vacuum leak & failed intake gaskets

Discussion in 'Fox 5.0 Mustang Tech' started by larrym1961, Mar 17, 2011.

  1. On an earlier thread I asked about a lean idle condition I was having, 18:1 or higher @ idle. One on the responses I got was maybe I had a vaccume leak before I installed my AEM Wideband, I did not think I had a vaccume leak issue, but since I am swapping out EV1 injectors for EV6, I thought I would pull the lower intake and see if there was a possible leak as I was starting to notice a small pool of coolant on top of timing chain cover. ( I had this happen before with a failed intake gasket) and when I got the intake off this is what I found, The gaskets on both sides had shifted and torn @ several ports. So I am sure now that was a huge vaccume leak. What would cause the gaskets to do that and how can it be corrected? I have had this problem twice now with these Fel Pro 1250 gaskets, and I don't want to replace them again, twice in two years is enough!

    Attached Files:

    • 006.jpg
      File size:
      189.4 KB
    • 007.jpg
      File size:
      193.7 KB
  2. 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. Bingo! no leaks, and no gaskets that shifted out of place.

    If you reuse the injectors from your old setup, a repair kit is available from most auto parts stores if needed. Coat the injector body "O" rings with oil before you use them and everything will slide back together.

    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 per kit. The following are listed at the Borg-Warner site ( BWD - Home ) as being resellers of Borg-Warner parts:

    Parts Plus - Premium Auto Parts & Accessories or Auto Value / Bumper to Bumper Quality Parts & Service - Home of the Aftermarket Auto Parts Alliance Group or Tires, Auto Parts Stores, Brakes & Automotive Parts | Pep Boys or Federated Auto Parts - Automotive Aftermarket

    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.
  3. Your using the 1250's thats your problem right there. Some people run them with no problems others have NOTHING but problems with them. Reading the posts on stangnet about them I'd say 25% of the people use em no problem, the other 75% dont like em. First time mine started leaking I changed them and never went back (had same symptoms, ran like it had a vacuum leak and leaked coolant on the timing cover). I just use the factory style I believe the felpro number is ms 9333-1 or something like that, just stock gaskets for a 5.0. I also like that they come with the rubber end seals and not the stupid cork ones. The metal core in them feels a lot better than the 1250's anyways, the 1250's look like paper. I believe I've seen Tmoss recommend using these as well but dont quote me on that, I dont want to speak for him.
  4. When I put a GT40 intake on my old motor I used factory 5.0 steel core intake gaskets I got from the Ford Dealer and did not have a problem with them @ all. When I took off the GT 40 to put on the new motor they still looked in great shape! Nothing like these did! Twice now as a matter of fact! And when I called Summit tech to see if they had a better gasket for the Trick Flow Intake, He told me that the "Fel Pro 1250's were the top of the line intake gasket" BS! I checked Rockauto and they have the Fel Pro MS93334 Intake gasket. Nick, thanks for the info!
  5. Once again jricker thanks for your advise! When I did the last intake swap I scraped all old gasket with a gasket scraper and cleaned with acetone as you mentioned. I did use Edelbrock Gasgacinch to tack the gaskets into place. I also used a Permatex water pump and thermostat housing sealant around the water ports too for added sealing insurance too. but oviously my efforts failed! And the gaskets slipped as you seen. So I am going to try a factory type steel core gasket this time and your weather strip adhesive trick and blue silicone. I just happen to have both!
  6. Yeah, the only thing I would be worried about is the size of the ports on the gaskets vs. the ports on your heads. I really don't know why the 1250's are so popular.
  7. Bought a set of the Fel Pro MS93334's @ Autozone this morning, ten bucks. The ports were pretty darn close but a little port matching with the Dremel and they are ready. Well if these gaskets tear then I have some real issues!

    With these steel core gaskets and jrichkers tacking trick this should hopefully resolve this gasket issue.:nice:
  8. printoseal garbage

    I learned about printoseal gaskets when i bought a 460 crate engine from ford racing for 5500 dollars, 8 years ago. The gall of ford racing to put toy vinyl printoseal gaskets on a expensive engine is beyond me. These gaskets are vinyl, how they can sell these to the public after all the complaints and evidence of the gasket actually melting. My 460 printoseal gaskets looked worse than yours after only 3 months. They completely separated and swiss cheesed because they are vinyl. They are only used by racers who tear down the engines after every race. I wouldn't go a quarter mile with these gaskets. It makes my blood boil when i see pics of your engine like that. Just think how many high dollar engines are ruined by these printoseal lemon gaskets. We should all e-mail and write to fel pro and complain that these gaskets should never be sold to the public. I don't want to hear that i didn't scrape my heads surface clean either or installed them incorrectly, bullcrap. The best gaskets out there are victor reinz nitro seal, they have the metal sandwhich reinforcement with graphite coated heavy duty fiber or the stock gaskets and if you just bought a ford racing crate engine, remove the intake manifold and throw the printoseal crap in the garbage, but cut it up in little pieces so no one else uses it. DON'T BUY PRINTOSEAL GASKETS.
  9. I have definatly learned my lesson on these piles! My Step Dad told me I should not use them and use some that have some steel in them and I did not listen and did any way. I guess misery loves company and another lesson learned, don't think you know it all when you don't! I should have went the same route I did 15 years ago when I used Ford intake gaskets on the GT40 intake I installed and had absolutly no problems with them.

    And your point is well taken!:nice: I hope any one else who sees this can learn from it.