Explorer EFI Conversion Cooling Question!!!

[broncoitis]

Ok, I know that alot of people on here are using the explorer gt40 upper and lower intakes with the Mustang Mass Air from the early 90's computer.

Recently had a coolant leak from somewhere after my conversion to EFI and I am pretty sure that it was coming off of the lower or Upper intake manifolds.

Currently running 76 heads on the Bronco and the water passages are not as close as I would like them to be but that is about as good as it is gonna get most likely.

I have removed both the upper and lower intake to fix this problem and this is the question. In the middle of the lower intake there is a water port that basically sends water up into the upper intake where the water flows around the EGR spacer (I think ?:?) and exits the side of the spacer and back down into the manifold on the top of the passenger side!

I have removed the EGR spacer completely from the upper intake so basically this port is flowing to nowhere for the most part. What is the correct thing to do?

I was thinking of installing a plug into the lower intake to block off any water from getting into the upper intake?

Should I reinstall the EGR with the block off plate and plumb that back into the return for the coolant?

Really need some advice because I don't wanna do this wrong this time because taking all this stuff off was really a bit of a PITA! Thanks! ?:?

 

[Big79]

I think the small hole your seeing is for air only.. Even a stock 5.0 intake off of a mustang and or explore or mountaineer, is the same way. Air only. How ever, there are factory cooling lines that go to the egr(that is antifreeze) But,the lines were from a metal tube that connected the heater core to the motor cooling system and is on the out side of the motor.

 

[Big79]

Your searching for a coolant leak? If you think it could be the lower gaskets not matching and and leaking then check your oil( if it has been ran a few time. It will turn your oil a milky color. Then you know water is leaking from your lower intake gaskets. Or maybe head gaskets? And if you converted to efi, then maybe even your timing chain gasket??

Just another mans thoughts..

 

[broncoitis]

I think the small hole your seeing is for air only.. Even a stock 5.0 intake off of a mustang and or explore or mountaineer, is the same way. Air only. How ever, there are factory cooling lines that go to the egr(that is antifreeze) But,the lines were from a metal tube that connected the heater core to the motor cooling system and is on the out side of the motor.

Ok, I am gonna take a closer look at the EGR spacer in storage but the hole that I am referring to is about the size of a nickel on the lower intake and the same size on the bottom of the upper intake. On the upper it comes out the bottom of the throttle body and is an oval shape. From there it looked like it went into the EGR spacer attached to the throttle body. There was also a metal like gaskey between the two pieces. ?:?

Come on everyone, I know that somebody knows exactly what I am referring to and what to do about it on here.

 

[broncoitis]

Oh yeah, the oil is getting changed and I am fairly certain there is coolant in it! I will know later after I get rid of the antifreeze.

To hopefully remove any confusion, the passage that I am referring to basically in the center of the first pic. It is the smaller round hole in the lower intake!

The second pic is what I plan on doing. %)

Hopefully this helps!

 

[rustbucket]

That hole is for exhaust gases to be drawn into the EGR. Not coolant.

 

[broncoitis]

That hole is for exhaust gases to be drawn into the EGR. Not coolant.

Are you positive on that? Just makin sure. Or i guess it could be for exhaust gases to be pulled out of the EGR. Right? ?:?

I thought it was a coolant passage.

 

[HGM]

Yea, that should be EGR, not coolant.. But, I wonder if you might have a leak in the lower, or passage alignment issue, that is alloing coolant to flow. Either way, I'm make EGR work to get the MPG benifit..

 

[HGM]

BTW, look at the bottom of the intake, follow the passage and see where it draw's off the heads.. Should help you ID what your looking at.

 

[Viperwolf1]

Are you positive on that? Just makin sure. Or i guess it could be for exhaust gases to be pulled out of the EGR. Right? ?:?

I thought it was a coolant passage.

That is hot exhaust gas only. If you are getting coolant inside the manifold it's probably coming from the EGR cooler plate. I had some issues with leaks there. Make sure you seal up around the studs and use the correct gasket.

 

[broncoitis]

That is hot exhaust gas only. If you are getting coolant inside the manifold it's probably coming from the EGR cooler plate. I had some issues with leaks there. Make sure you seal up around the studs and use the correct gasket.

My EGR is completely removed and there is no coolant flowing up there at all.

I take it there are only 4 water passages coming off of the heads then?

I guess that my leak is a result of a lack of sealant on my part and basically putting on the manifold gaskets dry! I think that there was also a really small vacuum leak that was effecting my throttle not coming down below 1000 - 900 RPMS!

Gonna go and prep for reassembly! ;D

 

[Broncobowsher]

Yea, that should be EGR, not coolant.. But, I wonder if you might have a leak in the lower, or passage alignment issue, that is alloing coolant to flow. Either way, I'm make EGR work to get the MPG benifit..

X3

The lower manifold that hole goes down to a couple of exhaust ports. No water anywhere near that.

But the upper has water at the EGR spacer (if you hooked up the little coolant hoses to the EGR spacer). I am guessing that is the source of the water. How about a picture of the top of the upper intake? I just want to verify your parts (or if you have some other strange issue)

 

[Viperwolf1]

My EGR is completely removed and there is no coolant flowing up there at all.

I take it there are only 4 water passages coming off of the heads then?

I guess that my leak is a result of a lack of sealant on my part and basically putting on the manifold gaskets dry! I think that there was also a really small vacuum leak that was effecting my throttle not coming down below 1000 - 900 RPMS!

Gonna go and prep for reassembly! ;D

Yep, two coolant passages in each head. What intake gaskets are you using? I've had problems with the felpro 1250 gaskets. I now use the 1250S3 gaskets and they have been great. The S3 gaskets are not cut for the EGR/heat riser ports so they would work well for you.

That plug will work to block the exhaust gases. That way you don't need to bolt the EGR spacer on. Just bolt the throttle body directly to the upper.

 

[broncoitis]

X3

The lower manifold that hole goes down to a couple of exhaust ports. No water anywhere near that.

But the upper has water at the EGR spacer (if you hooked up the little coolant hoses to the EGR spacer). I am guessing that is the source of the water. How about a picture of the top of the upper intake? I just want to verify your parts (or if you have some other strange issue)

Bowsher,

Yeah, thanks for the advice. I have the spacer completely removed so there is no coolant flowing up there at all. I am pretty sure that the water was coming from the rear water passage on the driver side head. The coolant passage back there just come to a dead end in the intake manifold it seems.

Yep, two coolant passages in each head. What intake gaskets are you using? I've had problems with the felpro 1250 gaskets. I now use the 1250S3 gaskets and they have been great. The S3 gaskets are not cut for the EGR/heat riser ports so they would work well for you.

That plug will work to block the exhaust gases. That way you don't need to bolt the EGR spacer on. Just bolt the throttle body directly to the upper.

Ok, that is what I thought and didn't realize that there were exhaust gases running thruough the manifold and what not. I will check on the gaskets that I used but pretty sure that they are not the 1250's! Boy, I really don't wanna take this thing apart again. Gonna go and check the gaskets! ;D

 

[broncoitis]

BTW, look at the bottom of the intake, follow the passage and see where it draw's off the heads.. Should help you ID what your looking at.

Good tip HGM! It was the center port on the head and the water ports are on the corners!

 

[broncoitis]

Everything Back Together!

Ok all is back together and my fingers are crossed!

The Gasket set that I used was the FelPro MS90103-1 the intake gaskets are part # 5511.

Used "The Right Stuff at the front and rear of the intake and went with that around the water ports on both sides of the gasket. A thin layer is all I used.

Additionally I also used tha gasket adhesive around the ports going into the heads coming off the intake for a bit of insurance! If this doesn't work then there are bigger issues out of my control.

Gonna give it a couple hours to dry and fire it up! If this operation was a success then the RPM's should come down to around the 700-800 range with no leaks! ;D

 

[broncoitis]

Thanks to everyone for your feedback on this it definitely helped for sure and hopefully will steer someone else in the right direction.

Got everything put back together and fired it up and all seemed good and then the antifreeze starts gushing out by the timing chain cover! So there I am staring at it in disgust and then im like ok maybe it is something you overlooked! YEAH! forgot to tighten one of the hose clamps and problem solved.

Have a piece of cardboard sitting under the truck tonight and will see what is on it in the morning! Hopefully NOTHING!

I am optimistic that this problem has been put to bed once and for all. ;D

Next on the agenda, the rear axle seals that I mistakenly forgot to put in! %)