Someone suggested I put cardboard on the "outer side" of the radiator. I have done this, managing to fix it firmly in place. The engine and my heater warm up about twice as fast as before the cardboard -- very nice. Would you say this cardboard-on-the-radiator idea is the same general idea as the winterfront?
Provided I keep a close eye on the temperature gauge so the temperature goes no higher than "normal" range, in your opinion, am I asking for trouble of any kind? I am amazed at how quickly the temperature gauge gets to normal (and how fast the interior warms up) with this cardboard-on-rad idea and really enjoy it (-20 here today), but don't want to do any damage to the engine. Is there any risk to my engine using the cardboard? I have the radiator about three-quarters covered. The quarter across the top of the radiator is uncovered.
ANSWER -- Placing cardboard in front of the radiator is an old trick, but a winterfront works better. The winterfront (because it covers the grille opening on the outside of the vehicle) will still allow some air to pass through the radiator. The engine might not warm up quite as quickly as when blocking the radiator, but there is less chance of overheating the engine.
A winterfront also places less load on the engine fan. If cardboard blocks all the air flow to the fan, then the load on the fan is even, but if air can get to one portion of the fan, then that side of the fan will have a higher load on it than the rest of the fan blade area. This causes a side load on the fan drive -- the water-pump bearings on a mechanical fan or the electric-motor bushings on an electric fan. This can cause premature failure of the fan bearings.
For the short term, cardboard will work if you keep an eye on the temperature gauge so the engine doesn't overheat. For the long term, I would have a winterfront made up if necessary. Many automotive upholstery shops can make a custom winterfront for your vehicle.
QUESTION -- My 1995 Oldsmobile Royale LS has the auto climate control system with a separate passenger temperature control on the passenger-side armrest. All right-hand vents blow only cold air on all settings. Can you advise how to diagnose this problem and correct it? The vehicle has 112,000 kilometres on it and is like new.
ANSWER -- This dual-zone system has two separate doors inside the heater housing to control the temperature for the driver and passenger side. Each is operated by an electric motor connected to the HVAC (heater/ventilation/air conditioning) programmer. The programmer is a black module bolted to the right rear of the heater housing under the dash and will have several vacuum lines and an electrical connector going into it.
The motor for the driver's-side temperature door is located inside the programmer, while the passenger motor is external and connected only by wires to the programmer. The passenger-side temp motor is bolted on top of the heater housing just to the left of the programmer and it is connected to the temperature door with a "link" or threaded rod.
Watch the passenger temperature motor under the dash to see if it moves. If it tries to move, disconnect the arm and try to move the door manually. There may be something dropped down the defroster that is blocking door movement. If the motor doesn't try to move, check all electrical connections at the motor and the programmer. If the motor moves when the driver's control is changed, but not the passenger control, the wiring should be checked from the control to the dash display panel. Look for breaks in the wiring at the passenger-door hinge area first.
If none of the above helps, then the problem is either in the dash control head or in the programmer. The easiest way to diagnose further would be by using a scan tool to view system data. A visual and physical inspection of connections and linkage may find the problem, however.
Jim Kerr is an experienced mechanic, instructor of automotive technology and member of the Automobile Journalists' Association of Canada. You can e-mail questions to Jim at the address below.