Frozen Manifold Heat Control Valve

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Duggie

Duggie

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I've read about cold running issues on \6s that had aftermarket exhaust manifolds with no ability to heat the intake manifold with the exhaust.

My manifold heat control valve is frozen in the position shown in the pic below. I've soaked it in penetration oil for a couple weeks with no change. What's a rookie to do? Soak the whole thing in vinegar and check it once a day until it's free? Smack it with a BFH to knock it out? Let it ride where it is?

Fish or cut bate - fish or cut bate - fish or cut bate.:realcrazy:

Exh Heat Valve1.JPG

Exh Heat Valve2.JPG
 
Duggie said:
I've read about cold running issues on \6s that had aftermarket exhaust manifolds with no ability to heat the intake manifold with the exhaust.

My manifold heat control valve is frozen in the position shown in the pic below. I've soaked it in penetration oil for a couple weeks with no change. What's a rookie to do? Soak the whole thing in vinegar and check it once a day until it's free? Smack it with a BFH to knock it out? Let it ride where it is?

Fish or cut bate - fish or cut bate - fish or cut bate.:realcrazy:

View attachment 1715578359
View attachment 1715578361
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Depending upon the weather where you drive, a working exhaust heat stove can help drivability. Problem is service kits for the slant six exhaust heat stove are no longer available. I would try a really good penetrating oil like Kroil before I dismounted the manifold to soak it in vinegar or Evaporust. But to get it free and working I bet that is where you end up.
 
SeaFoam Deep Creep. Spray it down good. Tap the ends of the shaft back and forth. Spray some more. Repeat. Keep workin with it, it'll free up.
 
Use the correct "tool" (chemical) for the job. That is this stuff, which is not interchangeable with any other penetrating oil or fluid—you'll know it as soon as you smell it.

Also realise that you may or may not be able to get this valve to unstick and stay unstuck. After many decades and thermal cycles, sometimes they're just done, especially this early (pre-'71) type.

A working heat control valve is a very good thing to have, and not just if you live someplace cold. Many people don't clearly understand why the valve's there. "Rip it out/block it off/weld it shut" etc is advice worth smiling, nodding, and ignoring.

There used to be rebuild kits (shaft, plate, counterweight, counterweight key, thermal spring, antirattle springs, stop dingus) but they've been unavailable for many years. At this point a manifold that's used enough to have a perma-stuck valve is also likely to be warped and/or cracked; the fix is a new manifold—see here for particulars.

And since you've got the manifold off, see here for hardware info.
 
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slantsixdan said:
Use the correct "tool" (chemical) for the job. That is this stuff, which is not interchangeable with any other penetrating oil or fluid—you'll know it as soon as you smell it.

Also realise that you may or may not be able to get this valve to unstick and stay unstuck. After many decades and thermal cycles, sometimes they're just done, especially this early (pre-'71) type.

A working heat control valve is a very good thing to have, and not just if you live someplace cold. Many people don't clearly understand why the valve's there. "Rip it out/block it off/weld it shut" etc is advice worth smiling, nodding, and ignoring.

There used to be rebuild kits (shaft, plate, counterweight, counterweight key, thermal spring, antirattle springs, stop dingus) but they've been unavailable for many years. At this point a manifold that's used enough to have a perma-stuck valve is also likely to be warped and/or cracked; the fix is a new manifold—see here for particulars.

And since you've got the manifold off, see here for hardware info.
Click to expand...

Soco the dog says he cannot find that page with the penetrant.
 
aint hard.....https://www.amazon.com/dp/B00BV4DBAU/?tag=fabo03-20

Rob says tap the shaft back and forth and work it, baby! That is 'sound' advice...get it? I took a bike chain off after 9 years of sitting exposed that would stay horizontal if you muscled it straight. Soaked it in Vinegar for 2 days and then motor oil for 2 more. Worked each link and its back to normal. Some links took a trip to the vice and a hammer to fold them over but they all freed up. That valve must be very free, as in tap it and it will bounce off its thermal spring tension. Suprised they dont leak when they are free.
 
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We use a 50/50 mixture of ATF and acetone for stuff like this. It penetrates like no other and could spare you the hassle of having to remove the entire exhaust. I’d give it a thorough spray down (let it sit 24 hours), let the vehicle barely heat up (for 2 minutes or less) and then man handle it with your best pair of grabbers and or a bfh.
 
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Thanks you guys! I've been wanting to try the torch and wax routine. Looks like I'll start with the 'soak and tap' while I work on putting the engine and transmission back together.

slantsixdan said:
the fix is a new manifold—see here for particulars.
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That's why I don't gamble. I just paid $70 to surface the intake / exhaust manifolds.

HA!
 
RustyRatRod said:
Soco the dog says he cannot find that page with the penetrant.
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That's cuz I fumblefingered while pasting it in. It's fixed now (or you could just click here). This stuff used to be called "Manifold Heat Control Valve Solvent", and now because most cars don't have manifold heat (or control valves for it), it's called "rust penetrant". Same recipe, though. It's not just another penetrating oil, it's formulated to dissolve the carbonaceous exhaust buildup that sticks the shaft in place. Kroil's terrific, but it's a different tool.
 
I soaked the bottom of the exhaust manifold, including the heat control valve for 24 hours in white vinegar. Figured there was nothing to lose while the solvent is in transit.

The valve free' d up! Rotates way past open and closes without binding. Lucky day!

Now to find a Home Depot anti rattle spring.
 
Duggie said:
I soaked the bottom of the exhaust manifold, including the heat control valve for 24 hours in white vinegar. Figured there was nothing to lose while the solvent is in transit.

The valve free' d up! Rotates way past open and closes without binding. Lucky day!

Now to find a Home Depot anti rattle spring.
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I always thought the spring was bi metallic and reacted to the heat of the manifold to close the damper as it got hot. I don’t know that as fact, it’s just how I thought that it worked, so I don’t think that just any spring will restore the OE action.
 
Now you can return the $13 can of Gearhead Cologne. Vinegar, the other acid! The anti rattle spring is just to keep it from bouncing around, very light weight. should have a type of cloth bumper wrap where the riser weight hits bottom so it doesnt make a noise too.
 
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my68barracuda said:
I always thought the spring was bi metallic and reacted to the heat of the manifold to close the damper as it got hot. I don’t know that as fact, it’s just how I thought that it worked, so I don’t think that just any spring will restore the OE action.
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That is correct. It "slacks off" as the engine warms and allows the valve to open very easily against exhaust pressure.
 
pishta said:
Now you can return the $13 can of Gearhead Cologne. Vinegar, the other acid! The anti rattle spring is just to keep it from bouncing around, very light weight. should have a type of cloth bumper wrap where the riser weight hits bottom so it doesnt make a noise too.
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I figured I would spray the "Gearhead Cologne" on the shaft at oil changes to keep the carbon build up under control.

Thanks for the tip on padding the arm weight so it doesn't rattle.

One for the win column!
 
RustyRatRod said:
That is correct. It "slacks off" as the engine warms and allows the valve to open very easily against exhaust pressure.
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Yep. And I wouldn't have know there was an anti rattle spring on the other side without having read about it in the reprinted Dodge Factory Service Manual I learned about on this site. Man, I've had this car for a month and that book is already dog eared and grease stained.
 
pishta said:
Now you can return the $13 can of Gearhead Cologne. Vinegar, the other acid! The anti rattle spring is just to keep it from bouncing around, very light weight. should have a type of cloth bumper wrap where the riser weight hits bottom so it doesnt make a noise too.
Click to expand...

The spring is bimetal. It is tight when cold and gradually loosens up as the engine warms. When the engine is fully warm, the valve is partially open and opens fully when any throttle is given. Here is operation when the spring is cold. I will be glad to shoot another video while hot if you want and you will clearly see the difference.

 
Duggie said:
Yep. And I wouldn't have know there was an anti rattle spring on the other side without having read about it in the reprinted Dodge Factory Service Manual I learned about on this site. Man, I've had this car for a month and that book is already dog eared and grease stained.
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Yes....yall are obviously talking about the "other" small spring. John and I are referring to the "wound" spring behind the weighted wheel. Check out that video I posted up there ^^^^^.
 
Cool stuff Rusty. And I like the way you routed your heater core hoses away from the valve cover. Mine were shorter and went right over the top. And is your battery cable to starter routed to spec? I have that hangar on my manifold, but mine was wire tied to a power steering hose.
 
The "wound spring" reminds me of the old wall thermostats with the mercury switch inside.
 
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