same thing happened to me and it was the heater core hoses. It would only leak when the presure was up and since it was a pinhole, it would evaporate on the engine. I finally found it when the hole got much bigger smile I could not tell by looking at the hose on the truck. take them off and inspect.

Last edited by zarktheshark; 07/14/10 01:14 AM.
'88 Raider. 2.6L dead...2.4L swap in progress, AT, 33's, 2 bouncy seat,AC, CC, 2.25 exh, 2" Tbar, 2" BL, rear DB, rear LSD,4.90's, SW hubs,gen2 uca's, KYB shocks, snorkel, elec fan, MSD.

'99 chev k3500 crewcab
'15 Subaru XV
'03 BMW i325