Renix intake manifold heat shield

[DirtyComanche]

Is it kosher to remove and discard the intake manifold heat shield on the Renix 4.0L?  I assume it is there to help prevent overheating the injectors or fuel rail, however the HO does not have one and has no such issues.

 

I'm just plugging away at a header swap right now, and debated removing the heat shield as it might make it easier to put the intake back on.  If it serves no practical purpose I would rather do away with it permanently.

[gogmorgo]

You could pull it off and see what happens, but I'm pretty certain the HO's did have a heat soak issue, especially the later years. If there wasn't a recall there was at least a TSB.

[HOrnbrod]

They did, especially with the later intake manifold. The below was one of the cures. It first came out as a TSB "debris" shield, but it worked well as a heat shield too. There were also a couple of other TSB's regarding injector heat soak and individual injector wrapping but I found no need to do them after using the below.

 

[DirtyComanche]

I'll put it back on then.  Too bad it's so ugly.

[fiatslug87]

Paint it with some engine paint.

 

[gogmorgo]

I might be concerned that in doing that you'd significantly reduce its reflectivity enough that it might no longer be effective. A ceramic coated (or even exhaust-wrapped header that doesn't radiate heat would be as effective if not more so than the heat shield, as it would also reduce the negative effects of heat elsewhere in the the engine bay. But at the same time it's also much more expensive, or a much bigger PITA/uglier solution in the case of the exhaust wrap, than leaving it as is...

[DirtyComanche]

I debated wrapping the header.  My tick with the heat shield, other than being ugly, is it's effectively an intake manifold heater.  Not that I should care too much about performance at this point, but I'd like to wake the motor up a bit because I think I'm on the bad side of the power/weight ratio for snow.

 

It being ugly isn't a big deal, everything under the hood on this thing is ugly.  When I go it there was probably more oil on the outside of the engine than in it.

 

A piece of clean stainless would look a lot better though.

[Megadan]

I've been running mine without one for almost 3 years now unwittingly.  Never knew I was supposed to have one.  I've never had a problem so far, but I do have a ceramic coated header.  Still radiates heat some.  If you are worried about it's ability to reflect heat, then line the bottom of it with this.  Yes, it's kind of pricey. a 24" by 12" roll is $31.49, but I've used it before and it does work extremely well.   https://www.pegasusautoracing.com/productdetails.asp?RecID=11221

[Dando]

I have also had mine removed for almost a year with no apparent issues.

[DirtyComanche]

Both of you guys see good hot summer weather, eh?  Do you have any other mods that might be relevant, such as hood vents?

 

I've been out of the Jeep stuff for a while, so I don't remember lots of things, but was there major documentation of early HO engines having heat soak issues?

 

I'm still messing with the exhaust, so the intake isn't back on yet anyways.

[Megadan]

We get well into the 90's in the summer with high humidity to boot. Not sure on the HO heat soak issues because I have a Renix.

[HOrnbrod]

Both of you guys see good hot summer weather, eh?  Do you have any other mods that might be relevant, such as hood vents?

 

I've been out of the Jeep stuff for a while, so I don't remember lots of things, but was there major documentation of early HO engines having heat soak issues?

 

I'm still messing with the exhaust, so the intake isn't back on yet anyways.

 

I don't recall any TSB's regarding heat soak injector problems on the early HOs, but there were a couple on the 99's and up with the new intake manifold. THIS was one of them (download .pdf).

[ParadiseMJ]

I ran mine (Renix) without the "shield" after I did the head.  In the summers here the temps run around 90 to 100 just about every day  It partially melted the plastic wire loom material, so I put it right back on.  I even have two of them and considered sandwiching them to add a bit more protection, but found that the one was fine and effective.  I kind of like it being there anyway since my feeble fingers regularly drop screws and nuts, and with it there I don't have to go hunting for parts.

[Dando]

Both of you guys see good hot summer weather, eh? Do you have any other mods that might be relevant, such as hood vents?

 

I've been out of the Jeep stuff for a while, so I don't remember lots of things, but was there major documentation of early HO engines having heat soak issues?

 

I'm still messing with the exhaust, so the intake isn't back on yet anyways.

I'm in cleveland oh, we get both below freezing and over 100*. No hood vents. As mentioned I did tie the wire loom up higher to make sure it stays away from the manifold. I do have manual control of my aux fan. And I have also swapped from closed to open cooling, doubt that really makes a difference.