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Car down on power and misfire, rough idle, mostly in closed loop mode(warmed up)

302 Hi Pro

Boss 302 - Racing Legend to Modern Muscle Car
2,009
439
Southeast
twistedneck said:
its pretty sad that for all this time i was driving and looking at oil oozing out of the pcv inlet to the intake.. i was like, is that just leaky or is it extra oily? i bet a good catch can, or better yet a breather system would have dealt with the blow by issue w/o a problem.

Only 15,000 miles and it looks this bad (see pics below) - the cam overlap, huge amount of extra overlap in my cam tune, and a lot of blow by oil!!!

https://onedrive.live.com/redir?resid=88D807241B608921!37164&authkey=!AMGqQ2t2TgJZFfw&ithint=folder%2c

if the new O2 sensors fix the misfires and IF i can keep the oil out of the intake - will that carbon on number 8 cylinder ever go away? it looks like it would cost HP. piston tops and combustion chambers bad too..

Twisted neck:

Oh I am sorry to see that carbon build up. When you run all of that top engine cleaner through your intake system, you should then change your engine oil and filter.

Wonder if your engine is also suffering from excessive cylinder blow by? Might be worth running a cylinder leak down test. It's a pain, but it might identify a cylinder for you to more closely examine upon tear down.

I have read the new Aluminator engines are running Manley rods and Mahle pistons, if so that might be an option.

Is this a "U" code 302 CID engine?

Good luck with your repairs
 
302 Hi Pro said:
Twisted neck:

Oh I am soy to see that carbon build up. When you run all of that top engine cleaner through your intake system, you should then change your engine oil and filter.

Wonder if your engine is also suffering from excessive cylinder blow by? Might be worth running a cylinder leak down test. It's a pain, but it might identify a cylinder for you to more closely examine upon tear down.

I have read the new Aluminator engines are running Manley rods and Mahle pistons, if so that might be an option.

Is this a "U" code 302 CID engine?

Good luck with your repairs

How do I tell if its a "U" code and what is the significance?

I just put a brand new bank one O2 on finally found one in stock at NAPA for $140. Same sensor on Rock Auto for $80, ahh well. Good news is it runs just like new! big power is back. I'm soooo happy. but i'm also so sad now that I know my car has carbon build up. I am going to run the CRC intake valve cleaner system today. Do you think that will f up my O2 sensors again? If it really works there is going to be a lot of smoke. this is solvent based not oil based like Seafoam so any smoke should be my carbon burning.

Thanks again for everyone's support on this forum. If you have not found out and hopefully you wont, when your race car isn't running right its not a good feeling especially having thrown ideas and fixes at it for 3 weeks. Ya'll helped me through. OK its probably going to puke again soon but at least I know whats going on. Needs a re-build soon enough.
 

Grant 302

basic and well known psychic
Well, I doubt it's going to 'puke' again...but if it does, it sounds like you'd know exactly what to do now.

I'm guessing it should get better. If I'm wrong, then a breather and new O2 sensors should do the trick.
 
I've been recommending the F150 EcoBoost PCV for along with not compression braking unless on the race track for these oiling issues.
If you remove the stock PCV you will find there is no baffle under the unit in the valve cover like older 4v's and the valve train will spray oil right into the PCV, which is very free flowing in stock form, too free flowing IMO. When coupled with high vacuum under engine braking a significant amount of oil can be sucked into the intake manifold.

The 2013 EcoBoost F150 PCV has a one-way valve for boosted applications that acts as a baffle to catch much of the oil, but of course not all of it.

FYI, engines that are babied + drivers that compression brake tend to have the most carbon buildup. Beating the piss out of the engine (on good fuel) every now and then is a good thing. I've found the road course is excellent for heat cycling.
 

Grant 302

basic and well known psychic
I've been recommending the F150 EcoBoost PCV for along with not compression braking unless on the race track for these oiling issues.
If you remove the stock PCV you will find there is no baffle under the unit in the valve cover like older 4v's and the valve train will spray oil right into the PCV, which is very free flowing in stock form, too free flowing IMO. When coupled with high vacuum under engine braking a significant amount of oil can be sucked into the intake manifold.

The 2013 EcoBoost F150 PCV has a one-way valve for boosted applications that acts as a baffle to catch much of the oil, but of course not all of it.

FYI, engines that are babied + drivers that compression brake tend to have the most carbon buildup. Beating the piss out of the engine (on good fuel) every now and then is a good thing. I've found the road course is excellent for heat cycling.

Thanks for the info and confirmation. My GT definitely runs better after a track day and running ~50% race fuel. I really notice after running on the Roval, where you can mat it 3 gears 3rd thru 5th.
 

GB218

TMO Addict
66
4
I've been recommending the F150 EcoBoost PCV for along with not compression braking unless on the race track for these oiling issues.
If you remove the stock PCV you will find there is no baffle under the unit in the valve cover like older 4v's and the valve train will spray oil right into the PCV, which is very free flowing in stock form, too free flowing IMO. When coupled with high vacuum under engine braking a significant amount of oil can be sucked into the intake manifold.

The 2013 EcoBoost F150 PCV has a one-way valve for boosted applications that acts as a baffle to catch much of the oil, but of course not all of it.

FYI, engines that are babied + drivers that compression brake tend to have the most carbon buildup. Beating the piss out of the engine (on good fuel) every now and then is a good thing. I've found the road course is excellent for heat cycling.
Shaun,
Dumb question: will running the JLT oil separators help prevent or minimize these oil issues?

Thanks,

GB218
 
Even if you go breathers and no vacuum ports from the CV to intake tract you will STILL get oil burning off in the engine if you compression brake.

The very high vacuum in the manifold from using the engine to slow down will pull oil past the valve stem seals and into the intake runners.
 
Even if you go breathers and no vacuum ports from the CV to intake tract you will STILL get oil burning off in the engine if you compression brake.

The very high vacuum in the manifold from using the engine to slow down will pull oil past the valve stem seals and into the intake runners.

Shaun,

If I were to ask for a track (road course) tune, would you recommend against having an "engine brake" tune?
Now I'm really wondering if the track key is really not a good idea on track ???
 
Quick update:

As suspected the car still had a slight hesitation from low speed take off and the idle was a bit rough.. a little down on peak power even after the bank 1 O2 sensor change.

I checked the throttle body and intake for oil and they were mildly oily and the bottom corner tb bolt was hand tight and there was evidence of a small amount of oil leakage. i fixed that - retest - no change.

Next up, I made the change from my OEM PCV valve to the 2013 F150 Ecoboost. The difference in restriction was at least 50% - i.e. the F150 PCV was much more restrictive. Also, my old PCV did not click back and forth when i shook it. it just stayed in position and it had a strange shaft protruding out the middle that was not held vertical it was flopping around.

Long story short after replacing the PCV my low speed stumble issues are gone and the idle is a lot smoother, power is clearly back.

Next up, replace bank 2 O2 sensor, replace MAF, and replace the fuel filter, then run a leak down test.
 
Another update for the record:

Ran a compression test, engine was warmed up.

cyl psi
1 157
2 160
3 156
4 158
5 160
6 162
7 166
8 167

Also, i scoped the bores they look good.
 

302 Hi Pro

Boss 302 - Racing Legend to Modern Muscle Car
2,009
439
Southeast
superhero said:
Those seem like good numbers with CYL 8 being the highest.

Totally agree with SuperHero, those are good numbers for a warm engine. It's also nice to learn that you scoped your cylinders and they looked good. How did the carbon look on the tops of your pistons?

Do you have any other concerns now that it's running better with the new F150 PCV valve and new O2 sensor?

Keep us posted,
Dave
2HP
 
302 Hi Pro said:
Totally agree with SuperHero, those are good numbers for a warm engine. It's also nice to learn that you scoped your cylinders and they looked good. How did the carbon look on the tops of your pistons?

Do you have any other concerns now that it's running better with the new F150 PCV valve and new O2 sensor?

Keep us posted,
Dave
2HP

Carbon is pretty much the same as it was in this pic way back when I changed heads 10,000 miles ago.
reassembly.jpg


The carbon on the intake valves is slowing going away. I've been using the B12 and then looking at the valves you can notice its doing a slow but good job on that. The spray intake valve cleaner helped too, but not as much as half a tank with a full bottle of B12 Nuclear solvent.

it didn't like good amounts of throttle with low rpm from a stop and when I changed pcv valves, that problem disappeared! explain that?? the idle is still not perfect but its 95% and it does still misfire a little bit here and there on part throttle conditions where you barely give it gas and hold a speed. Also, since the O2 and PCV, gas mileage is back to normal.

Something tells me that other O2 is also gummed up or toasted from years of E85 w/o ever running gasoline, stable, or anything. Ford F150 manual states must run a full tank of gas at least once every 3 months if you use E85 all the time. I still don't plan on doing that but I will run stable during the storage period this time!

A friend told me it might be cam position or sensor or cam actuator related also. Thoughts on that?

Anyone else out there run E85 this long?

Also, I can't figure out why number 8 has much greater pressure. I did notice hand tightening the pressure tester did have a slight effect on the readings. its a pretty old tester. Number 8 was almost 4% higher compression than the average.

FYI - just like the past 3 years now I keep getting daily P0300 and P0302 misfire codes. These seem completely un related to the issue at hand and happen after about a day of driving. Like everyone else I went after the neutral profile relearn process because I did swap my clutch. that didn't take care of it at all. then I put the o-ring ckp sensor fix on the sensor itself.. still the random and #2 misfire. then I swapped the cam wheel to cobra jet. no fix. heads didn't fix it, new intake and TB didn't fix it. new cams either or e85! probably wiring harness or ECU?
 
The wonders of electronics. What ever happened to the good old points/ capacitor/rotor and cap. Keep us posted. This is how all of us BMO users get schooled.
Class is in!
 

302 Hi Pro

Boss 302 - Racing Legend to Modern Muscle Car
2,009
439
Southeast
Low speed or light throttle hesitation and rough idle. I was thinking about this and asked, is there a common thread between these two conditions? The only thing I can think of, (Depending on how light is the Throttle), on low speed acceleration, and a rough idle condition is Vacuum.

It's a long shot but worth checking for any vacuum leaks.

As far as power, is it possible the knock sensors are pulling timing? You can test knock sensor function as well as other sensors prior to replacement. Maybe something to consider?

Other possible causes could be fuel injectors, injector spray patterns, these can all be bench tested.

Keep us posted with your progress and good luck.
Dave
302 Hi Pro
 
4,985
5,802
Something to consider here, at Mosport Kurt's car started dropping cylinders, the engine started overheating and went to 250 plus even out of the draft, we looked over everything, o2 sensors, pulled plugs, checked inlets and crawled all over that car, in the 2nd race it got worse, we thought we damaged the engine in the first race so, as a matter of course we ran the car on the dyno.
The motherfreaking rear abs sensor was activating when heated and causing the car to go into limp mode off the corners..........

just sayin'
 
302 Hi Pro said:
Low speed or light throttle hesitation and rough idle. I was thinking about this and asked, is there a common thread between these two conditions? The only thing I can think of, (Depending on how light is the Throttle), on low speed acceleration, and a rough idle condition is Vacuum.

It's a long shot but worth checking for any vacuum leaks.

As far as power, is it possible the knock sensors are pulling timing? You can test knock sensor function as well as other sensors prior to replacement. Maybe something to consider?

Other possible causes could be fuel injectors, injector spray patterns, these can all be bench tested.

Keep us posted with your progress and good luck.
Dave
302 Hi Pro

That hesitation went away when I put in a new pcv. I was shocked. I did use the f150/ecoboost one per shaun's recommendation.

It's still idling a little bit rough. Putting a new driver's side o2 on tomorrow.
 

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