engine failures...

nick122590

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buddy has had numerous issues with his 5.0. knock sensor, heads, and now his #8 cylinder is fried. dealership is giving him a hard time about it saying he must of beat the piss out of it or its tune. they should be calling back today to tell him what they found when the checked the computer (the car is bone stock never tuned or anything). has anyone else heard about issues like this?


and no. its not the kid from the recent thread.
 

03GTGreen

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It was pretty common on tuned cars at first, maybe Drew or Pratt can chime in
 

Eagle

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What is this head issue you speak of?

Mine has been pretty solid. #8 has happened to others though, was definitely tune related in most cases however. Hopefully the dealer comes back with good news.
 

Chester Copperpot

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Did he buy it brand new or used? If new and he's never tuned it he can fight Ford. If used, he's basically fucked if it ever had a tune.

"Beating on it" is such a bullshit cop-out for dealers. It's a fucking performance car, meant to be beat on. Honor your god damn warranty you ass fucks.
 

The Beast

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What dealer is this? Is there any signs of abuse? I hope he gets the right answer today. The motor is expensive $$$
 

Zack

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My buddy at Van Drunen Ford replaced a coyote engine with the exact same problems. Same story too...not tuned or driven hard.

Ford knows there is a problem with some of the engines.
 

SC Cheesehead

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My buddy at Van Drunen Ford replaced a coyote engine with the exact same problems. Same story too...not tuned or driven hard.

Ford knows there is a problem with some of the engines.
Interesting.

You think it's tied into issues with cooling, etc., like on the 4.6?
 

Eagle

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Everything I've ever seen about #8 failures was around fueling issues, usually related to the car being tuned improperly.
 

willizm

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I hope they take care of the issue. FWIW I saw a 5.0 with low miles and a procharger installed throw a rod on the dyno with conservative boost pressure and a spot on tune. During the pull the car did fine with no knock or great/conservative AFR, then during deceleration it threw a rod. I really like these 5.0's, but seeing things like this make me sad. :( I really do hope that Ford steps up and takes care of it though.
 

C.Evans

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It's due to design of the cooling passages in the Coyote engine. The number 8 cylinder has the least amount of coolant passages surrounding it and is also set back the furthest in the engine bay. The ring gap is too small for the amount of heat that is created in the cylinder and it breaks the top ring land off of the piston after the ring ends butt together. Major cylinder wall scoring then happens. How is his oil consumption? Was there a cyl. 8 misfire code?
 

Eagle

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It's due to design of the cooling passages in the Coyote engine. The number 8 cylinder has the least amount of coolant passages surrounding it and is also set back the furthest in the engine bay. The ring gap is too small for the amount of heat that is created in the cylinder and it breaks the top ring land off of the piston after the ring ends butt together. Major cylinder wall scoring then happens. How is his oil consumption? Was there a cyl. 8 misfire code?
I'm not sure about that... but maybe so :dunno:

Everything I've read shows fueling, timing and KR to be the suspect causes of failures. #8 also happens to be the last cyl to get fuel from the stock rails.

That thread I posted is cool cuz good content is mainly from a tech repairing a car that was traded in to a Toyota dealer with #8 issues.
 

nick122590

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What is this head issue you speak of?

Mine has been pretty solid. #8 has happened to others though, was definitely tune related in most cases however. Hopefully the dealer comes back with good news.
my buddy is into cars but when it comes to actual tech talk hes clueless. lol. all i know is something was wrong with the valves on the pessenger side head. not sure why both were replaced. im not naming the dealer yet. ill see how it turns out first. and yes. bran new literally off the showroom floor. i think it only has around 2k miles
 

C.Evans

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A good test to see if the number 8 cylinder is getting too little fuel or too much timing... hold the throttle steady at 2,500 rpm, take a temperature reading of the exhaust manifold coming out of cylinder 8, now take a reading of any other cylinder. You should try that on your car.
 

Eagle

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Seems that its understood that #8 runs leaner than the rest, even based on the install docs that come with a new crate 5.0:

IMPORTANT NOTE: The calibration of the PCM you have received requires use of this air box/MAF sensor system
exactly as received. Any changes to the air inlet system will result in changes to how the air entering the engine is
measured and will require modification to the PCM's calibration.
Ford Racing recognizes that it may not be practical to package this Air Box/MAF sensor system in some vehicle
applications. The recommendations listed below are intended to serve as guidelines for designing an air inlet system that
will provide good control system performance once the control system calibration has been modified to work with the new
Air Inlet System:
1) Flow Profile: the MAF sensor should be located on a straight section of zip tube where the flow profile is
generally uniform. If the sensor cannot be located on a straight section put the sensor on the outside radius of the
zip tube so the sensor is located in the higher flow velocity area.
2) Flow Area: Keep the cross sectional area of the MAF sensor tube as close as possible to the cross sectional
area of the original induction system.
3) Flow quality: minimize flow direction changes and maintain smooth tubing to minimize air flow disturbances and
turbulence.
4) Flow pulsation: install sensor at least 6 to 8 inches upstream of the throttle body.
5) Transient performance: installing the sensor too far upstream of the throttle body (>24 inches) will result in
transient lean/rich spikes due to the additional amount of time required for the measured air flow to travel from the
MAF sensor to the intake manifold.
6) MAF sensor contamination: A) install sensor in upper half of cross sectional area to minimize possibility of
condensation coming in contact with the MAF sensor element. In other words, if a clock is superimposed on a
cross section of the zip tube, the sensor should be installed somewhere equal to or above the 9:00 and 3:00
positions. Most OEM applications have the sensor located at the 9:00 or 3:00 location. B) Sensor must be
installed downstream of air filter and upstream of blow-by inlet. Ideally, sensor should be located 3 diameters
upstream of the blow-by inlet.


This is interesting too:

The engine harness and controls package M-6017-A504V is designed to operate with the UEGO sensors in the
2011-2012 Mustang GT stock locations. Moving the UEGO sensors to alternate locations can result in the need to
recalibrate the PCM.
Here are some tips if sensors have to be relocated.
The best option is to locate the sensor so it is sampling from all 4 cylinders and at a distance that does not require
modification of the UEGO harness.
NOTE: Modification of the UEGO harness can affect function of UEGO sensor.
If your header design will not allow you to sample all 4 cylinders without UEGO harness modifications, a better alternative
is locating the UEGO sensor to sample from a single cylinder.
The cylinders that have (on average) the closest A/F ratio to the bank average are cylinder #4 (on bank 1) and cylinder #7
(on bank 2). If that's not possible due to packaging constraints, the next best choices are cylinder #3 (on bank 1) and
cylinder #8 (on bank 2). Calibration required!

It seems to imply to me that #8 is going to run leaner than the average at least a little-surely your second choice average would want to be leaner than average, rather than richer.
 

ilikemtb999

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So are people just tuning a bit rich or is there a way to squeeze more from the #8 injector compared to the rest?
 

Chester Copperpot

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I've noticed there's two scenarios where the #8 issue has appeared. People who immediately put tunes on the brand new engine at <500mi or people who broke their engine in according to the manual and were easy on the car until then. The cars that haven't popped or don't have issues? The cars that were beaten like two dollar hookers from day one but waited to put a tune on or haven't at all. There's been a few cases of bone stock 5.0s popping #8.

I fall into the last category. My car ate a quart of oil from 28-4000mi and in the last 8000mi it hasn't burned a drop. Checked regularly every or every other gas fill up. Yes I'm that anal.
 

Eagle

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Reconfigure the fuel feed to be in parallel rather than series would probably be good too.
 

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