboard/water ski lol.

[Kyle H]

Head Gasket
Head gaskets can be a cause of overheating, oil consumption or coolant in the oil. I have only heard of one case of a head gasket failure on a 1.8T and it was on a car running 30 lbs of boost and used head bolts. This is a repair better left to an experienced mechanic and is generally a last item to do after all other possibilites have been evaluated. overheating is usually the water pump, and coolant in the oil is usually the oil cooler failing internally.

Oil Cooler
The Oil cooler on these cars uses a plate and plate heat exchanger. Oil on one side, coolant on the other side. Often the brazing on teh cooler can fail and oil and coolant mix together. This is often misdiagnosed as a bad head gasket. To test this remove the coolant hoses and apply air pressure to the oil cooler and watch for leaks. Oil cooler is located above the oil filter.

http://audiforums.com/forum/showthread.php?t=36092
(hey, audiforums is good for something

Compression test and blow-through test (for the cooler) will be done tomorrow.

[Kyle H]

nicee. I was suppose to be attending UCSD or UCI right now, but with the lack of aid and parental asistance (mom would only agree to pay 10% of my tuition, and she makes way too much for me to wualify for any aid or grants), I ended up going to community college. I'm a freshmen in college, so it was pretty much impossible for me to cough up nearly 25k :|. I've been to Lake Shasta to wakeboard/water ski lol.

Oh nice. I'm going to community college here in san diego... it's good stuff. way more fun than sdsu (seriously, my girl goes there and the people drive me crazy).

Lake shasta is good shit. I grew up on one of the mtns overlooking the lake about 1000 feet above it... Now I'm about 5 miles from Whiskeytown lake (that lake it way more fun, no crazy bay area tourists )

[B518T]

yo kyle...you already know that my $ is on your oil cooler...

and yes...just do a compression test first thing tomorrow...but I am not anywhere near convinced that you blew your H.G.

I just remembered something about the oil cooler that steve at 02 told me...

apparently the 1998 A4 came with two different oil coolers...and you wont know which one you have until you remove it and read the part #...

from what I remember there was a 200$ one and a $300....obvioulsy those are stelership prices...

just found my invoice...here's parts, #'s and $'s

068117021B OIL Cooler $206.80
058121058B Hose 29.95
058121058C Hose 39.95
038117070A o-ring 5.95
058121132 Flange 6.95
N90316802 O-ring-switch, plug 1.95
058121687 Gasket 3.95

so it looks like stealership pricing on parts will be about $300....and you will also need new oil/filter and coolant...

I am guessing that you can get most of what I listed above wayy cheaper....you prolly dont need to replace those two hoses...since you arent having big external leaking problems...I had to replace my hoses cuz they were all sorts of buldging and busted up...

gl man! hit me up after your compression test...I want some good news...

your car is in my prayers...lol

[dwi_gti]

its your oil cooler, happens all the time. its 60$ off germanautoparts. just need that and the o-ring. its easy to change out. You should also flush out your coolant system to get all the oil out. I used dish soap and a garden hose and just let it run for 30mins till it was clean.

[AudiA4_20T]

its the HG, I've had both go on my car

[Kyle H]

its the HG, I've had both go on my car

What makes you think it's the head gasket over the oil cooler?


and another picture, because everyone loves pictures:

[Kyle H]

The fuel pump fuse is #28, correct? I just want to double check before spraying fuel all over the place.

[djwimbo]

The fuse #'s should be on the side panel you pull off to access them.

It takes 2.5 seconds more to just unplug the fuel injectors for a compression test than it does to pull the fuse for the pump. I prefer that method, it seems to start up easier after the test is done too.

I've seen a lot of oil cooler failures, it's about half and half if they're leaking externally or internally. Without removing the oil cooler I'm not sure there's a way to honestly check it on the car. The downside to doing the compression check is that it won't be 100% accurate b/c the engine isn't up to operating temps.

[Militant-Grunt]

Wow that is bad. My vote is headgasket.

How many miles on the car?

[Kyle H]

141,xxx miles, autocrossed and drag raced pretty often the last 35,000 miles, chipped for ~300 miles.

[Militant-Grunt]

141,xxx miles, autocrossed and drag raced pretty often the last 35,000 miles, chipped for ~300 miles.

Yeah def headgasket then, thats about the mileage they fail. On my 98.5 I had my oil cooler fail, it never mixed coolant with oil. Just leaked oil onto the ground.

[Kyle H]

180, 172, 165, 175. ~9% variance (on a cool engine)


Oil cooler it is!
(unless the head gasket it leaking in a funky way)

[AudiA4_20T]

thats not bad, but thats a lot of build up for it to not be the HG...

Why is your milk yellow? mine was brown

[Kyle H]

thats not bad, but thats a lot of build up for it to not be the HG...

Why is your milk yellow? mine was brown

oil change ~200 miles ago... i'm assuming very fresh oil and clean filter?

[Kyle H]

Oil cooler came today, I drained the oil and pulled out the coolant reservoir, pulled out the old cooler and put on the new one, and now I'm stuck.


How the hell do I flush the coolant/oil mix from my system? It's too thick to just pressure-wash out with a hose...

HELP!