Hello all. Longtime lurker, now it's time to seek assistance. I have a 2004 F150 FX4 5.4L with 173k miles on it. I have noticed a couple of things that have got me thinking whether it's time to get a new vehicle.

1. Excessive oil consumption. At 169,000 miles, I got an oil change (always use Mobil 1 synthetic 5W-20) and they said I had no oil and showed me the dipstick. Now at 173k, no oil again. I've parked it overnight in parking spaces with no oil stains and in the morning there are still no oil stains.

2. The engine sometimes sounds like a hard drive working. I looked online and it seems to be pre-ignition. I've used 93 octane, 89 and regular 87 and while 93 makes the sound less, it's present in all octanes. I only use Chevron gas. I've tried using injector cleaners, same thing. It doesn't do it all the time.

3. When the vehicle is running, a smell of fuel is present (doesn't smell inside the cab). Maybe bad cats? They've never been changed. I think that means the engine is running rich.

4. When accelerating, I most of the time hear a small high-pitched whistle sound.

The only things that aren't OEM on my vehicle is my exhaust and I have a full K&N filter kit. Everything else is stock. Anyways, with all these issues, plus a cranky a/c and heating system...it makes me wonder if a new vehicle is due.

Thoughts?

Thanks,

GF147

 

Yeah, I'd start looking. When the 5.4 3 valve starts doing things like this it's going to be expensive.

 

Thanks for your input. Appreciate it.

 

My 04 with 185k on it uses about a quart in between, not a big deal. But i mean if your just putting the 7 quarts in and not checking it until the next change you may do alot of damage. I usually go about 1500 miles without haveing to add any but i mean a quart here and there is cheaper than a new truck.

 

Yeah I've never added a quart here and there on any vehicle I've had. I am still concerned that it goes through the whole 7 quarts between oil changes. Is it because of age of the engine?

What about the pre-ignition?

 

Sounds like its on its way out if its burning oil like that. And when you changed the oil and saw no oil on the dipstick, I doubt it was completely dry because the dipstick only shows about 1 qt of oil, and if you were driving it with no oil it would have blown by now. Also, what kind of maintenance has been done on the truck? Have you changed sparks plugs, fluids, and filters throughout the truck?

 

Spark plugs were replaced with OEM ones a little past 100k and then due to misfiring, were replaced again not too long ago. Coolant has only been flushed once (which was well overdue) and fuel filters have been very irregularly replaced (last one being at the most recent oil change).

Other than that, nothing else has been done to the truck engine-wise. I suppose it's mostly my fault for not being perfect in maintaining it.

 

I would top off the oil with the vehicle level and cold. check the oil level at much shorter intervals to see how quickly it's consuming oil, like maybe 400 miles or every tank of fuel. regarding the fuel smell, is it coming from inside the engine compartment or underneath? make sure you don't have any air leaks around your cold air kit.

 

Underneath. I've checked the intake and it is nice and secure.

 

Dude if it was going thru 7 quarts you would know cause your a$$ prolly would be walking lol. Just keep a check on it once a week see how much it uses. If nothing is on the stick, add a quart, or most of one anyway, i think ford says up to a quart every 2k miles is within its range, i usually have to add 1.5 in between changes at 4k miles. Just keep an eye on it.

 

Maybe because you never check it judging by your opening post?"No oil" on the dipstick means the oil level is just not up near enough to full to register. 2 quarts low might take it low enough that it doesn't register as the dipstick isn't intended to register it all .... it's just intended to help you maintain the level within a quart of full.

You could easily be using only a quart every 2K miles and see this.

Cats can just go bad over time, whistles can mean simple vacume leaks (hoses) ... and when mine smelled like gas when running I found a squirrel had eaten into the vapor return line big time and that he had also just pricked the high pressure supply line so I had a pressure leak when the FP was running. A fuel leak at the right spot will result in a lean condition and even spark knock. Lean conditions can also hurt cats.

 

Oil loss with no sign of a leak can be a bad PCV, use only Motorcraft. Your whistle could be from the PCV as well.

It's worth a shot at the cheap stuff first.

 

From what I have read, the 3V 5.4L V8 doesn't have a PCV valve. I will investigate further. Thanks for your response.

 

My 3v has a PCV valve. They are about a buck and a half at my local O'reily's store.