QuestionWhat can I do? Radiator new, oil pump new, thermostat new, no blown head gasket, no cracked head or block, hoses all in good shape. The left head appears to have overheated more aggressively than the right. Can I have a restriction of flow within a head or something?
AnswerHi Bruce,
Obstruction is a possibility but the passageways should be larger than in the rest of the system so I would not give that a high priority unless the history has been of poor prior maintenance of the cooling system.
Are your fans coming on as expected?
Any possibility of dragging brakes?
Has there been a test for exhaust gas in the cooling system or otherwise how do you know there is not a head gasket leak?
Another possibility is trapped air in the system. Try draining down a couple of quarts, then try:
Starting with a system that has been drained via the radiator:
Close radiator drain, hand tighten only
Install cylinder block drain plugs if removed earlier (located behind each exhaust manifold)
Attach one end of 1/4 inch ID clear hose that is 4 feet long to the bleed valve on the thermostat housing. Route the hose away from the accessory drive belt, drive pulley, and electric fan. Place the other end into a clean container. The hose will prevent coolant from contacting the accessory drive belt when bleeding the system during refill operations.
Open the bleed valve
Slowly fill coolant fill coolant pressure bottle until a steady stream of coolant flows from hose attached to the bleed valve.
Gently squeeze upper radiator hose until all air is removed from system.
Close bleed valve and continue filling to the top of the coolant deaeration pressure bottle.
Install cap on coolant pressure bottle
Remove hose from bleed valve
If none of these work out, please tell me a blow by blow discreption of what happens after a cold start-up.
Roland
