How can radiator coolant leak on a 1990 Acura Integra if there is no visible sign of a leak anywhere?

Answer 1

The radiator coolant could be going through the engine and out the exhaust. The first thing to check would be to look for steam coming out the tail pipe. Warm the engine thoroughly (drive it 20 minutes or so), then park it, leaving it run. Check the tail pipe(s) (exhaust) for any sign of stream. Finding steam coming out the exhaust, along with a reducing quantity of fluid in the radiator or overflow bottle, might mean you have a leak between the cooling system and the combustion area of the engine. As this leak gets worse you will notice the engine running more and more rough, needing a tuneup, or not wanting to run at all. This kind of a leak can usually either be found as a cracked engine block, a cracked head, a warped head, a blown head gasket or a combination of the above. These are listed in order of highest repair cost to lowest. Many times these symptoms show up after the engine has overheated, since this overheating can cause warps, cracks and blown gaskets. To further investigate, a repairman will usually do a compression check next. A low compression on one or more cylinders will point to the problem areas. The repairman may also pull some spark plugs and compare the type of wear among them. If the coolant leak is near one or two of the spark plugs it will show signs of discoloration and point to the problem area. After confirmation of any of the above, it's probably time to disassemble the engine to some degree and make repairs. Typically, dependant on the type of engine or vehicle, the repairs can cost upward of $300.00 to maybe more $1500.00. If the engine block is cracked, you can spend a lot more for a replacement engine.