P0303, cylinder #3 misfire.

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ORRadtech

ORRadtech

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I'd borescope #3 after letting the car sit overnight if you can.
I don't have a borescope yet, sounds like a good excuse to buy a new tool!
I assume that I'd be looking for coolant on/in the cylinder? Anything else?
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The wider gap could be be the culprit but like you said the whiter ceramic is something to keep investigating. Coolant could be washing it clean. Then again 0.040 is a really big gap so on plugs that old that could totally be it.
That's my sincere hope! Put about a hundred miles on it yesterday and it's definitely running noticeably smoother, especially the idle. Still no return CEL.
 

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I don't have a borescope yet, sounds like a good excuse to buy a new tool!
I assume that I'd be looking for coolant on/in the cylinder? Anything else?
They can be had for quite cheap nowadays. USB type is like 30 dollars
 
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Well hell!
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Time to research options...

For the record, still no CEL but it is losing coolant.
 
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I don't mean to scare you or say for sure its a head gasket. I just mention it because it was my recent experience, (in my case #2 misfire) and I went through all the usual suspects (new plugs, swap coils) and then wanted to rule out HG since its a known issue. I had trouble believing that it could be a blown HG with a leakdown loss <5% but in my case turned out to be true.
Might I ask if your engine was repaired under warranty? If not who did the repair? Ford or an independent shop? Also, what was done and what was the cost- if you don't mind sharing.
 

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Sorry man, I know that feeling.

I bought the Facotry repair manual and requisite parts and did it myself. Was out of warranty. I’ve read the cost is around $2-4k in labor. It’s a lot of work so I could see how the bill would be pretty steep. The actual parts are not expensive if you get OEM, it’s just the time and struggle at a few points. Prob $100 in parts. The option to consider is upgraded head studs which depending on what you get are either $200 or $400 for a set. If you’re not beating on the car a lot or running big power then I’d probably do the regular ARP studs. Or you can go all out and get CA625+ studs. Studs offer much better clamping load and consistent torque than the oem bolts so should help prevent the same failure mode in the future.
 
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Sorry man, I know that feeling.

I bought the Facotry repair manual and requisite parts and did it myself. Was out of warranty. I’ve read the cost is around $2-4k in labor. It’s a lot of work so I could see how the bill would be pretty steep. The actual parts are not expensive if you get OEM, it’s just the time and struggle at a few points. Prob $100 in parts. The option to consider is upgraded head studs which depending on what you get are either $200 or $400 for a set. If you’re not beating on the car a lot or running big power then I’d probably do the regular ARP studs. Or you can go all out and get CA625+ studs. Studs offer much better clamping load and consistent torque than the oem bolts so should help prevent the same failure mode in the future.
It kinda looks like that's the direction I might be headed. I've been having some trouble finding a place that's actually willing to do a head gasket. They'll gladly replace an engine but won't do a head gasket. Still looking but losing hope on that front.
Fortunately I've got another car to drive and a BIL I may be able to talk into helping. I definitely plan to upgrade the gasket and the studs whoever does the work. I assume you bought the tool to set the timing? Any other special or odd tools I'll need? I've no plans to build it nor beat on it I just don't want it to happen again...
 

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Sorry to see that man. Honestly seems like this happens way too often to even stock Ecoboosts once you pass the 60 or 70k mark. Pretty shocking.

As far as DIY, it's not super hard but it's not easy either. Lots of ways you can make a mistake that could destroy the engine. Cleaning the deck and head surfaces is one of those. Gotta block off all the oil and coolant ports with foil or tape to avoid shavings getting in. Timing setting is also a critical thing to get right.
 
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Scootsmcgreggor

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It kinda looks like that's the direction I might be headed. I've been having some trouble finding a place that's actually willing to do a head gasket. They'll gladly replace an engine but won't do a head gasket. Still looking but losing hope on that front.
Fortunately I've got another car to drive and a BIL I may be able to talk into helping. I definitely plan to upgrade the gasket and the studs whoever does the work. I assume you bought the tool to set the timing? Any other special or odd tools I'll need? I've no plans to build it nor beat on it I just don't want it to happen again...
Yeah a couple tools.

Timing tools for 2.0/2.3 Ecoboost. Happy to send you mine I won’t need them again.

Giant strap wrench for crank pulley. 18” handle.

Torque to degree indicator.

Crowfoot wrench for torquing hpfp hardline.
 
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An update.
First the car.
The car is running well, no CEL, no overheating, very minor idle anomaly and as of the last few days no coolant usage, neither the oil or coolant appear to be contaminated. I'm not understanding the lack of coolant usage. Up to this point it's been losing 5 or 6 ounces a week. Ironically this kind of worries me for the reason you'll see below.
Next, the situation.
While collecting the various things I'll need for the repair I ran into some potentially fantastic news. At 77+k miles I believed all my warranties had expired. Since I purchased the car under CPO I have found that the drive train warranty is 100k miles. From my reading I believe the headgasket is a covered item. I'm currently waiting for my Nov 10th appointment to take it in for evaluation.

That's where the current lack of coolant usage concerns me. I fear that Ford will deny to replace the headgasket for lack of symptoms. I have photos of the old plugs and from the borescope showing coolant weeping into the cylinder but I don't know if that will be enough to persuade them.
I'm in the unenviable position of actually hoping the leak gets worse...
 

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An update.
First the car.
The car is running well, no CEL, no overheating, very minor idle anomaly and as of the last few days no coolant usage, neither the oil or coolant appear to be contaminated. I'm not understanding the lack of coolant usage. Up to this point it's been losing 5 or 6 ounces a week. Ironically this kind of worries me for the reason you'll see below.
Next, the situation.
While collecting the various things I'll need for the repair I ran into some potentially fantastic news. At 77+k miles I believed all my warranties had expired. Since I purchased the car under CPO I have found that the drive train warranty is 100k miles. From my reading I believe the headgasket is a covered item. I'm currently waiting for my Nov 10th appointment to take it in for evaluation.

That's where the current lack of coolant usage concerns me. I fear that Ford will deny to replace the headgasket for lack of symptoms. I have photos of the old plugs and from the borescope showing coolant weeping into the cylinder but I don't know if that will be enough to persuade them.
I'm in the unenviable position of actually hoping the leak gets worse...
That’s great news! I have 2018 Eco PP and I was dealing with a p0303 code about 6 months ago. Dealer swore it was a faulty plug until it happened 3 times in a row. It would only misfire on cold starts in the morning. One of the more experienced techs did a pressure test on the cooling system and looked into the cylinder and found coolant. Ford ended up putting a whole new short block and a new head in the car. I also had a very small amount of coolant leaking in.
 

krack999

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Sorry to hear all this.... here is some advice...

1. Collect an oil sample and send it to Blackstone labs once you have about 1,000 miles or more on your current oil change. They will tell you if there is coolant in your oil sample or not. Trust me, they have a lot of Mustang Ecoboosts that have coolant in the oil.
2. Mark your current coolant level on your coolant reservoir.
3. Wait for your oil analysis to come back. Then, take analysis along with those pictures and talk to a Ford dealership. There are some in Atlanta that will take you seriously. DM me for more info.
4. They will probably do a leak down test and not find anything. This failure mode for some reason does not fail that test.
5. Then, they will probably fill up your reservoir with coolant and tell you to bring it back after driving the car 5,000 miles.

Good luck! I think these are great cars, however, the headgasket issues are real. I would even ask the dealership if you can furnish or pay for them to put in better head studs instead of re-using the factory head-studs.

etable 7/2/20,
An update.
First the car.
The car is running well, no CEL, no overheating, very minor idle anomaly and as of the last few days no coolant usage, neither the oil or coolant appear to be contaminated. I'm not understanding the lack of coolant usage. Up to this point it's been losing 5 or 6 ounces a week. Ironically this kind of worries me for the reason you'll see below.
Next, the situation.
While collecting the various things I'll need for the repair I ran into some potentially fantastic news. At 77+k miles I believed all my warranties had expired. Since I purchased the car under CPO I have found that the drive train warranty is 100k miles. From my reading I believe the headgasket is a covered item. I'm currently waiting for my Nov 10th appointment to take it in for evaluation.

That's where the current lack of coolant usage concerns me. I fear that Ford will deny to replace the headgasket for lack of symptoms. I have photos of the old plugs and from the borescope showing coolant weeping into the cylinder but I don't know if that will be enough to persuade them.
I'm in the unenviable position of actually hoping the leak gets worse...
 
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