More Than Meets the EYE

Recently we serviced a 2003 Honda Civic. Primary problem was a failed radiator that would leak out water as fast as you pour it in. Often times, cooling system service can be more complicated that a simple leak.

A good tech will always ask WHAT, WHERE, WHY.
Why did the part fail? What could have caused the failure? Where could other problems be related to the failure? And most importantly, are there any problems that may be a result from the failure?

Our first concern was not for the radiator, but damage that may result from a cooling system failure.
We were asked if it could be driven. The customer reported the gauge DID go into the HOT range. The vehicle had failed on the road, but made it home. We have serious concerns about Hot Hondas. The tend to warp heads and blow gaskets!
Times are getting tougher financially for a lot of folks, so I was inquired as to if the car could be driven safely, as it could save the tow bill.

Please note: Driving with a coolant leak can do major damage! Driving an engine with abnormally high engine temperature can do damage. If you are NOT familiar with how important it is to keep the engine cool, DO NOT DRIVE. Serious damage can follow, and cooling systems are CRITICAL to engine operation. If you question at all whether you can safely make it to the shop, DO NOT DRIVE.

I had the customer verify how the vehicle ran. Given it started smoothly, idled immediately without any roughness or abnormal operation; the decision was made to limp it to the shop. I asked that in order to be extra safe; after driving one mile, stop the vehicle and allow it to cool. Then make sure some water was added to compensate for any lost [it was a big leak], and allow the heat to soak out of critical components. Again, dangerous condition, opening a hot radiator, if you do not know to be very careful, DO NOT OPEN A HOT RADIATOR. Temperature gauge was watched carefully, and temperature never went over normal. A short time later, he pulled into the shop.
Attempted limp results were a successful trip to TASC.

First thing we do was to check for exhaust gas in the cooling system. Because of emission services in our area, exhaust gas analysis something we do regularly. Our CO standard is anything over 50ppm is questionable. We have seen vehicles with over 100ppm that run fine for years. [my techs car for example, 7 years!]
Many things can affect these readings including head surfaces with a higher that specified roughness average [ RA].   New gasket technologies require special surface preparation. Consequently, resurfacing in the aftermarket must be specified by the repair shops, and unfortunately, many do not check or demand the correct RA numbers, or have the tools to check it. You can't overstate how important it is to have a good machinist when remanufacturing cylinder heads! Back to the repair...

Once repairs had begun, we found the failure. The lower seam on the copper/brass radiator had opened. Also the core was rotted and the fins were falling out. Hoses were in good condition and the radiator was replaced. We also found a little damage to the lower radiator mounts due to something hitting underneath the car prior to the failure. Potentially it could have been a cause, but the parts were old, so we ensured that they were properly straightened to support the new radiator.

Ken likes to use a vacuum test prior to filling the radiator. This test device ensures that there are no further leaks in the system. It also helps to ensure that coolant fills all the voids found on Honda vehicles. After filling, the vehicle is run; thermostat is checked to be opening properly, and cooling system pressure is watched, and fan operation is verified. After a trip around the block, the customer was called and the vehicle delivered.

Lord willing, we will not see any further problems.
Overheating is a serious event. If it is possible, do not drive, but tow the vehicle. I have seen serious damage due to overheating, and a tow could prevent hundreds + in repair costs. Overheating damage must be carefully inspected. Make sure your repair shop checks everything so you don't spend more money than you plan for.