Possible Blown Head Gasket???

[bark]

My g/f has a 98 WS6 M6 with 63K miles on it. She told me her coolant light came on so I checked the reservoir and the coolant was low but it also had the "milkshake" effect. I checked the oil and it was clean but overfilled, damn quicklube place. I havent had alot of experience with engine problems but I know that the milkshake effect is caused by an oil/coolant mixture. Im not sure if a headgasket could be blown or if it could be something else like the dexcool tuning to crap.
Any ideas on what it could be? I'll do a compression check and see if anything comes of it. Anything else I should look for? Thanks

[0rion]

The compression test should tell you if a head gasket is gone so that question will be answered. Is the car running bad or have any symptoms of a blown head gasket? Since the quicklube place overfilled your oil I'm wondering if they checked and topped off her coolant also and maybe put the green glycol shit in there. That will certainly foul up your cooling system. Good luck and post back what you find.

[bark]

the car seems to be running ok, just a little short on power (running consistant 14.1s at the track). If the compression check is fine I'll go from there. I'll have her flush the coolant and I'll change the oil myself. Is there any pro's/con's from changing the dexcool over to the green stuff? It seemed to help my gm car run a little cooler.

[SeVeReDiStOrTiOn]

If you change the dex to the green coolant...make sure you get all the dex out first. Dex cool is known to sludge a lot if air gets into the system for long periods of time. Now it won't look like a milkshake though...just a sludge, if you don't know the difference then put some oil and coolant/water into a glass and mix them.

Have the coolant checked for hydrocarbons BEFORE you flush the system....this will show you if there's combustion gases in the coolant. Low compression isn't always a for sure sign that it's a head gasket....could be another internal prob like a ring. Is there oil on the spark plugs?

What is her trap on that 14.1? What is the 60ft? Were you driving or her? If it's trapping around 102-106 it should be ok...could also be the track or elevation.

[bark]

trap was 103 mph, her driving with 2.2 60's on street tires. Might be just her learning to launch the car. I hope I find this to be an easy fix becuase I really dont have the time to tear off the heads with my 2 cars down and the tracks opening up.