Lower Intake Attempt #3

Keith5.0GT

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May 29, 2017
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hey everyone. Quick question. I’m about to do my lower intake gasket for the third time this year. Hard to see back there but my best guess is that’s it. So I’ve done it twice, and both times I use permatex black in the lifter valleys and no gasket like everyone says but I get oil going down the bell housing and under the car. The gap between the mating surfaces seems to be about 3/16”. Anyone know if this gap size is normal? Everyone acts like it’s easy to seal but I can’t get it. I have a big tube of “right stuff” this time and I’m hoping to get a good enough bead to seal!! So yeah anyone remember what gap they had in the lifter valley to lower intake? I’ve done rear main seal and every other gasket there is. Just have a stubborn leak in the back. Thanks! Wanna be leak free.
 
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jrichker

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Do it this way, I can assure you that it works...

Intake manifold removal and replacement.

Revised 8 Jul 2017 to add diagrams and bolt torque information

Here's some help...

Vacuum line connections:
One large vacuum line from the upper front goes to the carbon canister

One large vacuum line from the rear goes to the vacuum tree.

One small line in the front feeds the Smog pump solenoid control valves on the rear of the passenger side wheel well..

One small line in the rear goes to the fuel pressure regulator.

One small line in the rear goes to the EGR suction regulator.

One large line in the rear goes to the PVC valve.

Diagram courtesy of Tmoss & Stang&2birds - Typical Vacuum Routing for a Fox stang 5.0:
mustangFoxFordVacuumDiagram.jpg


Diagram courtesy of Tmoss & Stang&2birds - Intake manifold bolt tightening sequence for a 5.0 Fox stang:
FordIntakeTorqueSequence.gif


Intake manifold to head bolts
--Step 1 96 in/lbs
--Step 2 16ft/lbs
--Step 3 23-25 ft/lbs

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

Here's some tips...

Tools: a good torque wrench is a must have item. A razor blade scraper that holds a single edge razor blade from Home Depot or Ace hardware is another handy thing. Get a Chilton or Haynes shop manual - you'll need it for the bolt torques and patterns. The intake manifold has an especially odd pattern. You'll need access to a timing light to set the timing after you re-stab the distributor. Look in the A/C repair section for the fuel line tools. They look like little plastic top hats. You will need the 1/2" & 5/8" ones. The hat shaped section goes on facing the large part of the coupling. Then you press hard on the brim until it forces the sleeve into the coupling and releases the spring. You may need someone to pull on the line while you press on the coupling. Put some motor oil on them when you put the line back together.

The A/C Compressor comes off with lines still connected. Mark all the electrical, smog and vacuum lines with tags to help you remember where to re-connect them. If you have a digital camera, take several pictures.

Whatever you do, don't skimp on cleaning the gasket surfaces. New gaskets need to seat against bare metal and not the residue left from the old gaskets in order to seal leak free. This is the most time consuming and tiresome part of the job. When all the surfaces are free of dark specks and are smooth enough that when you run your fingernail over the surface, you don't feel any raised places, then it is clean enough.

Put some cardboard in the lifter valley to help catch the gasket scrapings. Have a shop vacuum handy to suck up the scrapings and any coolant that leaked into the lifter valley.

Look for little things that need to be replaced like the short hose from the thermostat hosing to the water pump, damaged vacuum lines and hose clamps that are rusted or broken.

Plan on cutting the thermostat to water pump hose, or removing the thermostat housing. Also plan on removing the distributor to get clearance to remove the intake manifold. Remove #1 spark plug, stick your finger in the spark plug hole and crank. When your finger gets air moving past it, stop cranking. Turn the engine until the timing marks line up with the pointer. Now you can pull the distributor out. Be sure to put a rag or cap in the block where you removed the distributor. It will save you trouble if something falls into the empty distributor hole.


My favorite trick that saves time and effort is the stay in place gasket. Be sure that you scrape (don't use a wire brush) all the old gasket material off, then clean all the surfaces with acetone or MEK.

When the surfaces are clean, use weather strip adhesive on the head to manifold surface. Also use the weather strip adhesive on the side of the gasket that mates to the head. When you are done, the head surface and the gasket surface that mate together will have weather strip adhesive on them. Follow the instructions on the tube or can and when it gets tacky, press the gasket down on the head.

Clean the area where the rubber rails mount to the block in front and in the rear with more acetone or MEK and do the same trick with the weather strip adhesive that you did to the heads.

Coat the rubber seals and the gasket area around the water passages with lots of Blue Silicone gasket sealer and put it together. TADA! no leaks, and no gaskets that shifted out of place.

Fuel injector seal kits with 2 O rings and a pintle cap (Borg-Warner P/N 274081) are available at Pep Boys auto parts. Cost is about $3-$4 per kit. The following are listed at the Borg-Warner site ( http://www.borg-warner.com ) as being resellers of Borg-Warner parts:

http://www.partsplus.com/ or http://www.autovalue.com/ or http://www.pepboys.com/ or http://www.federatedautoparts.com/

Most of the links above have store locators for find a store in your area.

Use motor oil on the O rings when you re-assemble them & everything will slide into place. The gasoline will wash away any excess oil that gets in the wrong places and it will burn up in the combustion chamber. Heat the pintle caps in boiling water to soften them to make them easier to install.

Plan on doing an oil change within 2 hours of run time on the engine. This will get the debris and coolant out of the oil pan.

Consumable items:
Upper manifold gasket
Fel Pro 1250 or equal lower manifold gasket set.
Short formed hose between thermostat hosing and intake manifold
6 ft 7/64" or 1/8" vacuum hose
2 ft 1/2" heater hose
1 1/2 ft 5/8" heater hose
Blue Silicone sealer
ARP antiseize or equal for the bolts
4 each 3/4" hose clamps (spare item in case the old ones are bad)
4 each 1/2" hose clamps (spare item)

What can happen if you don’t use the stay in place gasket…

Ask Nicoleb3x3 about the intake gasket that slipped out of place and caused idle and vacuum leak problems that could not be seen or found by external examination. Spay everything with anything you have, and you won't find the leak...
photodisplay.php
 
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mikestang63

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Aug 27, 2012
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you need to let the RTV cure before you lay the intake down
Cut down some threaded rod to use as a guide in the 4 corners of the heads as a guide so you can lay the intake down straight .
I would lay down a thick bead on both china rails and up a ways onto the intake gasket
Do NOT use the felpro regular 1250 or 1262 gasket. Get the 1250S or 1262S with the steel reinforced ports, The regular paper ones are prone to leaking.
Also I do not recommend using any RTV on the intake gasket or around the water ports. That will just lead to the intake gasket deforming and leaking.
Also, when you lay the intake down, just install the bolts finger tight and let it sit overnight
then go back and torque it down and repeat torquing all the bolts for several rounds.
Once you have run a few heat cycles torque the bolts again
For the intake gasets, put some gaska cinch on them so they dont slip when you install the intake
Do not overtorque the intake bolts and torque them in 3 steps. I normally go 10 20 then 25

Has your intake or heads been milled? If so, both should be milled the same amount or you will have gaps
 
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Keith5.0GT

Active Member
May 29, 2017
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you need to let the RTV cure before you lay the intake down
Cut down some threaded rod to use as a guide in the 4 corners of the heads as a guide so you can lay the intake down straight .
I would lay down a thick bead on both china rails and up a ways onto the intake gasket
Do NOT use the felpro regular 1250 or 1262 gasket. Get the 1250S or 1262S with the steel reinforced ports, The regular paper ones are prone to leaking.
Also I do not recommend using any RTV on the intake gasket or around the water ports. That will just lead to the intake gasket deforming and leaking.
Also, when you lay the intake down, just install the bolts finger tight and let it sit overnight
then go back and torque it down and repeat torquing all the bolts for several rounds.
Once you have run a few heat cycles torque the bolts again
For the intake gasets, put some gaska cinch on them so they dont slip when you install the intake
Do not overtorque the intake bolts and torque them in 3 steps. I normally go 10 20 then 25

Has your intake or heads been milled? If so, both should be milled the same amount or you will have gaps
Thanks. I use the steel reinforced felpros, and the guide rods threaded in. I did wait the recommended time for the rtv, on the package, but maybe I should have waited longer for it since the bead is pretty thick....Heads are stock and I don’t think anything has been milled, couldn’t say for sure about intake though. I’m gonna try my best, again haha.
 
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vristang

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Sounds like you have doing it right. If there is excess pressure in the crankcase, it will blow out that seal.
Have you done compression and leakdown checks recently?

Is pcv system intact?
 

Keith5.0GT

Active Member
May 29, 2017
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Sounds like you have doing it right. If there is excess pressure in the crankcase, it will blow out that seal.
Have you done compression and leakdown checks recently?

Is pcv system intact?
Pcv is intact. I haven’t done any compression tests but I’d like to one day. I got it back together and it has to be right, so after I get a cooling problem figured out I’ll see how it is.