Taking on Intake
#1
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Getting ready to start my intake adventure. I have been having some problems with cold idle recently likely related to my ISV. Sx briefly improve with the WD-40 spray but then quickly degrade. The problem hasn't been too bad, so I have just put up with it.
But, it is now the dead of winter and driving opportunities aren't great, so it is the perfect time to take care of it as I also a few other issues to take care of like the Vac line under the throttle body that has come disconected.
I went through the cars maintanence file and found that the intake gaskets and knock sensors were done in 2002. I have already done most of the vaccum lines (all I could reach) and fuel lines are new with Roger's kit all last year.
So, while I am in there, what all should I be replacing? Money is not unlimited, I have about $1K saved in the shark fund currently. I already have the ISV purchased, and figure I will be replacing the Hall sender, and TPS. Also the flappy actuator, oil filler O-ring, and the thermostat. Also, vac lines and rubber elbows. I will check the function of the knock sensors but don't think it is likely for them to be ready for replacement just yet. Same goes for the gaskets. If they seem anything other than rubbery and compliant then I'm getting new, but if they still feel good, I'm thinking I'll just leave them since they are just 6 years old.
Also was originally planning to powdercoat the intake but after reading a recent thread I think I may just do the prep and spray with Duplicolor.
Lets see, should I send off the injectors? Worth it for the cost?
Also, anything else I'm going to regret if I don't do while I'm in there?
But, it is now the dead of winter and driving opportunities aren't great, so it is the perfect time to take care of it as I also a few other issues to take care of like the Vac line under the throttle body that has come disconected.
I went through the cars maintanence file and found that the intake gaskets and knock sensors were done in 2002. I have already done most of the vaccum lines (all I could reach) and fuel lines are new with Roger's kit all last year.
So, while I am in there, what all should I be replacing? Money is not unlimited, I have about $1K saved in the shark fund currently. I already have the ISV purchased, and figure I will be replacing the Hall sender, and TPS. Also the flappy actuator, oil filler O-ring, and the thermostat. Also, vac lines and rubber elbows. I will check the function of the knock sensors but don't think it is likely for them to be ready for replacement just yet. Same goes for the gaskets. If they seem anything other than rubbery and compliant then I'm getting new, but if they still feel good, I'm thinking I'll just leave them since they are just 6 years old.
Also was originally planning to powdercoat the intake but after reading a recent thread I think I may just do the prep and spray with Duplicolor.
Lets see, should I send off the injectors? Worth it for the cost?
Also, anything else I'm going to regret if I don't do while I'm in there?
Last edited by 928autobahndreamer; 03-31-2009 at 08:50 PM.
#2
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I just installed knock sensors myself and as cheap as they are IMHO I would do them too, tough choice as they aren't too old.
I would replace all the o-rings on the water bridge while you have it apart too, and the fuel lines, etc.
I just did this so I know the list just grows and grows.
I would replace all the o-rings on the water bridge while you have it apart too, and the fuel lines, etc.
I just did this so I know the list just grows and grows.
#3
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if you are going to re-finish the intake ..then valve covers as well then you would look at a different kettle of fish altogether. I am pulling mine when i get back from leave 23/01 and have invested heavily with Roger
#4
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I think you have most of the key components identified for replacement, and the ISV is the most expensive item.
Check all the hoses under the intake - very likely some are crumbly. Check to see how tight they are at the plastic connectors at elbow of throttle body, and how tight the conenctors are in the rubber elbow (mine were very loose, so I replaced everything).
Consider replacing the big rubber elbow where MAF joins throttle body.
Summit Racing does a set of Ford Motorsport injectors which are direct replacement, apart from needing larger o-ring at the lower end. They are so cheap that you will probably save against having existing injectors cleaned, and cleaning doesn't fix all injector problems by any means (I had leaky originals on 88 S4).
Basically if you're not in a hurry and can wait for parts, just carry out careful inspection while intake is off and then decide what needs replacing. You probably won't have to repeat this for life of the car so worth doing thoroughly.
Check all the hoses under the intake - very likely some are crumbly. Check to see how tight they are at the plastic connectors at elbow of throttle body, and how tight the conenctors are in the rubber elbow (mine were very loose, so I replaced everything).
Consider replacing the big rubber elbow where MAF joins throttle body.
Summit Racing does a set of Ford Motorsport injectors which are direct replacement, apart from needing larger o-ring at the lower end. They are so cheap that you will probably save against having existing injectors cleaned, and cleaning doesn't fix all injector problems by any means (I had leaky originals on 88 S4).
Basically if you're not in a hurry and can wait for parts, just carry out careful inspection while intake is off and then decide what needs replacing. You probably won't have to repeat this for life of the car so worth doing thoroughly.
#5
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There are several studs with rubber shockpads for the throttle body and airbox that should be replaced.
Consider also the crank position sensor, although, it can be done later because accessiblility is reasonable under the air cleaner assy.
Big O-ring where MAF meets throttle body.
I think there is a PCV valve in the vac line leading from the base of the oil fill spout, there is on 86 at least, you might check the diagram to be sure.
The little clips that attach the spark plug wires to the valve covers (brittle).
Injector seals if you are pulling the fuel rails.
Note on the Duplicolor: If you can powder coat --- do that! Or use Duplicolor heat resistant engine paint. I'm not that happy with the Duplicolor wheel paint, which scratched on reassembly yesterday.
Good luck!
Consider also the crank position sensor, although, it can be done later because accessiblility is reasonable under the air cleaner assy.
Big O-ring where MAF meets throttle body.
I think there is a PCV valve in the vac line leading from the base of the oil fill spout, there is on 86 at least, you might check the diagram to be sure.
The little clips that attach the spark plug wires to the valve covers (brittle).
Injector seals if you are pulling the fuel rails.
Note on the Duplicolor: If you can powder coat --- do that! Or use Duplicolor heat resistant engine paint. I'm not that happy with the Duplicolor wheel paint, which scratched on reassembly yesterday.
Good luck!
#6
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8 new spark plug well seals
26 rubber grommets for cam cover bolts
2 cam cover gaskets
timing chain tensioner pads (the top ones are cheap and are the ones that wear)
4 o-rings for the 2 beather hose attachments and 2 plastic blanks on the other cover
paint cam covers to match intake
If you can check EZ-K faults using a JDS Spanner or Bosch Hammer, check for Hall sensor faults and replace while you're in there - sooo much easier to replace when you have the right-side valve cover off due to increased room.
Oh - don't forget the addition of the metal crush washers to the valve cover bolts to prevent leaks - there's a porsche tech bulletin about it and a specific part number for them.
#7
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I did a thorough intake refresh last fall, parts alone, including ISV were 1100ish. wish it was a cheaper job.. You're 1k should get you most of the way there for underhood parts.
I didn't pay to have injectors cleaned (swapped labor with a friend) or paint intake which I did myself, both of which will cost you if you choose to do them. Injectors were DIRTY and the car had about 105k on her. Ran much better after the cleaning.
I'm a newbie here still, but I'd say do everything you can while you're under there.
I didn't pay to have injectors cleaned (swapped labor with a friend) or paint intake which I did myself, both of which will cost you if you choose to do them. Injectors were DIRTY and the car had about 105k on her. Ran much better after the cleaning.
I'm a newbie here still, but I'd say do everything you can while you're under there.
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#8
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Looks like everyone above has listed the things you'll need. Roger has a list of all of the parts he recommends replacing in an Excel spreadsheet that you can pick from if you like.
For the injectors, read up on here about them. Most will tell you to just replace rather than clean. They can't 'balance' them unless you send more than your original 8, and even then IMO it's better to go with new. Anything that has moving parts can wear out.
Those studs or standoffs get really brittle and need to be replaced. I also found O-rings inside the throttle body that were really brittle and leaking in mine, but I don't know what the inside of the S4 throttle body looks like.
If it's a winter project, you could probably just keep taking things off and make a list as you go. Being methodical and cleaning everything. If it's plastic or rubber and hasn't been replaced, it likely should be. You'll be good for another 20+ years.
I went with the duplicolor high heat paint and it looks MUCH better than the flaking stuff from before, but I also managed to scratch the valve covers after install so be careful.
For the injectors, read up on here about them. Most will tell you to just replace rather than clean. They can't 'balance' them unless you send more than your original 8, and even then IMO it's better to go with new. Anything that has moving parts can wear out.
Those studs or standoffs get really brittle and need to be replaced. I also found O-rings inside the throttle body that were really brittle and leaking in mine, but I don't know what the inside of the S4 throttle body looks like.
If it's a winter project, you could probably just keep taking things off and make a list as you go. Being methodical and cleaning everything. If it's plastic or rubber and hasn't been replaced, it likely should be. You'll be good for another 20+ years.
I went with the duplicolor high heat paint and it looks MUCH better than the flaking stuff from before, but I also managed to scratch the valve covers after install so be careful.
#9
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Clean both the ground points in that area while you have the intake off. I took them loose even though they looked clean and tight...there was some corrosion between the mating contact surfaces. Hit it with a dremel tool and wire wheel...nice and clean! And that one is a no cost job!
Crank position sender might be good but the sensor half of the connector will probably crumble so keep an eye on that possibility.
Vacuum the area around the injectors real good before lifting the intake to keep stuff from falling into the valve area when you are lifting the intake off.
The heater valve is much easier to access while the intake is off....
Crank position sender might be good but the sensor half of the connector will probably crumble so keep an eye on that possibility.
Vacuum the area around the injectors real good before lifting the intake to keep stuff from falling into the valve area when you are lifting the intake off.
The heater valve is much easier to access while the intake is off....
#10
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Here is a link to our Intake Refresh Kit page. If you use the drop down options to select the items it will give you all the part numbers which will help you source what you need.
https://www.928gt.com/pc-25785-1403-...for-87-95.aspx
Also here is a link to some of our other Kits which might come in handy for other projects.
https://www.928gt.com/showcategory.a...03§ionID=0
https://www.928gt.com/pc-25785-1403-...for-87-95.aspx
Also here is a link to some of our other Kits which might come in handy for other projects.
https://www.928gt.com/showcategory.a...03§ionID=0
Last edited by Jeannie928; 01-12-2009 at 01:30 PM.
#11
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Thanks for the replys.
I am looking to go ahead and do the passenger cam cover while I have the intake off. One of my first jobs on the 928 was removing the driver side cam cover as it had something rattling around inside. Turns out I had the cam end plugs come loose. I replaced all the gaskets on the drivers side and replaced the cam end plugs with the proper pins. Unfortunately I did not refinish the single cam cover while I had it off. So, now I'm not sure whether to leave the cam covers with their original paint or re-pull the drivers side while the passenger side is off and refinish all of them. The paint was still stuck on pretty tight on the cam covers. But, with refinishing the intake the cam covers will look odd if I leave them alone or only refresh one side.
Anyway, I will update here occasionaly as I progress and will include pictures as I go. That way you guys can knock me upside the head when you see something else that needs attention or something being done wrong. Trust me I will appreciate it.
I am looking to go ahead and do the passenger cam cover while I have the intake off. One of my first jobs on the 928 was removing the driver side cam cover as it had something rattling around inside. Turns out I had the cam end plugs come loose. I replaced all the gaskets on the drivers side and replaced the cam end plugs with the proper pins. Unfortunately I did not refinish the single cam cover while I had it off. So, now I'm not sure whether to leave the cam covers with their original paint or re-pull the drivers side while the passenger side is off and refinish all of them. The paint was still stuck on pretty tight on the cam covers. But, with refinishing the intake the cam covers will look odd if I leave them alone or only refresh one side.
Anyway, I will update here occasionaly as I progress and will include pictures as I go. That way you guys can knock me upside the head when you see something else that needs attention or something being done wrong. Trust me I will appreciate it.
#13
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Yeah, I had considered carefully taping and masking everything around that driver side cam cover and giving it a good cover coat with matching paint so it wouldn't stand out.
I read that thread as well and I think this will be the best way to go since it is tight and dry and everything looks good on that side. I would hate to mess it up and maybe start a new leak by pinching a gasket trying to reinstall. It was a PITA getting it all in just right last time.
I read that thread as well and I think this will be the best way to go since it is tight and dry and everything looks good on that side. I would hate to mess it up and maybe start a new leak by pinching a gasket trying to reinstall. It was a PITA getting it all in just right last time.
#15
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I did my intake R&R last year and did not replace the ISV or the TPS but did perform all tests plus a good cleaning. I also did not replace the flappy mechanism, all was checked good
All hoses, gskts, seals, vac lines, fuel lines, knock sensors, injectors cleaned etc etc..............many posts.
All hoses, gskts, seals, vac lines, fuel lines, knock sensors, injectors cleaned etc etc..............many posts.