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Engine Changing lower intake gaskets

  • Thread starter Thread starter 91GTstroked
  • Start date Start date Jun 26, 2020

91GTstroked

15 Year Member
Jun 14, 2007
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Jun 26, 2020
#1
  • Jun 26, 2020
  • #1
Hey guys,

Looks like I have a massive lower intake gasket leak. Right behind the distributor on the block where rtv goes.

Just looking for tips and advice. My first time doing it. I planned on changing out fuel injector o-rings, distributor o-ring while I'm at it.

I have fel pro 1550S-3 gaskets, arp intake bolts, and right stuff rtv.

Thanks for any help you can provide.
 

90sickfox

Wasn't a pretty sight...and I've got big hands
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Mar 2, 2015
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Jun 26, 2020
#2
  • Jun 26, 2020
  • #2
You can use right stuff by itself to build a valley gasket but you must let it sit for a few hours before starting the car. You can cut the heads off the old bolts and slot them for a flat head screw driver. They'll help make sure you drop the intake down straight with less chance of shifting the gasket.
 
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Mstng93SSP

You have a nice rear end there Dave.
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Jun 27, 2020
#3
  • Jun 27, 2020
  • #3
What heads/intake are on your car?
 

91GTstroked

15 Year Member
Jun 14, 2007
503
282
93
Jun 27, 2020
#4
  • Jun 27, 2020
  • #4
Mstng93SSP said:
What heads/intake are on your car?
Click to expand...
Gt40 tubular intake and gt40x heads. I was told they are port matched. We will see if I even have the correct intake gaskets.
 
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91GTstroked

15 Year Member
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Jun 27, 2020
#5
  • Jun 27, 2020
  • #5
Little done today. I don't have a schrader valve on fuel rail. So I'll wait awhile and let pressure settle on it's own.
 

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General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
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Jun 27, 2020
#6
  • Jun 27, 2020
  • #6
Those look like stock fuel lines, no schrader valve?
 

91GTstroked

15 Year Member
Jun 14, 2007
503
282
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Jun 27, 2020
#7
  • Jun 27, 2020
  • #7
General karthief said:
Those look like stock fuel lines, no schrader valve?
Click to expand...
Nope, I have my Autometer sensor there.
 

Mstng93SSP

You have a nice rear end there Dave.
15 Year Member
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Jun 27, 2020
#8
  • Jun 27, 2020
  • #8
Those are the correct gaskets for that combo. Engine bay looks great!

Chris
 
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91GTstroked

15 Year Member
Jun 14, 2007
503
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Jun 27, 2020
#9
  • Jun 27, 2020
  • #9
Mstng93SSP said:
Those are the correct gaskets for that combo. Engine bay looks great!

Chris
Click to expand...
Awesome, and thank you!
 

91GTstroked

15 Year Member
Jun 14, 2007
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Jun 28, 2020
#10
  • Jun 28, 2020
  • #10
Hey guys,

I need some opinions on gaskets. My car had fel pro 1262s gaskets. I have 1250s3 right now.

Pictures below, should I order the 1262s?

Or will these work if I get them moved up?
 

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M

Monkeybutt2000

Mustang Master
Aug 11, 2019
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Jun 29, 2020
#11
  • Jun 29, 2020
  • #11
Those will be fine. I like to use indian head or gasgacinch on the gaskets. Then they're "glued" to the head.
 
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91GTstroked

15 Year Member
Jun 14, 2007
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Jun 30, 2020
#12
  • Jun 30, 2020
  • #12
Monkeybutt2000 said:
Those will be fine. I like to use indian head or gasgacinch on the gaskets. Then they're "glued" to the head.
Click to expand...
Thanks for the help. I plan on using Permatex high tack around the water jacket ports to help keep them in place. Also cut the heads of old bolts to set in heads as a guide.
 

91GTstroked

15 Year Member
Jun 14, 2007
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Jul 2, 2020
#13
  • Jul 2, 2020
  • #13
Update:

Hey guys,

I finished up the install yesterday and let it sit for about 20 hours before starting it. Filled the coolant, set the timing and let it run up to operating temp.

No leaks, so I let it cool down some and re torqued the lower intake bolts and changed the oil.

I haven't driven it yet, but had it running for quite some time in the garage.

I appreciate the help!
 

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Cheapskate207

The left one hangs a little lower
5 Year Member
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#14
  • Jul 2, 2020
  • #14
I’ll bet it runs better now!
 
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jrichker

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#15
  • Jul 2, 2020
  • #15
91GTstroked said:
Hey guys,

Looks like I have a massive lower intake gasket leak. Right behind the distributor on the block where rtv goes.

Just looking for tips and advice. My first time doing it. I planned on changing out fuel injector o-rings, distributor o-ring while I'm at it.

I have fel pro 1550S-3 gaskets, arp intake bolts, and right stuff rtv.

Thanks for any help you can provide.
Click to expand...

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:

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


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.

Putting the distributor back in and setting the timing.

Revised 15-Apr-2016 to add fix for TFI hitting the thermostat housing while trying to set the base timing at 14°.

You can forget about anything beyond this point if you don't have access to a timing light. You will never get the timing set right without one.

Note: If you don't have access to a timing light, most of the larger auto parts stores will rent or loan one if you have a credit card or leave a cash deposit.


Putting the distributor back in is fairly simple. Pull #1 sparkplug, put your finger in the sparkplug hole, crank the engine until you feel compression. Then line up the TDC mark on the balancer with the pointer on the engine block.

The distributor starts out with the #1 plug wire lined up at about 12:00 with you facing it. Align the rotor to about 11:00, since it will turn clockwise as it slides into place.

Align the distributor rotor up with the #1 position marked on the cap, slide the distributor down into the block, (you may have to wiggle the rotor slightly to get the gear to engage) and then note where the rotor is pointing.
If it still lines up with #1 position on the cap, install the clamp and bolt. If not, pull it out and turn 1 tooth forwards or backwards and try again. Put the #1 spark plug back in and tighten it down, put the clamp on the distributor, but don't tighten it too much, as you will have to move the distributor to set the timing. Note that there is no such thing as one tooth off on a 5.0 Mustang if you follow the spark plug wire order on the distributor cap. If it doesn't align perfectly with #1 position, you can turn the distributor until it does. The only problem is that if you are too far one way or the other, you can't turn the distributor enough to get the 10-14 degree optimum timing range. If the TFI prevents the distributor from being turned enough to get 14°, there is a simple fix. Pull the distributor out and turn the rotor 1 tooth counterclockwise Don't move the wires from the positions shown on the cap on fuel injected engines!!!! The #1 position cast into the cap MUST have the spark plug wire for #1 cylinder in it. Do it differently and the timing for the fuel injectors will be off. The computer uses the PIP sensor to time injector operation by sensing the wide slot in the PIP sensor shutter wheel. If the injector timing of #1 and the firing of #1 do not occur at the right time, the injector timing for all other cylinders will be affected.

Setting the timing:
Paint the mark on the harmonic balancer with paint -choose 10 degrees BTC or 14 degrees BTC or something else if you have NO2 or other power adder. I try to paint TDC red, 10 degrees BTC white and 14 degrees BTC blue.

10 degrees BTC is towards the drivers side marks.

Note: setting the timing beyond the 10 degree mark will give you a little more low speed acceleration. BUT you will need to run 93 octane to avoid pinging and engine damage. Pinging is very hard to hear at full throttle, so it could be present and you would not hear it.

Simplified diagram of what it looks like. Not all the marks are shown for ease of viewing.

ATC ' ' ' ' ' ' ' ' ' '!' ' ' ' ' ' ' ' ' ' BTC
---------------- > Direction of Rotation as viewed standing in front of the engine.

The ' is 2 degrees.
The ! is TDC
The ' is 10 degrees BTC
Set the timing 5 marks BTC. Or if you prefer, 5 marks towards the driver's side to get 10 degrees.

To get 14 degrees, set it 7 marks BTC. Or if you prefer, 7 marks towards the driver's side to get 14 degrees.

The paint marks you make are your friends if you do it correctly. They are much easier to see than the marks machined into the harmonic balancer hub.

At this point hook up all the wires, get out the timing light. Connect timing light up to battery & #1 spark plug. Then start the engine.

Remove the SPOUT connector (do a search if you want a picture of the SPOUT connector) It is the 2 pin rectangular plug on the distributor wiring harness. Only the EFI Mustang engines have a SPOUT. If yours is not EFI, check for a SPOUT: if you don’t find one, skip any instructions regarding the SPOUT
Warning: there are only two places the SPOUT should be when you time the engine. The first place is in your pocket while you are setting the timing and the second is back in the harness when you finish. The little bugger is too easy to lose and too hard to find a replacement.

Start engine, loosen distributor hold down with a 1/2" universal socket. Shine the timing light on the marks and turn the distributor until the mark lines up with the edge of the timing pointer. Tighten down the distributor hold down bolt, Replace the SPOUT connector and you are done.

The HO firing order is 1-3-7-2-6-5-4-8.
Non HO firing order is 1-5-4-2-6-3-7-8



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...
 

silverlx50

15 Year Member
Apr 4, 2007
168
62
38
Jul 7, 2020
#16
  • Jul 7, 2020
  • #16
That is one PITA job. I did mine twice and thought I was good both times until I was told I had a vacuum leak. I sprayed brake clean, flammable and not the best choice, and found leaks both times. I used studs to set the intake down and RTV to hold the gaskets in place but still, no luck. I think a spray adhesive plus to hold the gaskets in place and RTV in the front and rear valley's and water jacket ports are a must.
 
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