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View Full Version : Knock sensors on 2003 Motors


TripleTransAm
10-02-2003, 02:00 PM
Having the 2003 Marauder 4.6l DOHC apart, it's easy to see the single knock sensor and wiring, on the driver's side of the block valley cover. Funny thing is that there is a fitting for a second knock sensor at the exact same spot on the passenger's side of the valley.

Why did they get cheap on us like that? Obviously the engine is set up for easy dual knock sensors (a la 2004), so why cheapen the product like this for 2003? (and suffer all the 'Honda Accord' comments like it did on the mag road tests?).

If I keep my present engine, I'm installing the second knock sensor and wiring and will wait for the official Marauder upgrade kit to show up, if Mercury shows some sort of interest towards their 2003 owners who supported them like we did.
Marauderman
10-02-2003, 02:14 PM
With so manny '03's out there--seems like an idea Dennis will probably work on that will give us a way to have it installed--like

"Here is a new part for you wanting duel knock sensors"

We all know --it has to happen--he has surprised us all and even I've bought from him and still haven't met him as yet...but I know he likes my money............:lol:
sailsmen
10-02-2003, 04:10 PM
You may need an '04 EEC.
MitchB
10-02-2003, 06:31 PM
So can anyone quantify the benifit of having the additional knock sensor?

Mitch
DetGeno
10-02-2003, 07:15 PM
Not trying to rub it in but ya'll should of went to Ennis, Steve Babcock stated that an upgrade will be available for the 2003's soon and they are looking into the cost factor and making sure that the fitting hole for the other side is treaded for installation. He also mentioned that some engines came treaded and some didn't and the one's with the untreaded holes will have a tough time to get the upgrade. TTA can you tell us if yours is treaded inside?
TripleTransAm
10-02-2003, 07:27 PM
Mine is threaded.
DetGeno
10-02-2003, 07:37 PM
MitchB this tread will help!

http://www.mercurymarauder.net/forums/showthread.php?s=&threadid=4463&highlight=dual+knock

Excellent TTA you are the only official MM owner that have confirmed Steve's statement. Steve himself was not sure either when I approached him with the question on treading. So now I just hope that they could make it affordable for all of us!
MitchB
10-02-2003, 09:04 PM
I understand what the advantage of having an additional knock sensor should be, but does anyone have any quantifiable numbers to prove this is worth the effort? Any numbers?. Do the 04s run any better, make more power, get better fuel mileage? Can you run more spark and make more power? I had a discussion with a certain someone a while back about how the EEC uses the knock sensor input(s) and how you can tune the associated calibrations. I can see how this might be an advantage on a blower car where the MBT (minimum spark best torque) curve would actually cross the knock threshold, but on most normally aspirated applications???

Mitch
RCSignals
10-02-2003, 10:34 PM
TTA, why was your engine apart?
Dr Caleb
10-03-2003, 07:46 AM
Originally posted by RCSignals
TTA, why was your engine apart?

http://www.mercurymarauder.net/forums/showthread.php?s=&threadid=5268
Racerx88
10-03-2003, 07:56 AM
Ok, let me ask a probably dumb question, but couldn't the wiring for the second sensor be spliced into the wiring for the first, so that the computer would have two sensors worth of signal to pick from? Like picking up sound from two different directions with one microphone.:confused: :confused:
TripleTransAm
10-03-2003, 07:13 PM
Originally posted by MitchB
I understand what the advantage of having an additional knock sensor should be, but does anyone have any quantifiable numbers to prove this is worth the effort?


Reports from some of our first 2004 Marauder owners are favorable. Very favorable. Considering the ridiculous cost-cutting going on at Mercury/Ford, one would think that throwing on a second knock sensor for the heck of it would be a waste of money.

As for quantifiable numbers, that's pretty hard to say unless you run two cars back to back with identical conditions. Gas quality, atmospheric conditions, etc. could all affect the tendency of an engine to knock. But the end-all to this debate is just how aggressive the PCM calibrations will be taken, with these 2 sensors. Adding the ability to read 2 sensors instead of 1 while keeping the same lame spark tables won't get you anything... the idea appears to be that the low RPM spark tables can be made more aggressive for better response, because of the greater safety net of a second knock sensor, focusing on the passenger's side of the engine instead of relying on one knock sensor on the driver's side to pick up everything.
TripleTransAm
10-03-2003, 07:21 PM
Originally posted by Racerx88
Ok, let me ask a probably dumb question, but couldn't the wiring for the second sensor be spliced into the wiring for the first, so that the computer would have two sensors worth of signal to pick from?


Not a dumb question at all, and I don't think I know the answer. The knock sensor isn't really a microphone (ie. air-to-electrical transducer) but some sort of piezo sensor as I understand it. Vibrations in some media (ie. the metal in the engine block or heads) get picked up by a material that can convert these waves to an electrical signal. The PCM will then filter out the garbage that isn't knock, and react accordingly when it 'hears' something that does resemble knock.

So perhaps wiring two sensors in parallel or series might affect the electrical circuit in some way that would make the 2003 PCM not detect the proper pattern of real engine knock.

I suppose there would be all sorts of more aggressive fine tuning available with two separate inputs. For instance, if both sensors picked up exactly the same 'ping' at exactly the same time, the PCM code might be smart enough to say "hey, how can 2 cylinders be pinging at EXACTLY the same time? so that must not have been knock at all... carry on!" instead of blindly thinking "oh crap, I heard something metallic... quick, pull back some timing!!!".

This last theory is indeed possible... I can take a screwdriver and tap the side of the engine block near the knock sensor on my GTA and watch the PCM pull back timing. Not the same response on the other side of the engine... so I assume the PCM is coded a little conservatively, since there might always be the chance that something bad is going on with the other side of the engine that it can't pick up.
TripleTransAm
10-03-2003, 08:14 PM
The spot for the second knock sensor (the original one is the wired sensor on the valley 'pan' ).
TripleTransAm
10-03-2003, 08:14 PM
And the nice thread job. :D Thanks, Ford!
MapleLeafMerc
10-03-2003, 09:18 PM
Thanks, Triple-

As an owner of a Cdn market MM, I'm keen to hear your thoughts!
MapleLeafMerc
10-05-2003, 08:10 AM
TTA, could you elaborate on 'official Marauder upgrade kit' please?

Thanks!
TripleTransAm
10-05-2003, 04:29 PM
I'm referring to the upgrade that Steve Babcock hinted might be available for owners of 2003 MMs, at their own expense. It involves updating some hardware to 2004 specs, which is supposed to yield some improvements in low end response.
warren
10-07-2003, 07:06 PM
We need to stay on this.
My good Ford source says that a brand new (3-500miles)
04MM will get scratch off the line and
a new 03MM would not!
In part some of the extra low end torque is coming from the new dual knock sensors.
In view of the fact that our MM's go away
in 05 we need to keep pushing for
upgrade kits, etc. Remember once out of sight, also out of mind.

Warren B. :confused:
joflewbyu2
10-08-2003, 06:27 AM
my 2003 with K&N panel filter and full Borla cat back will spin from a dead stop without touching the brake. at present time no chip nor tuner. 10,000 miles and feeling stronger than new. using 5w-30 mobil 1 oil too.
studio460
10-08-2003, 05:36 PM
Originally posted by warren
My good Ford source says that a brand new (3-500miles) 04MM will get scratch off the line and a new 03MM would not!

Warren:

Well, that supports another post seen here before--I think Directedby posted that he had just received his '04 Marauder a few weeks ago, and he said that he could burn rubber "no problem." The car was new and 100% stock, I believe. Oh, and this is on the same crappy California 91-octane "premium" gas we have here that I use. I barely break traction at all in my '03 300B, even after my recent FordChip dynotune.

I am definitely considering the dual knock sensor upgrade, if offered. This should provide double insurance against detonation, and the resulting increased risk of catastrophic engine failure due to detonation for those of us planning to put superchargers on our cars. And ESPECIALLY for those of us in California with its anemic 91-octane "premium."

Triple-T:

Thanks for the great photos and informative posts! What would your estimate be in shop hours to install the second knock sensor? That looks like it might be a pretty involved install. Thanks.

joflewbyu2@aol:

That's amazing! How do you get your car to do that? Didn't you used to have a Superchips MicroTuner? Is your Borla a cat-back only exhaust? Did you change cats too? X-pipe? Thanks.
TripleTransAm
10-08-2003, 08:31 PM
Originally posted by NBC Shooter
What would your estimate be in shop hours to install the second knock sensor?


As of this morning, my MM has 2 knock sensors. ;-) One is non-functional, but it's the thought that counts... right?

Right?

Anyway, it's there for when/if the upgrade comes out.

As for complexity... well, it ain't easy, especially if your MM doesn't have the threaded second boss. Looks like you gotta yank the upper and lower intakes to get access to the valley area shown in the pics. Probably a half-day's work.


By the way, good point about the second sensor and crappy gas. Never thought of it that way... makes sense.
warren
10-23-2003, 05:10 PM
We need to keep on this thread.
Has anyone checked out the wiring on the 04's vs. 03's for the knock sensors???
At least it would be a start as to what to do.
Many of us live in areas the only serve 91octane gas and the dual sensors would
help our situation.

Thanks,
WarrenB :help:
TripleTransAm
10-23-2003, 06:40 PM
The wiring for the extra knock sensor has been run on my MM (darn it, I forgot to show y'all at Hershey the lovely routing of the extra wiring on my 1/2 Cobra motor ;) and also to show off the new routing of the driver's side harness - behind the driver's side head as supposedly it should be, so no more possibility of slicing or rubbing).

The pins where the new knock sensor is wired into the '04 PCM are there on the '03 PCM but are listed as not used (and no corresponding wires are present on the PCM connector). Now the big question is whether the '03 PCM has the internal hardware necessary to accept this new input.

The '04 PCM has a new part number and the '04 MM PCM so far is being delivered with a MAV2 tear tag for the calibrations. So we're not sure yet whether we can simply wire the extra sensor to the '03 PCM.

More info to come.

By the way, when reassembling my MM, my technician rerouted the infamous problematic driver's side harness (the one that got sliced through on the cowl bracket near the brake booster). He ran it where he indicated it should have been run in the first place, behind the driver's side head. In doing so, he noticed that it comes into contact with some 'gutters' that channel cowl water accumulation to the ground. They are plastic, but he was worried they might over time chafe through the harness once again and bent them slightly out of the way.

I forgot to pass on this info earlier, and I'm wondering if this even deserves its own thread, but here it is... just another something to maybe get checked out. (I suppose one can only get to these gutters from underneath the car?)
MapleLeafMerc
10-23-2003, 08:28 PM
TTA, you est. a half day to install the second sensor. I wonder how long it would have taken Ford to do it during assembly.
TripleTransAm
10-24-2003, 09:48 AM
MLM, it was just a rough estimate. But, yeah, talk about getting cheap on the assembly line. $50 Canadian ( I assume that's their cost, list is $58 Can) across 18000 Marauders per year can really add up...

(... boy did we show them! What with only buying 7000 or so instead... that'll teach 'em! LOL!)

The funny part (or extremely sad, depending on your state of humour) is that the Mach 1 (same motor?) apparently has both KS's installed and functional. *sigh*

Thanks a lot, you cheap bastards...
TripleTransAm
10-24-2003, 09:52 AM
Update:

MAV2 (2004 Marauder code) cannot be loaded on a 2003 PCM. The 2003 PCM has hardware revision MPC-198, the MAV2 code requires a hardware revision of MPC-19D. That means a whole new PCM.

I brought up the issue of tranny differences. Ford parts listings say one thing, sales/marketing information says another. Some more research on my part is needed, but I'll post the results shortly. In the meantime, if someone with a 2004 MM could tell me what's written on the little tag on their tranny, that would be most helpful.