Toyota Corolla '02 Stalls Out When Heater Is Turned On. - Corolland: the Toyota Corolla Forums

Hi, could really use some help.

I have a 2002 Toyota Corolla with over 130,000 miles. Recently when I turn on the engine and the heater is in the on position already the engine makes an uneven noise and then stalls and dies out. I took the car to be checked out at a shop and they performed the following: radiator drain and fill package, three-step pro fuel package, tuneup package and a few other things. Their notes: stalls through idle no CIL. Has PO 420 in memory/history codes cat efficiency. Found plugs fouled, valve cover seals leaking, replaced coils/plugs/gasket, if light returns may require cat. May also require IAC motor, but working at this time.

After picking up my car it continues to do the same thing. When I turn on the engine and the heater is already in the on position the engine stalls and dies out. When I turn on the vehicle with the heater in the off position the engine turns over fine but when I do turn on the heater it stalls out and dies.

The mechanic recommended that because there is some type of cleaning solution in the fuel system or engine that I should continue to drive it because it can take 4 to 5 hours to work itself through the system.

He said that if the problem persists it could be a more expensive repair but he could not give me a quote.

I'm hoping that this issue is more common than not I have seen it come up a few times and Google searches but I'm just looking for any advice or recommendations. Thank you for reading and appreciate any assistance you can offer.

Have you cleaned your MAF/IAT sensor on the intake?

Sure it is just heat or is it also set to defrost too?

To me, initially, sounds like a charging system issue, as the blower motor can eat up a fair amount of electrical power. If the defrost is on - that will also kick on the A/C compressor - which adds to the engine load. The IAC is "supposed" to bump up the idle to prevent the car from stalling. From their description - sounds like they already checked on the IAC valve.

Start with all the electrical accessories off, start the car, and let it settle down to a steady idle. If it can't do that - you have other issues that need to be addressed first. Once idle is maintained - kick on the electrical devices, one at a time - find out which one causes the idle to cut and stall out the engine.

I'm curious on why they thought they have to drain and refill the cooling system - did you make sure they put in Toyota Red coolant and distilled water and not just a "compatible" coolant? This assumes that you had Toyota Red coolant + distilled in there.

Also not sure what they mean by a "3-step pro fuel package". I'm assuming that means clean the throttlebody, check the air filter, and add a can of injector cleaner to the gas tank - typical for most places. I'd actually be surprised if they did anything "pro" to the fuel system, as that requires them to partially disassembly the fuel rail to really clean it.

Dom has a good point that the MAF is very commonly overlooked for cleaning. The usual approach is to just replace the sensor, but many owners found that cleaning it with the appropriate solvent works wonders for engine performance. There are tons of videos and a few DIY guides on this forum that can help you do this yourself.

Tune up package?? Nothing really to tune up on these cars - other than a visual inspection. The fouled plugs are actually more telling. Did they give you the old plugs? How they looked, how they were fouled is VERY important - can tell you a lot on what was going on with the engine.

Remote possibility that there is an issue with the VVT-i system, in particular the OCV (oil control valve) and its associated filter. If those are clogged, the VVT-I actuator could be running the wrong valve overlap - which can affect engine performance.