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rowekmr's avatar
rowekmr
Explorer
Sep 10, 2015

08 F450 6.4L Wrench Light on?

Hello
I bought a 08 F450 Stake Bed from a local company that claimed coolant in the oil and it was deemed too old to fix. It was one owner with 88K miles. I took it to mechanic/friend 180 miles away who replaced the front engine cover that had signs of cavitation and drained some oil out of the IC. He replaced the coolant with Ford Gold and performed an oil change.

Driving it home towing a Uhaul auto transporter trailer with a 03 Chrysler Town and Country on steep small hills the wrench symbol illuminated. I stopped and shut the truck off to check all the fluids and when I restarted it the light was off but after driving about 10 minutes it came back on again. After about another hour I stopped again to recheck and the light did not come on after restart but it did shortly after towing on flat lands. I plugged in my scanner this morning after it sat all night and there were no stored or pending codes, the CEL light was still off and the wrench did not come on when I started the engine. I am new to the 6.4L's and wanted to know possible causes of the wrench symbol illuminated.
  • rowekmr wrote:
    Hello
    I took it to mechanic/friend 180 miles away who replaced the front engine cover that had signs of cavitation and drained some oil out of the IC. He replaced the coolant with Ford Gold and performed an oil change.


    So when you say he found "signs of cavitation" can I assume that he did not find a hole all the way through the front cover? If so, it's not fixed yet. I agree with others that say it "could" be an oil cooler problem or a head gasket problem. Either way, it's bad news.

    If so, get it fixed or this is what's going to happen.
  • I would agree about the failing oil cooler; we have had a couple of these fail on 6.4L's at work along with countless other items. I think in some ways these engines were actually worse than the 6.0L.

    Your post has made me want to go out in the garage and kiss my 6.7L Cummins! I do not miss all of the issues with those Navistar issues that cause people to guess at the issue and hope for the best. I truly hope for the best for you in this case and please post what the issue ends up being.
  • Sounds like failing oil cooler to me and like others have said your scanner may be too generic. The code would be a p012F that sets when the ect/eot correlation is more than 35 degrees. This illuminates the wrench light when it happens but goes out when back in spec. The cavitation of the front cover could have caused this but also the many coolant leaks those motors have may have created some less than optimal coolant mixtures somewhere along the line. I've done many oil coolers on 6.4l and what you are describing sounds about right.
  • Great buy...of course I did I offered to pay the business what they paid for it new because I didn't want them to suffer any depreciation anxiety at closing. LOL just kidding :)

    From my reading and talking to 6.4L gurus the head gaskets don't fail as much as they did on the 6.0L's. Some of the weaknesses/issues with these are the valve train which wear out or fail, cracked pistons or some have front cover cavitation that allows the oil/coolant to mix like this one. The latter many say are concentrated to the 450/550's which have a deeper rear gear thus spinning the engine and ultimately the water pump much faster and having a pressure drop in the pump that causes bubbles to form which eat away at the metal. Ford updated the front cover design on these.

    While I did a complete bullet proof on my 6.0L I am of the consensus if it ain't broke don't fix it on this truck. No bullet proofing unless it has failed. This one will be a project that will be sold not a DD or a hard working truck.

    rhagfo wrote:
    rowekmr wrote:
    Hello
    I bought a 08 F450 Stake Bed from a local company that claimed coolant in the oil and it was deemed too old to fix. It was one owner with 88K miles. I took it to mechanic/friend 180 miles away who replaced the front engine cover that had signs of cavitation and drained some oil out of the IC. He replaced the coolant with Ford Gold and performed an oil change.

    ...............


    Coolant in the oil. :S

    Most likely a failing head gasket, or oil cooler.
    I hope you got a really great buy on it, as it sounds like it could use a Bullet Proofing.

    Bullet Proof Diesel
  • rhagfo's avatar
    rhagfo
    Explorer III
    rowekmr wrote:
    Hello
    I bought a 08 F450 Stake Bed from a local company that claimed coolant in the oil and it was deemed too old to fix. It was one owner with 88K miles. I took it to mechanic/friend 180 miles away who replaced the front engine cover that had signs of cavitation and drained some oil out of the IC. He replaced the coolant with Ford Gold and performed an oil change.

    ...............


    Coolant in the oil. :S

    Most likely a failing head gasket, or oil cooler.
    I hope you got a really great buy on it, as it sounds like it could use a Bullet Proofing.

    Bullet Proof Diesel
  • What kind of scanner are you using? Universal OBD2 readers won't read the Ford specific codes, and there's lots of them on a diesel. Wrench light can be many things.