I have a 2001 Honda Civic Ex that goes into limp mode when the weather is hot. It only happens in hot weather: I drove it during the cooler months, and no problems. Also, it doesn’t have any problems if I drive it at cooler times of the day (evening, night).
When the weather outside is hot (~75+ degrees) I can only drive my car for about 20 miles before the check engine light comes on and it goes into limp mode, where the engine just shuts down and I cannot accelerate above 30mph. The engine is still running, but when I push on the gas pedal I can only go like 20-30mph. This happens when the ac is on or when the ac is off, but will happen sooner if the ac is on.
When this happens, I pull over to the side of the road and wait several minutes. Then I can restart my car and drive a few more miles, and then it happens again: limp mode. Then I pull over again, wait, and restart it. It starts fine.
In the winter months I don’t have any problems, and my car drives fine.
I have had the thermostat replaced, and the temperature gauge does not indicate overheating.
The reference to a “clogged cat” means that the catalytic converter may be clogged, which can certainly happen with a 12 year old car.
The only solution–if that is the problem–is to replace the catalytic converter. This car may have two cat converters, but I don’t recall that detail offhand.
Another possibility is a fuel pump that is failing.
Anyway…the first step is to go to a parts retailer like Autozone, Advance Auto, O’Reilly, or (possibly) Napa, and ask if they will check for trouble codes that have been stored by your car’s OBD system. Then, come back to this thread and post those codes for more specific advice.
When I read “limp mode,” I first thought you must be driving a hybrid, but my second thought was that it could be the transmission if yours is an automatic. Automatic transmissions rely on a radiator to cool down the transmission fluid, and if parts of your transmission cooler are clogged, it could explain why your car is going into “limp mode.”
My last thought is that “limp mode” must be what happens when your E.D. drugs stop working.
Whitey, I also didn’t infer that it was a clogged cat. 0798Honda suggested this as a possibility, but I’ve never seen a clogged cat change performance due to weather. Generally when a problem is heat sensitive I look for electrical things with windings…but only after I check the codes. Honda people tell me that there’s a “main relay” under the dash that can get heat sensitive, but generally that causes stalling.
So, I have the same problem , same year. Did you figure it out ? I’ve put a few bucks into the car, and I don’t feel like giving up on it yet.
It does have to do with overheating, maybe some electronic protection to prevent blowing the engine I was thinking. It suddenly happens, usually after being stuck not moving in traffic, in the heat, goes about 15 or 20 mph until it cools for an hour.
Did you figure it out?
So are you saying the temperature gauge is rising beyond normal?
Things to check:
Coolant. Level and condition - if the level is low, find the leak. Easiest way is to run the car up to temperature, and then pop the hood and look for the spray of water/steam. There will be a couple of small-diameter hoses on the back side of the motor that you need to look at, as well as the heater hoses which should be behind the motor on the passenger side. Don’t forget to check the radiator cap too, but of course don’t touch it or take it off while the system is hot.
Before doing any of that, while the engine is cold, open the cap. You should see some fluid when you look down the hole. Then look in the reservoir bottle because it’s easier to see the color and condition. It should be green or yellow depending on what you have in there, and it should be clean. It should not be brown, and it should not be murky. If it is, and especially if it looks kind of like chocolate milk, then you may have bigger problems.
Radiator itself, for leaks or heavy cooling fin damage.
Radiator fan - these are not driven off of the engine, so the electric motor can fail, or something in the circuit can fail. I’d look hard here, because that’s a pretty classic cause for overheating in traffic but not elsewhere.
This is something you don’t want to put off - no engine is happy being overheated but Honda motors of that vintage are quite sensitive to it. It doesn’t take much at all to warp the head and then you’re in for spending some serious money.