Paul,

IMHO you have a head gasket leak or an oil cooler leaking into the coolant.
Why do I say that?

1. it appears that your coolant is contaminated and the contaminate is
eating the seals, petroleum products will eat the rubber.

2. If your system was over pressurized it would blow out the cap (should be
checked)... good chance this over-pressurization comes from something that
can produce a higher pressure that is in the system.... One of the things
that come in contact with the coolant system is combustion pressure (head
gasket leak).

Things I would check.
1.  Look in coolant reservoir to see if there is a sheen on the surface of
the coolant (you may have to take some out and put it in a clean bowl to see
the sheen); and I would check the cap to make sure it releases at proscribe
psig.

2. if there is a sheen do compression check and check oil cooler.

Thanks,

Jere
90 GL
88 GL

 -----Original Message-----
From:   Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]  On Behalf Of
Paul Cavanaugh
Sent:   Thursday, June 28, 2001 4:41 PM
To:     vanagon@GERRY.VANAGON.COM
Subject:        4th heater core burst in 1 year!

My 1990 (180k miles) GL automatic just had it's 4th rear heater core
burst in 12 months!

It also has burst two (metal) differential coolers, flooding coolant
into and ruining my transmission.

Any ideas what could be happening?

My friends are urging my to give up the car (and I am tired of
pulling up the flooded carpet)!

Thanks!
Paul