ive got a 2003 toyota camry 2.4L 4cyl. 190k miles. the problem im having is the car is VERY underpowered. it feels like its pulling a heavy trailer or like there was a rag shoved into the intake. it’s sluggish all the way thru the power band but it hardly has the power to go above about 5k rpm. other than that theres no running issues with it. no misfiring. no weird noises. good gas mileage. runs very smooth and quiet.
parts i’ve replaced, all OEM:
everything in the fuel system, pump, filter, pressure regulator, all 4 injectors, checked the lines for any kinks
air filter, MAF sensor, o2 sensors, catalytic converters, including manifold, i even tried driving with the exhaust disconnected, no change, throttle body clean. taken the intake all apart and looked for any restriction, found nothing, no vacuum leaks, checked with a smoke machine
spark plugs, crank position sensor, timing chain, intake variable valve timing gear, timing chain guides, oil control valve. timing is 100% correct.
alternator battery water pump and belt tensioner.
compression is over 200 psi and that’s without putting oil in the cylinders
no change going from regular to premium gas.
with everything i’ve replaced it would seem to me its getting plenty of fuel, air, spark, no exhaust restriction, timing is right. compression is good.
possible excess carbon buildup on the intake valves???
i have a dealer level autel scanner, is there anything specific in the live data i should pay attention to?
Instead of throwing parts at the problem wouldn't it be better to analyze live data to get an idea of what's actually going on? Was there any indication that any of the parts that you replaced were actually bad?
the problem is there is not 1 sign of anything not working correctly other than low power, all live data looks perfect.
the problem is there is not 1 sign of anything not working correctly other than low power, all live data looks perfect.
Ah, I missed the part in your post about the live data looking OK. How is compression? That thing is a couple of decades old after all. Always good to check the basics. Also is there any indication that your transmission is slipping like engine racing without road speed increasing correspondingly?
nope, like i said in the post compression is above 200 psi. transmission shifts flawless, it feels low on power even revving in neutral or park
Sorry about that, it's a fairly long post with a lot of whitespace between paragraphs and I didn't catch everything in it. Sure sounds like an exhaust restriction but you've already replaced the cat. I didn't see anything about the muffler, that might be restricted internally due to deterioration. (I assume you've already looked to see if there's something obvious like a crushed exhaust pipe.) It would be interesting to temporarily run open header and see if the engine revs better in park.
Rats, looking again I see you've already tried the open header trick! It seems you've pretty well covered the usual suspects. Is valve timing OK?
yes, i replaced the timing chain, guides and sprokets myself with OEM parts and did everything exactly by the book. it had the common vvti rattle on cold starts which is why i replaced those parts in the first place, it solved the rattle but not the power issue
i should also mention the car has SLIGHTLY better acceleration on a cold start than once its fully warmed up, not a huge difference but something worth noting
Well I have to admit I'm out of ideas on this one. Like I said you've covered all the bases I would normally look at for a lack of power situation. However I have never owned a Toyota - maybe Scotty or at least someone specifically familiar with that engine might be able to come up with something.
im hoping so. thanks!
We have 06 Camry with 375k miles. I don't notice slow acceleration in our car. Maybe it's normal to do that in your case. Most of the parts in our car are original for example the timing chain, guides, sprokets etc.... Scotty Kilmer actually featured our camry in his video when it had 316k miles. The title of the video is called "WHY THE HELL HAVE YOU NOT BOUGHT THIS CAR". He mentioned my mass air flow sensor was not at 2.4L and it was reading somewhere at 1.8L and my car still didn't have the acceleration problem. What is your Mass air flow sensor reading is it reading 2.4L? I would check that out as well. Good luck.
