bad engine coolant temp sensor?
 

so ive been having a rev limit of 4k rpm when i cold start my car. if i let it warm up and restart the car it stops. if i reset the cel while its warm it does not come back on until i cold start again. so i replaced the engine coolant temp sensor but it still does the same thing. any ideas?

thanks

Re: bad engine coolant temp sensor?
 

what is the actually engine code being thrown?

Re: bad engine coolant temp sensor?
 

i dont know. i didnt run a diagnostic. i know i should have done that in the first place but i didnt and i wanted to see if anyone had any suggestions before i do.

Re: bad engine coolant temp sensor?
 

do you have k-pro ?

Re: bad engine coolant temp sensor?
 

No

Re: bad engine coolant temp sensor?
 

anytime you have a cel the first thing you should do is check it. it's free at some places. knowing the code will save you a lot of time and headache.

Re: bad engine coolant temp sensor?
 

yeah def get it checked out to see what code its throwing...autozone or advanced auto is free like vladd said

Re: bad engine coolant temp sensor?
 

Hey Dave don't sweat it... you got to learn sooner or later how to do things right the first time... what I suggest is go get that code and comeback here and post it and will give you a hand at figuring it out!

Remember when it comes to check engine light always get the code it help to point you and us in the right direction!

Re: bad engine coolant temp sensor?
 

Very true and well said.

Re: bad engine coolant temp sensor?
 

Are you sure it's not just the fast-idle for cold starts? :crook:

It sounds like your temp sensor is working fine to me.

Re: bad engine coolant temp sensor?
 

I thought it was IACV but someone cleared the codes......NOOB

Re: bad engine coolant temp sensor?
 

why are you even reving it to 4k when its cold???

Re: bad engine coolant temp sensor?
 

thats honestly not gona hurt it, as long as it has oil in it 4k is nuttin. live where its cold you realize it could take 30 mins for a car to start to get warmish

Re: bad engine coolant temp sensor?
 

when you turn on a car that is cold, the ecu is running in open loop which means the AF mixture is running rich, which then could cause your catalytic to run dangerously hot and cause a fire.

TS is saying his revs are limited to 4k..which is limp mode. which means there is something wrong with the car and the ECU is trying to prevent a major problem.

i say you replace the ECT sensor.. and you'll be ok

Re: bad engine coolant temp sensor?
 

been doin it for 20 yrs never had a problem, been a honda mechanic for 6, but yeah the car is in limp mode, and more than likely it is the ect sensor, but getting the code would be a sure fire way to know the ecu is doing.

Re: bad engine coolant temp sensor?
 

I doubt you have ran a car "hard" like this for 20 years and not had to replace the prematurely worn : catalytic converter, piston rings,o2 sensors.
Congrats on being a honda tech, but this problem just isnt relevant to Hondas...It goes for all cars...

Re: bad engine coolant temp sensor?
 

i know that, and i dont stick at 4 grand, i let the car typicaly go to 4 grand and then shift, ive never had to replace a cat, or an 02 sensor on my cars, piston rings yes, but that was a racing motor and didnt see cold weather. the only vehicle ive owned that wasnt a honda was my ford diesel, 4 grand wasnt exaclty gona happen on that truck.. lol but i do understand what your sayin

Re: bad engine coolant temp sensor?
 

what i have been saying is that if you run a car hard without letting it properly warm up there will be repercussions. You stated there wouldnt be.

Re: bad engine coolant temp sensor?
 

Is your car auto trans?

Have you try the same thing with the AC on at high?

Re: bad engine coolant temp sensor?
 

no i ment you can go to 4 grand with out hurting it, i wouldnt sugest doing it all the time or staying at 4 gand or above while cold.

Re: bad engine coolant temp sensor?
 

hey guys sorry its been so long since i posted. i got the code read and its p1259 which is vtec failure. so i reset the CEL to see when the light came back on and it come on below 4k rpm but only on cold start if i let it warm up and reset the CEL it doesn't come on at all.

Re: bad engine coolant temp sensor?
 

check your oil

Re: bad engine coolant temp sensor?
 

the oil level is fine. im going to change it in about an hour. ill post the results afterward

Re: bad engine coolant temp sensor?
 

i changed the oil. its still doing the same thing.

Re: bad engine coolant temp sensor?
 

bad vtec solenoid?