Good Evening Everyone,

I've just done some researching on an issue that's been driving me crazy ever since I bought my '02 but that I've pretty much just let go until recently. I'm having a very similar issue to what Five0guy has here in post #26: https://www.ford-trucks.com/forums/4...k-knock-2.html

When I first bought the '02 almost four years ago with 84k on the clock, it did run fairly rough. It was bone stock and I immediately changed the oil/filter, plugs, and air filter. That helped quite a bit, but it certainly sounded much different from the '05 with the same drivetrain we already had (and have had since new), which had 27k on it at the time. Today, the '05 has almost 56k on it and the '02 has about 117,500. I do realize the '05 doesn't even have the mileage on it that the '02 had when I bought it, but they both haven't changed at all in the way they sound, and it is distinctly different. The '05 seems to just run much smoother as a whole.

Within the past couple years, the '02 has developed the noise I describe above. Here's what I have done:
- Plugs about 86k (Motorcraft SP-479, gap @ .054")
- COPS recently, about 115k
- Cleaned MAF
- Ran 93 octane for a tank recently and it certainly seemed to help
- Never has thrown any codes
- Fuel filter about 116k
- I have run a few of those additives that are supposed to help clean out the engine, around 110k.
- Most of the time I do fuel up at different stations, and the noise usually happens from most if not all of the places. Sam's Club regular is the worst, Shell isn't that great either, BP seems to work best for me at least for the stations around me.
- None of these items have rid it completely of this issue, but as a whole I certainly think it has made it a little quieter.

Right now, it looks like I'll be checking the exhaust heat shields and access plates this weekend. The problem is very clear in the 1400-1700 RPM range, when I am having to go up a slight incline locked in OD (about 45-52 mph). Any slower than that and it will downshift, any higher seems to not make the noise (or as loud). Nothing seems to be really unusual in the >3000 RPM range, other than the '05 does seem much smoother here. I haven't noticed any major knocking or anything though.

I do have a question in the mean time though. I have a Scan Gauge on it constantly monitoring the engine and trans temps, instant mileage, and mph. I've put the SG on the '05 with everything in the same setting, and the engine temp comes up very different. On the highway after an hour or so (full operating temp), the '02 will only get up to maybe 182 degrees max in the summer solo and 173-175 in the dead of winter. The '05, under the same conditions, will range from 186-193 degrees. The dash needles between the two aren't in a different position that I can tell.

The '02 was originally a Hertz rental is the Miami area, so it was originally ordered as a pretty basic Limited for a warm climate. The '05 was built for a Michigan delivery and has just about every option except the PSD. But both are V10s, both 3.73 rears.

Is there any reason for the difference in temperatures? I'm not sure if this is a problem for transplanting them to cold northern climates or not. Both will certainly crest 200 degrees towing, but these are just the solo temps running on the highway.

Thanks!
Jon

 

It could be something as simple as the difference between cylinder-head temperature, and thermostat cross-over temperature. Or, they have a different thermostat in it. Hertz might, in hot climates, put a cooler thermostat in it.

As for the pinging, does it get better/go away if you use 93 octane?

 

Sounds like;
1.-If the knock is almost gone using 93 oc., it's probably spark knock!
2.-Since your '02 runs cooler than your '05, it probably has a 160 degree thermostat in it, judging from your temp. ranges!

 

Hi Art,

It does get a little better with 93, but still not 100% gone. After changing the fuel filter, the experience on 87 has been improved though (except on Sam's 87). There doesn't seem to be as much of a difference between most 87 and 93 now. I was hoping that the coils and fuel filter would take care of it, but I wasn't so lucky.

I'm having a tough time trying to describe what's going on with it. It seems like, aside from the rumble thing from 14-1700ish, there's just some sort of underlying fairly constant wooshing noise in all RPM ranges. It becomes especially noticeable when starting up from a stop and trying to keep it under 2000, there's this low pitched hum from about 17-1900. I should try to take a video again, I made an attempt before but with the camera I used, it wasn't picking up the engine sound much at all. This hum goes away if I step on it harder...believe me, the temptation is there if the gas gauge didn't fall so much! Edit: I forgot to mention it got a new Gates belt in July too, so I doubt a loose belt would be causing any of this.

I have to say though, it doesn't seem like it's lacking power at all. I'll admit I haven't had a heavy load behind it in some time though, so it's hard to judge if it is lacking anything.

bgblk71merc, do you know what the other thermostat choice would be then? Would it benefit me at all to swap it out?

Thanks!

Jon

 

Hi Everyone,

Just thought I'd pass along a quick update. I finally got a chance to get under and check out that dust cover on the bell housing. While the cover itself didn't seem that loose, the part right above that the cover plate wedged up against certainly was loose. Ran a bead of silicone along the top and side edges of the removable cover plate and it has now fixed the problem!

Here all along I was thinking it was a problem with something internally in the engine!