Toubleshooting Leak Coolant Engineradiator
Coolant leaking from an engine indicates a serious problem and one that can lead to expensive repairs if the causative factor is not diagnosed and remedied without delay.The radiator is not actually part of the engine proper, but it is the most common place for a leak in the coolant system to transpire. Even if coolant appears to be coming from the engine, it may still be the result of a radiator leak, and the coolant is simply being blown onto the engine by the cooling fan. Such a possibility should be eliminated before continuing on with a coolant leak diagnostic inspection of the engine. If it is the radiator, and yours is a late model car, you can probably get a new replacement for 2 or $300 at the local parts store. If you can wait a few days for delivery,Rockauto.comis a good source and usually has the best prices of on-line parts dealers.Focusing now on the engine, the first objective is to identify the exact locality of the leak. The most common place for a coolant leak is the water pump or hoses connecting between it and the radiator. Use a flash light to inspect these areas first. Check heater hoses too, and sometimes there is a heater bypass that routes coolant through an electrically actuated valve mounted on the top or side of the engine.If the hoses all look good, further inspection around the water pump would be the next step. Some newer cars actually have the water pump built inside the engine and special tools and knowledge are required to access it. If was is leaking in this area, and you still want to further diagnose the problem yourself, a good place to start would be the service and repair manual for your make an model. (Mfg. Manuals are a little pricey, but a tool well worth the price tag if you plan to do your own repair work-seehelminc.com. Incidentally, the average water pump R&R at a dealer will cost more than $1,000 on most newer cars.)If the leak is not coming from around the water pump, the next thing to check would be the freeze plugs. They will be small indentations about 1 1/2 inches in diameter located along the sides of the engine block. They can rust out, although this is rare these days since antifreeze generally prevents such corrosion. Replacing a freeze plug, assuming you can get at it without pulling the engine, is not a big deal.From this point onward, the possible leak scenarios become more devastating. If the leak originates where the engine head(s) attaches to the block, a blown head gasket may be the source of the leak. If it is only leaking to the outside, replacing the head gasket will fix the problem, but if coolant is also getting into the cylinder(s), an engine rebuild may be necessary. If this is the case, there are some test that can be run to determine the extent of the damage. For instance, if coolant is getting into the cylinders, then exhaust gases are also getting into the coolant system and are detectable with the right equipment.A cracked head or engine block would be the most serious source of a coolant leak and require a major overhaul to fix. Purchasing a new crated engine from the manufacturer may actually be the least expensive way to go. Recently I picked up such an engine for my 2000 Chevy Malibu for under $2,000. Just the machining to rebuild the old engine would have exceeded that amount. This new replacement was complete and ready to install and came with a 10 year 100,000 mile warranty from GM.Of course, not a lot of people work on their own cars these days, but troubleshooting a coolant leak in the engine is not that complicated, and if you know what your dealing with, you are much less likely to be “taken for a ride” by the service manager when you take your car in for repairs at your local car dealership.
