Plenum finally off
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
Plenum finally off
In pursuit of new injectors ( or whatever else ) I started the teardown phase. Following some advice I'm trying to remove the Plenum with only the torx bolts, vacuum hoses and all other things unattached. Well things don't normally as planed. The darn thing wouldn't come loose by tapping up on the plenum with a rubber mallet. I finally had to remove the lower runner bolts on one side to allow for some play to work it free. I used a wide putty knife to gently wedge between the runner and plenum and pry, ever so gently while working it along the length of the joint freeing it up enough to pull it up. I noticed that some gasket material was missing and broken after it was removed. I'm planning to remove the runners, intake manifold (to check for leaks) clean and reseal anything that looks leaky. Hopefully the gasket material is recoverable at the bottom of the runners. Any suggestions to what I might replace, check on or look for while removing and inspecting?
Le Mans Master
Joined: Aug 2003
Posts: 9,884
Likes: 3
From: Magnolia Mississippi
St. Jude '03-'04-'05-'06-'07
Replace all the gaskets... take the bolts down to a bolt store, and get some grade 8 allen head bolts to replace the torx bolts. Clean the TB and the plenum (TB cleaner works fine)...watch out for vacum hose breakage.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
I wonder if someone used some RTV to seal as it should not have been that tight.
You should be able to get the gaskets at Auto Zone. You could pick up a "Top End" kit which has the intake base gaskets too. Once you have fresh gaskets installed they will be reusable.
You should be able to get the gaskets at Auto Zone. You could pick up a "Top End" kit which has the intake base gaskets too. Once you have fresh gaskets installed they will be reusable.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
gaskets
I replaced all my intake aluminum with stuff off an 88, and it sticks together like glue. I would think you are doing just fine, I wouldn't replace the manifold gasket. if they don't get moved, they seal just fine
Burning Brakes
Joined: May 2004
Posts: 1,230
Likes: 27
From: Athens Ohio
I removed mine about 2 years ago on my 86. That darn thing would not come loose. I made the mistake of taping the runners with a rubber mallet. That was a big mistake. I didn't realize they were so thin. Well I had to replace one of the runners. I guess 18 years of never being remove and 90,000 miles make them stick a bit.
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
Runners turn
Well I went to bed after getting the plenum off. The runners didn't seem to want to budge much. I did work them around a little and I can see a gap occuring. I might be using a small steel putty knife and work it into the gap and slowly pry it free. I do want to remove the intake manifold to clean and inspect it. Im woried about gasket matter falling in the intake. If it does find its way into the manifold can it travel any further ? Any suggestions or hints getting the runners off ?
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Race Director
Joined: Jun 2004
Posts: 13,943
Likes: 705
From: WI
When removing the plenum for the first time, I believe there are stock plastic pins. These have to be busted or there must be enough gap that they don't prevent upward movement. When I took mine apart I removed the drivers side runner first.
Yeah check the bolt that goes in from the other side.
Gasket matter could fall through the runner into the intake. Once the runner is off you should be able to clean it up fine.
Yeah check the bolt that goes in from the other side.
Gasket matter could fall through the runner into the intake. Once the runner is off you should be able to clean it up fine.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Are you sure you have all the bolts out. There is one on each set of runners that is removed from the other side.
The one on into the left rear runner flange is tough to access due to the dist being in the way.
BTW, when you install the pieces be sure to well start all the Torx bolts before using a wrench on them to avoid stripping. The plenum will likely require some grunting to get all the bolts hand started as the offset of the runners from one side to the other tends to skew the plenum.
Last edited by 65Z01; Dec 5, 2006 at 12:20 PM.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
When you decide to to get the gaskets...get Felpro for the complete intake. You can buy the whole set. Use "The Right Stuff" on the intake manifold and leave out the front and rear S-shaped gaskets and jsut use the RTV. I believe a 5/16" bead is what you need there. Inspect everything good. When you get the injectors make sure they have 0-rings around them and use a little oil on them and they just pop in. Also replace the fuel rail to fuel line o-rings. They are brown colored and made for fuel. If you use regular black o-rings there will be a fuel leak. Make sure to connect all the sensors back when installing. I forgot to connect the MAT sensor and it is very difficult to reach once everything is togather. You might want to replace the vac lines while your at it.
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
I found those pesky little plastic pins, PITA. Plenum was fun cleaning off the old gasket, stuck good. Will probally report myself, the attachment showing how is good info, the corners in my plenum don't seem as square as the diagram shows, mine as slightly more rounded off. Oh the gas line on the fuel rail, kind of comical, once removed the darn thing wouldn't stop pouring gas. Nurse ! clamp! Oh its only me at midnight, after 5-10 minutes I got a bolt with teflon tape in there to stop the bleeding, patient stabilized. But the whole house stunk like gas 
and my wife had to wake me at 6am to tell me about it. 
and my wife had to wake me at 6am to tell me about it.
Race Director
Joined: Sep 2003
Posts: 16,836
Likes: 337
From: Database Error Indiana
While you are there, replace the oil pressure switch. Its near the distributur with the oil sending unit. These tend to leak. The oil will run down the wiring conduit to the oil filter and make a mess. When this happened to mine I had a real hard time figuring out where the leak actually was. Only a $13 part but it made a nasty mess. 
Only a $13 part but it made a nasty mess.
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
Originally Posted by Spankyellow
While you are there, replace the oil pressure switch. Its near the distributur with the oil sending unit. These tend to leak. The oil will run down the wiring conduit to the oil filter and make a mess. When this happened to mine I had a real hard time figuring out where the leak actually was. Only a $13 part but it made a nasty mess.
Only a $13 part but it made a nasty mess. Today was productive day, got the day off from work, didn't call my wife and went to the garage. Got the driver side runner off, got the fuel rail off, got the EGR valve off, got the Distrib. out. Drained the coolant. Saturday, will remove the thermostst, and manifold. Questions,,, the gasket kit, does it have the gasket for the front and back of the manifold ? Should I use it ? Should I use Right Stuff only ? With gaskets being more advanced today then yesterdays batch can't decide which way to go.
Pro
Joined: Aug 2004
Posts: 623
Likes: 1
Use the RTV on the ends. Run the bead about a half inch up the head overlaying the intake to head gaskets. Let it skin up for a while before installing the intake. I think that is what most people do today. What I did on my last rebuild without a leak.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Don't forget this
Anytime you are running a steel bolt into aluminum you should coat the bolt with anti-seize. If you don't, you run the risk of the bolt seizing the next time you try and take it out. It usually galls the bolt threads with aluminum and then you really have a problem .
.