98 Taurus DOA, Need Help!!

98' Taurus, 3.0L. Ran great up till today. Car started "pinging" (valve rattleing) under hard acceleration at first. Within a few stops around town it would idle very rough with a lot of valve clatter at a stop. Engine would smooth out and quite down after pulling away from stop. I got up on the freeway and everything seemed to be working fine, then the clattering started at speed, the service engine soon light came on, loss of power (engine sounded like it was backfiring) and eventually complete motor shut down. I opened the hood after the coast to a stop and I could smell hot oil, looks like something was causing a leak at both valve cover gaskets as well (maybe related to problem). Engine will turn over and acts like it wants to start but will not catch. Please help!!

when you turn over engine does it sound different, for example like it is turning over easier than normal. Check the engine for compression. Sounds like a timing belt or chain, or possibly a valve dropping into the piston. Chances are if you heard a lot of noise and the timing belt or chain isn't broken then you most likely effed the engine.

The first thing you need to do is pull or get pulled the error codes from your car's computer. It will give you an idea of what is going on.

not necessarily, working for a ford dealership for several years has taught me that when major problems are encountered in an engine it will set sooo many codes that it is useless as guessing, but it is a good place to start. frankly when cars ar fuckin up like that you should stop immediately and call a tow truck because it only gets worse

What you probably learned is that Ford Service Technicians are sloppy in their troubleshooting. I've learned by working with these systems for the past 20 years that codes can be very helpful when used properly, and ALWAYS point to the fault. They don't necessarily point straight at the fault, but in almost every case, even the most elusive of problems including myriads of failed wiring, PCM failures, eprom dumps and what not that I've encounted, I could always back-trace the resolution to the fault codes, even if I did not see the connection during diagnosis.

Major problems do not set "myriads of codes". A single problem can set more than one code, and I've seen up to three for some failures, but not "myriads". The extra codes are always faults that occur down-stream of the source fault, and are there because of the source fault. The only exception are unrelated failures setting different codes. The only times I've seen myriads of codes that didn't point to the problem was when the PCMs were bad, and a few cases of flood salvaged cars.

One should never "guess" at codes. Read them, read about them, understand them, and use good troubleshooting techniques.

In this case, keep in mind that codes will not appear for spun bearings, slipped cam gears, broken valve springs, etc. If something mechanical took a nose-dive, the codes will not tell you too much of use. You could get a code for a bad cam-sensor if, say, your cam drive gear has stripped and is spinning freely on the shaft. That kind of thing may show up, but most often you get no errors for mechanical failure. And hopeless is right, it's not good to drive a car that suddenly starts making pinging type noises.

For some useless FYI, pinging is not valve rattling. Pinging occurs when hot-spots in the combustion chamber ignite the fuel prematurely. What then transpires is the flame-front spreads out in the chamber while the cylinder is still on it's way up. The two meet at some point and the expanding gases physically slam the piston very hard. The force is so great that the oil film between the piston rod and it's bearing is over come and the bearing surfaces slam into each other. This is what makes the noise you hear during "pinging", and it's not a good thing to hear unless you drive a diesel. Spreading into another FYI, a diesel motor is designed to operate exactly like a motor that is pinging, the mixture self-igniting early. However, diesels are designed to take those extreme forces on the piston, rod and crank, and that's why they sound odd and seem to last forever. They are essentially motors designed to take combustion abuse, and it's typically hard to damage the lower end of a diesel motor.

Yes Grasshopper - listen to FlamingTaco, he know's his doo-doo. So you ask then - what can make those combustion chamber hot-spots? Well....many things. Low compression, lean burning late model engines are ping-prone...thats why they have EGR valves to let in some exhaust gas to cool cylinder temperatures. But your ping-problems didn't occur as a result of a bad EGR valve....no, much worse. The symptoms you describe sound like those encountered when a car overheats. Cylinder temps climb and ping starts....keep driving and engine gets hotter....ping turns to knocking (severe preignition and detonation)...engine hotter, piston tops turning red.....fianally......seizure. I don't think your timing chain jumped or broke. The car would just lose power, not sound like popcorn. Also, the burning oil from the leaking valve covers is probably normal seepage that is burning because things are so hellfire hot. I agree with the idea of the compression test. Sorry but it sounds like the engine is toast.

Thank you brooster42, I am merely suggesting that checking it for compression is much easier than having it towed somewhere or finding a friend with a scan tool. People in this forum are looking for suggestions not to be told, go get the codes pulled, yes in a perfect world everyone could afford to take their car and have it fixed but this is the real world, people do things themselves even if those of us with experience don't reccommend it. And no codes don't ALWAYS point to the fault they can point to a fault in backwards ways etc. An example would be a sunfire was towed in, car made loud noises then quit. We had codes for EVERYTHING, yes it told us something was fucked but some of the codes were caused by the fact that the valve shattered the piston after the spring broke and thus blew metal out the intake, which caused codes for everything including the IAT. Now yes they were caused by the engine going but in a very odd way. it took us longer getting these codes than it took us to do the compression test. But yes if the symptoms aren't clear then you should go to a scan tool, but if they are clear any good mechanic should be able to figure out the problem.

I would consider you scenario rare at best, but, yes, if you blow engine parts up the intake from the combustion chamber, chances are you are going to see a few codes get triggered. Of course, if the piston hit the valve and shattered, people down the street and around the corner should have heard that event. The customer describing the problem as "there was a loud sound like someone dropped a 5000Lb mirror right next to me, and the engine died" should have tipped you off ;)

If that wasn't enough, attempting to start the motor should have revealed the issue since one of the cylinders would be free-wheeling. Starting should be lopsided, and a little fast.

These aren't really on topic for this thread, but just for poops and giggles:

Newer motors tend to be high compression rather than low. You can lean out the mixture more with higher compression, improving gas consumption and reducing bad pollutants (as long as you keep combustion temperatures below 1300ºC). While you are correct about the EGR system being useful for reducing pinging, it cannot be used for that. Under WOT, there is little manifold pressure, to draw in exhaust gases. Also, you want the most power under WOT, and exhaust gas in the chamber would not allow for full power. So, for these reasons, most EGR valves close for WOT events. WOT is the condition under which you would be in most need of controlling pinging; so we use the knock sensors, to retard timing when pre-detonation events begin.

Interesting side notes:

When driving at partial open throttle, the EGR systems improve gas mileage by reducing pumping pressures on the pistons.

Not all modern cars have EGR systems. If a vehicle meets NOx emmisions standards, and it is not going to be sold in California, the mfg can opt to delete the EGR system. What seems to be practice with the big three, though, is that they only consider this option for cars sold with manual transmissions. Almost all automatics, where an EGR system was in use on the vehicle model, will have the EGR regardless of emmisions ranking or state of sale. This probably has something to do with efficiencies of production.