Common 4.6L V8 2V Problems

[Orange 94]

This thread will cover some of the common problems with 4.6L V8 2V in the SN95. The information in this thread was provided by members of our community, thank you all that helped.


If you have any questions after reading this thread please try using the search bar located in the top right. Chances are there is already a topic covering your exact question.
After trying the search bar please feel free to start a thread in the appropriate section for addition information. Our community is happy to help!



Lastly, if you have any corrections or addition information please post it in this thread! I'll add the information to this first post!

Thanks!



1. Ticking lash adjuster.
Solution: Buy a tool such as http://www.shopfreedomracing.com/2V-4V-V8-and-40L-SOHC-Valve-Spring-Compressor-ST-103.htm
miss.mod.50

2. Coolant Leaks.
The 2V intake manifold (notably the one with the plastic crossover) is use to cracking after a while.
Mine cracked at about 110,000 miles near the thermostat housing.
The newer intake manifolds (Post 01+) came with an aluminium crossover that was an ideal replacement.
You can now also find the NPI version of the intake manifold with an aluminium crossover if you don't want to upgrade.

This is the crossover:

And here is a comparison of the plastic vs. aluminium crossover:

Ferocious

3. Hanging Idle
The 2V motors were known for a dreaded hanging idle when letting off the gas.
This can sometimes be traced back to the IAC restrictor plate.
To fix this issue just make a custom gasket that will restrict even more airflow from the IAC and your RPMs will drop noticeably faster.

The plate is between the IAC motor and the plenum:

Here is the difference between the stock plate and the one you should make/buy:
[URL="http://i.imgur.com/nuxVrhAl.png%5b/IMG"]http://i.imgur.com/nuxVrhAl.png[/IMG[/URL]]
Ferocious

[B][SIZE=3]4.[/SIZE][/B] [B]NPI Top End[/B]
If you have a 96-98 GT, you have what is known as a NPI motor. This means that your heads, cams, and intake are [B]non-performance improved[/B].
In 1999, Ford revised their 2v engine for the mustang and freed up airflow by throwing on PI (performance improved) heads, cams, and intake. This gave the 2V an extra ~45 HP or so.

Here's is a comparison of the top end parts:
[IMG]http://i.imgur.com/fnvkzDal.png


Here are the specs on the cams:

Cam Name: Intake | Exh | LSA | Overlap
----------------------------------------------------------------------------------------------------------
Ford 92-98 2v: 0.480 | 0.480 | 115 | -42.0°
Ford 99-04 2v: 0.505 | 0.531 | 115 | -25.5°
----------------------------------------------------------------------------------------------------------

The PI headswap is a cheap and rewarding swap for anyone with an NPI.
Swapping PI parts onto your NPI motor will also bump up your compression and net you a few ponies.

You can find writeups on the swap here:
http://sn95forums.com/showthread.php...bout-NPI-vs-PI
http://sn95forums.com/showthread.php...adswap-and-You
http://sn95forums.com/showthread.php...Install-How-To
http://mustangforums.com/forum/4-6l-...d-to-know.html
http://www.allfordmustangs.com/forum...ustang-gt.html
Ferocious

5. Spark plug separating issues. http://fulltorque.com/pdf/Ford%20Tec...20Bulletin.pdf
miss.mod.50,nightfire

6. Valve seals on 97 and back IIRC go bad around 120k miles
slow90coupe

7. Timing chain guides wear or break
nightfire,sn95jones

 

[ScottyDsntKnow]

5 thread spark plug heads up to 2003. Be extra sure to use a torque wrench on heads prior to 2004 but if you don't use one you can blow out the head threads on any head even the 8 thread 2004-up Romeos.

 

[Goldmember]

5 thread spark plug heads up to 2003. Be extra sure to use a torque wrench on heads prior to 2004 but if you don't use one you can blow out the head threads on any head even the 8 thread 2004-up Romeos.

Not strictly true. I thought the '04 was immune until I lost the #4 plug.

I would like to add that unless the head is damaged beyond repair, the factory-approved fix is called a Time-sert. Basically a threaded insert that is locked into place and is actually stronger than the rest of the head. Good for the life of the vehicle. Don't listen to morons (sadly we are overrun) who will tell you to replace the head wholesale, this procedure cost me a little over $200 at my local Ford dealer, and I have no doubts about its strength and reliability.

Edit- My '04 was built in 8/03. Possibly, it came with leftover '03 castings.

 

[Goldmember]

Also, for the IAC restrictor plate, get several copper pipe caps at Home Depot or similar (about 50 cents a piece).

Drill each with a different size hole, I believe somewhere in the 3/16"-3/8" range is the sweet spot. The cap goes in the hose leading to the IAC.

If the car will hold an idle, you've done it right. If the hole is too small it will stall pretty quickly and you will likely get a CEL.

Edit- I ended up going 1/4". Had a hard time holding a steady idle with A/C on, this cured that. The "snap crackle pop" between gears is a nice bonus.

 

[Goldmember]

Also, when you're in the field without pictures:

NPI intake- first runner goes to #1 cylinder
PI intake - first runner goes to #5 cylinder (on side of thermostat housing)

 

[NEURON]

Great thread, would be nice to be updated with more problems.

 

[Swapfox2145]

Great write up this has helped me solve a couple issues with my sn95 thanks!