I did but I am now skeptical that it was actually generating smoke. I had made a “paint can” smoke generator and it is about 15 years old and lent to a few friends. I was checking it out a couple of weeks ago and noticed the heater wire is not attached to the power. I didn’t test for smoke output when I used it (due to excitement and not thinking the shop would have left vacuum leaks after replacing all of the tubings, etc). I bought a simple smoke generator that I tested and know generates smoke. I think I need to retest to be sure. Leaks are the only thing that make sense to me at this point.

Ok, well I am seeing a lot of smoke from multiple places.

I had the shop put in a pop up valve in the new airbox. It is leaking. Not where it is glued to the airbox. Pushing down on it doesn't seem to make a difference. I put a rubber glove over it to stop the leak there so I could find others.

I definitely have leaks around the #4 fuel injector and maybe some on the driver's side bank. I gave the shop new injector O-rings and the leak doesn't appear to be coming there - it is coming from the insert sleeve. I also gave them a set of sleeves and O-rings but this were not installed apparently.

Also, there is a lot of smoke coming from around the fan shroud - seems like from below it as you can see in the photo. This is the largest amount of smoke I've ever seen from this car over the 4 smoke tests I've done over 16 years of ownership. Any ideas where this is coming from?

And, there is smoke coming out of the large (~3" D) heater duct (see photo). I don't think I've come across any information about smoke here or sealing it off. Thoughts on this?

Right now the sun is to my back and low in the sky so there is a lot of glare and very difficult to see. I need to wait until dusk and get out my light bar and rerun the test and try to track where the leaks are. It didn't seem like there were any leaks from the front side (towards the firewall). The smoke that concerns me is 1) the quantity of smoke coming from the fan shroud area and 2) the popup valve. The injector leaks I've had before and didn't seem to greatly affect tuning in the past. Although I wanted to get new sleeves and O rings installed while the shop was in there.

Thoughts and recommendations appreciated please.

http://forums.pelicanparts.com/uploa...1730654187.png
http://forums.pelicanparts.com/uploa...1730654187.png
http://forums.pelicanparts.com/uploa...1730654187.png

Not seeing any pictures

and now I know why. I just tried to repost them but they didn't show up again. One was too large so it failed displaying them.

Here they are.

Meanwhile, it has been too cold to work on the car today. Tomorrow should be fine so I hope to dig in and find the leaks. I did order some silicon plumbers putty/tape that I can use to plug things so I can focus on finding leaks. I am mostly concerned about the quantity of smoke coming up the back - seemingly behind the fan and shroud (towards the rear of the car). It is not coming out of the tailpipe. I didn't see any smoke coming from the front (towards the front of the car) of the airbox. All of the vacuum hoses were replaced.

I am perplexed with the new popup valve apparently leaking. Even pressing on it quite hard there was still smoke coming out near the hinge side. Something to investigate for sure.
http://forums.pelicanparts.com/uploa...1730757257.jpg
http://forums.pelicanparts.com/uploa...1730757257.jpg
http://forums.pelicanparts.com/uploa...1730757257.jpg

Pop up valve is installed incorrectly. Your lid would hit the air filter during backfire. Hinge should be towards back of air box.
http://forums.pelicanparts.com/uploa...1730811632.JPG

Thanks Ed - that is how the shop set it up and he's the one that encouraged me to install it. I owned the car for 16 years without one. Of course, the one big backfire I had did take out the airbox!

But, even installed incorrectly oriented, that would not cause it to leak at this point. If I have to replace the new valve because it is faulty, I'll orient correctly.

Just FYI, this shop has a 4.9 star rating and decades of followers. A close Porsche friend of mine (RIP Chris Bennet) had recommended this shop many times.

With Sully on this.

http://forums.pelicanparts.com/uploa...1730814742.jpg

But others feel differently and do install them on top of the fins. Maybe try some caulk or glue on the hinge side just temporarily to see if that stops the POV leak.

Had you just run the car prior to doing a smoke test where these pics were taken? I had smoke from my fan once but it was oil dripping on the hot heat exchangers and wafting up and out the fan.

Yeah, I am going to use moldable silicone putty to temporarily plug leaks as I find them so I can focus on finding them all. The amount of smoke coming up the back though quickly obscures everything. I should be able to get out in the garage tonight and do more investigation, perhaps it is coming from the #1 intake boot (which was replaced but made not clamped properly, etc.

http://forums.pelicanparts.com/uploa...1730817631.jpg

Smoke out through the fan duct usually comes from leaking intake manifold gaskets. The smoke seeps out past the gasket, under the shroud, and out the fan duct.

Thanks Pete. I didn't get a chance to work on the p-car last night but hope to tonight. The intake manifolds were all cleaned as part of the airbox replace, along with gaskets but I will absolutely check them. It did seem like a lot of smoke was around intake #1 so that will be a good place to start.

Smoke coming through fan - what could it be?
 

Ok, I was finally able to do some more smoke testing this morning. I've attached a link to a video that shows it billowing out around the fan blades. There is no smoke coming from around any of the intake gaskets on either side and nothing I can see from outside of the fan shroud.

What can this possibly be? How can I figure out where it is coming from? Do I need to take the fan off?

https://youtube.com/shorts/yCet0CNN6xc

That's a lot of smoke. Before you pull out the fan, look under the car and see if smoke is coming out around the exhaust port gaskets, then seeping up through the fins, then out the fan duct. Otherwise, yes, you will have to pull out the fan to see.

Do you think smoke in this area is a vacuum leak? The car is on the lift so I can take a look underneath in the morning. Thanks!

The CIS intake systems sits entirely above the shroud, except at the gaskets between the intake runners and the heads. Unless someone connected some hoses where they are not supposed to go, I don't know of any other ways for smoke to get under the shroud in that quantity.

I lifted the car and ran the smoke test so I can watch underneath. Here's a link to the video: https://youtu.be/-_uq94os3r8

The first smoke appears at 39 secs. I clearly see smoke streaming in front of the #6 exhaust port - it isn't the port gasket, seems to be coming from a gap in the deflector shield around the cylinder housing. There is. a little from a similar place on #5.


At 1 min 57 sec I cleared the smoke and got a good video of smoke streaming out a slot just ahead of the #6 exhaust port.

I could not tell how much smoke was filling the top side since I was below. I will have my wife watch the top while I watch the bottom to see where the smoke appears first.

I can clearly see the #6 intake runner and its gasket and I didn't see any smoke in that area on previous tests.

I cleared out the smoke and lowered the car and set up my camera to watch intake 6. Don't pay attention to my narrative - I was watching via a mirror and did not see what the camera saw. You can see a tiny wisp of smoke just below and to the right of the copper nut and then it increases and comes from other areas after that.

https://youtu.be/aIPeUUhoQi8

So, I suppose if the gasket is leaking on intake 6, as you say Pete, the smoke would be trapped been the shroud and engine and could stream to the rear to escape - and escape around the cylinder baffle plates like I saw in the underneath video posted before this one.

Now what!?

To me there's way too much smoke underneath the engine...which must not be there...
Make sure to get to know where this is coming from exactly. Following the second video I cannot imagine that this would come from the intake runner #6 only. To me it seems that there's another leak under the fan shroud?!?

Thomas

The best I can tell after multiple smoke tests and videoing and carefully watching above and below the engine bay is that I don’t see the leak so it must be under the shroud and most likely on the right side.

I don’t get discouraged easily and after having my car in a professional shop for 6 months and then working through many big issues and now this vacuum leak that I can’t find, I am at my wits end. The weather is getting too cold to work
In my garage. I just don’t have anymore plans. I cant remove the engine now as it’s too cold and I’m too old.

Un-explitive-believable. I just can't accept failure and not solving a problem so I went back out to the garage, Literally stuffed myself into the engine bay so I could see around to the front side of intake #6 and found this. The first photo is just the setup so you can see what I am doing - mirror and lighting on the front-most nut of intake #6 with a pick tool lifting the washer. The second photo is a close up of the mirror where you can see the tip of the pick under the washer. This bolt wasn't even screwed down! Not even a little.

I don't think I can get to it to tighten it though. I might have to modify a wrench to make a stubby or something. And it likely is not the only one? The shop did not drop the engine to do the airbox replacement so maybe this was hard to get to?

If I have to remove the CIS system it should be a LOT easier since it was just removed and all of the frozen hardware was replaced and anti-sieze used on it.

Thoughts and ideas welcome.

http://forums.pelicanparts.com/uploa...1731270725.jpg
http://forums.pelicanparts.com/uploa...1731270725.jpg

You can do a partial drop of the engine. Search here in the forum on how to do. This seems not to be very helpful to get a few inches more room to work on the CIS but it makes the difference to pull the whole CIS from the engine if necessary.

https://www.pelicanparts.com/techarticles/911_partial_engine_drop/911_partial_engine_drop.htm

https://forums.pelicanparts.com/porsche-911-technical-forum/734835-how-do-you-do-partial-engine-drop.html

Yup and I am back to where this all started last April! See https://forums.pelicanparts.com/porsche-911-technical-forum/1160979-its-time-air-box-replacement.html#post12240127

But it will be easier now since all hoses were replaced, frozen bolts replaced and torqued, etc. Now the issue is the weather since my garage is unheated and I have to work with the door open since it is on my lift.

How do I get this nut on and tightened! ?
 

Well, I am back at it today on a not-too-cold Saturday morning. As I discovered last Sunday, the outermost nut attaching the #6 intake was not even snugged down. So the plan was to tighten that and run another smoke test. I went back in with lights and a mirror to pinpoint the nut and was able to get a view of the inside-most nut that holds intake #6. Guess what, it is completely missing! The washer is there but no nut and no sign of the nut anywhere. He used new copper nuts so they are easy to spot (but not magnetic).

I'll need to find a replacement nut somewhere, not sure how long that will take. But, I went ahead and tightened the outer nut using a 1/4" flex 13mm socket and long extension. With just this one #6 intake nut tightened, I ran the smoke test. The amount of smoke was significantly less (coming up through the fan) but enough to be problematic most likely. So now I need to figure out how to get in there to install that nut. I'm going to remove an easily accessible nut from one of the intakes on the left side (1 thru 3) to use on #6 so I can get that locked down and retest.

However, I can't even get my hand in there to feel it. I can see the stuff looking under the #5 intake though but it is tucked back pretty far.

This is an 83 CIS system with all of the extra goodies on the right side like the AAR and AAV. I need every trick, tip, and recommendation available to install this nut. What can I do? This would be equivalent (I think) to re-installing a new airbox in the car. All of the intakes were cleaned, new hardware (so none of the buts/bolts are locked). I am not sure if the CIS with intakes is re-installed with the AAR and AAV attached though - would removing one or both of these give me access to the nut?

I'm at the end of my rope and just need someone else to finish this off. I'm really overwhelmed with what was done/not done to my car.

I did remove the AAR and disconnected and pushed the AAV out of the way. I still couldn't access that stud to put a nut on. After reading a bunch of posts and looking things over, it seemed that if I could get the #4 intake off, I might be able to get the nut on from underneath #5. I pulled #4 injector and discovered that the O ring was not replaced nor was the injector shroud (I knew that and I had asked the shop to replace them with the Porsche parts I provided). Even though the rubber intake sleeves and clamps were replaced and accessible, the studs are too long to remove the #4 intake so I loosened the nuts on #5 but still not quite enough room to remove it.

In all of this today discovering that the injector O rings had not been replaced, the #4 injector is really nasty looking (carbon and discolored) and several other bracket nuts/bolts missing, I've decided to find another shop to do the work. I got recommendations for another well regarded shop and will have the car transported there on Friday and have them go through everything.

One thing I did not mention but it is gnawing at me - the original shop owner that had the car all summer passed away on Nov 5th. His funeral was this morning. I really liked him, he was knowledgeable, friendly, and had a very strong following of happy customers all over New England. He passed quietly in his sleep. He was only 2 months older than me. I don't have any bad feelings and have never gotten angry or upset with him all this time. I know he appreciated and respected that. A part of me wanted to find and fix my car to show him how much I care about it and to share what I learned with him. He has replied to all of my emails over the last 5 weeks that I've had the car back and discovering things. I sent him an email last Sunday about the loose #6 intake nut but unfortunately, he had already passed away.

I am going to admit defeat on this one and try another shop. I'm 99% sure that the last problem is the vacuum leaks at #6 intake but I just don't have confidence that there are no other issues hiding and I don't have the time or facilities to do this one on my own. I will report back and close out this thread once the car is running as it used to.

Tough situation for sure and a lot you will probably never know from his side of the story. Seems odd that he left so many things undone but its pointless now to speculate. You obviously know your car and have a long history and attachment. Hurts to pay for something twice but probably your best option now. Best of luck and let us know how things work out.

I agree. If you don't have the time to continue to find and fix things that were not done right, It's best to try a different shop. But, when you take it to another shop, clearly explain what happened, what's wrong, and judge whether they will provide a better result.

As much as you want to take it someone and just be done with it, one of the reasons I do my own work is that I've had so much poor work done by supposed "professionals." It ends up saving me not only money, but more importantly, time and frustration.

I hear you. I’ve been on Pelican for 22 years and have never had a car worked on in a shop. I rebuilt MFI in a 70S, went through CIS on this car several times too. A bad back and really bad knee makes it much harder for heavy wrenching now at 66. I love it but I also don’t have as much free time as I used to. Rene was a highly respected Porsche specialist. And highly recommended by my buddies. I’ll never know why my car and experience was not good. To his credit, he did not want to charge me but I insisted on paying for parts and the original airbox replacement. I’ve checked the new shop out too and he has a similar high rating. There is a review from this summer from s guy with an 81CIS Porsche that he apparently did great on

I just wanted to follow up with an update. After much research and talking to local Porsche folks, I decided to take my car to Randolph Racing in Stoughton, MA. Kevin (the owner) has an excellent reputation and experience with SCs and many other Porsches. In fact, he was rebuilding an engine on another 83 Cabriolet. I had the car flat-bedded to his shop and filled him in on this backstory.

After looking the car over he called me with not entirely unexpected news. The engine has been developing oil leaks and with 191K miles on her, I've know for a while that a rebuild was probably in the cards sooner than later. Kevin confirmed that and believed that several head studs were broken and the cam tensioners were shot (which I was aware of and had on my list to service asap). And now the fun begins...

I could have just had a stock rebuild, but what's the fun in that? I've always wanted a more performance-oriented Porsche so I opted for a performance rebuild. So here are some of the upgrades: a 3.6 964 crankshaft with cross drilled center main bearing for improved lubrication, WEB-CAM 20/21 cams, Mahle 10 to 1 98mm pistons and cylinders (3.0 t0 3.5l upgrade) Wavetrac diff, hydraulic chain tensioners, SACHS Performance clutch, and a Billy Boat header and muffler (and oh does she sound sweet!). Of course I got the sheetmetal powder coated, new trans/engine mounts, and lots of other details while "we were in there".

I got the car back on Friday late afternoon and, or course, it snowed Friday night and Saturday and rained Sunday! I only got to drive the 65 miles home mostly on the interstate. But, boy was that fun (even keeping below the 4000RPM break in period). I get to put 300 miles on her and then back to the shop for head stud retorquing and valve adjustment and swap out the break in oil and I want to have her dyno'd then too just to see what I really have for HP and torque.

Kevin was great on the communication and invited me in to see the rebuild several times over the winter and he actually drove to my house unexpectedly to show me his work and let me take it out for a short spin around the neighborhood. Overall, I put some money into the rebuild but it is a completely different car now and I anticipate it to be worth every penny! I can't wait to start racking up more miles, I put about 100K of the 191K on the odometer and bought the car in June 2008 - so we have a bit of history together!

Hey, that's great news and a good story. But please tell us about your air induction and fuel injection with this new 3.45L engine. Surely, you aren't still using the CIS intake runners and Fuel Injection system?

I wasn't ready to take the leap to EFI so it still has CIS intake runners and CIS.

Well, then- that's interesting, and maybe even a bit unusual. Did you do anything special with the fuel delivery, heads and exhaust? I'm asking because in my 3.2SS project, my research was 'generally' pointing to my intake air and fuel delivery being pretty much at maximum capacity. I say 'generally', as I haven't seen any hard rules or evidence of just how much displacement can be obtained from CIS. But 20 years ago, one or two Pelicanites successfully got somewhere around 3.5L, I think. One went by the name of Dane, as I recall.

When you get well acquainted with your engine's characteristics and performance at different rev ranges, could you post your detailed impressions? I think that would be both valuable and interesting. I'm specifically wondering how much performance you are getting at, say, 4500-6500, where the demands should be greatest. Thanks for sharing. This thread might keep going for a while with folks wanting to better understand specific results of the engine formula you have.

911MANN, when I take the car back in for head stud retorque and valve adjust at 500 miles I'll get the details on the injection. Kevin at Randolph Racing has been doing this a long time and I saw the dyno results from a 3.0 he completed before my engine and it looked good. I am going to get my car on the dyno when I take it in and I'll report back. Happy to share info as it comes in.

Sounds good. I bet the torque is impressive!

Did that non-OEM copper (?) nut work itself loose due to expansion ? I assume it was installed "tight".

It was not installed tight (there was 15 miles driven since it was installed at that time) and the inner most nut was completely missing.