Exhaust Manifold Stud Replacement Questions

[Muad'Dib]

What does it sound like to you Blaine B.?

 

[RaccoonJoe]

Hrmmm....this sounds like a very interesting thread.

Seems that I've got a similar issue on my 89. I've been fighting with an extremely low idle, the exact same as OP. Mine will idle that low for hours, not just at cold start.

My tick seems to be *mostly* cured after running a quart of MMO and a 2nd oil change with a quart of Risoline. Now, instead of being quiet, then getting louder and louder, then stopping for a few seconds, it's quiet, then ticks for a second or two, then quiet again.

I know my exhaust is louder than it should be, even with the new muffler and such. The PO told me that the manifold/downpipe was re-welded (apparently had cracked once before), but after a recent wheeling trip, I'm now almost positive that it's cracked again.


My question is this: Do these manifolds warp like many others do?? My manifold is ~20 years old...if I go find another at the boneyard, what are the chances that it will work?? Or would I be more likely to find all used manifolds have warped beyond use on any motor except the original??

 

[Blaine B.]

I'm not sure, like I said I suppose it could be an exhaust manifold leak since the stud is missing which would be a pretty big leak compared to what I've heard.

It just sounds different to me, is all. Who knows.

 

[5-90]

Hrmmm....this sounds like a very interesting thread.

Seems that I've got a similar issue on my 89. I've been fighting with an extremely low idle, the exact same as OP. Mine will idle that low for hours, not just at cold start.

My tick seems to be *mostly* cured after running a quart of MMO and a 2nd oil change with a quart of Risoline. Now, instead of being quiet, then getting louder and louder, then stopping for a few seconds, it's quiet, then ticks for a second or two, then quiet again.

I know my exhaust is louder than it should be, even with the new muffler and such. The PO told me that the manifold/downpipe was re-welded (apparently had cracked once before), but after a recent wheeling trip, I'm now almost positive that it's cracked again.


My question is this: Do these manifolds warp like many others do?? My manifold is ~20 years old...if I go find another at the boneyard, what are the chances that it will work?? Or would I be more likely to find all used manifolds have warped beyond use on any motor except the original??

They can - but I've not seen it to any significant degree yet. The RTV Copper I use on gaskets is mainly a long-standing habit that I see no reason to break - but a thin layer will also help if you have a mildly warped flange.

Still, before you do anything else, take a couple of minutes and check the stud nuts on the flange at the collector (they fasten the downpipe.) It's amazing how often they come loose - and you may need a new "donut" there as well (they're fairly cheap - I just don't recall the number offhand.)

 

[Muad'Dib]

Well it turns out that i bought the head set (all the gaskets from the head up)
A valve spring compressor.
A new Exhaust Manifold
Remanufactured Mustang 5.0 Fuel injectors (that were flow tested ultrasonic cleaned new parts etc..)
and all the exhaust hardware.
I did not have enough money for three things i wanted to get.
1.) New Lifters
2.) New Push Rods
3.) New Head Bolts. (I cant believe these are like anywhere from 80-120 bucks!)
I probably dont "need" to replace the lifters and pushrods, but i figured it would have been a good thing to do while i was dug in that far!
Im also about 95% sure that the head has never been removed, so if i end up removing it, ill be ok to re-use the head bolts. Since they can suposidly be re-used once and only once.
If you have any comments about my game plan, please dont hesitate to post.
I have one last question ...

If i do end up removing that head, and since i will not have replacement lifters, what do you think i should do?
Should i remove each lifter individually and lube it with assembly lube or just leave them alone?

Thanks!

 

[5-90]

Well it turns out that i bought the head set (all the gaskets from the head up)
A valve spring compressor.
A new Exhaust Manifold
Remanufactured Mustang 5.0 Fuel injectors (that were flow tested ultrasonic cleaned new parts etc..)
and all the exhaust hardware.
I did not have enough money for three things i wanted to get.
1.) New Lifters
2.) New Push Rods
3.) New Head Bolts. (I cant believe these are like anywhere from 80-120 bucks!)
I probably dont "need" to replace the lifters and pushrods, but i figured it would have been a good thing to do while i was dug in that far!
Im also about 95% sure that the head has never been removed, so if i end up removing it, ill be ok to re-use the head bolts. Since they can suposidly be re-used once and only once.
If you have any comments about my game plan, please dont hesitate to post.
I have one last question ...

If i do end up removing that head, and since i will not have replacement lifters, what do you think i should do?
Should i remove each lifter individually and lube it with assembly lube or just leave them alone?

Thanks!

Leave the lifters alone (unless there's something obvious that should be handled) and clean the carbon out of the chambers and off of the pistons - Scotch-Brite discs work well for that, and they don't remove material.

Paint the heads of the cylinder head screws (a simple mark will serve) after you've torqued them back down, so you know they've been removed and you'll get a new set for next time.

 

[Muad'Dib]

Thanks sir!

 

[imma honky]

If your block is anywhere near as gunked as mine was.....
I had to use a plastic scraper and a shop-vac to remove all the build up.

 

[Muad'Dib]

Blah! i keep thinking of more things!

Should i replace the freeze plug on the head?

 

[PornstaR]

Blah! i keep thinking of more things!

Should i replace the freeze plug on the head?

Only if they are leaking........... this all really sucks. Fun thing is I get to do it really really soon on my 90, same low idle, loose intake bolts, leaky intake, broken rear stud. im gonna try to EZ out it out (hopefully there is enough room) blah blah have fun!!

 

[Muad'Dib]

Nope not leaking .. ill leave it alone also. I got myself an easy out set, but i have heard that they break too easily in this application. I doubt that there will be enough room anyway. That stud is way too close to the firewall.
Im thinking that it will be just much much easier to remove the head with the exhaust manifold and intake manifold still bolted up. Then when re-assembling doing the same in reverse.
What do you guys think? Should i just remove the exhaust / intake manifolds first and check the stud or just remove it all as an assembly. I hear its much much easier to torque it all up when the head is removed. Advise?

 

[WEJOXJ]

Well put 5-90. If the manifold isn't coked or cracked reuse it unless you want to pony up some money for an aftermarket.

 

[5-90]

Nope not leaking .. ill leave it alone also. I got myself an easy out set, but i have heard that they break too easily in this application. I doubt that there will be enough room anyway. That stud is way too close to the firewall.
Im thinking that it will be just much much easier to remove the head with the exhaust manifold and intake manifold still bolted up. Then when re-assembling doing the same in reverse.
What do you guys think? Should i just remove the exhaust / intake manifolds first and check the stud or just remove it all as an assembly. I hear its much much easier to torque it all up when the head is removed. Advise?

If you're going to end up pulling the head, I find it much easier to pull the head and manifolds as a unit. However, get some help - unless you're a big guy (like ZacSquatch, YuccaMan, or me, for instance.) That head is cumbersome on its own, and quite unbalanced when it's got the manifolds attached.

Something else I find helpful - get some 1/2"-13 threaded rod, and cut three or four pieces about 8" long. Thread loosely into the two front and one or both rear screw holes, and use them to position the head (so you don't "scrub" the gasket.) Start a few screws, then remove the alignment pins and replace with screws as well. MUCH easier that way, methinks (and I'm mildly surprised I didn't mention it earlier...)

When a broken screw needs to be removed, I'll usually start drilling with a left-hand twist drill bit - about half the time, the drill will get started, take a bite, and back the screw out for you...

 

[Blaine B.]

If you leave the manifold/intake attached the head will be quity bulky for removal and installation. I'd say you'd need a cherry picker for removal, I don't think you could manuver it by hand with all of that still attached.

 

[5-90]

If you leave the manifold/intake attached the head will be quity bulky for removal and installation. I'd say you'd need a cherry picker for removal, I don't think you could manuver it by hand with all of that still attached.

You can - but it's difficult! A crane is a huge help, or a partner/helper you can trust. (With a job like that, two sets of hands will still need to answer to one brain!)

I know it's possible tho - I've done it twice. Just be sure to "plan the move" and make sure everything else is clear between the engine and the bench...

 

[imma honky]

If you're going to end up pulling the head, I find it much easier to pull the head and manifolds as a unit. However, get some help - unless you're a big guy (like ZacSquatch, YuccaMan, or me, for instance.) That head is cumbersome on its own, and quite unbalanced when it's got the manifolds attached.

Something else I find helpful - get some 1/2"-13 threaded rod, and cut three or four pieces about 8" long. Thread loosely into the two front and one or both rear screw holes, and use them to position the head (so you don't "scrub" the gasket.) Start a few screws, then remove the alignment pins and replace with screws as well. MUCH easier that way, methinks (and I'm mildly surprised I didn't mention it earlier...)

When a broken screw needs to be removed, I'll usually start drilling with a left-hand twist drill bit - about half the time, the drill will get started, take a bite, and back the screw out for you...

lol, I pulled the head off and out on my own ..... and I'm a wee fella(110 pre dump) But then again, people always under-estimate me.

 

[5-90]

lol, I pulled the head off and out on my own ..... and I'm a wee fella(110 pre dump) But then again, people always under-estimate me.

If you feel confident to handle something that's about two feet long, weighs about 80#, and is not well-balanced, then go for it! If you don't feel confident, get help you can trust.

There's nothing saying that "wee folk" can't do heavy work - my wife (5'2") tosses my arse around the backyard when we spar - and I'm 6'3" and 260#. No, I don't "let" her do it - she was taught well. There are times when leverage is a factor - my 36" sleeve can do jobs that her 28" sleeve can't, and her 28" sleeve can do some jobs easier that my 36" sleeve can't.

It mainly comes down to knowing your limitations. People get into trouble when they don't...

 

[imma honky]

If you feel confident to handle something that's about two feet long, weighs about 80#, and is not well-balanced, then go for it! If you don't feel confident, get help you can trust.

There's nothing saying that "wee folk" can't do heavy work - my wife (5'2") tosses my arse around the backyard when we spar - and I'm 6'3" and 260#. No, I don't "let" her do it - she was taught well. There are times when leverage is a factor - my 36" sleeve can do jobs that her 28" sleeve can't, and her 28" sleeve can do some jobs easier that my 36" sleeve can't.

It mainly comes down to knowing your limitations. People get into trouble when they don't...

Tis' true. Help is nice, was just saying it can be done solo, without breaking a sweat. BTW, i got a hoist to put the bugger back in though.

 

[5-90]

Tis' true. Help is nice, was just saying it can be done solo, without breaking a sweat. BTW, i got a hoist to put the bugger back in though.

Cheeky. I didn't have one last time - thus, the "alignment studs" in my toolbox...

It's amazing what we can do once we dispense with "I can't do that!" isn't it?

 

[imma honky]

Cheeky. I didn't have one last time - thus, the "alignment studs" in my toolbox...

It's amazing what we can do once we dispense with "I can't do that!" isn't it?

While it may not be the best thinking, If anyone asks me "how things are going", my response is "i'm not dead yet". Cause I'll be damned if I give up. But then again, stubborn runs in the family, but so does ingenuity.