any mechanics here?

[Paducah Home Theater]

The missing that I reported seems to be directly related to the high octane gas I put in there.  Rather than fixing the rattle, it made the engine miss easily while not doing jack squat to the rattle.  I burned through the gas I had in there already then filled it back up with normal gas, it's already better.  For whatever that's worth, not sure what that means.  

[jason str]

Probably bad gas.

 

Premium does not exactly fly off the shelf.

[Wolfbane]

The missing that I reported seems to be directly related to the high octane gas I put in there.  Rather than fixing the rattle, it made the engine miss easily while not doing jack squat to the rattle.  I burned through the gas I had in there already then filled it back up with normal gas, it's already better.  For whatever that's worth, not sure what that means.  

 

High octane gasoline will not make your engine miss (it burns slower, not faster than regular gasoline in a combustion chamber). Where did you purchase it?

Edited May 9, 2016 by Wolfbane

[mustang guy]

Yeah, what Jason said. Premium gas sits in those tanks longer because it is sold less. It can go bad. If you buy high test, it's best to get it from one of those big gas stations that has a million cars a day. The only disadvantage to those stations is they use less additive than the branded stations. For example, Speedway is owned by Marathon. The gas sold at Speedway is not branded Marathon even though it is Marathon gas, it just has less of the Marathon additives. If you go to a Marathon station you will get gas that has more additives, but since those stations aren't as heavily used and the gas is more expensive, sometimes you end up with old gas. It's a damned if you do situation.

 

As Wolf sort of said, high octane resists exploding more than low octane. I wouldn't say it explodes slower though. Once it ignites, it should have the same energy. The reason for high octane is so the air/fuel mixture in your cylinder doesn't ignite from the heat and pressure before the spark plug has a chance to fire. If it does, that's called preignition, and it makes a noise. Think of it this way, it is pushing the piston back the way it came. 

 

If you put high octane from a busy gas station in, the problem should get better if you are having preignition.

 

Somebody earlier mentioned carbon buildup. That can hold heat and cause preignition. There is this product called Sea foam. It dissolves carbon really well and won't hurt your engine.  

[Ceptorman]

 

Having truck troubles, don't know what to do about it.  Will try to outline it best I can.  2004 Ford F-150.  

 

1. Biggest issue is that upon acceleration, especially in a situation where I'm going at highway speeds but then press on the gas to go up a hill or pass a car without downshifting, something rattles really bad.  It sounds like you put gravel in a tin can and start shaking it hard.  

 

2. I took it to a transmission shop thinking it was the transfer case, since it also would not go in 4wd.  He said the solenoid for the apparently weird Ford 4wd system from that year was sticking so he replaced it.  Still rattled though.  He said transmission, transfer case, and axles were fine.  He put new seals in the rear axle since it has been leaking for a long time.  Recommended a tune-up.  

 

3. Took it to my normal mechanic and explained what is happening.  It also sometimes clicked in the front and had some low frequency grinding so he honed in on that.  Found that a hub had badly rusted, partially disentegrated and chunks of rust was falling off and getting on the inside, so he replaced it.  The clicking and grinding has stopped.  Still rattles though, at least when I drive it.  

 

4. This same mechanic inspected underneath and did not find any loose heat shields which is what I suspected.  

 

5. Upon actually riding with me, when I accelerated and it rattled, this same mechanic instantly said that it was a premature firing problem, Ford trucks are notorious about it, and the dealership can re-flash the computer to compensate for it.  Also said it definitely did NOT need a tune-up, for some reason.  

 

6. Problem is though, I talked to this dealership, there is no bulletin on this issue nor any issue known to them where this would actually fix such a thing.  I have an appointment for them to diagnose it but crap, this is getting old, and they don't seem to think that a need to re-flash is the issue.  

 

7. Only thing I can think of on my own is that the catalytic converter(s) has clogged and/or disintegrated, and upon acceleration under a load, the exhaust pressure is rattling a bunch of rusted junk inside of it.  I have an appointment with a muffler shop tomorrow, I guess we will find out.  It will not rattle just revving the engine though, has to be under a load.  

 

 

Any other ideas?  

 

 

I'd suggest you trade it in on a Chevy

 

I was waiting for this response, surprised it took 75 post to see it

[Ceptorman]

The reason many car manufacturers recommend premium is because they test the car with premium, and they want the consumer to get the most out of the car. You might get slightly less fuel mileage with regular fuel, and less performance, but the regular fuel saves some money. Most of the time regular fuel will not harm the vehicle.

[Ceptorman]

Try to find ethanol free fuel if you can.

[CECAA850]

Somebody earlier mentioned carbon buildup.

 

If you run premium gas in a vehicle designed for regular it can cause excessive carbon build up.

[mustang guy]

 

Somebody earlier mentioned carbon buildup.

 

If you run premium gas in a vehicle designed for regular it can cause excessive carbon build up.

 

It's kind of a catch 22 then. You have a car with carbon buildup that is suffering pre-ignition because of the added heat that causes, and the high test gas builds the carbon deposits.

 

Has anybody thought to check the coil packs, wires and plugs? 

[mustang guy]

 

I always apply a liberal amount of anti seize on new spark plug threads in aluminum heads.

 

Highly doubt most technicians even bother using it, the above picture shows what is likely to happen without it.

 

 

The problem with this design isn't the threads you can see that they're fine.  There's a long end on the plug that sticks down into a chamber.  The chamber fills up with carbon and basically bonds itself to the plug.  Maybe never seize would help?  I don't know.  This is a chamber/plug design that didn't really pan out.

 

Seems to me that removal of the plugs on a regular basis to clean them with sea foam would be a good idea. I drive a Ford truck now, but it's a diesel. I am very very happy that diesel fuel is less expensive than gasoline as it should be.

 

Go test drive a Superduty with a diesel in it. Mine is 11 model, and has tons of bells and whistles. It also has lots of dents and scratches, but it can pull a stump out of concrete and it rides like a sailboat in a following sea.

[jason str]

Premium fuel does not cause carbon buildup, this is old outdated information from when lead was used to raise octane levels.

 

Driving like an old lady causes carbon buildup, premium fuel contains additional cleaners and should help clean carbon deposits.

 

Transmission fluid cleans carbon deposits, soak overnight for best results. It will smoke like crazy when it starts and should be taken out on the highway afterwards to remove remaining carbon deposits.

 

I have seen carbon deposits so large that when they come loose they were mistaken for a rod knock.

[Paducah Home Theater]

Has anybody thought to check the coil packs, wires and plugs? 

 

 

Supposed to be happening Wednesday.  Hopefully they won't rape me on the charges.  I am getting the converter pressure checked today.  Wednesday I have the dealership diagnostics scheduled and they're going to put new coils and plugs in.  I just don't know if I should just do the coils and plugs only then see if it gets fixed, or if I should go ahead and pay the $130 to diagnose it while it is there.  

[Paducah Home Theater]

I have seen carbon deposits so large that when they come loose they were mistaken for a rod knock.

 

The one thing that keeps bugging me is that it started right after I hammered it on acceleration several times while testing after I swapped transmission fluid and filter.  Just wondering if something got broken loose at that time.  

Edited May 9, 2016 by MetropolisLakeOutfitters

[CECAA850]

Premium fuel does not cause carbon buildup, this is old outdated information from when lead was used to raise octane levels.

 

You are corrects,I had a flashback.  Been sniffing too many gas fumes.

[jason str]

 

I have seen carbon deposits so large that when they come loose they were mistaken for a rod knock.

 

The one thing that keeps bugging me is that it started right after I hammered it on acceleration several times while testing after I swapped transmission fluid and filter.  Just wondering if something got broken loose at that time.  

 

 

You should always run through your gears after a transmission fluid change, best to get all the air out before checking your fluid level.

 

You probably drained the valve body causing your transmission to delay your going into gear, hydraulics don't work right with air pockets.

 

May have busted a motor or transmission mount in the process, that can cause a rattle as well as your powertrain will move more than it should causing interference where there previously wasn't any. 

[Paducah Home Theater]

 

 

I have seen carbon deposits so large that when they come loose they were mistaken for a rod knock.

 

The one thing that keeps bugging me is that it started right after I hammered it on acceleration several times while testing after I swapped transmission fluid and filter.  Just wondering if something got broken loose at that time.  

 

 

You should always run through your gears after a transmission fluid change, best to get all the air out before checking your fluid level.

 

You probably drained the valve body causing your transmission to delay your going into gear, hydraulics don't work right with air pockets.

 

May have busted a motor or transmission mount in the process, that can cause a rattle as well as your powertrain will move more than it should causing interference where there previously wasn't any. 

 

 

I did at first on the normal gears but forgot reverse.  I did in fact have an air pocket in reverse, which I only realized after I started to pull out in front of a truck on a blind corner at the end of my road.  Tried to back up and the truck just sat there.  It finally jammed into gear pretty hard.  It was fine after that.  The rattle didn't start at that point, I test drove it some more and it was fine, that's when I was accelerating hard.  Left on a trip the next day, got 15 miles down the road and it started rattling.  I explained this to two mechanics at the transmission shop and they could find nothing wrong with the transmission or transfer case.  Of course their litmus test could very well be whether it rolls down the road or not.  It did sit at the transmission shop for a week though, and I was expecting a full rebuild.  They just gave it back to me though.  

Edited May 9, 2016 by MetropolisLakeOutfitters

[mustang guy]

The tranny flush is probably only improving lockup instead of robbing power from the rear wheels. This tells me the problem was probably there before the flush, and the added strain on the engine due to the improved lockup made you aware of it.

 

It could be a motor mount, but the ratting rocks description sound too fast for that to me. Sounds like valves or ignition which goes in line with what most folks have been saying. By the way, coil packs are easy to test. You just disconnect and reconnect them one at a time while at idle and when you pull one that doesn't sound worse, then it is a bad one. Don't stop until you have diagnosed all the packs in case you have more than one bad.

[Paducah Home Theater]

The tranny flush is probably only improving lockup instead of robbing power from the rear wheels. 

 

The only other weird thing going on is that it does buck at 42 mph if you're trying to drive steady on flat ground.  I was told by the transmission guys that this is 100% due to the engine because at this speed, the transmission was in lockup so anything weird going on can be nothing but the engine.  That's when they told me to get a tune-up then come back to them if it persists.  

[JJkizak]

That means your lock up filter/valve may need replacing. It should be a smooth back and forth transition which is very noticeable at 42/43 MPH.

JJK

[CECAA850]

That means your lock up filter/valve may need replacing. It should be a smooth back and forth transition which is very noticeable at 42/43 MPH.

JJK

 

I think what's happening is that the engine is experiencing it's highest torque load at that speed.  Ignition problems will generally rear their ugly head then.