Code P0302

Tiny
JUSTINVOIGTS
  • MEMBER
  • 2003 FORD CROWN VICTORIA
  • 4.6L
  • V8
  • 2WD
  • AUTOMATIC
  • 75,000 MILES
P0302 cylinder two misfire I drove car fifty miles each way trip half way through trip to there check engine light came on flashing throttle de rate felt the miss. Got home scanned removed coil and plug Motorcraft plug tip was burnt off spark plug fix a thread came out too. Bought new plug installed new insert with red loctite still missing. Swapped coil and plug still there. Compression test revealed 30 psi. Removed lifters were collapsed replaced with Melling from auto zone. Was fine not coding out still felt slight misfire after twenty miles misfiring again bad p0302 again. Fuel pressure dampener is right above cylinder two is damaged will this cause misfire. I am a B tech twenty years experience it kind of has me baffled. I am hoping it is not bad valves. It is my own car I paid $1,300.00 for it plus $600.00 in parts it needed. Cannot afford to put another dime in it I bought because usually reliable. I have the MSD red coils in it it is police interceptor. I forgot tested for vacuum leaks with can of carburetor clean none found. EGR not sticking or clogged. Please help. HHC
Sunday, October 29th, 2017 AT 10:44 AM

22 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 52,568 POSTS
Does the cylinder still have low compression? I can see how lifters could solve a low compression issue. It sounds more like a piston or valve is damaged. Can you please recheck the compression and get back to me.
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Monday, October 30th, 2017 AT 2:50 PM
Tiny
STEVE W.
  • MECHANIC
  • 14,837 POSTS
A leak down test would tell you if it's piston/valves real quick. Pressure dampener would effect all cylinders.
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Monday, October 30th, 2017 AT 4:00 PM
Tiny
JUSTINVOIGTS
  • MEMBER
  • 11 POSTS
The cylinder has no compression nor has any with oil in cylinder. I just don’t feel like pulling motor in my driveway I’m gonna sell the car I think or drive till it falls apart or until 2019 September when inspections due again.
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Monday, October 30th, 2017 AT 6:42 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 52,568 POSTS
Sounds good let us know if you change you mind and want help we can get you any diagrams needed to get the job done.

Please use 2CarPros anytime, we are here to help. Please tell a friend.

Cheers, Ken
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Tuesday, October 31st, 2017 AT 10:54 AM
Tiny
JUSTINVOIGTS
  • MEMBER
  • 11 POSTS
Today I ran a bunch of simple green and water through a vacuum port and took it on 295. This misfiring seems to come and go while applying heavy throttle is this a sign of a valve issue or rings? It’s usually there at idle though. It seems it got a little better after I did that what do you recommend do u think I should hook washer pump line up to vacuum port hit it on highway run a couple filled bottles through it to see? This happened with the misfire after I did sea foam in oil gas and intake.?
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Tuesday, October 31st, 2017 AT 12:35 PM
Tiny
STEVE W.
  • MECHANIC
  • 14,837 POSTS
It sounds like carbon is breaking up and holding a valve off it's seat.
I would probably run a leak down test to determine where the leak is but I would bet it's a valve problem. In most engines you can remove the rings and still get a lot of compression. BUT stick a valve open on it will go away instantly.

I've seen carbon build up in ex-police cars from the way they are driven. Patrol and highway ones are usually pretty clean but the ones used locally get loaded up with carbon from the constant short trips and no real load on the engine.

It might clean out with steam but it may need to be opened up to actually remove it all.
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Tuesday, October 31st, 2017 AT 6:10 PM
Tiny
KEN L
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I an thinking it could be a broken valve spring as well. Maybe you should pull the valve cover and take a look
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Tuesday, October 31st, 2017 AT 8:38 PM
Tiny
JUSTINVOIGTS
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  • 11 POSTS
I didn’t see anything obvious I did replace the two lifters for that cylinder already the other day. Do you think those two lifters can be bad already I do hear noise coming from that head now again it was very quiet after I replaced them.
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Wednesday, November 1st, 2017 AT 3:22 AM
Tiny
KEN L
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Can you shoot a quick video of the noise so we can hear it?
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Wednesday, November 1st, 2017 AT 6:21 PM
Tiny
JUSTINVOIGTS
  • MEMBER
  • 11 POSTS
Question if I pull valvecover again on right side pull intake should I be able to see a bent or burnt valve if I do can I put vise grips holding chain to cam gear then pull cam gear off then pull head and send it out. I am trying to get away with not pulling front cover and taking timing chain off the job calls for 16 hours and pulling motor I don’t have a cherry picker at home nor air compressor for air ratchet all I have is Milwaukee 1/4 3/8 and powerful 1200 ft lb 1/2 inch guns do you know? Yesterday sucked can sea foam into intake while giving it gas obviously did that twice half can each time letting it sit a half hour in between. No Change did the same thing with a gallon of washer fluid no change I don’t know let me know please. Just so u know too it has fresh oil 520 synthetic and a bottle of Lucas and when I did lifters lost some oil and put in a bottle of marvel 120 miles ago because I read that will help sticking valve
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Thursday, November 2nd, 2017 AT 7:08 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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Thanks for the videos they really help. First you won't be able to see a burn valve from above. It sounds like you have a camshaft lobe that is worn down. Please remove the valve cover on the side that is making the noise and check it out. Take videos if you can so I can see.

Nice work, Ken
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Thursday, November 2nd, 2017 AT 10:07 AM
Tiny
JUSTINVOIGTS
  • MEMBER
  • 11 POSTS
Not sure where noise is but #2 is the dead cylinder firing order 1234 right side 5678 left side I can’t get valvecover all the way off cause of evaporator I snuck the lifters is it normal for cams to wear in 75000 miles seems premature let me know if u think you’ll be able to see it from the front thanks
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Thursday, November 2nd, 2017 AT 11:04 AM
Tiny
JUSTINVOIGTS
  • MEMBER
  • 11 POSTS
I don’t know if this helps butt first acceleration it kinda bogs down but when I am moving and stomp on the gas it takes off like a freight train no noticeable miss oh and when I did the lifters I didn’t notice anything wrong with cam I actually rotated engine till the lobe was at 1200 to get out the rockers on both valves for that cylinder. There was nothing wrong with lobes except a little line on each one not even deep I tried to catch it with my fingernail on my finger.
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Thursday, November 2nd, 2017 AT 1:10 PM
Tiny
STEVE W.
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You replaced just the lifters correct? Not the cam follower/rocker arm? When you took it apart was everything still in the correct position, the arms still correct? I'm wondering if they may have bent a valve stem just enough that it binds. With the cam profile and rollers if the arm fell just a bit at an angle it could have pushed the valve enough to bend it.

I would still do a leak down test.
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Thursday, November 2nd, 2017 AT 5:08 PM
Tiny
JUSTINVOIGTS
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Yes when I put in new lifters which were collapsed the rocker arms were still on there perfect. I don’t have the tool to do leak down don’t have money for it oh well. Thanks
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Thursday, November 2nd, 2017 AT 5:23 PM
Tiny
STEVE W.
  • MECHANIC
  • 14,837 POSTS
Got an Advance or Autozone around? They have them as loaner tools as do some other places. OR you can simply use the hose for a compression tester. Bring the engine to TDC on compression for cylinder 2. Lock it in place so it cannot turn and apply about 30-40 PSI to the hose screwed into the plug hole. Then just listen for the air leakage. You don't really need to know the percentage, just where the leak is.
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Thursday, November 2nd, 2017 AT 7:39 PM
Tiny
JUSTINVOIGTS
  • MEMBER
  • 11 POSTS
Just ran live data while driving under wot my fuel pressure drops to 15 psi is this normal?
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Friday, November 3rd, 2017 AT 8:26 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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No this is not normal it sounds like you have a fuel pump that is going out. Here is a guide that will give you an idea of what you are in for when doing the job.

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

and the video

https://youtu.be/SOmd3BoE4YU

Here is some diagrams of what it will be like for your car (below)

Please let us know what happens.

Cheers, Ken
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Friday, November 3rd, 2017 AT 11:55 AM
Tiny
JUSTINVOIGTS
  • MEMBER
  • 11 POSTS
Thank you but I have already replaced the fuel tank myself with car on jack stands at dads house only took a little over an hour. I won’t have to drop the tank as your illustrations show because it is a police interceptor the tank is on end fuel pump goes in through the side. Remember this is a returnless system no Schrader valve that was just the pressure read from scanner I know my dampener is damaged I can get a whole rail with injectors and dampener and electric fuel pressure regulator for 40 should I do it. I know this won’t help compression issue but may help misfires somewhat. I know there is a leak too because it takes a little cranking to get it started no fuel leak though I think it bleeds down.
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Friday, November 3rd, 2017 AT 12:11 PM
Tiny
STEVE W.
  • MECHANIC
  • 14,837 POSTS
15 psi suggests the pump control module has a problem OR that dampener has a real problem. You may want to tie into the line and see what the reading is there. A bad pressure sensor could cause the same issue.
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Friday, November 3rd, 2017 AT 6:12 PM

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