Bad Intake coolant leak, retorque or replace?

[slowRoaner]

Was all ready to fire up the newly installed efi, poured in the coolant, and two streams started leaking out of the intake manifold. One on the front passengers side just behind the thermostate housing between the head and manifold, and the other on the rear driver side. I have read about the faulty 1250 gaskets( http://classicbroncos.com/forums/showthread.php?t=226843&highlight=intake+manifold+coolant+leak) , and im pretty sure that is what I used. I torqued the manifold to spec and used plenty of orange rtv sealer when installing. Should I retorque and fire it up for some heat, or should I just assume its leaking internally as well and replace all the gaskets again with 1250-S3 ??

 

[Viperwolf1]

Retorque won't stop that leak. Take it apart and see what's going on.

 

[blubuckaroo]

I've had my share of problems with the Fel Pro 1250 but the leaks usually develop after a fair amount of running and heat cycles. Maybe the heads or intake manifold weren't compatible with the gasket you chose?

 

[DirtDonk]

x2 on the take it off and see what's up solution. Too big of a leak to be a simple torque issue. And since it's already torqued properly, re-torquing it would be VERY unlikely to fix it.

Good luck though. Hopefully the gaskets are just the wrong ones or have shifted (but both of them though?) when installing the heads. I'd have to go with the wrong gasket possibility. Consistent leaking points, and a huge flow.
Either that or something got stuck under there before installing. Missing any heater or choke control cables by any chance! ;D

Oh, and on a side note, is there a plug in that front hole in the timing cover? Down low there where the car or 2wd truck dipstick used to go. Usually tap and plug, or insert a "mini freeze plug" type thingy in there.
Maybe you did and it just doesn't show up in the pic, but I wanted to bring it to your attention in case you hadn't.

Paul

 

[slowRoaner]

well the intake manifold is off of a 88' thunderbird, and the heads are just the stock 71'. I ordered a 1250-S3 that will be here tomorrow and have started to take it apart.

from what I read the 1250-S3 felpro should be the one I need? is there something else I should be looking at to identify if this is the correct gasket for my set up?

 

[70_Steve]

Hard to see in the pic, especially the one with the alternator, but it looks like the intake gasket slid.

Buy four 5/16 x 4" bolts and cut the heads off. Screw one in each corner bolt hole. Then drop the manifold down over these studs. That will keep the gaskets in place, and the manifold from sliding the gaskets as you lower the manifold.

I got my engine back from the machine shop a couple years ago, and had that same leak on the drivers rear of the head. The gasket had slid down when they installed the manifold... So, you wouldn't be the only one to have done that...

 

[slowRoaner]

got it apart, there was water sitting in valley. im thinking I need to use more ultrablack rtv and the stud idea from 70_steve this next go around. Nothing super obvious as far as gasket being the wrong size. I probably just didn't get it straight and a good seal. thanks for all the input and advice, I will let you know how it turns out tomorrow when the gasket arrives

 

[70_Steve]

got it apart, there was water sitting in valley. im thinking I need to use more ultrablack rtv and the stud idea from 70_steve this next go around. Nothing super obvious as far as gasket being the wrong size. I probably just didn't get it straight and a good seal. thanks for all the input and advice, I will let you know how it turns out tomorrow when the gasket arrives

Pull the distributor so you can set the manifold down straight on the gaskets.

More gasket sealer is not the answer. The gasket should seal with no gasket sealer at all. That being said, I use HighTack spray on the intake runner portion of the gaskets (both sides) and a VERY thin coat of RTV around the water port. The key is to get the gasket positioned correctly, then setting the manifold down straight onto the gasket.

 

[half cab]

XX2 on the studs n pulling the distributor.

 

[Dutton]

I have found that a 1/4" bead of silicone on the front and back runners works better than a gasket. I normally do not use and silicone on the gaskets.

 

[half cab]

Have you had the heads off?

 

[73azbronco]

Instead of cutting bolts, you can buy threaded studs at ACE for cheap.

 

[Viperwolf1]

The problem is you have the early style small water port heads and the late style large port gasket. Coolant is leaking in the upper corners because those heads don't have enough meat to them there. The 1250-s3 gasket has the same large ports. You need something like an edlebrock 7220.

 

[slowRoaner]

I believe viper wolf is right. the coolant ports were too big and not sealing. Went to autozone and grabbed a MS 90103-1 Felpro gasket they had in stock, it was much smaller and made for the earlier head with smaller coolant ports.

no I have not had the heads off. Also got some threaded studs from ace for cheap ;D and will pull distributor

some pics for comparison

 

[Desert Dweller]

The problem is you have the early style small water port heads and the late style large port gasket. Coolant is leaking in the upper corners because those heads don't have enough meat to them there. The 1250-s3 gasket has the same large ports. You need something like an edlebrock 7220.

Been there done that.. Same thing happened to me on a 351W rebuild with early heads....

 

[savage]

Hey slowRoaner,if you end up buying the edlebrock 7220 intake gasket, they come with two smaller gaskets for the cross over if you have ,that puts heat into the manifold,because I forgot them and had to reseal mine.you will either use one or the other, to let it flow or block it off.

 

[Viperwolf1]

Hey slowRoaner,if you end up buying the edlebrock 7220 intake gasket, they come with two smaller gaskets for the cross over if you have ,that puts heat into the manifold,because I forgot them and had to reseal mine.you will either use one or the other.

Only one side is open on the EFI intake (I think driver side) and that is used for EGR. If you use EGR you don't want to plug that hole.

 

[blubuckaroo]

Hey slowRoaner,if you end up buying the edlebrock 7220 intake gasket, they come with two smaller gaskets for the cross over if you have ,that puts heat into the manifold,because I forgot them and had to reseal mine.you will either use one or the other, to let it flow or block it off.

I'm a bit suspicious of those little heat riser insert gaskets. Especially on aluminum intakes. When my Fel Pro 1250 intake gaskets split, I found those inserts hadn't been crushed much and were still considerably thicker than the rest of the gasket. I'm thinking they kept the rest of the gasket from being properly crushed. The areas that split were right next to the inserts. The reduced torque spec for the bolts on aluminum intake manifolds probably made it worse.

 

[savage]

blubuckaroo,when I forgot them I started a thread here to see if I needed them. The answer I got was the main intake gasket was not made to take the heat that's why the small gaskets are made of a different material.Edlebrock 7220 intake gasket are what Edlelbrock says to use on their aluminum intake so Ill see if I have a problem later,hopely not. The little heat riser gaskets come with the intake gaskets.

 

[blubuckaroo]

blubuckaroo,when I forgot them I started a thread here to see if I needed them. The answer I got was the main intake gasket was not made to take the heat that's why the small gaskets are made of a different material.Edlebrock 7220 intake gasket are what Edlelbrock says to use on their aluminum intake so Ill see if I have a problem later,hopely not. The little heat riser gaskets come with the intake gaskets.

Even though the little inserts come with the gasket set, they are a lot thicker and harder than the rest of the gasket. They look like trouble to me.