after some hard runs and a 4 minute cool down, I popped the hood and can hear my overflow tank bubbling. Went to touch it and felt it burping. Was just wandering if anyone else's car was doing that too.

mine along with vihn's. could be a blown hg...

do a few pulls, wait for it to cool down. take out the overflow tank and see if there is oil in it.

James

That's a major symptom of a dying headgasket. Oil doesn't have to be present in the overflow.

whats an overflow tank?

-------jezreel
hrc stage 1, sfmu, ml, prokits, egt, boost gauge, apexi tt, costum dp, dynotune fp gauge. gst muff, turbo spoiler

the over flow tank is the little platic tank to the passenger side of your car. It has a little tube running from your upper rasitor hose/thermostat housing to its top.

Ok a tip passed on to me is to let it idle an feel the upper radiator hose for any pulses... your palm is more sensitive for this, oh and yes make sure the hose is cool...

have you changed your thermostat lately? hows the coolant? its level? what radiator cap are you using? hows the radiator..? the sensors?

I hope it's not the headgasket. I have the mls one that I put in when I did my rebuild a year ago. Anyways I just checked the overflow tank and it's almost empty. I guess this is a good thing.

by the way, there is no oil in the overflow tank.

I dont get oil in the over flow or the radiator, and i dont get coolant in the oil... but mine still boils.

swapping to the gst cap reduced it a bit , but it still happens. Next im going for the howell 160 thermostat.

Mine was doing the same thing......only on hard third or fourth gear pulls. I could rip first and second gear all day long, but as soon as I would hammer it up top......bubbling coolant and overheating. Turned out it was my head gasket :-( But thats fixed now.

Mine does the same thing. 3rd and 4th gear boosting boils the coolant and kicks a quart of it out the overflow. The rest just sits in the reservoir and boils. Also get surging in the water lines on warm startups.

- No oil or coolant mixing anywhere
- Greddy 18psi radiator cap
- Just rebuit 6 months ago
- Brand new OEM thermostat
- 4 layer MLS head gasket with mopar gasket spray
- Good condition radiator
- Reused waterpump, currently 75k miles on it

Refilling the radiator several times in a row seems to fix it for a few days until enough air is in the system that it starts boiling again.

I would hate for it to be the headgasket. That'll be a whole day lost again to changing the headgasket. I thought the mls would withstand this kind of thing.

check your coolant level..... and make sure the tstat opens up if you filling it up.....

it could also be that when doing too much consecutive boosting and not enough cool down time, that it's too much overload for our sucky radiators to handle. once you get an alluminum radiator like a fluidyne or something like that, it'll cool a lot better. also you might want to wire both a/c and radiator fans to turn on together to help cool better or turn on your A/c on after boosted runs.

Headgaskets seperate four things: atmosphere, coolant, oil, and combustion. Blowing the headgasket can introduce any two of these things, or more. I would suggest a compression test and a leakdown test to confirm or deny HG issues. If the leakdown test pressurizes the cooling system, then the head gasket is suspect at best.
Best of luck,
-=B-=

You said your overflow tank always ends up empty? if so, that is NOT good. you dont want it to be constantly getting empty. Bad as it is, it sounds to me like your HG is on the way out. sorry man, and i really hope im wrong.

1999 Black C5
1997 Silver RS
Wiseco 8.8:1 Pistons(back to low compression!)
Eagle Rods
T3/T4 Turbo
Custom FMIC
Greddy Exhaust
440's
Most current 1/8th mile time: 8.3@90mph 2.015 60'(Nitto Drag radials, i suck)

Sounds like headgaskets for you and thedawg...... :-( I'd keep your fingers crossed because you never know......

OK, I finally got my computer back, now I can start posting again.:-)
Anyway, most of the symptons described are what I've had for the last month or so. I also checked and/or replaced the thermostat, upgrade to a Fluidyne radiator, water temp sensor, did compression test, looked for visible oil/coolant--all good. I haven't done a leakdown test, but I suspect it's the headgasket. What's worse with my situation is, a lot of engine oil recently leaked from my exhaust camshaft seal--this was after a 22-23 psi run one night. It sucks, but I will probably have to change the head gasket and other seals:(

Well, I just did a compression test... all I can say is OWNED. :( x(

170 - 171 - 165 - 115

I really REALLY hope its the headgasket and not the JE's. blah.

Man, now I'm scare to do a compression test. I have this feeling, that I'm gonna be owned! Dammit, classes just started yesterday too. It's school season, this is not suppose to happen now.