81 sc airbox question

bagpiper47 · 01-20-2005, 06:52 PM

I just had my newly purchased 81 in for it's 90K service at a Porsche dealer in Denver. I wanted to have a pop off valve installed but they said the airbox is damaged and I should wait to have it put on the new one. My question is how am I driving it with a broken air box? and the 7 hours labor to intall have me shivering in fear! Do they have to remove the engine? They also mentioned a clutch for 11 hours and $1000 for the clutch. also a fuel pump, Brake calipers & rotors, Cam tower lines?, and warm up valve, idle air control valve, Oxygen sensor, and finally a engine blower cooling fan. How can this car need so much stuff and run like a bat out of hades? It does start hard after only sitting for a short time (1-3 hours) but otherwise just runs great.
Any help would be a great help. I am planning on getting a service manuel and see what minor items I can tackle myself.

ruf-porsche · ruf-porsche's Garage

As they would say in Forest Gump

RUN FOREST RUN

Didn't you get a PPI before buying the car?

Find some local Pelican in CO, buy them a couple of beer or whatever they drink and ask them for their opinion.

None of the repairs they mention except fot the airbox (Ipossible vacuum leak) would cure the hard start.

Jesset100 · Jesset100's Garage

Welcome to Porsche ownership and the board. That's a nice car. Is the interior tan?

clevy70911T · clevy70911T's Garage

Mine had a small crack along the drivers side, near the crease where the upper and lower parts screw together. I used epoxy to fix, but I went the long route and removed the entire CIS(partial drop) to do it right. I put my pop-off valve in before, knowing I could take it out and install it in the new airbox if I had to go that route.
I might as well start your DIY, do-it-yourself, with the pop-off valve project.

bagpiper47 · 01-21-2005, 05:26 AM

Thanks for the reply's. Heard of a good independant in Denver called Stuttgart motors will call them today and see how much to put a new box in. It has a burgandy cloth interior and tes I did have a PPI but wont be getting it serviced there that's for sure.

sagacis · 01-21-2005, 06:57 AM

If the airbox is working, why would you wait to install the pop-off valve? If (or when) you replace it, you can throw it away with a hole drilled in it just as easily as one without the hole. The pop-off valve isn't expensive, and may keep your airbox functioning much longer. That sounds like a scam anyway, if the car is running fine.

Get
101 Projects and other manuals so you know what needs to be done. Search back threads. If she's driving, drive her!

--sagacis

Hladun · 01-21-2005, 07:04 AM

A car won't "run just fine" with a broken airbox. The problem you describe is usually the check valve in the fuel pump (which can be replaced without a new pump). You can confirm this by doing a resting pressure test on the CIS system.

Stay away from that dealer. You have an old car, things will be worn on it. Do safety and needed repairs but be careful not to get sucked into the vortex of replacing everthing.

bagpiper47 · 01-21-2005, 11:42 AM

Thanks, Wonder if it wouldn't be cheaper to switch to carb's instead of Injection. No smog worries and am stuck working here for 8 more years.
I'll check the check valve.

juanbenae · juanbenae's Garage

1st thing i would do, find a new mechanic. do a search for grady clay here. he is up in colorado and might have a recommendation of someone to see.

Hladun · 01-21-2005, 12:14 PM

The CIS system is actually a very good system. It works if the fuel pump runs (and the Porsche fuel pump is very reliable). But it’s highly adjustable and has usually been completely screwed up by quarter turns here and there. There should be a rule that no one can post a CIS fault until they have checked the fuel pressures with a proper gauge and set the CO with a proper gauge.