Now, Try a <i> Cheap</i> Way to Find That Darn Leak
Question: My 1986 Oldsmobile Ciera four-cylinder slowly loses coolant with no visible leak. My mechanic’s first solution to this problem was to rod out the radiator, but this had no effect.
Next, he replaced the heater core, but the problem remained. Now, he says the head gasket leaks. I don’t see any steam in the exhaust pipe, though.
Do you have a suggestion?--P.W.
Answer: Your mechanic has used an amateurish trial-and-error procedure to diagnose your problem and even at that made a number of dubious repairs.
Your first step should be to dump the mechanic and find a garage that knows where to find the problem in a hurry or can at least make a systematic diagnosis. My hunch is that both repairs were completely off track in finding a leak.
Generally, a radiator is rodded out when it is dirty or clogged and causing the engine to overheat. The procedure involves disassembling the radiator and literally pushing a rod through the coolant tubes.
The heater core is replaced only when it leaks or is clogged and not supplying heat to the passenger compartment. It is an expensive item to replace, because it involves disassembling a good part of the dash.
On a 7-year-old car, the most likely thing leaking is the rubber heater hoses or radiator hoses, if you haven’t replaced them. You should carefully inspect the fittings and attachment points. I would suggest that you or your mechanic begin by tightening the clamps on the hoses, if they have screw-type clamps.
If the quick-and-easy fix doesn’t solve the problem, several tests should be able to track down the leak’s source.
First, verify that coolant is leaking. The cooling system should be pressure-tested, in which a mechanic attaches a pressure gauge at the radiator opening, pumps up the pressure and monitors the system for leaks.
The mechanic can run a compression test to determine whether the head gasket is leaking. This does not always work, because the gasket could be leaking fluid into an oil channel, rather than into the combustion chamber. Cross your fingers that this isn’t the problem, because it could get expensive.
And finally, if you don’t get a straight answer about where the system is leaking, try a can of radiator stop-leak. A lot of professionals look down on stop-leak products, but if you have a pin hole in a radiator or heater core, it could provide the lowest cost fix. It is not likely to do any damage.
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Q: I was told to check the pressure in my tires when they are cold. But by the time I drive to the service station, the tires will not be cold any longer and I am worried I will not get the correct pressure. Should I inflate them to a higher pressure?--A.I.
A: Unless the service station is more than a few miles, you should not have a problem. But if you want to be certain, there is an easy way to get the exact pressure. Over-inflate the tires by a few pounds one evening and the following morning before you drive, let the correct amount of air out.
