SOHC_MShue

One of my friend's has a boosted z6 that is going through all kinds of problems at once. First his ecu took a crap on him so he had been driving around on mine for a couple of days. Then he found that he has a major coolant leak somewhere and loses coolant at an alarming rate. Now we think he may have blown a headgasket. He said the other day he noticed that at part throttle the car would stumble around down low until it got into boost, but if he just went wot even at low rpms the car would accelerate fine. Also that same day he said the car started overheating(may just be because he lost a lot of coolant around the same time..) and he also noticed some white smoke coming out of his tailpipe. I'm not sure if this was burning coolant or just condensation.

The smoke out the tailpipe leads me to believe that the headgasket is blown. It is hard to tell though because there are no noticable leaks and there is a coolant leak so obviously the coolant overflow never even gets a chance to fill up, which in my experience is the first sign of a leaking headgasket. Is stumbling around at partial throttle a symptom of a blown headgasket? Or is this problem fuel related? I have blown 3 headgasekts on my y8 and never had any stumbling at partial throttle in fact the car ran fine other than the overheating. Oh and he also has arp headstuds in the z6 as well.

Let me know what you guys think.

johnny5gti

if his oil is real like milk choclate type then yeah

Syner-G-Racing LLC

well...white smoke is normally a lean condition or serious condensation in the tail pipe, or cold weather...if its blue ish then its buring oil, if its black its rich or burnt cat.

if its drinking coolant then its definately a headgasket or a cracked block...another way to find out is to take off the radiator cap and see if its bubbleing (due to the air leak from the head gasket)

for the part throttle hesitation...its hard to hold compression with a crack in the block or a leaking head gasket...If it drives fine at wot because its holding more pressure than leaking out.

my recommedations would be to take the valve cover off and check out the oil journals for sludge, and then do a leak down test/ compression test. if its bad then pull the head.

SOHC_MShue

well the thing is leaking coolant really bad somewhere and that is why its losing so much. You can see a huge puddle under the car after driving for a little while. Like I said we drove it around last night and there was no overheating or anything. I guess its gonna be hard to tell without fixing this coolant leak.

sheissrx

I thought he just replaced the HG? Damn I'm glad I didn't buy it . Check the oil to see the condition. If he has a blown HG or cracked block, it should be milky, because of the coolant and oil mixing, but like I said, if nothing mechanically is fucked up, it might be an o2 sensor or intake sensor. Have you guys checked the cam timing to see if it might've jumped? Have you checked ignition components(unlikely but possible) they'd be screwed up from the turbo. I knew another guy with a turbo running shitty afc hack, his car would just shut off, like 10 times before he got to the end of the block from his driveway. Just perform a full engine and component inspection. The problem will present itself .

SOHC_MShue

nah he hasn't changed the headgasket yet. The car has been sitting for about a month because he hasn't had time to change it, but now were not sure if the headgasket is even blown.