Three problems related to coolant leaking have been reported for the 2004 Toyota 4Runner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota 4Runner based on all problems reported for the 2004 4Runner.
Loss of coolant with no visible signs of leaking. Replaced so many things and keep getting misfires and vsc lights on constantly. Rough start up for about 30 seconds every time started. Slight over heating if idling . . . All points now lead to blown head gasket in which I read more and more and common with 04 v6s.
Rough idle at morning start up. Vsc, trac off indicators illuminate. Obd ii code of p0306, misfire cylinder #6. Having to refill engine coolant on a weekly basis. Premature head gasket failure. Toyota super long life engine coolant is slowly leaking into cylinder #6. Rough idle noticeable at morning start up because the fluid builds up to a considerable amount overnight. Estimated cost to fix is $3000.
Engine is leaking coolant into the #6 cylinder causing misfire, rough idle, and check engine light to illuminate - apparently a very common problem with this v6, 4. 0l engine leaking at the #6 cylinder - obviously a manufacturing defect to have head gaskets failing at the same location.