Manifold Removal Tips

[Mobtown]

1988 SuperCab with a 2.9L, 4x4, and 5sp

I am getting ready to replace the entire exhaust. The manifold down pipe is nearly rusted through and the converter flanges are nearly gone and are leaking...

I am fairly skilled (I have done complete engine rebuilds before) and have fairly well stocked garage at my disposal but I am new to the 2.9.

Really I am looking for some tips specific to the Ranger. I know that rusted manifolds are a pain in general, but I thought maybe some of you could share your experiences.

For example, access to the back bolts is pretty limited, what sort of tools did you use and which accessories did you remove to get around the issue.

From what I have seen, I am tempted to do a body lift first just so I can get a few extra inches to work with...

Thoughts>?

 

[Bow_Extreme]

Try removing the inner fenders. That gives you a bit more room to work. It worked last night on my 94 4.0. I did have a couple bolts that I worked ever so gently but in the end, they all came out with ease. I'm sure a little applied heat would help but may want to limit the application.

 

[MAKG]

I got mine out of a 2.9L with a 1/2 inch impact wrench, some extensions, and a lot of time. A 3/4 inch probably would have gone a bit faster.

Though honestly, you're throwing out the manifolds. Just cut the Y-pipe bolts if they give you any grief.

2.9Ls are notorious for breaking manifold bolts at the heads. All I can suggest is a lot of penetrating lubricant and a SMALL impact wrench. If you break them, drill them out carefully. I do NOT suggest oxyacetylene heat on the heads unless you are going to flatten the flanges. Not to mention I think you may risk a crack or two on known crack prone heads.

 

[Will]

Unbolt the manifolds at the motormounts. Then put a set of manifolds on that have a 4.0 between them.

Don't take the manifolds off of the heads. Too risky. Even having to drill one could mean pulling the head off of the engine to get it done. I'm not good at straight drilling unless the head is leveled under my drill press.

Getting the Y-pipe off can be tough. They are bolts, not nuts on studs--which is stupid. They are also automotive things meaning that replacements aren't at your local True Value. You can put lots of heat on those flanges though. If you don't have a kit, go to True Value and get a MAPP/OXY setup. It uses little bottles the size of propane torch bottles--yellow for MAPP and red for O2. You can get then cherry red or even gas weld with it. Propane doesn't do anything in the heat department.

 

[Natedog]

Unbolt the manifolds at the motormounts. Then put a set of manifolds on that have a 4.0 between them..

AHhahahaha! I'd like to do that too. But my 2.9 stays for now.

MAKG, how about breaking them loose with an extension and a long handle ratchet? I've noticed that sometimes an impact snaps things, that could be loosened by hand and then removed with the impact (faster!) once they are broken loose...for instance the bed bolts...broke a couple of the clip nuts (on the frame) with the impact. Loosened the remainder with a breaker bar and EVEN pressure, then removed them with the impact once they were loose....no more snapped nut clip thingys.

On reinstall would you use exhaust gaskets? I know they didn't have a gasket stock, but my rebuilt motor has the gaskets in there like come in an engine gasket set.

 

[MAKG]

When I replaced the heads on my 2.9L, I didn't use the exhaust gaskets. I'd measure warpage on the flange surface and on the manifolds, and get them flattened (a big sanding belt will do -- no need for milling) if they aren't flat. Gaskets = leak sites. I have constant problems with that on my Chevy. Thankfully it doesn't have oxygen sensors....

As for the breaker bar, I could see where that would be a big deal with spring clips. But my experience was that the Y-pipe bolts actually came out after quite a lot of that, whereas I couldn't get enough leverage on the bolt (with the truck on the ground) using a breaker bar. Not because I don't have enough -- I have a 6 foot cheater and 3/4 inch ratchet that can take it -- but because the ground was in the way.

The bolts came out clean and undamaged. I was astonished. I expected buggered threads and was ready with the Helicoil. All it really needed was a run-through with a tap and four replacment bolts coated in Nev-R-Seez (they are just coarse thread grade 5 bolts -- nothing special). I probably could have reused the bolts after a good wire brushing....

Honestly, the BIG problem is the manifold-to-head bolts. I broke four. Fortunately, the heads were junk (cracked -- and painfully visibly so from under the valve covers), so I didn't care.

As for the Y-pipe-to-cat bolts, get a big breaker bar and snap all three. Replace with nuts and bolts from the hardware store. These are not EVEN worth fighting with.

 

[Mobtown]

Thanks for all the suggestions. I intend to trash the entire system so anything after the manifolds will get disassembled using a torch or will get cut. My only real fear is having to drill out broken studs. I need to try and avoid such a situation at all costs.

I am considering skipping trying to finess the nuts and instead just try cutting them, using a ton of PB, and a stud extractor I hope to have a better chance of not snapping any off.

I especially appreciate the idea of removing the inner fender. Any more of these types of suggestion that will help me get teh right access?

Also, I noticed the stock manifolds have heat shield and was wondering if I should wrap my headers before installation? I have noticed the bay gets very hot as it is and it seems like a prudent move...thoughts?

 

[MAKG]

It's not a heat shield. It's a warm air intake.

It's technically an emissions device, so disabling it is illegal and carries a hefty fine. It isn't used at WOT; the blend door is vacuum actuated.

 

[85_Ranger4x4]

It's not a heat shield. It's a warm air intake.

It's technically an emissions device, so disabling it is illegal and carries a hefty fine. It isn't used at WOT; the blend door is vacuum actuated.

It also helps warm up your engine faster, which is the main reason I would leave it alone if you can get it to work with the headers.

 

[Natedog]

It also helps warm up your engine faster, which is the main reason I would leave it alone if you can get it to work with the headers.

X2, it's useful.