can ect sensor or bad t-stat cause engine to run rough?

[eric]

2001 ford ranger 2.3 liter 5 speed

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Hello,

My thermostat is bad (gauge does not work and no heat) and check engine light came so I had it scanned at autozone. Guy said bad ect sensor and that is causing my truck to run a bit rough (tough to accelerate ).
I also get poor gas mileage and I was told this is because of bad ect sensor. Can I get your opinion? Do you think ect going bad will cause engine to run rough?

Lastly, can you please walk me through the changing of thermostat and ect sensor? Do I have to drain antifreeze? I think t-stat is at bottom of engine block. Can I simply pull hose off , unscrew / bolt t-stat and put on new one while pointing hose up to avoid spilling? How do I locate ect sensor ? I cannot find it.

Someone told me my coil pack was bad ( plug #3 was not firing) I do not know what kind of diagnostic he did. I was changing my plugs a while back and ripped wire out of plug#3 rubber cap that goes over plug. I put wire back in rubber cap and it started fine. When I finally changed my wires , I noticed that plug #3 wire was frayed. I told mechanic guy wire may be bad but he may not have been listening. I spoke to a dealer service dept and he said coil packs usually do not go bad Your thoughts please

Engine has been running rough for a while and when changed plugs they were pretty well worn out.

thanks in advance

 

[Earl43P]

"The ECT is third in command in the hierarchy of EFI sensors, this means this sensor is very important when calculating fuel ratios and timing curves."

from http://www.fordfuelinjection.com/?p=28


I believe you'll need to drain your coolant down below the level of the T-stat you plan to replace. I don't know about your ECT - it may not even be bad, but is simply reporting to the computer that the coolant isn't ever getting up to temp (from the bad t-stat). I've heard something about the new t-stats having a temp sensor built in and costing $140. Don't know if that's what you've got or not.


Welcome to TRS (an expert will be along shortly to help you with the other questions).

 

[Wicked_Sludge]

the ECT sensor is likely fine. the cumputer never tells you you have a bad sensor, it simply reports what the sensor is reporting. in this case, its low coolant temps due to a stuck-t-stat. i would replace the t-stat and reset the code and wait to see if it comes back on.

a stuck t-stat will cause all the symptoms you describe.

you can easily and controllably drain the coolant from the system using the petcock located on the lower corner of the radiator.

a bad coil pack would likely cause a miss in 2 cylinders (one coil fires two cylinders), and is usually enough to set off a misfire code with the computer.

 

[dorman68]

I think that it is for the ECT sensor to cause a rough running engine. One thing that I have seen on some of the 2.3L Rangers is that the IMRC(Intake manifold runner control) or the intake manifold swirl control valve vacuum solenoid is prone to sticking or the vacuum hose connecting to it deteriorates or falls off.