I have a y8 on six pounds of boost, good tune, but whenever under full boost for quick runs the car expells coolant out into the overflow tank until the radiator is completly empty. Anyone know what could be causing this?? I have to refill the radiator every morning after about twenty miles of driving. Why so much pressure forcing coolant out of my system, full boost creates coolant pressure???

Any help or suggestions would be greatly appreciated!!
thanks guys!

 

head gasket or head lift. are u using arp studs? is HG new or old?

 

yes the head gasket is old, could you explain what happening? I'd like to try and understand
thanks bro!

 

single cam head bolts streatch.
replace the head gasket, and install some arp studs.

 

dunno 4 sure but what he said.. the bolts can stretch causing the head to "lift" under boost pressure. letting the boost go into coolant passages and blowing coolant all over.. or u could have a HG leak.. either way pull the head .. its an easy job.

 

yeah everyone has the right idea 'head lift" and more then likely the headgasket. You don't have to remove the head to install the arp head studs on a SOHC. remove the plugs and rad cap to eliminate and pressure differances in the system. Open up a manual to see installation sequence and remove the oem head bolt one at a time and install the apr stud and torque it down one at a time. I have done this on a boost setup and has worked fine.

 

thanks everyone for the replies, you've taught me alot!! Time to get a new HG and ARP studs!

 

If your head is lifting already...replace the headgasket, dont just replace the studs.

If you have overheated the motor at least once, the block and head should be checked for straight as well.

Typical Y8 Bull$hit!