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Model 2262 Overheating


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Re: My 49 Deluxe 288 CID with 76K un-rebuilt miles. The radiator was recently professionally re-cored and the thermostat replaced (by me, with a modern 170-degree model), along with the top and bottom hoses and the two heater hoses leading to/from the engine block. Despite this, the temperature gauge will climb from its left-hand post steadily up to ?H? after only 12-15 minutes? idling. Yet during such times I don?t see any evidence of classic ?overheating??i.e. obvious steam, a red-hot engine, coolant gushing from the overflow pipe, etc. Even when the gauge shows ?H?, the radiator cap?a modern Stant 7lb. pressure type--can be safely removed. Although a finger-dip shows the temperature of the coolant in the radiator is somewhat elevated, a visual check by flashlight reveals not a lot of fluid turbulence going on in there. I also don?t feel a lot of coolant flowing from the radiator to the block via the top hose; top hose stays pretty flaccid and can be squeezed nearly shut with a little effort. The fan and fan belt are fine, however the water pump is original and un-rebuilt. Questions:

a. Is my water pump probably shot (as, deteriorated packing)?

b. Could my thermostat be failing to open (as, installed upside-down)?

c. Could the fact that I have not rebuilt (or even inspected) the firewall-mounted heater play in here anywhere?

d. Might I be a victim of the dreaded collapsed-water-distribution pipe in the head?

e. At rest with the key off, my temperature gauge routinely reads ?H?. When key is turned and power reaches the circuit, it slowly travels down to ?C? and then, when the engine starts, begins its climb up to ?H? again. Could the gauge simply be defective? I have read about gauges being ?(oriented) in the wrong direction?.

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1) are you sure that the radiator core that was used to "re-core" was of at least the same flow capacity as was in there originally..?

2) The 288-327-359 blocks, like all "straight eights"....have a lONG way for cooling water to go. Once I'd resolved the question of whether your gauge is correct ( by using an accurate mechanical guage as a temporary "check" against the built in system, and was satisfied there was sufficient "flow" thru the radiator/thermostat system (no hoses collapsing internally, etc).(this is why you should only use, on the "suction" side of the raditator, radiator hose with internal support springs)....next step would be to knock out all the "freeze plugs" (mistakenly called that....they are useless to protect a block against freezing...that is not what they are...they are actually "core plugs" to fill in holes during the casting process) and clean and inspect the cooling passages. You would be amazed at how much "crud" forms in old engines that have not had the benefit of frequent "block flushes"...

Let us know what you find !

Pete Hartmann

Big Springs, AZ

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Model 2262: I totaly agree with Peter. The first thing I would do as he stated use only radiator hoses that have internal wire support spring inside of them. Use these types of hoses on the bottom side. It couldbe that your bottom is being sucked closed . With a wire spring hose this will not happen. Alot of people make this kind of mistake and can't figure out why their engine overheats. Go the whole nine yards and have the engine professionally flush. See Peter we do agree on some things. <img src="/ubbthreads/images/icons/laugh.gif" alt="" />

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the gauges maybe bad. If they r electric gauges then the heat temp gauge mite be getting somekind of feed back thru other unrelated wireing. Check with a gauage that is KNOWN to be good.

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New developments. I removed the temp sensor from left rear of the block (clean coolant mix gushed out) and cleaned off the brown deposits which the years had deposited on the brass sensor body. Threaded it back in, then started car and let it run. A candy thermometer, used for measuring hot liquids and semi-solids up to 300 degrees or so, measured a coolant temp of max. 172 degrees after 15 minutes; at this same moment, the car's gauge read 3/4 of the way to "H". This sounds right, since the original 150-degree thermostat would have opened at 150, keeping gauge at the 1/2way mark. Since the replacement wouldn't have opened 'til 170, that's roughly 3/4, yes? Coolant will not go past 172 on my candy thermometer, nor will the gauge climb past 3/4 any more.

FYI, lower hoses are the correct (reinforced) type--it's the upper one that's flimsy. Am I out of the woods?

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One other thing to make sure of is the temp at the back of the motor. There is a water distrbution tube that runs inside the block behind the water pump that can corrode off causing the rear cylinders to run hot while the front is cool.

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