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Makes me question buying another three years of warranty.
In the US, you really can't extend the Porsche CPO without selling it back to the dealer and then buying it back from them again as a new CPO, but I have to say, I'm kind of happy my CPO is up in another few weeks...
I also kind of chuckle when I'm elbows deep in the car and notice something that previously wasn't done quite right, and know exactly what dealer last had their 'warranty' hands on that particular part! Not that I never have screw ups, but at least I own it when it happens!
I've always done that on my 996 Turbos were the fittings are barbed connectors and hoses, but on the 991, they look like hard-lines that are permanently glued with un-barbed connectors... I'm not seeing how zip ties would help much if the glue failed, but I guess it couldn't hurt! Have you seen them come apart? They look super tight on my car.
I use hairspray on all pressurized connections with the ban clampdown, etc...
In the US, you really can't extend the Porsche CPO without selling it back to the dealer and then buying it back from them again as a new CPO, but I have to say, I'm kind of happy my CPO is up in another few weeks...
I also kind of chuckle when I'm elbows deep in the car and notice something that previously wasn't done quite right, and know exactly what dealer last had their 'warranty' hands on that particular part! Not that I never have screw ups, but at least I own it when it happens!
Funny how things are so different, and we are both on the same continent - my guy told me that I am covered anywhere I take the car on the planet, this should be the same for every owner if they so desire.
But the truth is that I really want to finish the 996 before I take on another project, so I knew if I bought the warranty, I wouldn't bugger around with it.
Still, looking at those sexy pieces going on makes me wonder....
I've always done that on my 996 Turbos were the fittings are barbed connectors and hoses, but on the 991, they look like hard-lines that are permanently glued with un-barbed connectors... I'm not seeing how zip ties would help much if the glue failed, but I guess it couldn't hurt! Have you seen them come apart? They look super tight on my car.
Some of the slip joints were easy to pull loose on my car when I checked it. So I used Sam’s advice and cable tied each connection with a tiny tie.
I also kind of chuckle when I'm elbows deep in the car and notice something that previously wasn't done quite right, and know exactly what dealer last had their 'warranty' hands on that particular part! Not that I never have screw ups, but at least I own it when it happens!
I use hairspray on all pressurized connections with the ban clampdown, etc....
Curious but I'm not following what you do with the hairspray - pulling apart connections and using it as an adhesive on mating surfaces? Or spraying it on assembled junctions to act as a sealant against micro leaks? What does "ban clampdown" mean? TIA
So, you have a boost tube or anything that is under pressure and held together at the connection with some type of clamp.
As the connection goes together, you spray on your hairspray over the hose, pipe, connector etc., then assemble. Once the hairspray dries, and is clamped, it is almost impossible to break the connection because the force needed to sheer the hairspray is usually considerably higher than that of the pressure a given motor will generate.
I learned this trick from a friend of mine who is obsessed with racing in a straight line - I was continually blowing tubes of my 6.4l diesel at 50+ psi, so one day, when it was cool, I took all the tubes off of it and applied the hairspray fix and reassembled it, not a single blown tube since. So now, on every pressurized vehicle I own, every single pressurized connection has this fix on it, and touch wood, seems to be holding fine...
^ Glad I asked, I've struggled to get various boost connections to hold 24 psi on my supra for years, will definitely try the hairspray. And while we are at it, yes I do want to know about the panty hose trick.
I also want to add my experience over years of trying zip-ties as mini-clamps has been a repeatedly proven fail. When you add good tight pressure on the plastic tie with under-hood temp cycles, I find they are going to break within 2 years tops. Total lack of durability. Micro-sized actual hose clamps are the way to go for a lasting solution. I have ones that are small enough for the smallest of any lines on our car:
^ Glad I asked, I've struggled to get various boost connections to hold 24 psi on my supra for years, will definitely try the hairspray. And while we are at it, yes I do want to know about the panty hose trick.
I also want to add my experience over years of trying zip-ties as mini-clamps has been a repeatedly proven fail. When you add good tight pressure on the plastic tie with under-hood temp cycles, I find they are going to break within 2 years tops. Total lack of durability. Micro-sized actual hose clamps are the way to go for a lasting solution. I have ones that are small enough for the smallest of any lines on our car:
I was driving back to Fort McMurray one night with my Ex in my Excursion. It was winter, perhaps -27c, and I was around 130kms south of town, when suddenly I heard a snap and the power steering went dead, voltage output dropped to zero. Effectively the middle of nowhere, cold, miserable, just lovely all around conditions.
Popped the hood to discover the main drive belt had not only let go, it was completely shredded. I knew that there was no way it would make it 130k on the batteries without a charge, so I remembered reading about the elastic qualities of pantyhose and their ability to be used, in a pinch, as an accessory belt. So, much to my lady friends total irritation with the situation, I liberated a set of her stockings and wound it around the drives and accessories. I knotted the ends and put little loops in so I could use a ratchet strap to tighten it up as much as possible before I tied it down.
Although not ideal, I could see it slipping on both the voltage and injection pump (ran fairly jerky as fuel delivery was sporadic), I kept it off boost as much as possible and managed to make it back to town. The upside was that the bush fix was sufficient to get me home; downside was that the pantyhose, although still together, had melted somewhat and made a huge mess, along with a not happy female, it was an awesome trip.
For what it is worth, my preferred pantyhose for this application came from Victoria's Secret.
After upgrading to the DO88 Y-pipe, boot to throttle body, and plenum, very tight when testing from bottom of intercoolers.
This tests every portion of the boost system other than the lower boost hoses, which are removed to attach the test rig. The *only* thing that needed to be clamped off to properly pressure test is the one EGR vent connected to the y-pipe, a simple hose pinch clamp does the job fine. There is no need to block off at the throttle body, no need to pinch off the vent line down to the drivers turbo. If you are loosing air through that connection, you have a bad check valve.
Pressurized to 23 psi (~1.6 bar), very slow leakdown, less than 2 psi lost in 60 seconds. This is what you are looking for!
A big thanks to @Beezupra for another set of hands and help figuring out the best way to test these 991 Turbos!
...a couple of additional thoughts and lessons learned:
1. The small leaks that I did have would simply not have been detectable without real pressure testing. Smoke testing will not do it, and the turbos themselves will overcome small and medium leaks showing good boost pressure. You will be sacrificing speed to obtain boost and working your turbos at a higher duty cycle however.
2. A set of spare lower boost hoses that you are willing to cut up makes a perfect test rig. No need to even remove bumper or even engine cover to pressure test (though you will certainly be taking things apart to find the leaks if you have them!) Boost hoses you will need are 991-110-635-72 and 991-110-626-71. About $150 for the pair from a discount OE parts supplier.
3. For those that have 991.1 turbos. The y-pipe to throttle body boot (aka "distributor sleeve", 997-110-647-74) is prone to leaks (this is separate than there propensity to pop off). They leak right through the casing, I replaced it with a brand new one from Porsche and it was worse than the original one I had on.
But CAUTION, it has been recommended many times to use the 991.2 "upgraded" part (aka distributor sleeve, 991-110-677-71). I CAN NOT recommend this! Here's why: Quite simply, the part is too long. While the casing is much thicker and the clamps much improved, you have to kind of jam your y-pipe back into position with this part. This extra force presses on the throttle body and plenum and causes the o-rings that seal the plenum to the intake manifolds to leak! This was plain as day in my car... Putting on the improved boot with the y-pipe loosely installed in the car worked fine, pressure tested and held pressure. But once pushed back into position so the mounting studs went into the grommets, the plenum began leaking badly! This was easily repeatable, just by tweaking the y-pipe around a bit and seeing the leak open and seal. IF YOU HAVE INSTALLED THIS PART ON YOUR 991.1 TURBO WITH A STOCK PLENUM, I STRONGLY SUGGEST YOU PRESSURE TEST! Quite simply, it solves one problem but creates another. Your mileage might vary, but this on my car was a solution far worse than the original problem...
These are the o-rings that leaked like crazy on my plenum when the oversize y-pipe to throttle body boot was used. It tweaked the connection enough that it bled pressure. There are actually three sealing rings on each side... An o-ring on the intake manifold, an o-ring on the plenum (seen below), and a second sealing gasket on the tip of the plenum (also seen below).
4. On the boost control lines to the diverter valves... On the 991, these lines are hard plastic lines that appear to be permanently glued/shrunk onto hard plastic connectors. Examples are shown in green. I don't think these would benefit from zip ties. They do not come apart for service, if they are loose, you should be replacing the entire part. I don't see how a simple zip tie would hold these together if they failed, there are no barbs and no 'give' on either the connectors or the lines. A few other connection points use the same hard lines, but go into more typical flexible hoses, example shown in red. These *do* use hose clamps and I can see how they would benefit from zip ties. I've heard that the GT2 used similar control lines, but with more robust connectors. I'd like to investigate this further and see if I can find the part numbers for the GT2 parts, might be a worthwhile upgrade if these control lines are really problematic. Mine were rock-solid. No movement at all in the fittings, no bubbles when soap tested at 20+ psi.
...a couple of additional thoughts and lessons learned:
4. On the boost control lines to the diverter valves... On the 991, these lines are hard plastic lines that appear to be permanently glued/shrunk onto hard plastic connectors. Examples are shown in green. I don't think these would benefit from zip ties. They do not come apart for service, if they are loose, you should be replacing the entire part. I don't see how a simple zip tie would hold these together if they failed, there are no barbs and no 'give' on either the connectors or the lines. A few other connection points use the same hard lines, but go into more typical flexible hoses, example shown in red. These *do* use hose clamps and I can see how they would benefit from zip ties. I've heard that the GT2 used similar control lines, but with more robust connectors. I'd like to investigate this further and see if I can find the part numbers for the GT2 parts, might be a worthwhile upgrade if these control lines are really problematic. Mine were rock-solid. No movement at all in the fittings, no bubbles when soap tested at 20+ psi.
Yes, those are pesky little f***ers lol. I used oetiker clamps for those connections on a customers car and you'll never have to worry again. My personal car has been upgraded to Tial BOV, so I got rid of all that stuff. Less changes of leaks throughout the system.
After upgrading to the DO88 Y-pipe, boot to throttle body, and plenum, very tight when testing from bottom of intercoolers.
This tests every portion of the boost system other than the lower boost hoses, which are removed to attach the test rig. The *only* thing that needed to be clamped off to properly pressure test is the one EGR vent connected to the y-pipe, a simple hose pinch clamp does the job fine. There is no need to block off at the throttle body, no need to pinch off the vent line down to the drivers turbo. If you are loosing air through that connection, you have a bad check valve.
Pressurized to 23 psi (~1.6 bar), very slow leakdown, less than 2 psi lost in 60 seconds. This is what you are looking for!
A big thanks to @Beezupra for another set of hands and help figuring out the best way to test these 991 Turbos!
Slightly off topic, what do these cars make for stock boost and when tuned?
Just curious.
04-24-2022, 01:44 AM
