Cracked Intake Manifold ?

[MyLittle Pony]

So my wife called me on the way home something has happend to the Mustang (2001 with 81k) upon quick inspection i
Hear what sounds like a loud popping noise like like escaping and is consistant with the idle of the car. Not sure if its the manifold or possibly a bad coil no tools with me to remove the coil (3rd coil from the front on passenger side). Just seeing if anyone has had anything like this so i know what to expect also any replacement parts or upgrades thanks in advance.

 

[wmburns]

Does it sound like a lawn mower when running? If so, think "spark plug" blow out. You have the model year Romeo with the too few spark plug thread problem. Correct torque is VITAL. Goes double for the heads with too few threads.

I had this happen to me. I could look down inside the spark plug hole and see the threads were pulled right out.

While I normally work on my own cars I paid a profession to perform the thread repair. I figured he had the tool and the experience to do it right. $$ well spent.

When I rechecked the torque on the remaining spark plugs I found two more that had backed out. So I saved myself from having more blow out. This is what I get for going too long between checking.

Research http://www.timesert.com/

https://www.summitracing.com/parts/...ese1-_-lisle&gclid=CLm92oPq19MCFcK4wAod0OkO1A

http://www.denlorstools.com/home/dt1/page_64062/ford_spark_plug_blow_out_problems_how_to_repair.html

https://www.ford-trucks.com/forums/991189-spark-plug-thread-repair-with-photos.html

http://www.allfordmustangs.com/forums/4-6l-tech/886690-4-6l-2v-spark-plug-thread-repair.html

 

[MyLittle Pony]

Yeah kinda sounds like when you remove a spark plug. Could this simply be as easy as it backing out from vibration or more from stripping the threads on the plug or plug hole? Only had the car for 2 weeks so not too sure what previous owner has done.

It stalls when trying to move or idle

 

[Saberstang]

Indeed this is a common issue with the Romeo 4.6L engines. I know one person this happened to and had to replace both cylinder heads. If that is the case you will have to either replace your cylinder head/s or repair/rebuild your cylinder head/s this occurred in. Proper spark plug torque is a must in the Romeo or Windsor engines. I just replaced my Motorcraft spark plugs fortunately.

 

[MyLittle Pony]

Well turns out it blew out a plug going to try and rethread with helicoil for short term repair and looks like im going to be upgrading heads sooner than i thought.

Any recommendations for aftermarket heads i have victor jr setup in mind but open to any input/suggestions

 

[MyLittle Pony]

Well turns out it blew out a plug going to try and rethread with helicoil for short term repair and looks like im going to be upgrading heads sooner than i thought.

Any recommendations for aftermarket heads i have victor jr setup in mind but open to any input/suggestions

 

[Saberstang]

Well turns out it blew out a plug going to try and rethread with helicoil for short term repair and looks like im going to be upgrading heads sooner than i thought.

Any recommendations for aftermarket heads i have victor jr setup in mind but open to any input/suggestions

Well there is a lot of options to consider going with ported PI cylinder heads or aftermarket cylinder heads. A lot of good/reputable port and polishing services available out there. For future mods I am considering purchasing a set of new PI cylinder heads and sending them to Modular Motorsport Racing for there stage two port and polishing with a few of there options including stage one or two PI camshafts. In my opinion I don't think it is worth spending all the extra coin for aftermarket cylinder heads or ported aftermarket cylinder heads. There is more rwhp and rwtq to be made with aftermarket cylinder heads vs. PI cylinder heads but, I don't think it justifies the price you will pay. I also have a Romeo engine too hopefully I will be able to wait before I can do the PI cylinder head swap.

 

[MyLittle Pony]

So i take it the newer PI heads have had the plug blowout problem fixed ?

 

[Saberstang]

So i take it the newer PI heads have had the plug blowout problem fixed ?

The biggest reason that spark plugs blow out or strip is because people install the spark plugs without using a torque wrench yes a torque wrench. 12-15 ft. lbs is factory Spec which is barely more than hand tight. Spark plugs must always be installed on a cold engine never hot or warm. Any previous PI cylinder heads 99-03 has the potential to do it. 04- up revised PI cylinder heads with the eight thread plug holes could strip being aluminum. The previous 99-03 PI cylinder heads had only four threads and the later revised 04+ PI cylinder heads got the eight thread treatment. If you purchase new PI cylinder heads make sure they are the revised 04+ version but there still is a potential your spark plugs could blow out of your cylinder head/s.

 

[MyLittle Pony]

Thanks for all the info greatly appreciated

 

[wmburns]

There's no real reason why a correctly done spark plug thread repair couldn't be considered a permanent fix and be good for the life of the car.

+1 on using correct torque. But even when correctly torqued the spark plugs should be checked from time to time. For me 5 years between checks was too long. Shame on me.