Honda accord evap system and overheating problems

Hello, i recently bought an 07 honda accord and its been having some problems with overheating.
I pulled the codes and got p0497 and p0457. Its not the gas cap.

At first i thought it was the evap system purge valve, but from what ive been reading, that shouldnt cause overheating problems.

A little more context, the overheating isnt linear, itll start to overheat and then drop back down around normal, engine hasnt failed due to overheating but its still concerning.

Im kinda stumped here so any advice or help would be appreciated, thank you.

Update: got a hold of some fairly recent repair records. They had said that either the timing cover was leaking or the water bypass was leaking oil. Im not sure what either of these are, could they be the problem?

I wonder if the radiator is clogged or somehow damaged. Could also be a head gasket leak.

You may have purchased someone else’s problem. Any chance of a return period?

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You probably have two separate problems, an EVAP system problem(s) and a cooling system problem(s). With the engine cold, is the coolant level correct and the radiator full?

I wish, but no. I checked the radiator, but ill check the head gasket. Thanks

Yes, all fluids are good, ill check more into thw cooling system, maybe something is wrong, thanks

A pressure test would be a good thing to do.

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got a hold of some fairly recent repair records. They had said that either the timing cover was leaking or the water bypass was leaking oil, but i couldnt afford to fix them at the time. Im not sure what either of these are, could they be the problem? Called them, it might be the water pump

The Evap codes may be caused by a bad purge valve.

P0497 = Low purge valve flow.

P0457 = EVAP small leak detected.

If the purge valve isn’t closed completely when the system does its self test it can cause a small leak code.

If you just got this car, try replacing the thermostat. Sometimes thermostats stick causing it to open late.

Tester

On a used car with little or no maintenance history, you kinda have to start from square 1. Was a timing belt replaced on schedule or due now which would include coolant service and a water pump? Surging and then cooling down would suggest a lazy thermostat but could also be a head gasket leak developing. Also the radiator could be full of bugs. A simple check for exhaust gases and a coolant flush plus thermostat would not be overly expensive but a timing belt and pump is in the $1500 range. All stuff that needs to be expected to bring the maintenance up to current on a used car. Then of course brakes, hoses, tire, trans fluid change etc. just the way it is.

Is car a v6 or 4cyl? V6 has timing belt.

I concur. The evap codes are probably unrelated to the overheating. the only possibility I can think of the two problems being related is if the evap problem is making the fuel/air mixture incorrect. You could ask your shop do a fuel trim test to check for that.

Otherwise, for the overheating, start with the basics, my guess, it is one of these

  • Check the coolant level. Not just in the overflow bottle but in the radiator as well. Cold engine for this test.
  • Pressure check the cooling system to make sure it holds pressure to spec.
  • Radiator flow test.
  • Ignition timing test
  • Water pump flow test.

My WAG: Clogged radiator.

When does it do this, at idle like sitting at a red light, or while driving down the road, or heats up at red lights and cools back down above 30ish MPH, over heats in heavy slow moving traffic then cools back down once moving above 30ish MPH again…

Forget the evap stuff until the overheating is taking care of, overheating an engine can kill it, don’t need a working evap if you can’t drive it cause you blew your engine up… Now once the overheating is taken care of, then repair the evap system… Priority’s…

Make sure the radiator/cooling fans are working properly,
makes sure the cooling system is holding pressure INCLUDING the pressure (rad) cap, make sure the gauge is correct and temp sensor is not defective (given you a false reading), what does Live Data show compared to an infrared gun reading at the temp sensor…
What is the temps at both rad hoses, does the heater get very hot (almost burn your hand, or temp reading with gun)??
Make sure the T-stat is opening and closing correctly…

If you are unable to preform these checks then take it to a shop for a proper diagnoses and repair… I have seen more engine damage come from overheating than any other thing over the years…

Not making light of the evap system and it’s effects on whatever, but if you can’t drive it cause you overheated it one to many times trying to fix the evap leak 1st, then you are without a car waiting on a very costly engine repair…
It would be best to do it all at once, but not overheating comes 1st…