94 Taurus Engine stalls after a long trip, why?, Please Help!

Neil.... no one in their right mind will respond by email now that we've seen people post on here just to gather good email addresses...

sorry, blame spammers!

And as said... you can just find any web-capable PC and look it up on google groups.

Teknical opined in news: snipped-for-privacy@rogers.com:

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Backyard Mechanic
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SECTION 309-00: Exhaust System 2003 Crown Victoria/Grand Marquis/Marauder Workshop Manual DIAGNOSIS AND TESTING Procedure revision date: 01/29/2004

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Exhaust System Printable View (55 KB)

Special Tool(s) Exhaust Back Pressure Gauge 309-D002 (D95L-6000-A) or equivalent Socket, Exhaust Gas Oxygen Sensor 303-476 (T94P-9472-A)

Inspection and Verification

1.. Verify the concern by running the engine (with the vehicle on the ground) or road testing the vehicle to duplicate the condition. 2.. Visually inspect the components of the exhaust system and related controls that may affect exhaust gas quality or loss of power. 3.. Visually inspect for obvious signs of mechanical damage. Refer to the following chart.

Visual Inspection Chart Mechanical a.. Exhaust pipe pinched or crushed b.. Damaged muffler c.. Broken or damaged exhaust hanger brackets d.. Damaged catalytic converter e.. Cracked exhaust manifold f.. Dirty engine air cleaner g.. Loose or damaged heat shields

4.. Verify that the exhaust system is installed correctly, with clamps correctly located and tightened to specification. 5.. If the fault is not visually evident, determine the symptom. GO to Symptom Chart.

Symptom Chart

Symptom Chart Condition Possible Sources Action a.. Rattle, squeaks or buzz type noise - from the bottom of vehicle a.. Loose or damaged heat shield. a.. GO to Exhaust Heat Shields Component Test in this section.

a.. Loose or damaged exhaust isolators. a.. CHECK exhaust isolators are correctly installed. INSPECT the exhaust isolators for wear or damage. INSTALL new isolators as necessary.

a.. Damaged exhaust isolator hanger bracket. a.. INSPECT the exhaust system components for damage or broken hangers. INSTALL new components as necessary. CHECK for loose or damaged exhaust hanger brackets or fasteners. TIGHTEN bolts to specification or INSTALL new components as necessary.

a.. Loose or damaged catalytic converter or muffler. a.. MOVE the exhaust system to simulate the bouncing action of the vehicle, checking for exhaust-to-body contact while moving the exhaust system. Using a rubber mallet, TAP on the exhaust components to duplicate the noise concern. Lightly tap on the muffler, then the catalytic converter. Determine if there are loose or broken baffles in the muffler or a loose or broken element in the catalytic converter. REPAIR or INSTALL new components as necessary.

a.. Exhaust grounded to chassis. a.. INSPECT for signs of exhaust components-to-body contact. If necessary, CARRY OUT the Exhaust System Alignment in this section.

a.. Drone or clunk type noise - from bottom of vehicle a.. Loose or damaged exhaust isolators. a.. INSPECT exhaust isolators for wear or damage. INSTALL new isolators as necessary.

a.. Exhaust grounded to chassis. a.. INSPECT for signs of exhaust components-to-body contact. If necessary, CARRY OUT the Exhaust System Alignment in this section.

a.. Whistles, boom, hum or ticking type noise - noise tends to change as engine warms. Noises are often accompanied by exhaust fumes a.. Punctures in the muffler. b.. Broken, loose or missing exhaust manifold fasteners or gaskets. c.. Loose heated oxygen or catalyst monitor sensor. a.. REPAIR as necessary.

a.. Exhaust system leak. a.. INSPECT the entire exhaust system for leaks. CHECK for punctures, loose or damaged clamps/fasteners, or broken welds. EXAMINE the chassis for grayish-white or black exhaust soot, which would indicate exhaust leakage at that point. To magnify a small leak, have an assistant hold a rag over the tailpipe outlet, while listening for a leak. REPAIR or INSTALL new components as necessary.

a.. Catalytic converter. a.. MOVE the exhaust system to simulate the bouncing action of the vehicle, checking for exhaust-to-body contact while moving the exhaust system. Using a rubber mallet, TAP on the exhaust components to duplicate the noise concern. Lightly tap on the muffler, then the catalytic converter. Determine if there are loose or broken baffles in the muffler or a loose or broken element in the catalytic converter. REPAIR or INSTALL new components as necessary.

a.. Exhaust muffler/resonator drain hole enlarged due to corrosion. a.. NOTE: Check with vehicle on the ground, not on a hoist. CONFIRM drain holes are noise source. INSTALL new components as necessary.

a.. Hissing or rushing noise - high frequency sound. Vehicle performance is unaffected a.. Exhaust system. Exhaust flow through pipes. a.. CHECK the exhaust system for leaks. Using a rubber mallet, TAP on the exhaust components to duplicate the noise concern. Lightly tap on the muffler, then the catalytic converter. Determine if there are loose or broken baffles in the muffler or a loose or broken element in the catalytic converter. REPAIR or INSTALL new components as necessary.

a.. Pinging noise - occurs when exhaust system is hot, engine turned off a.. Catalytic converter/exhaust system. a.. Cool down pinging is the exhaust system expanding and contracting during heating and cooling. Condition is normal.

a.. Vibration - occurs at idle and at low speeds. Also accompanied by clunk or buzz type noise a.. Loose or damage exhaust isolator. a.. INSPECT the exhaust isolators for wear or damage. INSTALL new isolators as necessary.

a.. Loose or damaged exhaust isolator hanger brackets. a.. INSPECT the exhaust isolator hanger brackets for wear or damage. INSTALL or REPAIR as necessary.

a.. Damper broken or out of position. a.. CHECK for the correct damper orientation in this section. RELOCATE to correct position and tighten nuts to specification. INSPECT for missing or damaged damper. INSTALL new components as necessary.

a.. Exhaust system grounded to chassis. a.. CARRY OUT the Exhaust System Alignment in this section.

a.. Vehicle has low or no power - vehicle performance complaint a.. Exhaust pipe pinched or crushed. b.. Damaged catalytic converter. c.. Loose obstruction in exhaust. a.. Go To Pinpoint Test A to test for restricted exhaust.

a.. Restricted exhaust (possible frozen condensate in muffler). a.. CHECK drain holes for debris. PARK the vehicle inside to thaw. TEST vehicle for normal operation. If concern is still present, Go To Pinpoint Test A.

a.. Burning smell - usually occurs at idle, with possible traces of smoke a.. Foreign material caught in exhaust system. b.. Missing heat shields. a.. INSPECT the exhaust system for debris or missing heat shields. REPAIR or INSTALL new components as necessary.

a.. Odor - described as a sulfur or rotten egg smell. a.. Catalytic converter. a.. At times, a slight sulfur smell is normal for catalytic converters. The cause is the sulfur content in the gasoline being used. ADVISE customer, no repair required.

a.. Rich fuel conditions. b.. Miss-fire conditions. c.. Excessive sulfur content in fuel. a.. REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

a.. Visible rust on surface of exhaust pipes a.. Catalytic converter/exhaust system. a.. Surface rust is a characteristic of materials used on exhaust system. Exposure to heat or road salt may result in surface rust. INSPECT for perforations. If there are no perforations, condition is normal.

Pinpoint Test

NOTE: The vehicle can have a lack/loss of power, odor, a noise or a "no start" concern. These concerns may be related to the exhaust system. Carry out the following test, if no trouble codes were stored. This test is for diagnosing the source for these conditions.

PINPOINT TEST A: RESTRICTED EXHAUST SYSTEM TEST Test Step Result / Action to Take A1 EXHAUST SYSTEM INSPECTION a.. Inspect the exhaust system for damage or deterioration. Look for cracks, punctures, leaks, loose connections, dents or unusual bending. b.. Is the exhaust system OK? Yes GO to A2.

No REPAIR or INSTALL any damaged or deteriorated exhaust components. Test the system for normal operation. A2 BACK PRESSURE TEST a.. Position vehicle on a hoist. Refer to Section 100-02. b.. Connect a tachometer. c.. Using the special tool, remove the upstream heated oxygen sensor (HO2S). d.. Install the back pressure gauge. e.. Start the engine and gradually increase the engine speed to 2,000 rpm with the transmission in NEUTRAL. f.. Is the back pressure greater than 27.6 kPa (4 psi)? Yes GO to A3.

No No indications of a restriction have been detected. CONDUCT a diagnosis on other suspect systems. CLEAR the DTCs. A3 BACK PRESSURE TEST - CATALYTIC CONVERTER(S) ON, MUFFLER(S) OFF a.. Turn the engine OFF. b.. Disconnect the muffler assembly from the catalytic converter. c.. Repeat the back pressure test. d.. Is the back pressure greater than 27 kPa (4 psi)? Yes The restriction is in the catalytic converter. INSTALL a new catalytic converter. INSPECT the muffler to be sure the catalytic converter debris has not entered the muffler. CLEAR the DTCs. TEST the system for normal operation.

No The restriction is in the muffler assembly. INSTALL a new muffler. CLEAR the DTCs. TEST the system for normal operation.

Component Tests

Exhaust Heat Shields

1.. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to Section 100-02. 2.. Inspect the exhaust system for loose or missing heat shields or foreign material trapped between the heat shields and the exhaust system components. 3.. If any heat shields are loose, install worm gear clamps. a.. Use one of the following clamps: FOTZ-5A231-A or W705949-S300. a.. Trim off the excess ear of the worm clamp. 4.. If the heat shields are missing, install new heat shields or exhaust system components as necessary. 5.. If a rattle, noise or buzz condition persists, install a new heat shield. 6.. Lower the vehicle.

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Where do you see any mention from the shop manual about even a hint of over heat? You do not and never will. Explain how simple science says what you claim.

Reply to
pick one

DIAGNOSIS AND TESTING Procedure revision date: 01/29/2004

Reply to
pick one

A malfunctioning EGR valve can not add any exhaust gas. I didn't say _how_ it was malfunctioning, just that it was...

Interesting. How do you know this? Where did you read it, or more importantly, where can I read it? How about this hypothetical situation in which the O2 sensors are reading rather rich when the mixture is in fact just fine. What does the computer do? What does it do when the mixture leans to the point that it starts pinging and it cuts back on timing as the knock sensors tell it the engine is suffering pre-detonation? A lean mixture and retarded timing will certainly cause higher engine temps, and retarded timing can easily overheat an engine.

Reply to
Cory Dunkle

Hey Pick one, Putting our recent discussions aside.... First off, I don't think the OP has a plugged exhaust system. His description was a bit sketchy. I've seen symptoms similar to this on high mileage Tauri and it was usually fuel pressure related. Although it makes no real scientific sense and shouldn't happen, I have seen a restricted exhaust cause much higher than normal cooling systen temps, in severe cases to the point of overheating (usually the exhaust manifolds were glowing orange at this point). I don't know why or how. Once the restriction was removed the temps returned to normal. There is the possibility of a less than optimal cooling system before the restriction occured, or other underlying problems. After the restriction was relieved, operation seemingly returned to within mormal parameters. I was taught the same theory as you and don't dispute what you are saying BUT, I have seen it happen on more than one occasion. Regards, Tom Adkins

Reply to
Tom Adkins

Reply to
Bob

The job of the EGR is to PUT EXHAUST into the intake air. That is how ERG functions. By introducing a non-combustible gas into the intake it lowers combustion temperatures. An EGR will only fail in two ways open or closed. If it fails open? The combustion process is greatly impeded because the oxygen content of the intake air is reduced. It is not a lean mixture, the ratio of fuel to gas is the same, the only change is the composition of the gas, it's now more inert. That is how NOX is controlled. It was by accident that engineers found it also helped with knock, a nice side effect. Stuck closed? The engine will not over heat, might have some mild ping under load, most likely not enough to cause damage if all other systems are ok.

That will cost you, it's called class room training. You can also buy materials to learn what is going on.

That will not happen. Because of all the variables it is impossible to have a mixture that is just fine, as a result of this fact the ECM uses the O2's to determine if the mixture is too rich or lean. Typically the O2 when failing does not respond; the voltage signal says constant. That alone is enough to cause the ECM too know there is something amiss. When the ECM has an O2 that does not switch, it try's to make it switch to test it.

First off not all engines have knock sensors, second the ones that do; do not work in the way you are implying. When the ECM sees a signal from the knock sensor it only retards the timing a few degrees at most, it does not keep going until it does not see the signal any more.

This is not a race engine we are talking about, this is a production engine with the average compression ratios of 9:1 at the most for high performance engines, most are in the range of 8:1. The only thing that is going to happen is low power, lean mixtures are the result of not enough fuel volume which causes low pressure under load.

Reply to
pick one

That is the typical cause I'll agree but, a restricted exhaust will look and act just like low fuel pressure. You should know why.

You should know why EGR controls NOX, do you not? Answer that and we will move forward.

I have seen glowing exhaust at night, I can tell you it was not because of a restricted exhaust, would you like to take a guess as to what the cause was?

I have never seen it happen ,and I can tell you I have at least a few years on you.

Reply to
pick one

Yes, I know why.

Yes, I know how EGR controls NOX. I'm not arguing this with you.

No, I don't have a guess, from your description. I've seen a lean fuel mixtuer cause high exhaust temps and glowing exhaust. I'm not saying that a restricted exhaust will always cause overheating. What I have seen is exhaust manifolds glowing bright orange in broad daylight due to exhaust restriction, along with (to the driver) a sharp increase in cooling system temperature. The most vivid recollection was on a 1966 FE (428 cid) powered motor home.(the first case I ever saw). The H pipe was of a triple wall design and the inner "wall" collapsed, mostly plugging the exhaust flow. The only noticible concern was overheating and a slight lack of power. (Along with excessive heat radiating from the doghouse). Pick, I'm not disputing your theory, it is the same theory I have been taught for years. I just know what my eyes have seen and what seemed to be the cause. I won't say this is common, but i have seen it a few times.

I'm sure you do and I always bow to folks who have more experience and knowledge than myself. I don't claim to know it all. I don't want to argue with you for just that reason. I'd like for our conversations to be more reasonable. Maybe we both have things to teach each other. I'm sure you have experience I can learn from, just please don't discount mine.

Tom Adkins

Reply to
Tom Adkins

Good then you know that introducing more inert gas to the intake air does what? Lowers combustion temp's. Now you have a plugged exhaust. Exhaust does not leave. Because of that there is not a pressure drop or very little pressure drop in the cylinder because it's still full or partially full. Because of that little to no pressure drop little to no fresh air enters the cylinder at intake stroke. The cylinder is full of mostly inert gas. How well is combustion process going to be? Not very well. Just like when you dilute the intake air with a little exhaust you drop the combustion temp's, with a lot of exhaust you get even less combustion temp's. Low enough that the cooling system is way over capicity to do a real nice job of taking out any built up heat.

Years ago, a friend of mine, much like our friend Cory changed his timing chain and gear set. It was in a 302 Granada. He came over to my home later that evening too show off his handy work, only too find out on his way the engine had low power and smelled real hot. I looked at it and found the exhaust manifolds glowing. I turned off the engine and gave him a ride home. The next day Saturday I picked him up. I got out my compression gauge set and ran a compression test. All cylinders were low and even. The cause, he installed the chain with the cam gear off a few teeth. Now why did the manifolds glow?

Slight lack of power with a pipe that had collapsed makeing a pig plug? What do you take me for?

You then did not look for the true cause. I'm willing to bet the engine was over rich, very common with motor homes that are equipped with gassers that are not fuel injected.

There is no discount, I'm too the point and very frank. I'm not going to walk on egg shells for you or any body for that matter. You see something and admittedly do not know why it happens and want to insist that it's caused by ABC?

Reply to
pick one

lmfao a pluged cat wiull OVERHEAT

tard

lmfao ever see a plugeed one inside its MELTED

hahaha you have no cert

Reply to
pickone

A plugged cat is the result of an over rich fuel system combined with an air pump that pumps, you guessed it oxygen into the cat. Makes a real nice hot fire. The plugging is a result, not the cause.

Reply to
pick one

The hot light won't come on even if the engine is overheated, if it has little or no coolant.

Reply to
clemslay

No, a fuel injected engine running lean will run colder. Move into the '80s...

Reply to
clemslay

Wrong! That is true with a carbureted engine, but the opposite happens with a fuel injected engine. And you are talking about a Taurus, not a 289/302.

To the original poster, have you tried a new TFI module?

Reply to
clemslay

Intersting. How will a lean mixture burn colder? Car engines run richer that stoicheometric. Stoich is quite 'lean' for automotice engien standards and will burn too hot, causing damage to parts. I'm curious, if you are correct in that fuel injected engines running the same lean mixture as a carbureted engine will burn colder than a carbureted engine, please explain how that is. Leaner burns hotter, the flame front on the cylinder does not 'see' the fuel inject or carb. All it 'sees' is the air/fuel ratio, so how the air and fuel were mixed is irrelevant, or at elast should be as far as anything I was ever tought. Anyhow, please elaborate and explain how an engine running a relatively lean mixture will run colder with fuel injection than it would with a carburetor delivering that same mixture.

Cory

Reply to
Cory Dunkle

Yes, it will. The steam in the coolant system will reach a temperature hot enough to trip the temp sensor on hot.

Cory

Reply to
Cory Dunkle

Not only will the red light go out but if there is a gauge it will go cold.

Reply to
pick one

Alright buddy, you keep on believing that. Your theory is nice and dandy, but I speak from real world experience. Time to rework your theory, kid.

Reply to
Cory Dunkle

Just as others have said it is true.

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Reply to
pick one

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