coolant temp sensor?

What year and model vehicle?

Some vehicles have a single temp. sensor that controls the engine temperature (by controlling the engine cooling fans) *and* drive the temperature gage (thru the computer). If that's the case, you can get some indication of what's going on with that sensor by how the temperature gage is operating during and after warmup (in conjunction with other observations, such as operation of the cooling fans, actual engine temperature as measured by another known good source, etc.).

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Yes it can, a scan tool would be better so monitor what the temp is actually reading. What is the year, make and model?

Glenn Beasley Chrysler Tech

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this car is running bad now ,once it warms up. 1998 dodge stratus es 2.5v6. I think the cooling fan always ran more then I thought it should. I'll check it out with my scan tool. thanks

well, now with new plugs,wires,fuel pump, fuel filter, the car still does not run right. it misses and acts like it's not getting fuel when you step on it . could it be the coils shorting out under load? I know my repair manual says I can check the coils with my multi meter but how do you simulate it under load, if this is the problem. note: there are no codes of any kind coming up with this problem. I don't want to be a parts hanger but I had 2 distributors that were bad before,and the last one was changed in Feb 07. any ideas or checks I can do. would the dodge dealer find the problem on his expensive equipment? my mechanic friend did the fuel pump,filter, this weekend and the last distributor in feb 07 and he thinks it's an ignition problem. I thought I read somewhere if the voltage isn't right ,then the fuel won't pump? thanks for any info Randy

If you had a scan tool you would be able to read what the intake air temperature is and probably find out it is way to hot once the engine warms up. This is because your EGR valve is stuck open and allowing hot exhaust to enter the intake and causing a really lean condition. On a carbureted engine this would have caused a bad idle, since this engine is fuel injected directly into the cylinder all you may notice is a higher idle. Disconnect the EGR valve vacuum line and see if it makes a difference, If the Spring inside the valve is broken, disconnecting the hose may not make a difference. You want to take a shot at it? toss an EGR valve on it.

Glenn Beasley Chrysler Tech

Introducing exhaust gas into the intake does not cause a lean condition. The exhaust gas, being inert, dilutes the air/fuel mixture and it'll idle like shit whether the engine is fuel injected or not.

It will not idle like shit, it may have a slightly higher then normal idle, Map sensor will compensate for this leak. Take the EGR valve off and the engine will run at a high RPM. Not a rough idle.(It isn't a carbureted engine) The pcm will think that the throttle blade is open and compensate.What do you think the purpose of the IAT (intake air temp) sensor is used for????? Incoming cold air will cause a richer mixture, now suppose you have the intake Temp at 180 to 200 degrees from a stuck open EGR valve? Very lean condition with a possible hesitation an or ping on accel. The vehicle will run good until it reaches operating temps.

Glenn

Run good until it reaches operating temps? With a leaking EGR valve? Nope!

Taking the EGR off is not the same as the valve leaking exhaust gas into the intake. Removing the EGR will leave a large vacuum leak that will cause a high idle, and the PCM will add fuel because of the low vacuum sensed by the MAP sensor. Leaking exhaust gas into the intake will cause a shitty idle or stall, because the fuel/air charge will be too diluted by the exhaust gas to burn properly.

Yup, The intake air gets to hot, causing very lean condition

With the engine idling, hot or cold, if you pull the EGR open it will stall. Likely before you're even able to detect an IAT sensor temp change with your DRB. High temp is not the problem. Lack of oxygen and fuel is.

You obviously have no idea what EGR does.

well i got the car back and it ran fine until i got almost home. then loss of power, idled rough, and was hard to start once i shut it off. i do have a new EGR valve assy, i'll put on tomorrow.

Install the EGR valve, it will take care of the problem.

Tomorrow has come and gone long ago, when are you gonna tell us it fixed it?

Glenn

well glenn , its not fixed. i have a question for you . when using a spark tester and turning the engine over,should there be continuous spark at the gap of tester? when i do it on my #2 plug i can make a one count between sparks. is this normal? i thought it spun so fast that it should almost continuous? i also don't think it's real blue in color. thanks Randy

Is this vehicle a no start? I thought it was a hot drivability problem?

What you're describing sounds about right. The spark will not be continuous. You will only get a spark at one cylinder every other revolution of the crankshaft. Example: If the engine is cranking at

If it starts & runs, you're probably not going to determine the problem by looking at the spark. If you suspect an ignition problem, you really need to connect a scope to see what's going on.

Or you can keep throwing parts at it.

An engine cranking at 300 rpm rotates 5 times per second. Therefore spark will occur every .4 seconds on a single fire and .2 seconds on a double fire ignition system.

this was suppose to be a warmed up car issue now its a no start car issue. the plugs were wet and looked fouled so i'm putting in new ones. this went from just a bad fuel pump(so i was told ) to a host of other issues. first it ran then after a while it ran lousy ,so mechanic friend suspected bad coil,so reman distributor was put in. then car ran ok until 3/4 of the way home and it had no power and acted like it was starving for gas. once i turned it off ,it was hard to start again. this has been a frustrating ordeal and i'm not, nor do i like parts hanger mechanics. but once my friend said he wouldn't have given the car back to me if it was bad and i'm on my own now , i will find the problem through trouble shooting etc. thanks for all the input and sorry if it seems like i'm going in circles here on my posts. Randy

Yes, I should have said 2.5 times per second.