Bendito

Just bought a 00 ex & the check engine light is on. Autozone scanned it & came up crankshaft position sensor, knock sensor & coolant temperature sensor bad. I had actually just replaced the coolant temp. sensor before getting there so don't know why that came up. Anyway, do I have to replace the other 2? If it's not necessary then I wont because the knock sensor is 135.99.

Also I should say that the temp gauge on my cluster moves up about a quarter inch to the first line, even when warm it won't go up any further. I changed the coolant temp sensor, might the t-stat be bad too?.. This I do need to fix. Any input would be appreciated.

Red_Army

fix them all. or you'll be running around with a check light on all the time. and you'd never know when you get a new one.
it might be expensive but consider the one in there is 15-20 years old.

Bendito

So far I've replaced 2, the knock sensor & the coolant temp sensor but my temp. gauge still doesn't go up past the first line even after I pulled the ecu fuse & did the reset routine. Could the t-stat be stuck open & if so wouldn't that have shown up on autozone's scanner?

Bendito

I need to change the title to this thread..

HondaPartsHero

Is the heat the correct temperature? My civic temp gauge doesn't go past the first line either and works fine.

Bendito

How do you measure the heat. I just look at the temp gauge & it says cold.

HondaPartsHero

I mean the heat out of your vents, is it hot or just warm

lostforawhile

I had this issue on the 98, get a dealer temp sensor first, none of the aftermarket ones I found were the correct ohms range to make the gauge work right, I have a collection of about 7 of them, all supposedly for the same car, and none the same. If this doesn't work, the cluster has a voltage regulator built into the circuit board that controls voltage to the gauge, theres a good chance it's bad, stock clusters are usually all over ebay and the yards for cheap

Bendito

Just took a 20 min. drive & air coming out the vents never heated up.

lostforawhile

that sounds like a thermostat issue or a water pump issue, have you verified that coolant is actually moving through the system?

Bendito

I'm gonna try this on Monday, hopefully they have one in stock.

Bendito

Coolant seems to stay in the block, wouldn't the thermostat have thrown a code though?

lostforawhile

where is the thermostat from? a lot of the cheapo ones from the big box stores are crap,you can pull it out and boil it in some water with a thermometer to see if it opens

Bendito

I haven't swapped it out. I just bought the car & replaced the coolant sensor because it threw a code for it.

crawfo661

There is no code for a bad thermostat, if your not getting heat yours is bad. Replace it, that should still not give you a code for coolant temp sensor though. Check and make sure all the wires and connections are good, or find what the factory resistence is supposed to be and ohm your new sensor out

crawfo661

also your going to be running in limp mode untill you replace the crank position sensor

Bendito

Good to know, I thought it would have thrown a code. I'll replace the t-stat tonight, I have a feeling this is the problem.. Crank position sensor will get swapped out tomorrow & that should cover all my codes.. hopefully

HondaPartsHero

Wait what crank position code do you have? The crank position sensor on your car is in the distributor and is not replaceable, you have to replace the whole distributor. Can you take a pic of what temperature sensor you replaced? One is for the gauge and one is for the ECU. Post the exact codes you are throwing, should be this style ie P0420, or count the number of blinks by jumpering the service connector.

Bendito

Jumped it, codes: 6,23,54.. So I wrote those wrong up top, technically the codes are; water temp. sensor, knock sensor & crank "FLUCTUATION" sensor... Still the coolant temp sensor (water temp sensor) was replaced as was the knock sensor & my gauge still reads cold, the vents don't blow warm & coolant seems to stay in the block. My hypothesis, the t-stat must be stuck open.

Bendito

Im not changing the CKF, if I get a year out of this motor Im happy. I just want the temp. to run right!

lostforawhile

there are two temp sensors, the one for the gauge will have a single wire and looks like the older sensor,only bigger, I used to have the ohms range written down, but I can't find it, I ordered a sensor from everyone I could, and none of them were right, just stick with the factory sensor, the other one that throws the code is a two pin sensor with a plug, thats the one that will throw a code, if you need one PM me, I have a brand new one of those from Nappa, I think I screwed it in and the plug wouldn't lock in place, or something stupid, it will plug in though, you can probably work around that. I no longer have the car and don't need it. The one that runs the gauge doesn't connect to the computer in any way. If the engine is running rough or has a miss, you will get that crankshaft fluctuation sensor code, it's saying that the crank isn't rotating smoothly but is erratic, anything that causes a miss will trip that code.
if that coolant temp sensor for the computer isn't working it will cause the car to run badly and could trip the other codes

check the thermostat and then let the car idle with the cap off and make sure coolant actually flows, I had a water pump that failed and caused that

Bendito

Wow good info. The temp sensor I replaced is the one with 2 prongs & I got it from car quest, it also doesn't lock in place but plugs in. I bought the t-stat and will be changing that out today, if that doesn't work than I'll get a temp sensor from the dealer. Im going to reset the ecu after this & see if the codes come back.

Jimster480

You need to fix them all. Both of those sensors will cause the car to run in limp mode. that means no VTEC and retarded timing. This will cause poor acceleration/performance and bad gas mileage. YOu might be able to go to a junkyard to find the knock sensor though, but either way you will need to get one. You can check and see if yours is bad, it might be possible that it is disconnected or there is a problem with the wire. If you have another car to test it on I suggest you do that, as it is a expensive sensor.

Bendito

I replaced the knock sensor & the coolant temp sensor, just haven't reset the ecu yet.

Jimster480

replace the CKP also