Code P0302 misfire, cyclinder 2 issue, blinking CEL - 2010 SHO

Discussion in 'Generation 4 - General Discusson' started by Jeff szudy, Dec 1, 2017.

  1. Jeff szudy

    Jeff szudy SHO Member

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    Hello,
    New to forum, have a 2010 SHO throwing P0302 cylinder 2 misfire. CEL was blinking at times. I pulled plugs and saw oil in well. I'm not a mechanic so brought to Ford, performed compression test and said both cylinder banks leaking and failed test. They want to send heads out to be machined and quoted me 21 hours!
    I consulted with Ford mechanic back home and he thinks I should just replace Valve gaskets and Grommets, plugs and possibly coils and that should be ok, as I only have 40k miles and this would be very rare for head issues.
    Appreciate any thoughts you may have
     
  2. sperold

    sperold Last to Know

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    Do you have the compression test results for all the cylinders?

    If you do, was #2 cylinder low?

    Any discolouring of the oil?

    Is the antifreeze disappearing?

    Was the compression test performed the old fashioned way, with a screw in compression gauge. Or was it a reading off a scope?
     
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  3. Jeff szudy

    Jeff szudy SHO Member

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    Thanks! I just know that 2 cylinders failed compression test, per the service advisor. yes, cylinder 2 was one of them. Unsure of how compression test was performed. I never noticed any discolored oil, but was burning it although it smelled more like turbo carbon deposits
     
  4. SHOdded

    SHOdded SHO Member

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    Have your mechanic perform the compression test again, confirm. Valve cover gasket leaks do happen, pulling the plugs will confirm what is going on in the combustion chamber, should be one of the first things to be done.

    If it is a valve cover gasket leak, usually the symptom is misfiring. But if there IS compression loss, you will have to address that. Whether it is by using a product like AutoRx (stuck piston rings, eg) or as extreme as engine replacement (from a 2013+). Blocks do crack sometimes, so if AutoRx or similar products do not fix the compression loss, you will likely have to pull the engine. If you do that, might as well replace it. 40K in 8 years is VERY low mileage. I know a couple of people that maintain such low-mileage SHOs very rigorously. Is this one such SHO?
     
  5. sperold

    sperold Last to Know

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    The famous coking on the back of the intake valve could be an explanation for low compression (if the valve is being held open). Supposedly, they can be walnut blasted and checked with a bore-scope, which I have heard is a Ford specialty.

    Your local Ford guy is a little short of ideas if their suggestion is major engine work before exhausting the more likely candidates.
    Your down home guy sounds a little more reasonable.
     
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  6. Jeff szudy

    Jeff szudy SHO Member

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    Thanks all! I'm going to start with redoing compression tests, valve gaskets, grommets, plugs and coil #2 (misfire) and see what that does.

    @SHOdded My low mileage is mostly just due to living 2 miles from work!
     
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  7. SHOdded

    SHOdded SHO Member

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    cannot complain about the commute, LOL! But yeah, like sperold mentioned, coking is a problem, and it will increase in a severe service situation such as this. Definitely look into having the valves scoped to determine if that is the case here.
     
  8. sperold

    sperold Last to Know

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    Find a low reading cylinder on the easy side of the engine. Do the compression with a gauge and get a base number. Add oil to the cylinder and repeat the test. If the number goes up, the compression is escaping by the rings. If the number stays the same, the compression is escaping by the valve.

    If it turns out to be the valve not seating, I think the remedy is to do the walnut blasting and I think it involves removing the intake.

    I would investigate how a methanol injection system is installed by inquiring on this forum. If it involves port injection nozzles, then perform the drill and tap procedure while the intake is off and install plugs until you are ready to buy and install the system.

    I have no background in this, but I think some kind of modified water / methanol system will keep the intake valves cleaner.

    If I am wrong and the methanol system injects somewhere else before the runners, then it will be even easier to install.
     
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  9. BamSHO

    BamSHO SHO Member

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    Livernois is starting to do port meth injection, but still think they still sell the old setup too. I'm running the old setup. Which is a nozzle before the throttle body.
     
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  10. SilverSH0

    SilverSH0 SHO Member

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    Based on the low mileage the first thing I thought was potential coking on the intake valves. The oil into the cylinder is a good trick that I've never heard before. One could also use a leak down tester if their mechanic has one.

    I've looked at doing a walnut blasting on my car and it does involve removing the intake so you can get to the back of the valves. I've seen a buddy do it with a shop vac, pressure blaster, and a radiator hose (used to suck out the shells if a 3D printed one isn't available).
     
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  11. sperold

    sperold Last to Know

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    The valve coking issue on a direct injection engine has a lot of people worried, and not just on SHOs.

    I predict that people will develop water injection systems in the intake runners to solve the coke problem and as a bonus, increase horsepower by cooling the charge, like a last second inter cooler.

    Bosch already has a system called Water Boost that shows up in BMW and Porche high end models that increase horsepower and reduce emissions. I think these will be pirated and modified (even if you have to add a new shutter wheel) to resurrect SHOs that experience engine issues that are poorly diagnosed, or properly diagnosed and discarded by disillusioned owners.
    It will be something like cam welding for the GenIIIs that stabilizes an existing design, but in this case, adds a few new parts.

    Most owners will opt for the methanol injection system upstream of the runners, to remedy future coking, as BamSHO mentioned above; but many will go for the higher horsepower option that this type of system potentially offers, when the tuning industry gets on board.
     
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  12. Johnbigdog

    Johnbigdog SHO Member

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    Some of the new ecoboost have two fuel systems. Port and direct injection. This helps driveability and keeping the valves clean. I don' know if all direct injected engines will adopt this or just some.
     
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  13. BamSHO

    BamSHO SHO Member

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    Think it will across the whole engine line in time. All the 2018 Mustangs and F150s have both now. Its called PFDI now.
     
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  14. sperold

    sperold Last to Know

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    Does anyone know how the Ford 2 part system works?
    Does the engine use port injection at lower rpms and direct injection in the upper range?
    Or do they both work together?
    If they both work together, do they have a separate, regular fuel pump in the tank for the port injection system?
     
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