6ocyclehum

I'm going to replace all my coolant hoses, so I figure the intake needs to come off. (Doesn't it have to come off for pretty much everything???). Never done it, but really been dying to do it, now I have an excuse.

I guess I'll need new gaskets for it (although it was off very recently, right before I got it), I assume it's best to not reuse them.

When troubleshooting my boost issues, I used a heater hose to my ear to listen for vac leaks, and the idle speed control valve area was very suspect. I also have a bit of a lumpy idle, I replaced the TPS and it helped, but it still could be better. Should I replace the ISCV while it's possible?

I'll clean every contact I can get to while it's off, maybe the speed + reference sensors and main ground wil be a bit easier to get to with the intake off. I've not made it to them yet.....

Anyway, I'm just rambling, if there things I should address while it's off, please let me know! Thanks!

Mitch

Darwantae951

I re-used mine (I, too, recently replaced my gaskets) and I'm not having any issues.

I don't know of a way to test the ISV. I just cleaned mine and it helped my idle.

Cory9584

Gaskets can be reused but why? If you do i'd suggest a little silicone

while your in there, venturi delete kit if you dont already have it.

spoolin51

Darwin, definately consider the venturi delete....

Darwantae951

, I have factory venturi delete.

Because they were fresh and were fine. Why waste the money?

samluke

When they get old, ISCV's can leak out of the housing even if the hoses are new and tight. If the ISCV is still working mechanically and electrically, and you want to re-use it, you can test the assembly including the hoses, with the assembly off the car, and pressurized (15-20psi equivalent to boost). Its best to put the assembly underwater to show where the leaks are. I use black sealant to seal the housing crimps and also around the electrical connector, even on a new assembly, to minimize risks of leakage over time.

Personally I rarely change intake manifold gaskets, and I never use liquid products. From my experience, if you anticipate taking things off again (which is innevitable with a race car)then liquid gaskets create more problems than they solve and they are not required, unless there's a problem with the surfaces. I only use the liquid gaskets where Porsche says to use them, which is not many places.

If you don't think you will ever be taking the manifold off again, then new gaskets and silicon will certainly ensure you dont have any intake manifold to head leaks.

87944turbo

It's a good opportunity to address the injector seals if you haven't yet (http://www.rennbay.com/injector-seals-c-34.html) and also your grounds near the back of the block.

Here is the link to a ground cleaning procedure if you need one (http://members.rennlist.com/tom86951/)

951Porschiste

The following URL is a write-up I did a few years ago on the IceShark battery wire upgrade. The first part goes through the procedure for removing the intake manifold (with pics). I always replace the gaskets when i take off the intake manifold. Just make sure to remember that the intake 1 gasket is oriented differently than the gaskets for the other three intake ports.

http://my.execpc.com/D3/79/eelfner/9...rade%20Kit.pdf

bigdeano

You can reuse your gaskets... but chances are you'll have gasket material on the head and the intake... so you won't be able to reuse them. If memory serves me right i think 4 gaskets for the intake is about 5 bucks, so why not just go new for peace of mind if nothing else?

jerome951

A few thoughts/tips:

If you don't know when the vacuum hoses were replaced last, do it then. As someone mentioned, also a good time to clean the grounds on the bellhousing.

A ratcheting box-end wrench is a necessity for removing the throttle cable bracket. Start the bracket bolts before setting the intake back on. There isn't much room to work between the bracket and brake reservior heat shield.

A 1/4" drive swivel socket and extension is the only thing I've found to easily get the front mount bolt out.

Cut a slot in the dipstick tube bracket so that in the future you can just loosen the bolt on the intake rather than completely removing it.

Pulling the injectors out may be difficult if they haven't been moved in a while. You may want to use new o-rings when reinstalling to ensure a good seal.

Make sure you use a torque wrench when re-installing the manifold bolts to the head. Trust me, you don't want to strip one from overtightening. Use anti-seize when reinstalling any bolt into the alum head.

I've reused intake gaskets that were fairly new with no issues.

Keithr726

Overall its not to difficult but always be ready to find more to fix. My intake removal was supposed to be a weekend and turned into a mouth long $1k clean out.

Besides the ISV, vacuum lines, fuel injector seals. Its also a great time to install a MBC and new knock sensor.

6ocyclehum

Cool- thanks for all the tips! I just redid my injector seals and fuel lines, so that's done. I'm going to go ahead and get intake gaskets, just in case.

Which type of sealant works on the ISCV? Not sure mine is leaking, and not sure if I want to buy another right now, but if I could make sure it's sealed, I'd like to.

What size ratcheting box end wrench is needed for the throttle cable bracket? I have a few but they are US.

How failure prone is the knock sensor? I want to address everything I can , but I can see this escalating in price pretty quick! What is an MBC?

I found a coolant hose set for 951 from Paragon for $90, best price I found. However, it does not include the t-hose going to the turbo, says it's discontinued. I found it seperately elsewhere, but it's $50! Anywhere to check to get a better price on these? Anyone made one with a T fitting before? Looks like the hose going to the turbo has a bit a bend in, might be hard to copy....

Again- thanks much for the tips, will save me much frustration!

M Berg

Check the hose with a little valve on it at the top of AOS , especially the 90 gr close to the AOS, for cracks. Gets old from oil and heat. Probably time to change that.

DAR951

Listen to Jerome... he knows of what he speaks and these are all good tips most of which you won't find elsewhere (except maybe the reuse the gaskets bit... can't believe you do that JW...)

jerome951

I've only done it once, and only when the gaskets had < 10 miles on them.

It's my dyno-cheating method. When the engine is cold and the gaskets don't seal well, I get lower boost and stay under the hp limit. However, after the 2nd lap of a race when everything is hot, I'm running 16 psi. ;-)