QuestionQUESTION: We replaced the radiator, water pump and thermostat, but still boils out the overflow jug. Have tried burping it like you described to Stephanie, but still boiling over. No white smoke out tail pipe, can't see any leaking, other than from the overflow bottle, cooling fans are coming on, but the radiator and hoses on the right side are too hot to hold and on the left(driver side) are barely warm. So, could the problem be in the radiator, even tho it is new. You also mentioned restricted coolant flow through the coolant tubes, are they in the radiator, or the hoses outside of the radiator? Thanks for any help you can provide.
ANSWER: Hi Janet,
That is a curious situation. The most important fact is that the coolant doesn't appear to be flowing in sufficient quantity across the core of the radiator (through the coolant tubes, indeed). If the top hose and right side of the radiator are hot, then the thermostat must be open. Unless there is some sort of blockage either in the radiator tubes or in the bottom hose that returns coolant to the waterpump I can't understand why you aren't getting circulation. If this is a 3.3L engine it would be fairly easy to try a new water pump on the chance that the impeller were loose on that replacement pump, for example (but the 3.5L is too costly for that gambit because the pump is behind the timing belt which is a major job). If this is a 3.3L it would also be good to verify that the drive belt for the water pump/power steering/generator is not slipping.
How about the cap on the overflow jug, might it be leaky or opening at too low a pressure? Are you sure the level of coolant in the jug is at the proper line before you start the engine? Was the lower radiator hose checked for internal blockage? You could try disconnecting at the lower hose connection to the radiator and have a pan ready to collect coolant and at the same time assess the flow out from the left side of the radiator and from the end of the hose.
Those are the ideas that come to mind. Please let me know how you progress on this.
Roland
---------- FOLLOW-UP ----------
QUESTION: OK. This is a 3.5L engine and to replace the water pump was expensive. We did check to see if there was a blockage, and there wasn't. Someone suggested to check the manifold gaskets by checking the spark plugs, which we did, and sure enough, the plugs show that there has been water in there. Would this cause all the other problems that we have gone thru? We got estimates to replace the gaskets for $270 to $330, but if this is not the problem it would be more money down the drain. Would the manifold gasket cause boil over? Also, when draining water out to add antifreeze, would it have to be burped all over again?
Thankyou for all your help and time. Hope something will work.
AnswerHi Janet,
By 'check the spark plugs' do you mean remove them and inspect around the holes (external area) or remove and inspect the tip of the spark plugs that are inside the combustion chamber? If the evidence is coolant inside the combustion chamber then that is usually indicative of a head gasket leak rather than a intake manifold leak. However there are cooling channel in the intake manifold so that gasket could be a source of leakage too now that I think about it. However, the intake manifold itself is not pressurized positively so I don't quite understand how it would cause bubbling out of the coolant bottle if it leaked, and on the other hand a head gasket leak will definitely cause that sort of early bubbling, soon after starting up. So look again for the signs of white smoke. If it might be the head gasket (but determine which one by pulling all the plugs and cranking a cold engine over to see which side blows water out the spark plug holes) you would have to take off the intake manifold at which point you could check to see if it shows signs of a leak. If so, then replace the gasket before pulling a suspected cylinder head in order to replace the head gasket. If it is a manifold leak, maybe all you have to do is torque the bolts that hold it in place to the factory spec. torque level and that would end the problem.
Let me know what you learn.
Roland
