2003 5.4L coolant leak and engine misfire
05-30-2016, 10:51 AM
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2003 5.4L coolant leak and engine misfire
Really need some help with this one....
2003 F150 4WD, 5.4, with 104k miles
About 4 days ago, I felt like the truck was running a little rough at idle. Over the next two days, it got worse. Looked under the hood and found a lot of rusty looking coolant coming from reservoir cap and running down the engine compartment. Service engine soon light came on and started blinking. Brought it to Advanced auto. They read the code. #4 cylinder misfire. Took it home, flushed radiator and replaced all 8 plugs. Started it up, it ran great. Next day, went to work. Started fine and ran great. When I parked it at work, engine was running rough again and coolant leaking from cap again. After a few minutes, truck began to run fine at idle.
Truck has not been running hot, and gauge seems to be working fine. The two issues seem to be connected somehow, but I can't figure it out. Thought maybe coolant was getting into air intake, but the filter is new and dry. Also, the reservoir tank does hold pressure. I'm wondering if the cap is just releasing before its max pressure. I don't know. Been scratching my head with this one. Any ideas would be very helpful, thanks!
No other symptoms.. Oil is good. No white smoke, no other leaks I can see from heads. I'm really a time a lose here.
2003 F150 4WD, 5.4, with 104k miles
About 4 days ago, I felt like the truck was running a little rough at idle. Over the next two days, it got worse. Looked under the hood and found a lot of rusty looking coolant coming from reservoir cap and running down the engine compartment. Service engine soon light came on and started blinking. Brought it to Advanced auto. They read the code. #4 cylinder misfire. Took it home, flushed radiator and replaced all 8 plugs. Started it up, it ran great. Next day, went to work. Started fine and ran great. When I parked it at work, engine was running rough again and coolant leaking from cap again. After a few minutes, truck began to run fine at idle.
Truck has not been running hot, and gauge seems to be working fine. The two issues seem to be connected somehow, but I can't figure it out. Thought maybe coolant was getting into air intake, but the filter is new and dry. Also, the reservoir tank does hold pressure. I'm wondering if the cap is just releasing before its max pressure. I don't know. Been scratching my head with this one. Any ideas would be very helpful, thanks!
No other symptoms.. Oil is good. No white smoke, no other leaks I can see from heads. I'm really a time a lose here.
05-30-2016, 03:37 PM
#2
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If you are not holding pressure then replace your rad/reservoir cap. If you still have the original with the white warning label chances are even better it is toast. I read somewhere so many Fords had issues with them they were redesigned. A new one from Ford is your best bet and you will see that the new ones don't have a label but the warning info is painted directly on the cap.
I am not sure how that would make your engine idle rough though if you were not overheating. I think your problems are separate and you may want switch out your #4 coil.
You should post your actual code. It will give everyone a better idea of what is happening.
I am not sure how that would make your engine idle rough though if you were not overheating. I think your problems are separate and you may want switch out your #4 coil.
You should post your actual code. It will give everyone a better idea of what is happening.
Last edited by grizzstang; 05-30-2016 at 04:09 PM. Reason: Spelling
05-30-2016, 05:05 PM
#3
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Sounds like Combustion Gas is leaking to your cooling system due to bad head gasket. Can you see bubbles in coolant without the cap inplace?
Last edited by w0lvez; 05-30-2016 at 05:08 PM.
05-30-2016, 08:57 PM
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No bubbles in the coolant. Today I bought a cap at autozone. Only $5. I just wanted to see if that would fix the coolant leak, and I drove home after work and it did not leak, so I think that may have fixed the issue. I think the comment before yours may be right. Truck is still idling rough even without the coolant leaking. I may go get a new coil and see if that does the trick. I'll give the cheap cap a couple more days. If it doesn't leak, I'll buy a new one from Ford. I don't have the actual code. The guy just said it was "#4 cylinder misfire". Is there a way to test the coil?
05-30-2016, 09:24 PM
#5
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Good chance your heater core lines are leaking on #4 coil once conditions are meant. They won't leak all the time, - coolant may burst from one of the hose connections (usually the worm clamp connection) just briefly and hit #4 w/coolant. That will short the coil and all evidence can cook off before you notice it. You have to try and catch coolant in the #4 plug chamber before heat dissipation re-enables the coil, - to confirm this issue anyway. At some point, #4 will short out for good. Look for coolant stains in the area as well....evidence of any kind.
Not just theory, but it's happened in the past to quite a few...hard to catch. First thing I would do is clean that cap, - blow it out w/compressed air...blow some WD40 into the cap to assist with cleaning, then blow it out dry. Or replace the dang thing.
Might want to use a rag, hold it over #4 plug chamber best you can w/coil in place, blow compressed into the chamber and see if you notice any coolant on the rag. It'll shoot out of there w/some compressed air assistance.
Could this all be because of a bad cap ? Yes, it's possible, check it out.
EDIT: I must have missed your last post before submitting mine, - see that your trying a new cap. Good, - that might do it.
Not just theory, but it's happened in the past to quite a few...hard to catch. First thing I would do is clean that cap, - blow it out w/compressed air...blow some WD40 into the cap to assist with cleaning, then blow it out dry. Or replace the dang thing.
Might want to use a rag, hold it over #4 plug chamber best you can w/coil in place, blow compressed into the chamber and see if you notice any coolant on the rag. It'll shoot out of there w/some compressed air assistance.
Could this all be because of a bad cap ? Yes, it's possible, check it out.
EDIT: I must have missed your last post before submitting mine, - see that your trying a new cap. Good, - that might do it.
Last edited by Jbrew; 05-30-2016 at 09:30 PM.
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techrep (05-31-2016)
05-30-2016, 10:01 PM
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Good chance your heater core lines are leaking on #4 coil once conditions are meant. They won't leak all the time, - coolant may burst from one of the hose connections (usually the worm clamp connection) just briefly and hit #4 w/coolant. That will short the coil and all evidence can cook off before you notice it. You have to try and catch coolant in the #4 plug chamber before heat dissipation re-enables the coil, - to confirm this issue anyway. At some point, #4 will short out for good. Look for coolant stains in the area as well....evidence of any kind.
Not just theory, but it's happened in the past to quite a few...hard to catch. First thing I would do is clean that cap, - blow it out w/compressed air...blow some WD40 into the cap to assist with cleaning, then blow it out dry. Or replace the dang thing.
Might want to use a rag, hold it over #4 plug chamber best you can w/coil in place, blow compressed into the chamber and see if you notice any coolant on the rag. It'll shoot out of there w/some compressed air assistance.
Could this all be because of a bad cap ? Yes, it's possible, check it out.
EDIT: I must have missed your last post before submitting mine, - see that your trying a new cap. Good, - that might do it.
Not just theory, but it's happened in the past to quite a few...hard to catch. First thing I would do is clean that cap, - blow it out w/compressed air...blow some WD40 into the cap to assist with cleaning, then blow it out dry. Or replace the dang thing.
Might want to use a rag, hold it over #4 plug chamber best you can w/coil in place, blow compressed into the chamber and see if you notice any coolant on the rag. It'll shoot out of there w/some compressed air assistance.
Could this all be because of a bad cap ? Yes, it's possible, check it out.
EDIT: I must have missed your last post before submitting mine, - see that your trying a new cap. Good, - that might do it.
Here is what it looked like when I drained the radiator
Here is the #4 spark plug that I pulled out. It was wet and smelled like fuel.
Last edited by Dstone; 05-30-2016 at 10:05 PM.
05-30-2016, 11:01 PM
#7
You wont see bubbles in coolant because it doesnt circulate thru the reservoir.
Id be suspicious of hg leak until proven otherwise.
Watch level in reservoir when cold /hot. Should be exactly same day to day. Mark the res when cold. If its not, its due to gas in system.
Id be suspicious of hg leak until proven otherwise.
Watch level in reservoir when cold /hot. Should be exactly same day to day. Mark the res when cold. If its not, its due to gas in system.
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05-31-2016, 12:25 AM
#8
Senior Member
Looks like the Radiator Oil Cooler is leaking ATF. Check while the gear selector is in Drive or Reverse.
If your Cooling system is not holding pressure it will stay on open loop. Fuel to air mixture will be too rich.
Here's how to verify if the Radiator Oil Cooler is leaking.
If your Cooling system is not holding pressure it will stay on open loop. Fuel to air mixture will be too rich.
Here's how to verify if the Radiator Oil Cooler is leaking.
Last edited by w0lvez; 05-31-2016 at 01:04 AM.
05-31-2016, 12:57 AM
#9
Senior Member
No evidence of coolant on #4? Alright then, that's good! - Now swap #4 coil w/#1 to determine and confirm the coil as good or bad. If the miss follows, replace the coil. If not....swap the injector same way.
Most likley it's the coil in this case. By the looks of the plug, probably started out as a low grade miss that gradually got bad enough for the misfire monitor to pick it up. Check it first, I explained how, -unless you don't mind throwing parts at it lol.
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techrep (05-31-2016)
05-31-2016, 06:53 AM
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Yea,l ike I said, that may have worked replacing the cap. That would be cool, other then the coolant looking like shiii!
No evidence of coolant on #4? Alright then, that's good! - Now swap #4 coil w/#1 to determine and confirm the coil as good or bad. If the miss follows, replace the coil. If not....swap the injector same way.
Most likley it's the coil in this case. By the looks of the plug, probably started out as a low grade miss that gradually got bad enough for the misfire monitor to pick it up. Check it first, I explained how, -unless you don't mind throwing parts at it lol.
No evidence of coolant on #4? Alright then, that's good! - Now swap #4 coil w/#1 to determine and confirm the coil as good or bad. If the miss follows, replace the coil. If not....swap the injector same way.
Most likley it's the coil in this case. By the looks of the plug, probably started out as a low grade miss that gradually got bad enough for the misfire monitor to pick it up. Check it first, I explained how, -unless you don't mind throwing parts at it lol.
Swapping the coils... Did not think of that!! Thank you. Good idea. Also the new cap is on day two and no leaks. I think that issue is fixed. Now I just need to try swapping coils and see if that works. Thanks so much for town hall help guys!!! I'll let you know how it goes