Sorry for the clickbait, but I have a real mechanical dilemma that I've had trouble getting a response to in the past. (Hopefully) now that I have your attention, I just want to say that I love my CT and it's actually one of my favorite cars, but I am having an mechanical/existential crisis at the moment. I am really hoping to get some expert or at least sound advice here, so if you know anything please weigh in!
The car: 2012 ct200h base, 174k miles, 3rd owner, 2-3k miles driven were mine
The issue(s): Engine overheating, stop leak in the cooling system, Code P148F, triangle of death (check hybrid system), check engine light, white smoky exhaust, no heat on passenger side or windshield defrost (fixed)
Other factors: Cooling system flush performed, thermostat replaced, water pump replaced (neither were bad it seems), code reset, no coolant or water in oil, no shake or rough start, no actual leak (unless the stop leak solved this, but I can't know for sure)
The story:
My car has been trying to overheat intermittently since I bought it almost a year ago. The coolant temp. warning light would flash then go away before I even had a chance to pull over, so I thought it's probably a bad sensor and didn't rush to address it. Instead, I did a bunch of digging over time and never found any useful information, so I took a wait and see approach. Last month it finally took a **** and gave me the triangle of death. It tripped the fail safe to run exclusively on the ICE so it wouldn’t overheat the hybrid battery. The code it gave was P148F - engine coolant pump over revolution. I unhooked the battery and no more code, no more warning lights, car performs normally again, but still overheating.
I took it to Lexus where they charged me $130 to do exactly nothing. They wanted to charge me another $400 to do a coolant flush after they found stop leak in the reservoir that the last idiot of an owner botched whatever job they were trying to perform by not flushing it out of the system (and using it to begin with.) I did it myself instead for maybe $30 total, dumped the sludge, flushed under pressure with one of those hose kits, replaced the thermostat, then flushed the system normally while getting the engine up to temp to open the thermostat about 10 times with distilled water until it ran completely clear. Plus I did a blue devil coolant flush for about 2-4 hours and drove it (or whatever was close to the max time recommended in the instructions,) then replaced with coolant and continued with testing in maintenance mode ever since. During this process I also ran the heater which would blow very hot throughout the cabin after the car was up to temp, but during some tests it would blow cold just before it started to overheat. I would then stop the car, and found the coolant boiling and overflowing out of the reservoir, which could be what the last owner mistook for a leak. The flush seemed to solve the heater problem, so I don't think the core could be clogged. I was draining the system from the radiator petcock, so that wasn't clogged either. My last resort was replacing the water pump, which did not help either. BY THE WAY, the first replacement pump I got from Amazon was seized, so if you order from them be on the lookout for defective parts. Just a final note, I did not start to get smoky exhaust until after I had flushed the system. Again, I am not seeing any other tell tail signs of a bad head gasket, but what else could it be?? As far as having the head gasket replaced, I am considering doing it myself, but also entertaining the option of a whole new engine when I can get one with 50k miles for $1400. A HG fix upwards of $2k just doesn't make much sense to me as a first resort if that is indeed the problem. I figure that if someone wants to charge me $2k to fix a head gasket vs. replacing the engine with something much newer for the same price then I might as well try to do the head gasket myself first, then possibly replace with a newer engine. Also, does anyone know of or recommend a good head gasket kit? Thoughts please! Thanks for reading.
