ECT Sensor Replacement?

[Izzmo]

Since I replaced the coolant tank, the car has been running fairly good I suppose. I didn't notice any overheating problems for the first week, but they seem to have re-arose.

The Problem:
I am going down the street and highway and the temperature will just rise up to about 2/3 (pointing at the 30-34mph mark, car seems to run fine, transmission shifts kind of hard though or will wait a little long to shift then fast shift into the gear. If I step on it, the transmission shifts are a little "hesitated" but nothing terrible.

As I drive home it lowers back down to normal and sometimes will rise up a little, about half-way mark.

Fans work fine.. they come on with A/C and turn on high at 50%.

This a problem with the ECT, or what exactly is going on here? I'm not sure how engine temp really correlates to bad shifting.

 

[stephen newberg]

Well, also, it is summer. What kind of ambient temps are you driving in, and how hard is the engine being pushed for load? The water temp gauge is not hugely specific but in general it tends to sit a very small touch below half way when there are no coolant temperature excursions happening, but they do happen. I find them easier to see on my oil temp and trans fluid temp gauges. In hotter weather these both will show operating temperature excursions more quickly and accurately than the water temp gauge.

Might be worth while to pick up something that will read out at least the transmission fluid temps so you can get a better handle on things.

pax, smn

 

[Izzmo]

It's been 100 degrees or higher everyday for the past couple weeks here.

I usually read out temps on my laptop with the SCT tuner, but I'm on vacation and forgot to bring my tuner =/

Before I replaced the coolant degasser it was going just a smudge under the High mark on the temp. gage, but since then it hasn't ever really gone over 75%, which I suppose is a good thing.

 

[stephen newberg]

It's been 100 degrees or higher everyday for the past couple weeks here.

Ouch. I am sure that is contributing to it, but I think what you need, if the problem is showing up in the shifting, is to know what the transmission fluid temps are getting to. To look at cooling off stuff, keep in mind that the stock cooling system runs the trans fluid through a section of the radiator. It might be worth looking at all of that, that is, the the radiator itself, the trans fluid section going in and out of it, etc. The lower elbow on the trans fluid movement for the radiator on mine went out and rather than keeping it all happening in one place, I put in an FPS cooler. That has done a very good job of keeping the trans fluid at a reasonable temp, and also taken extra cooling load off the radiator for the normal engine coolant.

pax, smn

 

[Izzmo]

Where is the lower elbow on the radiator located for the trans fluid?

 

[SHOZ123]

Are the coolant tank and cap holding pressure?

 

[stephen newberg]

Where is the lower elbow on the radiator located for the trans fluid?

Down on the radiator coming in from the driver side, IIRC. You will find a 2 lines. Cannot hurt to see if they are starting to leak. But Paul had good questions too just above, and those need checking also.

pax, smn

 

[Izzmo]

Well funny thing happened. Went over a hard bump on the highway and immediately the low coolant light came on. I stopped over on the side, the degasser was empty and was leaking coolant all over the place. I have no idea where it was leaking from, just a loud hiss of the system depressurizing. Gotta tow it back to my place and start tearing it down.

Luckily the overheat lights didn't come on, but I might replace the oil anyways just in case.

 

[stephen newberg]

Ya, at this point my first guess would be that the lines to or from the transmission fluid cooling in the radiator have gone. You can buy new ones or buy a separate cooler, and both are about the same sort of money. I suggest going for the separate cooler. Most come with plugs that close off the previous run through the radiator and are complete to the transmission with their own leading lines.

I use one from FPS, and I think they are still available. They work fine.

pax, smn

 

[tqmx1]

If you have not all ready done so check the oil cooler coolant lines. Mine let loose at about 210k.