Mechanics

ENGINE CUTS OUT

1995 Ford Taurus

1995 Taurus SHO (3.0L 6cyl 5 speed manual) with 121000. I don't know the maintenance record - had the vehicle for only 3 months.

Car was running fine but one day the engine quit. Towed to mechanic and they tested everything and replaced alternator. Everything ran fine before that. After putting alternator in, every time I put the A/C, defroster or auto heat (using the climate comtrol) the car will quit when I stop and take it out of gear. The A/C doesn't have to be on if the defroster is on. The A/C works fine when I don't have to stop.

My dad says it is the compressor and there is a clutch in it that is probably going. That is an expensive repair and I don't have the proper tools to capture the refrigerant to do it myself. He said I may get by with adjusting the idle or compressor clutch. Should I try that first? Also, could they have adjusted the belts too tight with the tensioner when they put on the alternator? Thanks for the help.
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Paceclassa
May 31, 2007.




Does the service engine light come on? If it does, you need to get the computer scanned for trouble codes. To answer your question, the idle speed is not adjustable. The computer controls that. There are no adjustments on the AC clutch either. Just to clarify, the car only stalls when stopped and you take it out of gear. And only when the AC, or defroster is on. Otherwise it doesn't stall with the AC or defroster off. You might want to check for proper routing of the serpentine belt. It's on a sticker under the hood. You also should check for proper voltage from the alternator. Using a digital multimeter, you can buy a cheap one for $10 at walmart, set it to DC volts. With the car running and no lights or accessories on, place the red lead on the positive battery post and the black lead on the negative post. It should read about 13.9 volts. Turn the headlights, radio and blower on. It should still read about the same. I've seen new alternators that were bad out of the box. With the car off check the wiring on the back of the alternator for loose wires. If all of that checks OK, the problem might be the car needs a tune-up, or the idle air control valve might be bad or the EGR valve/system might be bad.

Tiny
Rudpro
Jun 1, 2007.
The engine light doesn't come on and it doesn't stall when the defroster or a/c are off. The car doesn't ride rough when they are on (although I noticed a slight hesitation in acceleration). The engine idles at 900 rpms. When the engine is cold and I put the a/c or defroster on - it sounds like the compressor starts and the engine rpms will drop a bit. The it sounds like the compressor kicks off and the Rpms will jump to 11-1200 then it sounds like the compressor kicks on and engine RPMs will drop some more. This will occur a few times before the rpms drop so low that the car stalls.

When the engine is warm, it will stall almost immediately upon taking the car out of gear - makes shifting a real pain. When I turn the A/C or defroster off - it runs fine.

This isn't the compressor? Good, then I won't have to mess with the refrigerant, the condenser or vacuuming lines. I will check the alternator and if it is bad I will complain to the mechanic. How do I test the idle air control valve or the ERG valve. Doesn't seem like it is the ERG because the car rides smooth andd not rough
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Tiny
Paceclassa
Jun 2, 2007.
When you turn the ac on, the pcm should compensate for the extra load by increasing slightly the idle rpm, it's possible that this function is not operating correctly. Will the car idle at all with ac on? How about with ac, headlights, fan on high? Maybe the idle control system is faulty? I know on some of the earlier moidels, if you turned the mode switch to ac, then ran a scan with the car not running, it would throw a code indicating that their was a problem with pcm controlling the idle speed, I think the older 2 digit code was 67, yours would be a 3 digit code. Just some thoughts.

Tiny
TaurusWheel
Jun 2, 2007.
Thanks guys. Not up on all the lingo. Tried finding pcm on the internet and I think it is the chip that runs everything. Right.

Car runs fine with the fan on high and/or the headlights on. That is why I thought it was the compressor. I thought the 1995 Taurus was the last year they made SHO model with the 6-speed, which people tell me is a very good engine made by Yamaha (who would have thought?).

Car will idle when when the engine is cold for about 90 secs or so. When the engine is hot it idles for only a few secs. You can see the engine trying to handle the extra load. The rpms bounce from about 11-1200 to 4-500 hundred and back again before it stalls. You can feel a fan kick on and the drag on the engine as the rpms fall, when the fan shuts off the rpms go back up, when it starts again. More drag and it does this until the idle rpms are so low that the engine stalls. When the car has been running for 5 miles or so, it just stalls when you take it out of gear. If you shift really fast, you can catch it before it stalls.

Can I go to autozone to check that pcm error code? If it is the PCM, how do I get a new chip? I really thought it was a compressor - I am soooo glad for your help before I spent a lot of money on something I didn't need.

Tiny
Paceclassa
Jun 2, 2007.
If the service engine light isn't on, it's probably not setting a code anyway. You might want to take it to Autozone and have it scanned anyway. Did you check everything lke I asked in the first post? If not, check it to be sure. Also, It may be the idle air control valve. The computer sends a signal to it to keep the idle speed where it should be. Let's check the other things first.

Tiny
Rudpro
Jun 2, 2007.
Start out by saying thank you to everyone. This is a great service and really helpful. I really couldn't afford to fix the A/C right now and it is getting hot here in South Texas. I think I figured it out.

I checked the voltage. 14.7 with nothing on and 14.6 with everything on - I am assuming that is OK. So I crawled under the car to check the serpentine belts, routed properly and all alternator wires connected. BUT.

I noticed that there was some oil around the valve covers. Nothing major - just didn't notice it. Cleaned it up and drove the car for 10 miles or so. It looks like there is a leaky gasket? Not much of a leak to be picked up by the sensor. Checked the oil and it was a quart and half low (I have put 3400 miles on the car since the last oil change). I needed a change so I replaced the oil and filter. And now it works perfectly. Didn't know low oil could affect that.

To start another thread - did a tune up, compression and leak test when I bought the car and all was good. Mechanic saiid car was in great condition. From the looks of the manuals, I may be able to fix the oil leak myself. Is that something I should try? How difficult would it be.

Tim

Tiny
Paceclassa
Jun 3, 2007.
Good for you. Just goes to show you and me to start with the basics. Remember to check all fluids on a weekly basis. When oil is fresh, after an oil change, you may not lose much oil the first 1000 miles. After that, the oil thins some and the leak accelerates.
As for your valve covers, you might want to try snugging the bolts first. You need an inch lb. Torque wrench. They should be torqued to 80-106 inch lbs. Start out at 60 inch lbs. And work your way around the cover and increase to 80 and then to 106. Make sure it's an inch lb. Torque wrench, not a foot lb. Torque wrench. If you can't get a torque wrench, try going around the cover and tightening the bolts a little at a time, about a 1/16th of a turn. Do not force it, the bolts could be snapped easily. The bolts should be good and snug, not very tight. If you want to change them, it doesn't look too hard depending on you skill level. Two things that are important, there are 2 spots on each cover that need RTV sealer. Also, you need to put thread sealer on the bolts. Send me a private message with your e-mail address if you want the procedure and a diagram.

Tiny
Rudpro
Jun 3, 2007.
Thanks again and I will probably send the private message when I have time to look at it next weekend. I will get an inch lb torque wrench and do just what you said.

I am not mechanically inclined but I am learning - once the house burned down and I had to get rid of the cars to help pay for the rebuilding, I have started to working on my older replacements. My kids love to help. I work on computers in my real life, so hopefully I can figure this out.

The SHO was purchased from a friend of a friend. I called him and he said it has a small leak in the oil pan but he never had any issues. The oil pan uses the RTV sealer also - I think. However, the oil pan is a pain to get to and if it is the oil pan, why don't I see a lot of oil on the ground and why is there oil underneath the intake (that really cool thing on top of the SHO engine is the intake. Right)? It isn't on top of the intake, just underneath.

Thanks again for the help !

Tiny
Paceclassa
Jun 3, 2007.
A leak from the oil pan is not unusual for a car with 120,000 miles. It's not a big deal as long as it's not a big leak and you check the oil regularly. You could try snugging the bolts on it too. Just remember to go around 2-3 times and don't overtighten where you could snap a bolt. The oil leaks as you are driving and spreads out across the undreneath of your car. That's why you don't see a puddle underneath your car.

Tiny
Rudpro
Jun 4, 2007.

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