knock sensor location 97 crown vic 4.6

I recently had to replace the intake on my 97 crown vic. while doing that I noticed there was NO knock sensor in the valley. there was a spot that looked like it should be machined out to have one, but nothing there. also were no wires leading into the valley, I was concerned that it might be in the rear of valley so I looked for wires. only thing there was the coolant tube and there was nothing under that also.

My question is where else would it be, the dealer I bought it off (Ford) could not find any manual reference stating any other location for it.

Reply to
dmac
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To the best of my knowledge, there is no knock sensor in the 97 CV; at least not in the civilian version.

Reply to
Happy Traveler

My question is where else would it be, the dealer I bought it off (Ford) could not find any manual reference stating any other location for it.

Reply to
Shoe Salesman

I was wondering if this was the case. thanks

Reply to
dmac

I am getting spark knock. cleaning MAF did not help. ECT, ACT, EGR, Fuel pressure all good. I will try colder plug next, hot and humid weather is the worst and gas grade makes little difference. thanks

Reply to
dmac

I've been getting spark knock on my '95 and have done all the usual things, like you. I am beginning to think my belt drive radiator fan (this car has both electric and belt driven) has a bad clutch. I never hear the fan roar anymore and the outdoor temp gauge used to be stable, now it changes a lot depending moving or stopped for a lite. It is most noticeable when the car is warmed up. Water temp gauge never goes above half, but I am not sure it is linear.

Good luck! Let us know what fixes it, please!

PoD

Reply to
Paul of Dayton

"dmac" wrote in news:1124645781 snipped-for-privacy@spool6-east.superfeed.net:

The colder plug might help.. but...Sounds a lot like Combustion chamber carbon buildup to me...

Do you ever let that horsie run? Or do you always drive it conservatively?

And what brand of gas do you use?

You might ask your local law enforcement person if they have that problem and what brand they use.

Reply to
Backyard Mechanic

replacing MAF fixed it. tried cleaning again yesterday and got better results that lasted 1 day. so I replaced it today, no knock, more power, and I expect it will slightly help mileage.

as far as gas, all brands and grades were doing it and this horsie runs a lot. that's why I was so concerned about the knock. the knock started about a year after I got the vehicle so I had a baseline to work from there. when I had replaced intake I checked egr passages on old manifold and they were clean, so of course new one was. I used that to rule out the egr system. I changed plugs about 3 months ago and even with 50K on them (original per previous (initial) owner) so I had to guess (correctly luckily) that chamber was not in to bad shape as far as carbon. previous owner also got into it at least once a week. I had checked with the dealer that services local sheriff vehicles, they are all 99 and up and had knock sensors, I figured I could not use anything from them as a baseline.

I had suspected MAF was the problem but I needed to rule out the other 5 or

6 systems that could also affect this, the biggest obstacle was determining if it was supposed to have the knock sensor or not.

Thanks all

Reply to
dmac

I'm not sure, but I would think that might affect it due to heat on the front intake runner. no matter what it probably should be fixed though. I also have belt driven as well as electric for the AC. let it idle for about

1/2 hr and fan should turn on during that time, I had to do it this way because I was never able to hear the fan, I do mostly interstate driving.

did you also check fuel pressure and pressure regulator? I have been told its one of the items commonly overlooked when diagnosing this issue.

I double checked mine today before buying the new MAF and key on engine off pressure was 35psi, key on engine running at idle was 30psi and open throttle while running was 40psi. disconnecting pressure regulator at idle was 40psi and did bog the engine slightly. also tested pump check valve, turn key on, waited 10 seconds, then key off and it held the 35psi for 30 minutes with no drop.

Reply to
dmac

Thanks for the repair report. Everyone around here appreciates it as much as I do.

I do plan to replace the fan clutch, I just need to wait a bit. The electric runs as soon as I turn the A/C on so it is working right.

I disconnected the electric a few weeks ago on a hot day for a test. I made an in-town stop-and-go driving run (lot's of stop - untimed traffic lights) and just really tried to heat it up. The fan never made much noise and the temp guage never went up above center. The clutch drag is the same if hot or cold, sat overnight or fresh off a hot drive. I'm fairly sure it's shot.

If I can't make the knock go away with the clutch, then it's time for a new MAF. I've done all the rest already. Your report tells me there sometimes is a difference between cleaning and replacing.

Thanks!

PoD

Reply to
Paul of Dayton

Hey Paul,

Why not do a little test? Contributes to the general knowledge on here.

Drive till ping develops then disconnect the MAF harness nad see what happens. If the knock goes away, and you've cleaned the MAF, then that's a pretty good indicator.

Of course all your other sensors have to be up to snuff for the car to run right.

"Paul of Dayton" wrote in news:NC7Pe.1441$ snipped-for-privacy@newssvr30.news.prodigy.com:

Reply to
Backyard Mechanic

Hey Backyard, that's a great idea! I'll do it soon and report back. Thanks!

PoD

Reply to
Paul of Dayton

I don't think that will prove anything. The ECM will most likely default a little rich. Swapping the old with a new will tell for sure.

Reply to
Shoe Salesman

I'm sure swapping it would tell but I'm cheap! There are no codes at present but the ping is annoying. I like to put my foor in it once in a while, yaknow?!!

I'm not too worried about it yet, my cash flow tells me a new MAF will wait a bit, anyway.

Thanks for the tip, tho.

PoD

Reply to
Paul of Dayton

"Paul of Dayton" wrote in news:lcFPe.3902$u snipped-for-privacy@newssvr17.news.prodigy.com:

Hey...if you have rattle at wide open throttle, that's serious.

Many MAF/ping problems manifest at tip-in, meaning slight acceleration from cruise... but you dont hear it at WOT because engine goes closed-loop and sends richer mixture for safety.

My prev. Tbird had occasional pinging at WOT in really hot weather, but always on tip-in when temp was over 85.

Solved with a used MAF from same series... I lost about 1/2 mpg though. I got it from a guy who was parting out, but I would think they are relatively cheap at salvage.

Here's something else to look for... check the ducting and screen just ahead of the MAF.. anythng that causes disturbance in flow can result in unequal airflow across face of the maf; ie, lower relative flow into the sensor tunnel.

Reply to
Backyard Mechanic

Thanks Backyard! I will try to get in there today. I appreciate all the tips.

PoD

Reply to
Paul of Dayton

I was getting it mostly at WOT (remember, I said I let the horsie run....) from mid rpm range and up. this is what confused me most and didn't immediately point me to MAF. tip in was not bad unless it kicked down and unlocked TCC, then it started as rpm came up. that's why I spent so much (wasted) time determining if in fact there was a Knock Sensor on this year crown vic. been running a few days with new MAF, no ping from 0 to 120 mph yet...seemed to have gained a little fuel mileage and can tow a trailer full of lumber at

80mph with no ping also.
Reply to
dmac

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