Cooland Temperature Sensor location?

Hey all! My 88 mustang post was getting really log so I'm starting a new one.

The mechanic said that both my o2 sensors are out and my coolant temperature sensor. He wants $388 to fix them (plus the $70 for the diagnostics he did). Obviously I can replace all three of those myself for about $100 from autozone.

However, I am unsure where the "Cooland Temperature Sensor" is on a 88 5.0. I see what they look like on the autozone site but not in my engine. I have a terrible Hayens manual and it wasnt listed in there either. There was a coolant temperature sending unit but thats probably not it.

Anyone have a picture or know where this thing is located?

Thanks!

Reply to
Cameron
Loading thread data ...

I should have mentioned that I found these two descriptions:

UNDER HOOD, CENTER, UPPER ENGINE AREA, PASSENGER SIDE OF DISTRIBUTOR, REAR OF WATER OUTLET, MOUNTED IN INTAKE MANIFOLD

Remove the ECT sensor, on 5.0 engines it is located at the front passenger side of the lower intake manifold

They didnt really help me locate anything, maybe I'm a dumdum :-) Hopefully the guy at the shop will be willing to point it out to me.

Reply to
Cameron

Seems right above the thermostat on that pipe that goes back toward the firewall ?? (93 5.0)

He could be shotgunning the O2 sensors, but they do get "weak" I have heard- never seen it.

Reply to
Chumky

I looked up pricing of $40 a o2 sensor at autozone and $24 for the coolant sensor. I went by the ford dealer and it was $94 for the o2 and $45 for the coolant. The ford guy recomended I buy their coolant one and the acftermarket o2s so I did. Letting the stang cool down before install that junk.

I thought the sensor was exactly where you described it and the ford guy confirmed that for me. Autozone site is just way wrong.

Hopefully I pass tomorrow, otherwise I;ll have to pay another $70 diagnostic to find out wtf else is wrong.

Reply to
Cameron

Oh I should have also noted that the previous owner of the car (for 15 years) had a H-pipe on their, but he had kept the o2 sensors and cats since

1991. We put them back up under the vehicle so the cats are probably still good but 10 years on a shelf of the o2s might have made them bad?
Reply to
Cameron

There was a recall on the cats for 1989, I got new cats put on by Ford in the 1989 for free (in about 1995) might check it out with ford, the inside would break loose and turn some, get noisy and plug up a little. not sure how the car would run without O2s in place, except rich, computer may still be learning the O2 sensors, or they could have drifted off some or both.

Reply to
Chomlky

Reply to
Michael Johnson, PE

That's a definite "must do". If you haven't already, do all of the following (this is from Tim aka Musttanguy):

A) Clean the throttle body w/sensor/TB safe cleaner B) Remove IAC and clean it along with the ports on the TB C) Remove the EGR valve and clean it along with the ports on the TB/EGR spacer. D) Pull apart both main engine harness connectors at back of intake and spray with electrical contact cleaner, alow to dry and snap back together. E) If MAF equiped spray the sensor with the same electrical contact cleaner.

FYI I wound up replacing the IAC and EGR on my 93. I cleaned them a few times but they were just shot. I also replaced my O2 sensors. All of the above are very easy to do.

Reply to
jmvannoy

MAF Is that the wire inside the unit ? never heard of cleaning that part, I thought it would throw the cal off. But my car runs lean, 93 5.0

Reply to
Yelmuhc

what and where the IAC ? -Thanks

Reply to
Yelmuhc

The aluminum housing right after the air filter box is the MAF sensor. Inside it is a tiny pair of wires with a resistor looking element located on them that are heated by applying a current through them. The resistance of these two segments change depending on their temperature. The more air that passes through the housing the less the resistance because the wires are cooler. Think of it as wind chill. When the two segments develop a dirty "crust" it insulates them from the air flow. This, in turn, raises the resistance which makes the computer think there is less air flowing through the housing than actually is. The computer then lowers the fuel injected into the cylinders which leans out the mixture.

The two segments aren't extremely delicate. They can be rubbed with a Q-Tip soaked in brake cleaner. The first time I cleaned mine a piece of dirty crust popped off one of the elements. Anyone using an oiled air filter like a K&N should do regular MAF cleanings because the oil from the filter will accelerate dirt collection. While cleaning the MAF also disconnect the battery for 30 minutes to clear the computer.

Reply to
Michael Johnson, PE

I took my MAF out and checked it and it was clean enough to eat off of as far as I could tell.

I changed out my o2 sensors ($40 each) with Bosch ones from Autozone and I changed out my Coolant Temp Sensor with the real one from Ford ($45).

Fired the bad boy up, added a bit of coolant, some bubbled out from the air in the lines. Wierd thing now is I saw some exhaust coming out the back. Wasnt any color really and it smelled like...exhaust. I havn't seen any exhaust at all until this time. However, it just rained and it was REALLY humid, could that make a difference (real foggy outside, etc)?

I had left off the battery cable to reset the computer and then took it for a 20 minute drive on the interstate and some back roads. Came home and no exhaust visible anymore.

Anyone placing bets on if I will pass emissions tomorrow? So far I've changed the t-stat, o2s, coolant sensor, and ran a tank of "Guaranteed not to pass" through it.

--C

Reply to
Cameron

LOL and be sure to read the recent entry when Dwight decided to clean his MAF sensor :-p

Reply to
WindsorFox[SS]

Whatever happened with that? Did he need a new one or was there something else causing the problem?

Reply to
Michael Johnson, PE

OMG is all I have to say. Took the car down to get it tested again: HC 239 allowed 220 FAIL CO 0.09 allowed 1.20

What a rip. However I have found some interesting information on the Tennessee DMV site: The owner of any motor vehicle which did not successfully complete an emissions test administered prior to the date fixed for issuance or renewal and, after attempting the repairs necessary to successfully complete the emissions test fails the emissions testing again, shall be eligible to apply for a waiver from further emissions testing for that year; provided, that the owner has attempted repairs to the vehicle in an amount of two hundred dollars ($200) or more, if the vehicle is a model year 1981 or more recent, or seventy-five dollars ($75.00) or more, if the vehicle is of a model year

1980 or older, or has attempted repairs in such amount as established by the environmental protection agency to make the owner of a motor vehicle eligible for a waiver, whichever is less. The waiver shall be granted according to guidelines and procedures established by the air pollution control board.

I've spent about $230 so far on this stuff, so maybe I can callthe County Clerk monday and be done with the whole thing for a year! Probably all I need to get the readings down is just a regular tune up, but I dont really want to keep going back and paying $10 for the test :-)

--C

Reply to
Cameron

What all this is telling you is the car needs some regular maintenance since the items you have replaced lowered you emissions readings. I agree that a tune up with new plugs & wires, throttle body cleaning, fuel injector cleaning, IAB valve cleaning/replacement will allow it to pass next year.

Reply to
Michael Johnson, PE

Wow so you "practically" passed. I bet it was the O2 sensors that brought you down to near-passing.

JV

Reply to
jmvannoy

"idle air control". Also goes by the name IAB for "idle air bypass." Thing attached to the side of the throttle body. It gets filled up with crap over time.

formatting link

Reply to
jmvannoy

Mine always dumps water out the exhaust from rain.

It will pass for sure. If not, go to another county

Reply to
Josh Thelmack

The car is running RICH. High CO, high HC is unburned fuel. OR oil. Does it use much oil? What do the plug isolators look like?

Does the car idle smoothly? I'd bet not. And I bet it's hard-start, hot.

Since you've changed the CTS, make sure the MAP sensor tubing is coonected to manifold. And I suggest changing the Fuel Pressure Regulator.. a common fail item in mid eighties.

THEN change oil before you take it back... that's first on everyone's tips to pass a marginal engine.

Reply to
Backyard Mechanic

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.