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Discussion Starter #1
Are they reusable? It’s for my 1990 3.8 N/A bird. I have a good size leak coming from the passenger side valve cover and would like to maybe just re-seat it. Maybe add a little gasket sealer too.

It’s my project/beater car so id like to spend as little as possible.

Thanks,
Dave
 

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Stroked and Blown
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Hey man, I need to replace my valve cover gaskets also. I originally wanted to do this myself, but the more and more I open the hood and look at them, the harder the process seems to be. Really this can't be a simple job can it? The whole upper intake has to come off, but there's not just a few bolts that need to be removed, there are hoses, wires, fuel lines, electrical shlt,:eek:

Have you ever replaced them before? What all needs to be done? It looks like a Royal PITA to do this. For a shop to do it though, you're probably going to spend over 1200 to get it done.

I'm sorry for hijacking your thread dude. I may start a new thread on this but I'm not sure yet. I've been doing searches here for 2 hours now and I can't find something useful enough that explains how to replace valve cover gaskets on a 3.8 Tbird, or more importantly, information that explains what, where, when and why certain things need to be removed just to get the damn valve covers off!:confused: :eek:
 

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Pedal Faster
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The rubber ones are reusable if they aren't deformed or anything, but the cork ones definitely are not.

1200 dollars... I think you're thinking head gasket job on that one. I would hope like hell that no one would charge that. Yeah, to do them you have to pull the upper intake, but there's not much more to it than that. Most of the stuff on the passenger side can be pushed out of the way, and there is nothing on the driver's side.
 

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Stroked and Blown
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The rubber ones are reusable if they aren't deformed or anything, but the cork ones definitely are not.

1200 dollars... I think you're thinking head gasket job on that one. I would hope like hell that no one would charge that. Yeah, to do them you have to pull the upper intake, but there's not much more to it than that. Most of the stuff on the passenger side can be pushed out of the way, and there is nothing on the driver's side.
What about all the stuff connected to the upper intake. I noticed under it, there are fuel lines, hoses, wires, possible sensors and the hoses have these wierd @$$ clams holding them on. Look like you might need a pliers to pull them apart.

How many bolts need to be removed to get the upper intake off?
 

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Pedal Faster
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Well if you don't have pliers, you might want to reconsider working on the car...

Yeah, there are a few vacuum lines on the upper intake, as well as coolant lines, but it's not like there is anything too complex. There are 6 bolts for the upper intake, and you can see them all.
 

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Stroked and Blown
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Well if you don't have pliers, you might want to reconsider working on the car...

Yeah, there are a few vacuum lines on the upper intake, as well as coolant lines, but it's not like there is anything too complex. There are 6 bolts for the upper intake, and you can see them all.

I have pliers as well as other tools.;) The clamps I was referring to look wierd, thats all. Like clamps I've never seen before. I'm not sure if a pliers or anything would take them off or not or do I need a "special tool" that only dealerships have. Once I remove the vaccum lines and coolant lines, is anything going to squirt out? I just want to know so if it is normal for something to squirt out, I won't freak out and assume I phucked up something. If there was a tech article on this, it would be real helpful. Also, are there any other seals I will need to replace once the intake is off?

Have you done this before dude?
 

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Pedal Faster
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I've had the upper intake off of my car more times than I care to remember.

You will want to replace the plenum gasket and of course the valve cover gaskets. If you do it without separating the throttle body from the plenum, then you don't have to worry about the throttle body gasket. You will lose some coolant from the coolant hoses (drain some out of the radiator before you start or you'll have a green flood) but that's about it. I don't think you have to disconnect the fuel lines to get the passenger side valve cover off, but if you do, you will have to go to Napa or somewhere and get the little plastic pieces that you use to disengage the spring locks where the fuel lines connect to the rails.

It really isn't that big of a job, just start by taking off the intake hose (hose from throttle body to air cleaner housing) and work from there. The first time I did it was a few years ago when I did the rocker arms on my car and I don't think I even needed a manual (but if you don't feel like diving right in to it, a Haynes manual is pretty handy to have around.)
 

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Discussion Starter #8
Eh, that does sound like a lot of work. I prob should at that point just get new gaskets instead of being cheap.

I haven’t really looked hard at what’s in the way. I just hope there isn’t air conditioner lines that need to be removed, not that the AC even works anyway. I don’t THINK it works, ahhh can’t remember now LOL. Can’t say I ever use AC in Maine though.

Anyway, thanks for the info. I’ll tackle this job at some point.
 

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BTW- I just came back from the junk yard. Removing the upper intake off of these cars is NOT that easy. The whole throttle body needs to come off. Several hoses need to come off. There are SEVERAL sensors, hoses, and wires in the way.

I removed all 6 bolts holding it on (This was very easy) However, it got difficult afterwards. There were several other bolts, sesors, hoses etc that needed to come off. I eventually got the whole upper intake removed (at least I thought so anyhow) and I was moving it up and down-side to side, but there was still something in the back holding it to where I couldn't get it off. Anybody know what this was? From what I could see, it looked like some hose with clamp that had a LARGE bolt holding it on, but I don't know if thats what it was. I do know that I was pi$$ed off when I was so close and still couldnt get the intake completely off.

Also, the wiring harness needs to be disconnected to get to the valve cover on the passenger side. The car I was taking apart was a 1989 Thunderbird 3.8 na. Mine is a 1996. I don't think they're that different are they?
 

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Motorboatin' SOB, Headlight Cleaning Guru
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sounds like the egr tube was still attached to the valve. unbolt the valve from the intake (two 10mm bolts i believe), and leave the tube alone. its a pita to thread it back into the valve. removing the upper isnt that hard. off the top of my head, there's the six bolts, 2 or 3 harnesses, throttle cables (leaving the tb and iac attached to the upper), one vaccuum line on top and one line on the bottom, and the egr valve. cover the lower intake ports with wide masking tape.

a little trick when installing the upper: use two skinny screwdrivers in the outer holes to keep the gasket in place when you position the upper onto the lower. then thread in the four center bolts, remove the two screwdrivers, and finish off with the corresponding bolts. dont overtighten the bolts, torque them to spec.
 

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Stroked and Blown
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Okay, Next time I go to the junkyard, I'll print that and take it with me. Does it matter what year MN12 I take the upper intake off of? I'm going to try again and get an upper intake off of one of these cars. I plan on getting it ported and polished and eventually installing it on my car (keeping the one on mine now as a spare for possible future use) Does it matter what year? I know the 3.8 n/a's are pretty much the same 1989-1997 but i certainly don't want to get one with less power. (1989-1995 140 hp) (1996-1997 145hp) Does the year of the upper intake matter? Is everything still the same on them?
 

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Pedal Faster
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There is a coolant hose in the rear that runs through the upper intake and out the front for warm-up purposes. On the reinstall, you have to finesse the rear coolant hose on to the upper intake because it is just an inch or two of flexible coupler which comes off of a steel pipe (in other words, you sort of "plug" the upper intake in to the coolant hose as you set the intake down.)

When it's time to reinstall, I usually take a glob of wheel bearing grease and put it on the very ends of the gasket (where the outer bolt holes are) and use that to stick the gasket to the lower intake.

It's kind of tricky but it really isn't that big of a deal.

I know the number of vacuum ports on the intake is different between the Mustang and Tbird V6s at some point, so not all 3.8s are the same, but I couldn't tell you if there are differences among just the Tbird ones. I'm sure Thomas knows more about that, he seems to be cutting them up every chance he gets. :D
 

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If your car is leaking at the valve cover gasket then you need a new valve cover gasket. Reusable does not play a part in that equation. Things don't get better all by themselves. If it is too much work for you then pay to have someone do it or live with the leak. But when something fails, you have to figure out what the cause is, or it will stick it's head up again. Point is, always replace everything taken off with new.
 

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Stroked and Blown
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There is a coolant hose in the rear that runs through the upper intake and out the front for warm-up purposes. On the reinstall, you have to finesse the rear coolant hose on to the upper intake because it is just an inch or two of flexible coupler which comes off of a steel pipe (in other words, you sort of "plug" the upper intake in to the coolant hose as you set the intake down.)

When it's time to reinstall, I usually take a glob of wheel bearing grease and put it on the very ends of the gasket (where the outer bolt holes are) and use that to stick the gasket to the lower intake.

It's kind of tricky but it really isn't that big of a deal.

I know the number of vacuum ports on the intake is different between the Mustang and Tbird V6s at some point, so not all 3.8s are the same, but I couldn't tell you if there are differences among just the Tbird ones. I'm sure Thomas knows more about that, he seems to be cutting them up every chance he gets. :D

I'm surprised Thomas hasn't chimed in on here yet. Maybe I'll pm him to tell him about this thread and see what he has to say. BTW- I think the biggest issue I'm going to have with this is getting the upper manifold off in the back part. As I said, I had the upper intake off of that 89 Tbird about 99%. If only I can get pass that issue on the back.
 

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Yout don't want to get the 96-97 upper intake unless you don't want to use it. It has a different number and/or placement of bolts. And, the power difference was mostly in the exhaust manifolds. They were tubular style.
 

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Stroked and Blown
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Yout don't want to get the 96-97 upper intake unless you don't want to use it. It has a different number and/or placement of bolts. And, the power difference was mostly in the exhaust manifolds. They were tubular style.
My car is a 1996. I was tearing apart a 1989 and was going to get the intake ported and polished and then use it on my 96. Would a 1989-1995 upper intake not match a 1996-1997 intake?

Basically, If I'm going to be using the intake on my 96, then should I get the intake from another 96/97 or would an earlier style match also?

Sorry for the confusion, I should have clarified that.
 

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Moderator, Iowa Chapter Director, Uber Luber, TCCo
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hey guys. Not real sure where to start there's a lot to cover, hah. Let's see. Differences in intakes between years:

89-90 intakes had the heater bypass run through the intake itself via two hose barbs on either side of the inlet neck right after the throttle body. Later years do not have this, they have a seperate metal pipe that runs from the front of the intake, underneath the inlet neck, to the back, which is held on by two bolts, one at the back of the drivers side head, and one at the throttle linkage bracket.

there are slight differences in vacuum ports between years, but they're all essentially the same, just different locations, plus or minus one small vacuum port depending on the year.

96-97 intakes use smaller bolts on the large 4 bolts in the center of the intake. If you have a 96-97, make sure you use another 96-97 intake.

There is a tube underneath the upper intake that runs to the EGR (i believe) it sucks to put back on after you've installed the upper intake, so try and put it on there while the upper intake is unbolted so its easier to reach.

No matter what year it is you'll have to disconnect these things to get it off:
1. 6 bolts that hold it to the lower intake. 4 center ones, and 2 on either side.
2. support bracket at front of upper intake that conects to a lower intake manifold stud.
3. throttle linkage from throttle body
4. EGR solenoid (2 10mm studs)
5. IAC and TPS wiring harnesses
6. vacuum lines. 1 main vac line, one small EGR pressure sensor vac line, and one evaporative emissions line.
7. heater bypass hose on 89-90 intakes.

Thats all I can think of.

The upper intake manifold gasket IS reusable, I've used one 4 or 5 times before, it wont leak unless you tear it upon removal. Get a new EGR solenoid gasket and get new valve cover gaskets if they are leaking. You should not have to remove your fuel rail to get the valve covers off. I know I didnt have to.

-Thomas
 

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Stroked and Blown
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Hey Thomas, you wouldn't happen to have a picture that shows the locations of these, would ya? If not it's cool.


4. EGR solenoid (2 10mm studs)
5. IAC and TPS wiring harnesses
6. vacuum lines. 1 main vac line, one small EGR pressure sensor vac line, and one evaporative emissions line.


I removed alot of stuff off of the 89 Tbird. (Im glad I didnt get the intake afterall, as I need a 96/97) Anyways, I removed alot of stuff off that engine and I don't know which was what.
 

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Motorboatin' SOB, Headlight Cleaning Guru
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ok, let's see if this helps.



green circle shows the vacuum lines. there's the thick rubber hose going into the back of the intake at an angle, held on by one hose clamp. the green hose attaches to the egr valve (or pressure sensor i believe). the emissions line that thomas is referring to is the pcv line that runs to the passenger side valve cover. that line is under the intake. just pull the pcv valve out of the cover and leave the line attached to the upper.

red circle is the egr valve, held on by two 10mm bolts. the bolts thread into the upper at an angle as well. they are kind of hidden.

yellow circle shows the iac harness. the tps harness cant be seen in this pic, but its located on the left side of the tb. its a black plastic sensor held on by two screws.
 

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Hey man, thanks alot for that pic! I really appreciate it and thanks to everyone else who has helped.



What is this right here. The piece below the red wire and how does it come off:

 
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