94 4runner running water sound -- head gasket?
I'm looking to buy a used 94 4runner. I found one yesterday at a great price, but when I test drove it I noticed a sound of running water from behind the dashboard. The sound appeared as I revved the engine up to about 1500 rpm, then disappeared after a few seconds. I was able to reproduce this several times during the drive.
I googled the problem and found that this is a fairly common problem among cars, caused by having air in the coolant system and fixed by simply adding some coolant. However, I also found two sites suggesting it could be caused by a leaking head gasket. Since this is the v6 3.0 engine prone to head gasket failure, I'm worried that's the culprit... I checked with a Toyota dealership and was told the head gasket was replaced in 1999. I did not see any white smoke from the tail pipe. Engine had lots of power and drove smoothly. It has 195000 miles on it.
Any advice? Do I still need to worry about the head gasket even though it was replaced 11 years ago? Would you advice me to drop this deal and look for another 4runner? Thanks!