Ever since I got my Ranger back in May 2007 (traded from a 1999 GMC Jimmy mid size SUV), I have notice an excessive knocking noise under moddest load on the 3.0 litre V-6 engine as I am shifting through the gears. First & second it's fairly quiet. But going through third, fourth and into OD I can really hear it knock.

Is this a common sound for this engine type?

 

Are you sure it is engine nock. Ones I spend 3 weekends trying to find what cause engine nock under load and later found it.... in tranny.... Bad bearings....

 

Welcome to FTE.

Engine knock on your 3.0L isn't "normal", but some folks have had various problems for a number of reasons.

What kind of engine "knock are you referring to, a mechanical knock, or spark knock????

I noticed you've posted on another thread about a EGR system P0401 code & having replaced your DPFE sensor a number of times with temporary relief, so maybe your referring to a spark knock problem????

Seeing as how you've had it scanned for trouble codes to get that code, post ALL the codes you retrieved on that scan, if any any more.

I think I remember you said it's mileage was around 70-80K & it's a 5 speed manual with cruise control????

Is it a flex fuel 3.0L????

Is it all stock, no mods like a performance chip, oversized tires, modified air intake or air filter, spark plugs, ect??????

Just some foundation questions to get us started on your troubleshoot.

 

Also, what gas ae you using (octane rating)

 

I use what the owners manual recommends - regular unleaded. But most gas station now sell E-10 blend. At $4.199/gal it's already rather expensive.

No modifications to this truck other than a home made bed cover. No performance chips that I know of.

It is an LEV - formerly Wisconsin truck. It has an awful lot of catalytic converters. I usually see up to two or three, but what this truck has is ridiculous.

The knock is quiet when the engine is cold. Even under heavy acceleration it is quiet. But up to operating temp, it's very noticeable. Hot summer months, it knocks all the time. There is a clicking noise if I shift too soon and lug the engine at lower rpms - around 1,000.

MPG still remains around 25 for stop & go driving towing a heavy load. And up to 28 for open highway driving.

Had to change the oil twice Saturday. The oil filter I got was defective. The rubber gasket blew out sending engine oil spraying everywhere. About 3.5 quarts drained into the garage floor. Used the whole 15 lbs bag of oil dry to soak that up.

 

Ok good feedback.

With the knock not being there when the engine is cold is a good clue, but may suggest that you have more than one problem as a root cause.

With the P0401 Insufficient EGR code & the fact that the EGR isn't online when the engine is cold & the air/fuel mixture is naturally richer, might suggest you still have a EGR flow problem & maybe a vacuum leak & or carbon deposits.

So, I'd begin with checking for vacuum leaks, especially to the EGR control system & any other under hood vacuum lines or hoses that are close to heat sources. The 4 banger has a curved rubber vacuum hose going to the EGR valve thats known to be prone to cracking.

If your vacuum leak trouble shoot doesn't pan out, maybe run this puppy by your favorite autoparts store & have a no cost computer trouble code scan done & see if your P0401 is still there & if any more trouble codes turn up, that may offer some good clues.

Other "ping" sources may be combustion chamber carbon deposits, vapor recovery system vacuum leaks, wrong heat range, or design spark plugs, cooling system in poor condition, a sticking, or incorrect heat range thermostat, bad gas, as has been mentioned & probably some more I've forgotten.

Anyway, with insufficient EGR, for which you do have a trouble code & which will cause ping, & you said changing the DPFE sensor did bring temporary relief, I'd first concentrate on putting the EGR system right first & see how things go.

Just some more thoughts for pondering, keep us posted.

 

Try a tank of 93 octane just to see if it clears up.

 

on 3.0 you can turn CKP to change ignition timong and stop nocking.

BTW. when 3.0 is old deposits of burned oil may increase compression ratio.

 

Paw Paw is right about the carbon deposits and this is a simple fix. There is a thread in this forum with a step-by-step procedure. I personally use Seafoam product for the decarbonizing with good results.

Russ

 

I have a 1992 with a 3.0 that would knock a lot under a load in hot weather. It would go away if I ran a tank of premium. Rather than go through the de-carboning process elsewhere in the site, I used 2 big bottles of Chevron Techron on back to back fillups. The stuff is kinda high, about $9 a bottle at Advance Auto Parts, but it cleared my knock up. I'm around 170,000 miles now & going strong although a guy is dangling a REAL nice, low miles 2000 Mazda B-3000 under my nose with a real good price. I'm getting real tempted to buy it and give my Ranger to my Son.
BPF

1992 Ranger SC 3.0
1991 Mustang LX 5.0

 

Advance Auto has the 20oz Techron Cocentrate Plus on a two for the price of one special, that works out to about $6 a bottle.

AutoZone has/had a special on the 20oz size too, but I don't remember if it's still on.

I too have successfully used it to decarbon my 4.0L pushrod & stop it's cold start up CCDI marble noise.

 

I replaced the Vacuume Control Solenoid bought at Chet Nichols in Bangor. I paid just over $33.00 with 6% sales tax. I tested it out with just the truck and the engine up to operating temp and the a/c on. No more engine knock at all. The engine ran beautifully smooth and quiet. But on flat land maintaining steady speed, the Ranger still stumbles and the Check Engine light still comes on with P0401.

Today I hauled back a garden tractor I spent a good deal of time to get running again. But won't get paid for the work I put into it till "maybe" some time next week. Some how I am not going to make a small engine mechanic at this rate. Any ways, the utility trailer weighs 800 lbs empty (5x8) and the 48" cut garden tractor weighs about the same with a 18.5 HP Briggs & Stratton apposed twin cylinder engine. Again the engine ran smooth and quiet.

So all this time I had a defective vacuume control solenoid which should have been replaced - not the DPFE!! But that too is bad now cause of the defective solenoid.

I can't beleive just how quiet and smooth the engine is now.

 

Good to hear things are better.

While replacing the EGR's vacuum switching valve, did you remember to disconnect the battery, to wipe the computers memory, so it can begin to build new fuel trim tables, ect & erase the old P0401 trouble code?????

 

Yes.

The instructions on the box highly encourage any work on a vehicle that the negative cable be removed for safty sakes.