Jason's 96 F150 5.0

[ford4wd08]

Well time is flying and my oldest (Jason) is 15. He will be driving soon, he has his learner permit already. We were looking on marketplace today just for giggles and I spotted a super clean '96 F150 2wd with a 5.0 & auto trans and 96K miles.

It was listed for $2K, I was crazy to not at least go look. A Uhaul rental later, it followed us home.

So the good, body is almost mint, original paint, minor surface rust in just a couple of places, but you'll be hard pressed to find a '96 this nice. The PO just had to auto trans rebuilt, still under warranty, and paid a more than I paid for the truck. Interior is mint.

The bad, it has a bad miss under load (lugging in gear, OD, etc.), PO said the shop he went to said it was internal to the engine, I'm not so sure yet... but we will get to that in a bit.

So, started playing with it tonight, I had codes for P0171 & P0174. I thought that it was just the passenger side giving me issues at first on one bank. I could see what looked like and crap aftermarket O2 sensor, so I replaced it tonight with a bosch unit, and it did run some what better, but still has an issue. I cleared the codes, and disconnected the battery, and no codes have registered after a short drive yet. I'm going to replace the driver's side O2 sensor tomorrow.

It is OBD2 being a '96 so that somewhat helps with trouble shooting.

I do hear some noises from the valve train I suspect that I'm not in love with, but the engine still runs pretty good at idle and with no load.

Any tips on where to look guys? You all have a lot more experience with the 5.0 then I do, I find it hard to believe the long block has crapped out in 96K miles.

I am going to replace some ignition components, it has some crap plug wires on it and I'm unsure of the plugs. I'm going back all motorcraft.

Worst case I would have to pull the engine and rebuild, I feel like I'll still be ahead on this truck.

Here are some pictures and the a short youtube video of the noise I am hearing --> https://youtube.com/shorts/5bWMbd0iW1o?feature=share

 

[dvdswan]

Nice steal.

 

[ford4wd08]

@19Walt93 @RonD @franklin2

I know there is an crosstalk issue with the 5.0, so they changed the firing ordered and all. I'm replacing the plug wires and plugs today. I'll make sure to route them correctly.

This already has the remote mounted TFI as well on the fender.

 

[ford4wd08]

Ok. A little more investigation this morning. Replaced both upstream O2 sensors and have no codes for lean banks. I believe that is fixed.

Pulled the plugs and it is definitely cylinder one.

I did a leak down on cylinder one and it held over 70 PSI, so it should run ok. Certainly not a dead miss I wouldn't think.

I'm wondering if it could be a bad fuel injector?

The wire set the PO put on was garbage. I have a motorcraft set coming to my locally O'Reilly's along with new plugs, rotor, and distributor cap.

I'll be confident on the ignition after that.

 

[19Walt93]

Nice clean truck. the firing order used to be 1-5-4-2-6-3-7-8 and changed to 1-3-7-2-6-5-4-8( like a 351) starting in Mustangs and then throughout the line. If the plug wires for 5 and 6 run close together it can cause induction crossfire, I've seen it cause burnt pistons if it's neglected for long enough. Almost never are rich or lean O2 codes caused by a failed O2, generally there's a rich or lean condition behind them. Autozone considers "O2 out of range" to be a diagnosis, it's a symptom. Two wheel drive trucks aren't very valuable here but I bet you could double your money on it because it's so rust free.

 

[ford4wd08]

Nice clean truck. the firing order used to be 1-5-4-2-6-3-7-8 and changed to 1-3-7-2-6-5-4-8( like a 351) starting in Mustangs and then throughout the line. If the plug wires for 5 and 6 run close together it can cause induction crossfire, I've seen it cause burnt pistons if it's neglected for long enough. Almost never are rich or lean O2 codes caused by a failed O2, generally there's a rich or lean condition behind them. Autozone considers "O2 out of range" to be a diagnosis, it's a symptom. Two wheel drive trucks aren't very valuable here but I bet you could double your money on it because it's so rust free.

I know one of the 02 sensors had been replaced with a junk one and it was barely screwed into the manifold. So I know they had tried to troubleshoot with that. I noticed something was leaking exhaust fumes when I reviewed it last night. That appears to have fixed that issue.

I decided to replace both just for good measure. They were so easy to get to on a 2wd, didn't even have to jack the truck up or take off a wheel.

Anyhow, I hope this is just ignition.. Would be the easiest to fix. They put junk accel wires on it. You pull them off the plug, it came apart, also the connect to the coil was crushed, so I'm praying it is that simple.

 

[RonD]

Leakdown at 70psi doesn't mean much without input pressure number, if input was 100psi then thats 30% leakage, should be 5% to 8%

Yes, cam was changed to reverse the Matched Pairs 3/5 and 7/4 in firing order
According to Ford engineers it was to change the intake manifolds "sound" for less turbulence

O2s use a chemical coating to detect oxygen in the exhaust, this reaction generates a voltage, reaction can only happen once O2 is heated above 600-650degF
0.1v in high oxygen
0.9v in low oxygen

As the coating/chemical is used up the voltage generated drops, so FALSE Lean is reported to computer(no code) and engine runs richer than it should, can be for a few Years
This of course costs you more money at the pump as MPG gets lower and lower, its not a sudden drop in MPG, its S L O W...........
100k miles or 12 years is recommended change time for O2s, after that the MPG starts to slowly drop from false lean

So an old O2 will eventually set Lean codes(fuel trim reaches +20%), at that point you will have already spent a few hundred $$$ on extra fuel, lol, so way more than the cost of a new O2 sensor, that you now have to get anyway
O2s are the ONLY sensors that have a KNOWN life span, its just physics and chemical science

 

[ford4wd08]

Leakdown at 70psi doesn't mean much without input pressure number, if input was 100psi then thats 30% leakage, should be 5% to 8%

Yes, cam was changed to reverse the Matched Pairs 3/5 and 7/4 in firing order

O2s use a chemical coating to detect oxygen in the exhaust, this reaction generates a voltage, reaction can only happen once O2 is heated above 600-650degF
0.1v in high oxygen
0.9v in low oxygen

As the coating/chemical is used up the voltage generated drops, so FALSE Lean is reported to computer(no code) and engine runs richer than it should, can be for a few Years
This of course cost you more money at the pump as MPG gets lower and lower, its not a sudden drop in MPG, its S L O W...........
100k miles or 12 years is recommended change time for O2s

So an old O2 will eventually set Lean codes(fuel trim reaches +20%, at that point you will have already spent a few hundred $$$ on extra fuel, lol, so way more than the cost of a new O2 sensor, that you now have to get anyway
O2s are the ONLY sensors that have a KNOWN life span, its just physics and chemical science

Supply pressure was 100 psi.

Did some more wrenching on it today. I think there is definitely something wrong with cylinder 1.

Not sure if it is worth tearing down to figure it out, or looking for a junkyard motor at this point....

 

[RonD]

With a Leakdown you can listen at the intake and at the exhaust pipe, escaping air at either means valve issue of course
Exhaust valve is the usual leak point

You can also listen at the Oil filler, or dipstick tube, air escaping noise at these openings means Rings are leaking

 

[ford4wd08]

With a Leakdown you can listen at the intake and at the exhaust pipe, escaping air at either means valve issue of course
Exhaust valve is the usual leak point

You can also listen at the Oil filler, or dipstick tube, air escaping noise at these openings means Rings are leaking

I'll pick up a stethoscope to help with the listening. They're relatively cheap.

I'll redo the rest to confirm things one more time for a sanity check. It could be a burnt valve like you mentioned. It is just that head it could be pulled with engine in truck I'm sure and fixed.

Guess it wouldn't hurt to check compression while I'm at it.

 

[RonD]

I just use a small hose, like a vacuum hose up to garden hose size, as a stethoscope, I always have some type of hose laying around, lol

And I also tape hose to end of a stick so I can listen to injectors or lifters as needed, even exhaust leaks
I am CHEAP
But seem to waste money on hoses since there always seems to be extra laying around, lol

 

[ford4wd08]

I just use a small hose, like a vacuum hose up to garden hose size, as a stethoscope, I always have some type of hose laying around, lol

And I also tape hose to end of a stick so I can listen to injectors or lifters as needed, even exhaust leaks
I am CHEAP
But seem to waste money on hoses since there always seems to be extra laying around, lol

Stethoscope was $5 at harbor freight. It would take longer to find some hose lol.

I have stuck long screwdrivers and stuff like that for listening before.

 

[RonD]

Yes, screwdrivers and slicks are good for vibration noises, not so much for air escaping noises

Years ago I got a stethoscope, ended up having to add longer hose to it, lol, so I thought why not just use the hose

 

[ford4wd08]

Code P0174 is back which is lean on bank 2. So that is driver's side I believe? Cylinders 5-8?

Hmm. I'm trying to be methodical about this, the only other thing I haven't checked is fuel pressure. It has 2 tanks, the rear is currently not working.

I just don't suspect fuel though, when you rev up it revs and doesn't act like it runs out of fuel.

Basically when you drive it shakes some at idle, but when it shifts to 3rd gear or OD (lugging the engine) it shakes the whole truck bad.

 

[ford4wd08]

And then you have the fuel pressure regulator....