Spark knock problem, tried the obvious, next steps?

[thatyoutubemechanic]

Hello all, I have a '02 Ranger with an annoying pinging issue. The plug wires and plugs were recently replaced, there is no EGR valve or knock sensor to check, I've tried running every injector cleaner in existence and running higher octane fuel does not help. Now going forward should I start replacing coils, injectors, check the timing chain health or start thinking about a valve job, or is there anything I'm not thinking of? Any advice is appreciated.

 

[Dirtman]

Run 110 octane, you'll be fine.

 

[Uncle Gump]

Hmmm... ya don't see many questions these days about ping/spark knock/etc...

Have you pulled codes... looked at any live data?

Does it have a tuner? Any go fast stuff like... cold air intake? Exactly what spark plugs are in it? Did it start this after you fooled with in some way?

 

[Dirtman]

3.0s are somewhat notorious for knocking/pinging. They run 9.5:1 compression but don't have a knock sensor so when they get old and carboned up they knock.

In theory if you put the wrong plugs in (too hot) it could cause the issue as well. Carbon cleaning, colder plugs, and high octane fuel may fix it.

 

[Uncle Gump]

So why didn't you just say that the first time?

I've never owned a 3.0L... but I didn't know they were notorious...

 

[Dirtman]

Because 110 octane is easier.

 

[8thTon]

Are you sure it’s pinging? Under what conditions does it do it?

 

[thatyoutubemechanic]

To answer all your questions (thank you for your responses), yes I'm fairly certain it's pinging, it starts a rattling noise under load and can be avoided by letting off/flooring the throttle. I know I've got the right plugs in with OE electrodes, couldn't tell you the brand though. All stock, no go-fast bits. No OBD2 codes to pull but I haven't looked at any live data. And to the 110 octane guy thanks for the real answer, I have considered running a smaller gap to get a shorter/colder spark if you think that could work?

 

[8thTon]

My 2004 3.0/auto has no ping issues at all at 130kmi, and I know it has plugs in it that are 1 heat range too hot. I think there must be something else going on.

Does it use oil? That could be responsible for carbon buildup.

Mine certainly does have an EGR, and the 2002 shows one on RockAuto. That's where I'd look first. Did someone remove it or is it there and maybe you just missed it? The ECU should know if it's working but who knows?

What plugs did you use and when did you change them? If you used something like Bosch platinum more than 3000 miles ago then probably 3 of them have lost their electrodes by now.

 

[Bgunner]

3.0 spark knock is usually seen under load but also with full throttle since this is also a "load" condition. Best checked going up a long hill since load is constant but full throttle can be applied and checked. The '02 motor is slightly different than the '94 I run, especially considering the 94's and before didn't have EGR's but did soon after, but spark knock is the same in all motors. Have you run a full tank of 93 or higher octane fuel. Now this doesn't mean when you hit half a tank stop and top off with 93 but means let the tank drain very low, practically empty, and then fill. Mixing octanes helps increase the octane in this case but many of the older 3.0's need higher octane to prevent spark knock.

 

[8thTon]

The camshaft position sensor might also be something to look at. These have a history of failing on the 3.0 with possibly catastrophic results because it also drives the oil pump. If the gear is badly worn it might have changed timing enough to cause this?

 

[91stranger]

Could be the camshaft synchronized too. These are notorious on 3.0s and are easy to replace and if you don't replace it then u can lose your engine. Or if you had it replaced then maybe it is out of time. If your not sure about the plug then I would just get some motorcraft plugs and check that off the list. To the people with 3.0s who don't check their camshaft synchronized then shame on them.. $100 part and maybe 45 minutes and you can save your engine.... there's lots of bad stories about these when people don't maintain them.

 

[19Walt93]

I've never seen a cam syncro damage an engine, I've seen many cause the engine to quit running. If you replace it the timing is critical, we always used the Ford cam syncro positioner tool from OTC but there are probably aftermarket tools available. If a 3.0 needs 93 octane to avoid spark knock it needs to be decarboned because they don't have enough compression to require premium fuel. High octane fuel burns at a lower temperature than regular so that it will tolerate high cylinder pressure, if you use it in a low compression engine it will actually build carbon faster. We used to remove carbon either with water or Ford combustion chamber cleaner. Care needs to be taken to avoid hydro locking the engine or overheating the cat. If you use the combustion cleaner you fog a warm engine at 2500 rpm with it and then shut it down for about 20 minutes, restart it and feed it the rest of the solvent. With water you'd spray it into the intake with the engine at 2500 or so. If you're nervous at all use the Ford stuff.

 

[cbxer55]

3.0 spark knock is usually seen under load but also with full throttle since this is also a "load" condition. Best checked going up a long hill since load is constant but full throttle can be applied and checked. The '02 motor is slightly different than the '94 I run, especially considering the 94's and before didn't have EGR's but did soon after, but spark knock is the same in all motors. Have you run a full tank of 93 or higher octane fuel. Now this doesn't mean when you hit half a tank stop and top off with 93 but means let the tank drain very low, practically empty, and then fill. Mixing octanes helps increase the octane in this case but many of the older 3.0's need higher octane to prevent spark knock.

Yeah, exactly. My 98, I run 93 octane in it full time. It pings something fierce on 87 and 89. Still pings lightly on 91. On 93, totally quiet. I'm fortunate that the only place that sells 93 in my area, is only 3 miles away. I've done the Sea Foam thing through the brake hose twice. Didn't do a thing. My truck, in addition to probably having 22 years and 166,000 miles of carbon build up, also doesn't have a muffler, has a MAC performance intake, a JET chip on the computer, and the EGR deleted. So yeah, it pings. 93 octane keeps it at bay. Someone once said here that using 93 octane is a band aid fix. I don't care, it fixes it. Thank God for band aid fixes! I look at carbon build up as a free increase in the compression ratio. If I have to run 93 to make it work, I'm good with it. Mine runs GREAT for being as old as it is. I like the truck and wouldn't trade it for anything else. I'll keep it til it goes BOOM, then figure out what's next.

I'm not hurting for vehicles, as my signature line shows. LOL!!

Unfortunately, 93 octane may be hard to get, depending on where you live. In Oklahoma, we usually don't have it. The station I get it from is a Sinclair. Their local deliveries are all 91. This guy has the 93 brought in from Arkansas, and it's Shell V-Power. He only charges about .20 cents more than the 91 everyone else has. He can't keep it in the tanks. All the rodders around here go there. Seen a dude with a big 48 foot offshore style deep-V boat filling up there. Had three Mercruiser outdrives on the back, twin counter-rotating props on each and three blown engines with double carburetors. Took 1000 gallons and he told me it wasn't full. Just wow! For a July 4th weekend at Lake Tenkiller. Expensive weekend. LMAO!!

 

[8thTon]

Yeah, exactly. My 98, I run 93 octane in it full time. It pings something fierce on 87 and 89. Still pings lightly on 91. On 93, totally quiet. I'm fortunate that the only place that sells 93 in my area, is only 3 miles away. I've done the Sea Foam thing through the brake hose twice. Didn't do a thing. My truck, in addition to probably having 22 years and 166,000 miles of carbon build up, also doesn't have a muffler, has a MAC performance intake, a JET chip on the computer, and the EGR deleted. So yeah, it pings. 93 octane keeps it at bay. Someone once said here that using 93 octane is a band aid fix. I don't care, it fixes it. Thank God for band aid fixes! I look at carbon build up as a free increase in the compression ratio. If I have to run 93 to make it work, I'm good with it. Mine runs GREAT for being as old as it is. I like the truck and wouldn't trade it for anything else. I'll keep it til it goes BOOM, then figure out what's next.

I'm not hurting for vehicles, as my signature line shows. LOL!!

Why would you delete the EGR and pay for 93 octane? EGR is only operational at smaller throttle openings, it basically doesn't hurt power at all.