Healey Journal

A Buyers Guide: Criteria for Buying a Rustbucket: Potential Cooling & Heating Faults

10) The Cooling System. The big Healey is notorious for keeping its passengers warm, even cooking the incautious ones. With a rebuild the introduction of insulation will be advisable. The usual effects of overheating should always be investigated- cracked and/or warped heads, blown gaskets, etc. though the Healey doesn’t seem any more prone to those difficulties than any other car. Certainly anyone rebuilding a Healey should have its radiator cleaned, even re-cored to allow more efficient heat transfer. Specialist vendors sell higher efficiency replacements and aluminium ones. Electric fans (~£90) and higher efficiency replacement fans are also available. Oil coolers (~ £100) too may be fitted. It is my intent to use an electric fan instead of the stock one, and to fit an oil cooler. I am also considering using specialist insulation coatings/ materials on the exhaust system so that heat does not radiate into the engine compartment. (UPDATE: I've had this done, but have yet to test it for its effectiveness) A louvered bonnet is also being considered to help dissipate the heat. (UPDATE: This too has been done.) Aluminium bonnets are readily available (~£400) but it may be possible to find a metal working shop to louver the existing one more cheaply.

    a) Radiator. The radiator is the heart of the cooling system. It can be checked externally for faults- certainly any leakages (or evidence of them) should be closely investigated. While cold the radiator should be checked for any physical damage- marks where the fan might have "kissed" it or road debris hit it. These points should be checked for evidence of repair- soldered holes, etc. The draincock at the bottom of the radiator should be checked to ensure it operates properly and is not damaged either. The coolant itself should be looked at and may provide some indication of further problems (oil in the coolant could be a very bad sign, bubbles while running, etc.) The radiator cap should be checked to see whether it provides a good seal at the proper pressure. Some aftermarket caps are not the proper depth and are rated for the incorrect pressure. Of course, in a major rebuild of a project such trivia as replacing the radiator cap is hardly worth much bother.... If its possible to check the system while its hot and operating at full pressure then problems with leaks may be more evident. As noted above the boiling out of a radiator in a good cleaning should be the minimum effort in a rebuild. My car came with an incorrect radiator- one with all the inlets and outlets on the wrong sides, and had to be replaced with a new one. A new standard, replacement radiator may be had for £150 (this doesn't come with the little brass badge that is on the front, middle of the top tank so be sure to keep that!) and high-efficiency aluminium ones are available too for ~£400. Radiator caps can be readily bought for £10 or so, and the draincocks for £7.

    b) Thermostat. The thermostat is a heat activated valve that stays closed until the engine warms up to operating temperature and then opens to allow coolant to flow through the radiator. The chief problem is that the thermostat may stick. In the closed position the coolant flow will not be adequate and the engine will overheat. This may be tested by taking the suspect thermostat and immersing it in a pan of boiling water. If it remains closed it is faulty and needs replacement. If the thermostat sticks open the problems are less severe- the engine will not overheat but it will take considerably longer to warm up and be less efficient as a consequence. Further problems may arise due to leaks from the thermostat housing's joint with the head- a replacement gasket will usually solve these very infrequent problems. The thermostat housing is aluminium and susceptible to corrosion internally. These should always be checked- particularly if they've been in service for 35 years the ill effects may well make replacement a sensible proposition. I wonder if painting the inside would help? A new thermostat should be installed when the engine is rebuilt and may cost the princely sum of £5, and a new thermostat housing can be acquired for £7 or so if needed.

    c) Water Pump. Does it pump water? But that's not the only criteria for a healthy water pump. A worn water pump is usually the fault of worn bushings and seals- these create noise, heat and often, leaks. The pump body and the impeller used to push the water through the system do not usually wear- it's the moving parts: the shaft and the bearings and seals in contact with it that do, and cause problems. Poor maintenance can cause problems too- an overly tight fanbelt can put unnecessary tension on the bearings (and also on the generator's bearings, too) and accelerate the wear.

    d) Hoses. Do they hold water? Either they do, or they don't; and there's not a lot of middle ground to worry about. They should be checked for obvious signs of external faults- cracks or other signs of aging, and damage like rubbing against something or being cut or hit. Standard hoses can be readily bought for a cost of £20 for both top and bottom hoses in the usual "rubber" or a set of silicon ones may be had for £45 for a set. Again, with the major rebuild the replacement of hoses is normal. With my car there were no hoses. As a side issue, replacement hoses do not always match the original ones- "universal" replacements may be the right size but have "corrugations" that allow them to flex. These work well enough, but they just don't satisfy the purists.

    e) Fan & Pulley. The pulley is straightforward enough. It would seem. But Healey's used two different sizes- one suitable for 1/2" fan belts and another suitable for 3/8" belts. Before you toss that useless old belt away check its size, and check that it fits properly to the pulley too. This simple consideration makes subsequent purchases easier. The original fan is a metal one with four blades. A physical check should ensure that the blades are all straight and undamaged, and properly positioned. Each should be held and checked its securely fixed- blades do loosen and have been known (rarely!) to come apart while under power. Replacement fans are available- both the original style and aftermarket higher-efficiency plastic bodied ones. Kenlowe makes an electric replacement fan too.

    f) Fan Belt. A minor item. As noted above this may be either 3/8" or 1/2" in size. As also noted above, it may be over-tightened and damage bearings. It might also be too loose and slip. It should be physically checked (hold it and bend it "backwards") for signs of age (cracks), misuse through over-tightening (a glazed surface) or damage (wear from rubbing, etc.). Again, as part of a major rebuild it would be replaced as a matter of course.

11) The Heating System. This consists of a blower located on the right front inner wing, ducting and a heater core mounted under the dash with a water control valve and controls for the air flow. Not a lot to go wrong. The blower should blow, the heater core and hoses should hold water, the control valves should open and close and the air control flaps should flap. That said, my car came with none of this in place. I obtained a useable used heater box reasonably cheaply, and a new blower with all the ducting and controls, less cheaply. Should all work very nicely when, or if, its ever needed.

     a) Heater Blower. The blower is a squirrel cage type fan powered by a single speed electric motor. This has little to go wrong. The fan may be imbalanced, perhaps by some type of damage, but that seems rare and unlikely. The electric motor may develop faults too, but again those seem uncommon, though faulty electrical connections (particularly grounds) should be considered. The mount may become loose, but that is minor and easily fixed. The ducting may be damaged but that too should be readily found. With my car all of this was missing so troubleshooting was not a problem. Figuring out where it all went and how it connected up was an issue, and a good look at others's cars soon put me right about those arrangements.

    b) Heater Box & Core. Located under the dash the heater box takes forced air blown by the under hood mounted blower and ducts and directs it through a radiator that takes hot water from the engine block and returns it through a hose/tube link to the bottom radiator hose. The box may be disassembled and the core and connections checked for signs of obvious leakage. The core may also be checked for blockages. All this was missing from my car and replaced by stock items from another long dead and departed Healey (for some reason I have a sneaking suspicion that THAT is exactly how mine might be described by its former owners....)

    c) Stopcocks: There are three of these in the heating/cooling systems altogether. One draincock on the bottom of the radiator, used to drain coolant from it. There is a stopcock located on the right rear of the engine block, to the rear of the distributor, used to provide heated coolant to the heater. This is basically an on/off fitting, although it may be used for some adjustment of the flow by setting it partially open. As a heater flow control it suffers from not being accessible while moving. Thus it is best to set it full open and use the heater control valve for making the "fine" adjustments in the coolant flow that are necessary. This may be readily done from the dash mount heater controls. The engine monted stopcock has a short handle used to open and close it. This is susceptible to breaking off. All are liable to internal corrosion but may be disassembled and cleaned up. All seem to be readily available as replacement parts too.

d) Ducting. There are five pieces of ducting on the Healey. One connects a fresh air intake control on the front left of the cross panel to the left side of the scuttle where it attaches to a screened intake. The second runs from a simple hole on the right front of the cross panel to the heater motor mounted on the rear of the right inner wing. Both this, and the one on the left are loosely secured by bands on the inner wings. The third piece of ducting then runs from the output side of the blower motor through a hole in the scuttle to the air intake on the heater box. The fourth and fifth pieces of ducting mount to the top of the heater box and are used to direct warm air to defrost the windshield. These are much smaller and fitted with "elbows" at both ends to connect to the heater box and to the vents. The ducting is readily available.

e-mail me