2001 Ford Taurus SES 3.o Vulcan -Pinging

Hi, new here...

In the 4 years I've had the car its never indicated a CEL issue. I'm not an expert and do not possess expensive diagnostic equipment. In time I found that the spark plugs on the rear bank were actually loose -_- Tightened those and engine performance improved but pinging remained. I have not replaced the spark plugs yet as I was concerned with finding the best fit for the engine and its conditions.

The engine pings under light-heavy load and on fuel that is 87-89 octane. Of course as the octane rises it does not ping as much. At 93 it seems to be completely non-existent. But its rated 87 in the manual so clearly something is not right and I have no idea what was/was not done to it before getting the car.

I'd say the piston tops have average carbon on top, nothing dramatic/crusty.... The assumption has been, it may be related to engine timing. I can say it most likely runs pretty lean, certainly not rich because even at the exhaust tip of the muffler -which MAY be the original factory, just swiping the inside, comes out completely clean. Whereas an older car I had which did exhibit air/fuel mixture problems was sooty..

I understand its a distributor-less engine wherein spark is controlled by the computer. I've read that timing *can't* be checked nor adjusted because of this. I assume what is meant by this is, its done through the diagnostic link?

I can't say for sure either if vibrations I feel with rising speed, usually above 40 and 45mph which seems to change somewhat are a drivetrain or engine issue. There have been times on the highway where it feels like it begins to "brake" itself, either as if the wheel brakes or an engine-brake if you will were being applied.. Honestly it feels a bit like an engine-brake. This is most-pronounced when I take my foot off the accelerator. You just initially feel like there is a drag, take foot off the accelerator and feels like a dramatic slow-down but touch the accel again and it immediately perks up, then you might feel the drag again, take foot off, dramatic slow-down etc. It usually does not last very long. Very odd behavior. Idk if this has anything to do w/ the aforementioned or if its just a whole other issue by itself.

Thanks for any help!

Hey Costar! I've seen a TSB for spark knock on these engines, but never performed it myself. Check out the link below:



A lot of it involves checking for a lean condition, which is the first thing that came to mind when you described your symptoms. You may not be getting lean trouble codes, but it could be that the engine is running lean enough to cause the pinging symptom anyway. Your inspection of the tailpipe might support this.

Checking the BARO PID is the easiest first step, followed by monitoring fuel trims while cruising and during the pinging. I've most often seen this symptom associated with a MAF issue, underestimating the incoming airflow. If you find a fuel trim issue, then let us know, and we can pursue that further.

The TSB ultimately ends with changing some settings inside the PCM regarding octane and timing, but you'll need a New Generation Star or other capable scanner to do it. You're correct that the PCM is solely in charge of timing on this engine, but you CAN observe the commanded ignition advance on scan data.

Thank you for the information Tyler! As I said, I don't possess advanced diagnostic equipment and one of those scanners not in my budget at the moment. I guess for now I'll have to just continue using higher octane fuel. I think the AC clutch/pulley assembly will need replacing soon as well. It makes weird "hnnnh" noises randomly when its NOT in use. It also leaves a dust, like that of brake dust on the pulleys on the engine.. BUT when the clutch engages all the noise goes away.

Interestingly, it took me some time to get the cooling fans to stop running on high all the time as I investigated. I think the high pressure switch/connector had some debris in it. I took the switch off the compressor and cleaned it, as well as the connector. So far no more problems w/ the cooling fans.

There have been other issues w/ the car. For now it gets me from point A to B but Ford really disappoints me w/ this model.

Costar wrote: Thank you for the information Tyler! As I said, I don't possess advanced diagnostic equipment and one of those scanners not in my budget at the moment. I guess for now I'll have to just continue using higher octane fuel.

No problem! I understand not having a scanner, no worries. If you wanted to take a shot at the problem, you could remove and clean the MAF sensor. It's a prime suspect for lean conditions under load, and cleaning it will cost next to nothing. Here's a video of Paul cleaning a similar MAF sensor, for reference:

I think the AC clutch/pulley assembly will need replacing soon as well. It makes weird "hnnnh" noises randomly when its NOT in use. It also leaves a dust, like that of brake dust on the pulleys on the engine.. BUT when the clutch engages all the noise goes away.

Ah yeah, classic symptoms of a failing compressor clutch. The bright side is that the compressor can come out the top on those engines, unlike the Duratec.

Thanks again Tyler! Actually I saw a link in the video's description for testing a MAF on a Ford. Of course he has his diagnostic tool as usual. But he also unplugs the sensor and the engine runs a bit better. If I were going to do that, it'd mean having to wait till all of the high octane fuel was burned and put 87 back in and see IF there was any improvement with pinging. Of course he also mentions that some vehicles will run as bad/worse by unplugging it. I was wondering about the knock sensor though. IF its supposed to retard timing when it detects pinging by frequency, then why wouldn't it stop the pinging?! As the only way for me to have reduced pinging is to either reduce engine load by letting off the accelerator and/or reduce the gear to bring higher revs with lighter throttle... Either way if I were to depress the accelerator more, increasing load, it'd of course ping worse...

I will have to look at the MAF sensor to see if its dirty. I was a bit puzzled by how dirty one of the MAF sensors he examined, was. My understanding is, IF the sensor is just after the air filter but before any PCV etc, then how would it get so dirty unless drivers neglect checking/changing the air filter etc.. As the air filter shouldn't allow such contaminants into the air stream.

I don't have a factory style manual for the car, just the el-cheapo from the parts store.. It does mention the MAF and how some signal variations can't be detected w/ a DVM... Of course most everything is referenced to be checked by a dealer/scan tool but it does provide a few bits on checking voltages for the sensor.

I haven't looked at the procedure for the AC yet but It would be nice to be able to replace the pulley/clutch assembly w/out having to evacuate the refrigerant.

Forscan software used with a decent OBD dongle should give you fairly deep access into your Ford's diagnostic system at low cost.

Forscan Home Page

OBD-Link dongles Home Page

Thanks Andy! Your "OBD-Link dongles..." link is 404 broken...
I've looked at the software and see it has iOs, Android & Windows compatible device capabilities. I've also found some of those adapters on Amazon which also have their specific OS support. My question is, how might I determine what I need? That is, FORScan has a list of compatible adapters and also Ford protocols. I know I can choose an adapter fitted to the device I want to use. However, how do I know what Ford protocol/bus is used since there seems to be different protocols/buses used for different adapters..

-- Tyler, as we were talking about the MAF.. Well I looked in this book and it had some values that the MAF on the car did not meet except the initial value. I have MAF cleaner. I decided to perform the test before cleaning and after. No apparent difference. The book states w/ ignition "ON", there should be ~10V-batteryV. There was 12.xV. It then stated that w/ the engine running should be ~0.5-0.7V and increasing to ~1.5-3V w/ increasing RPM. Well w/ the engine @ idle it was fluctuating around 13.x-14.05V and the same value w/ increasing RPMs. The oddity is, IF indeed the sensor is faulty, why would the car ordinarily run, for all intents and purposes, normal and lean, well at least not overheating nor running rich and bogging out....

I did find something else kind of interesting at the start. As I began reading, it recommended I check the schematics. I'm not quite sure I understand these as the sensor/cnctr has 6 conductors. However, when looking at the schematic in the book, there are only 4 conductors... Finally, I noticed all of the conductors were the same color on the cnctr, so what I thought was true, someone spliced in another cnctr. So I had peel back to find the conductor colors. The odd thing is, the colors don't match up 100% w/ what is in the schematic... I wish I had a factory manual... I'll attach photos.

Costar wrote: -- Tyler, as we were talking about the MAF.. Well I looked in this book and it had some values that the MAF on the car did not meet except the initial value. I have MAF cleaner. I decided to perform the test before cleaning and after. No apparent difference. The book states w/ ignition "ON", there should be ~10V-batteryV. There was 12.xV. It then stated that w/ the engine running should be ~0.5-0.7V and increasing to ~1.5-3V w/ increasing RPM. Well w/ the engine @ idle it was fluctuating around 13.x-14.05V and the same value w/ increasing RPMs. The oddity is, IF indeed the sensor is faulty, why would the car ordinarily run, for all intents and purposes, normal and lean, well at least not overheating nor running rich and bogging out....

I believe that first test was having you check the sensor power feed, on the red wire? If so, what you saw is perfectly fine. The second measurement... Which wire were you on? Not sure why your diagram shows four wires... Just to compare, I went and looked up a diagram on the BBB Industries site:



This is more consistent with what I've seen on Ford MAF sensors. The MAF signal wire should be pin 4, tan/light blue. I *think* that's what your book wanted you to be measuring, but I could be way off. :silly:

Finally, I noticed all of the conductors were the same color on the cnctr, so what I thought was true, someone spliced in another cnctr. So I had peel back to find the conductor colors. The odd thing is, the colors don't match up 100% w/ what is in the schematic... I wish I had a factory manual... I'll attach photos.

Thanks for the photos! Looks like someone did a decent job of sealing up those connections. Do your wire colors agree with the diagram I posted? Wondering if your book has a misprint.

Thanks! I didn't even know that BBB Industries site existed. Yes the BBB diagram matches the car cnctr colors.

This book has conductors 1 & 6 by color code BUT it does not show them going to the MAF. I'm wondering something.. I just happened to look up wiring diagrams for 1996 on the BBB site. My suspicion is confirmed... These Chilton manuals, basically Haynes now, cover more than one year of vehicles and don't always make that clear for each page. In this case the wiring diagram is for at least '96+ Taurus which has a 4-conductor MAF and a separate dual conductor IAT sensor. And like in this manual, the BBB diagram shows the separate IAT and it just so happens, it contains the missing conductors, gray and gray/red... -_-

So apparently during these different years they went from a separate IAT and MAF to an IAT integrated in the MAF...

These electrical symbols I'm not so sure of in the BBB diagram. I've looked them up now but after looking over this '96 trace across 3 pages, I do see two "RTN" which I assume means "Return?".. There is a "SIG RTN" -coming from the IAT and a "MAF RTN".

These are apparently on opposite sides of the PCM. I'm not sure if the book is or I am, confused... Testing the "MAF signal wire" it gives the values mentioned earlier but then it said IF its suspected the MAF is bad, stop engine, disconnect MAF harness and probe "MAF signal terminal" (same thing as mentioned earlier just the terminal on the sensor instead of the wire on the cnctr) to see if the reading is "infinite" for the "hot element" -the resistor. But the resistor then is the IAT component which is gray and gray/red conductors....

Do you have any idea either about what Andy was talking about above w/ the FORScan adapters? As I said, I've seen the adapters on Amazon but I wondered about the protocol/bus as mentioned on the FORScan site.
Say, is it likely that there are codes stored WITHOUT tripping the CEL? The CEL indicator illuminates on startup but never has it displayed otherwise.

UPDATING... I actually tried both of those w/ ground, the gray/red and TN/LT BLU. I had no readings.. I made sure there was conductivity from the probe to the pins but it was zero... at idle and rev... I guess I've sort of given up on trying to test that single sensor like this. I didn't really think about it BUT cleaning it yesterday might have somewhat improved throttle response, seems that way. I am however interested in the FORScan/adapters. I'll be reading up more on their site.

Costar wrote: Thanks! I didn't even know that BBB Industries site existed. Yes the BBB diagram matches the car cnctr colors.

This book has conductors 1 & 6 by color code BUT it does not show them going to the MAF. I'm wondering something.. I just happened to look up wiring diagrams for 1996 on the BBB site. My suspicion is confirmed... These Chilton manuals, basically Haynes now, cover more than one year of vehicles and don't always make that clear for each page. In this case the wiring diagram is for at least '96+ Taurus which has a 4-conductor MAF and a separate dual conductor IAT sensor. And like in this manual, the BBB diagram shows the separate IAT and it just so happens, it contains the missing conductors, gray and gray/red... -_-

So apparently during these different years they went from a separate IAT and MAF to an IAT integrated in the MAF...

:lol: OK, that makes a lot more sense.

These electrical symbols I'm not so sure of in the BBB diagram. I've looked them up now but after looking over this '96 trace across 3 pages, I do see two "RTN" which I assume means "Return?".. There is a "SIG RTN" -coming from the IAT and a "MAF RTN".

Yep, you're right on about the signal return. That's manufacturer-ese for sensor ground. Why not just call it 'ground'? 'Cause Ford. The symbols are a bit unique - the rightmost symbol, between pins 2 and 3, is for the MAF sensor and the hot wire. The middle one is the MAF sensor signal itself, and the left is the IAT (as you probably figured).

These are apparently on opposite sides of the PCM. I'm not sure if the book is or I am, confused... Testing the "MAF signal wire" it gives the values mentioned earlier but then it said IF its suspected the MAF is bad, stop engine, disconnect MAF harness and probe "MAF signal terminal" (same thing as mentioned earlier just the terminal on the sensor instead of the wire on the cnctr) to see if the reading is "infinite" for the "hot element" -the resistor.

Hmmmmmm, not sure what they're talking about on that one. Maybe they want you measuring resistance across pins 2 and 3? Kinda a confusing test! :lol: Would you mind taking a picture of that page, just for my curiosity?

Do you have any idea either about what Andy was talking about above w/ the FORScan adapters? As I said, I've seen the adapters on Amazon but I wondered about the protocol/bus as mentioned on the FORScan site.
Say, is it likely that there are codes stored WITHOUT tripping the CEL? The CEL indicator illuminates on startup but never has it displayed otherwise.

No, I've not had any experience with FORScan myself, but other users here have! JeffBirt and I were just talking about it in another thread .

It's very possible to have codes stored without the CEL, might be worth checking.

Ok, thanks. I'll include a photo of that page. As I said, I tried both, gray/red as well as the Tan/Lt Blu w/ the negative connected to the connector ground. I didn't feel like tooling around w/ it any more than I did as I had other things to do. But it'd be awfully difficult for me to probe the sensor's terminals inside when the sensor's terminals are pointing down and away. Its not on the horizontal like a lot of others. So unless that thing holds "heat" and voltage for "xx" time then it'd be difficult to do that. You probably know but I'll attach a pic for reference. There is just no way for me to see on that angle, what pins I'd be touching up inside the sensor without at least some disassembly. If that element/voltage cools/drains quickly then its pointless..

Pins 2 & 3 you mentioned are the pins which carried battery voltage when the igntion is "On". Frankly I thought the resistor was separate from the other components especially given that in fact in earlier versions, it was a separate component with its own wiring and that wiring remains w/ the same color codes.

Interesting.. Ha! I remember grabbing a spark plug wire on an old car and feeling the JOHHHHLLLTTT... Oddly for a few moments I felt stronger afterwards... xD

I was reading more on FORScan's forums and now I'm a bit concerned as he-Alex? mentions that these ELM327s I think it is are not working so well but are most popular and have a lot of cheap China knock-offs. His suggestion however is for better quality devices which cost in the hundreds of dollars so it doesn't make sense then as you might as well buy the more expensive, ready-made scanner...