Observations and Questions about my "new" SC.
 

I drove my new-to-me 1978 911SC this morning (the first time since Monday when I bought it) and naturally have some questions along with my observations. For discussion's sake, the car has 79k miles on it, is fairly original (but has been repainted in it's original color) and came with no service history. (I know...for shame...) I bought it fairly inexpensively, and I'm sure that will show in the next few months as I find out more about this car. But so far I like it a lot and overall I think it's a good car.

Observation #1:
Wow, this car is quiet. Maybe because I've been driving a ripper (1970 911T w/2.4 carb'd motor) lately, but this thing is so hushed! I have to admit, it's freakin' me out a little bit. I guess I'll get used to it. I did want a better daily driver, I suppose this is part of that.

Things I know it needs:
Four new tires and an alignment. Even though the wheels are large on the rears (6&7s), the tires are the same size! :rolleyes: ..and the rears are down to wear markers. I also bought a strut tower brace and wheel spacers (for the rears) from our host to go along with this.
Valve adjustment (the valves are noisier than the motor! - ok, not really), oil change, trans fluid change, brake flush. I honestly don't know that it needs all of that, but since I have no records, I'm going to do it for a good baseline (and to be sure my mechanic looks at everything).
Reverse light switch.
Fuel level sender (I have and will put in this weekend).
Misc trim bits (also have, but waiting to see if I keep it stock or do something "fun" with the body - i.e. Ruf bumpers or backdate).

Questions about things I may need:
My oil pressure gauge is pegged at the top...is this the gauge or a sender/switch on the motor?
My alternator light keeps a slight glow even after starting and running the motor. I haven't checked the charging system, but the car starts just fine after sitting for many days. I didn't notice anything visually unusual with the battery. That's as far as I've gotten.
I have a slight judder with a cold clutch on take-off...is this normal? I think it's partly due to my driving style...with this car I've been treating it like a newer car, taking off with few revs. When I bring the revs up, the transition seems a bit more precise. This only happens in first gear on take-off. Other gears I don't notice anything unusual about the clutch.

Observation #2:
I know I have "worn synchros", but is different than my '70. The '70 is just very stiff engaging gears. The '78 is less stiff, but if I'm not careful, I'll grunch first and third gears. I "have to be stopped" to put it back into first, and I have to shift slowly and deliberately when going into third. If I do that, everything is fine when I shift. If I rush, they grunch a little. And second gear rubs my thigh. :rolleyes:

Obserquestion:
I noticed that when I come off throttle, the motor takes a little while to settle back to idle. There's no "hessitation", it's just noticably slower than my carb'd 911T. Does this sound normal for a stock CIS? ..or is there tuning needed?

Other "must do's":
I have got to get rid of that rear window tinting. I literally can't see out the back unless it's bright sun outside and the Targa roof is on. Who would do such a thing?!?
I also need to remove the stone guards...I'm just not a fan.
Don't worry, I've found threads on both of these things!
Oh, and that front plate must go too...

Well, I think that's all for now. Would love to hear your thoughts and opinions on any of the above! Looking forward to a new chapter in the ever evolving stable at Casa Doug-n-Julie!

SmileWavy

http://forums.pelicanparts.com/uploa...1152878684.jpg

Re: Observations and Questions about my "new" SC.
 

Sounds like the Decelleration Valve is still hooked up. It's supposed to let the idle drop slowly so as to make downshifting easier. Most of the cars here have the line plugged off with a golf tee or a screw. (Do a search on golf tee). I think the decel valve on the 78-79 cars was a litle different than the later SCs but the concept is similar.

Interesting, thanks. Never heard of this. Learn something every day!

Nice looking car you snapped up.

A couple things:
I'd flush out and renew all fluids in that thing across the board. I'm biased, but a switch to Swepco actually helped my noisy Audi-designed tranny and the shifting improved. Maybe it could help with your syncro issues as well(?)

The pegged oil pressure definitely sounds like a sending unit fault. I had the same problem in my 944 after replacing some major oil seals. Turns out I didn't properly tighten the lead to the sender. Easy fix. Granted, it was a different car but the concept is the same.

No records for this car? Do did get a PPI, didn't you?:eek:

...er...kinda. My mechanic is his mechanic...and he knew the car.

Thanks for the tips. I'm definitely getting all fluids changed, and I'm fairly certain Ken uses Swepco. I'll make sure of it.

If it's too quiet, just gut the interior!;)

Looks like a nice driver. Driving to work should be more adventurous than with the old Subie. Just remember its almost 30 years old.

Doug: Been following your story for the past week or so. Fun to read about your experience. Some thoughts I offer in no particular order as I have a 1983 SC with 110K miles that is probably pretty similar.

1) I have the same "return to idle" issue you described, though mine tends to fluctuate with the weather/engine temp. Cold temps outside exacerbate the problem. Have not yet pugged the line to the decel valve, but based on everything I have read, I am sure that is the problem. Let us know if that fixes it.
2) I hate to admit that while diligent about engine maint (valve adjs, oil changes, tune ups, etc.) I have never changed my brake fluid or tranny fluid. No problems by the way (that I know of). I tried to have a local shop change the brake fluid about 10 years ago when I was getting new tires, and they said the bleeder valves were so stuck that they wanted my permission to risk breaking them before they applied more pressure. Of course, no new bleeders in stock, which would have stranded my car there. That scared me away from that task. Let us know if you change your fluid if you have any problems with the bleeders. I have also heard nightmare stories about how easy the tranny drain plus is to remove, and how the fill plug is impossible to get out. If you change this fluid, make sure you can get the fill plug out first (allen head of some sort I think).
3) I have the same synchro issue downshifting into first. Hit or miss, but I pretty much have built the habit of never doing it without a double clutch or a quick drop into 2nd while stopped before going into 1st. I think this is pretty common (though the swepco comment has me curious about changing this fluid)
4) As for clutch shudder question -- that doesn't sound normal, but from my experience, the clutch takeup on my 911 is not nearly as smooth as any other car I have owned. It just seems "clunky" and unrefined.

Good luck, and keep us posted.

Change all fluids, change ground strap, change sending units, get the valves adjustd and just drive it. They are indestructible....

You should have traded for my '87 Carrera Targa in GP White.

I offered, you declined (too far away, I understand).

Now you have a visually identical car (minus the crappy early US spec. head lights and fog lights) with lots of "issues".

Of well, I don't like brown all that much anyway! :D

My oil pressure gauge was pegged at the top too. When I would turn off the car it would stay there and then if I tapped on the glass it would drop. A new pressure sensor in the engine fixed this problem.

*I think*

I think, I have read here that the oil pressure gauge can be pegged becuase of a bad ground, or dirty electrical connections. I'd try a fix that way, before buying new parts.

Rich

Doug-you may want to replace the shifter bushings (see Wayne's 101 book) to help with the shifting into 3rd. Sounds like 1st gear syncro may be worn, something to address when you do an engine drop.

Thanks all for the replies!

The return to idle "problem" is just something I need to get used to. It sounds like it's normal, so I'm not worried about it. I may try the golf tee routine sometime, but not a big deal as long as there's nothing wrong with the motor.

Shifting...I'll look into new bushings. Hopefully between that and the new Swepco, it'll shift smoother. Of course, it's really not that bad...for a 915. As for the clutch, my mechanic will drive it and he's quite familiar with the cars. If he's not sure, I'll find a few other SC owners to drive it and see what they think. But I'm sure Ken will know fairly certainly about it's condition.

Thanks all for the tips on the oil pressure gauge. I've heard of many of these, so we'll be tracking down the cause starting with the "cheaper" routes to make sure. (..and for the record, I did try the "tap on the glass" fix...it didn't work.. :p ) I would bet it something simple like the ground strap or the sending unit. The oil temp gauge and oil level gauge work just fine. (..well, as well as an oil level gauge can work in an older 911..)

Garth - Love the interior idea. ;) Yeah, I kinda forget that this is still and "old" car. Before buying it, I read a lot of old magazine articles that just raved at how "civilized" it is, but then I forget that those articles were written in 1978, so for it's time, I'm sure they were civilized! Still, it is very different from my '70!

DDD - I'm learning to double clutch as well. That's very new to me. Usually I can get by with just a pause. It makes shifting kinda like learning to dance... "second gear...clutch...and-a one and-a two...and into third...and de-clutch"...smoooov.

Drago - Sorry man. Similar car but this one was just a half hour trip to Dayton, $9200, and a half hour trip back. Ease of transaction does play a factor into my car buying. :)

Thanks again all!

Doug, I bet it's synchros on your first and third gear. I can connect you with the shop that replaced mine if you are interested....they're local and they were recommended by Brian Copan (he builds for the ALMS/Rolex series). Let me know....

Slotcar, can you post it here? I'm in no hurry (it really isn't that bad...), but I'd love to know. If it is synchros, I will need an eventual rebuild and I'd love to have an option to Ken.

Thanks!

charging system light: i personally change batteries every two years whether needed or not..just cheap insurance. your battery may be old and putting quite a draw on your alternator. i'd pull the batt and take it to napa..let them see how it does under load. if it ain't great..buy a new one. one more piece of mind item in place. good luck!
ryan

Hi there... Just joining the fray here with my 167000 miles 83 SC which I also just bought (back, after a 6 year "loan" to a friend), and also after selling a 2.4 L long hood car... I'm pretty much in the same boat as you, hell my 73 was even a similar color as your car !

>Observation #1:
>Wow, this car is quiet. Maybe because I've been driving a ripper

Depends on the exhaust, but yes, it is quieter. More grunt down low, less screaming up high ! Even on my 83 which has an aftermarket exhaust (noisier), the noise inside the car is much less. Outside, it's much louder than the 2.4 though !
Did you also notice the difference in gearing and torque ? The S cis geared much longer in 1st and 2nd but it gets away with it thanks to it's 0.6L of extra torque ! ;-)

>My oil pressure gauge is pegged at the top...is this the gauge or a sender/switch on the motor?

Grounded circuit most likely. I think it pegs when grounded... Not a priority, you can check level on the dipstick, but you can replace the sender easily anyway. Check the ground there and the connection at the gauge, run another wire thru the car temporarily if need be, to rule out the wiring...

>My alternator light keeps a slight glow even after starting and running the motor.

That's the only thing so far that would worry me and make me go to the shop, I'd check the battery and charge it to make sure you are not taxing the alternator, but you might be in for new brushes or a rebuilt alternator...

>Observation #2:
>I know I have "worn synchros", but is different than my '70.

Most SCs do, in fact my 73 had better gears than the SC ;-)
Like everyone said, Swepco 201 all the way, new bushings, maybe a seine shifter gate, and see how it goes. I have a similar problem but first is like butter if I put it in second before to line things up, and heel and toe helps...a lot ! (well, on downshifts - on upshifts you gotta be slow and deliberate to not grind)

> And second gear rubs my thigh.

Also typical.

My recomemndations: Also consider a carrera oil cooler which is way more efficient than the stock trombone and you can rig a fan on it too ! And of course turbo tie rods... The SCs are really good cars, not the fastest, but a damn good workhorse. Mine's got 167K mi but I've seen with my own eyes some 350K one sand one with 400K when I lived in cali ! Solid motors !!!

Doug, Make sure your fan belt is tensioned properly and not glazed over. It could be slipping which may cause your Alt light to stay on, but also won't cool your engine properly.

my friend's 74 was much lounder than my SC, so that's a GOOD thing!

I had similar issues shifting and found that my transmission @ 112k miles just plain needed a rebuild. People just dont know how to shift these cars and beat the heck outa the syncros. I've let a couple of buyers drive mine and I grit my teeth every time they shift. Now, she shifts at any speed into first, never crunches or anything. I do have a sines gate shift kit and short shift kit so second is not in my theigh :)

Mine also has a slight shudder if I let out the clutch at low rpms. Not sure why this is, but it's not a big deal. Adjust your clutch cable and it may resolve the shudder (bowden tube may not be snug enuf).

I really have not noticed my idle going back down slowly. I may just be used to it, but I have not noticed it at all. I'm at about 130k miles and Deschodt is soooo correct when he says that these things run forever. That's why they call them 'bullet proof' ;)

Sheesh, 130K miles ? that's barely broken in ;-)

You are right, a rebuild may be in order, I should have said that instead of jsut saying swepco and bushings first.. In my case I plan on running the beast at track days instead of the boxster, so rebuilding the tranny is not the first priority, cooling is ! I can always trash the existing box and rebuild it later, when it really really needs it ! I found it funny that my ex-73T shifted so much better than my 83 ! It really is down to mileage, a proper 915 is a very sweet gearbox !

Yeah, I love having the bigger motor. Screamers are fun, but get annoying on the drive home from your fun.

Thanks for your comments!

Will do! I've nonticed that the whole back of the car seems to get very warm. The oil temps go a little above "half way", but still far from the "red zone" on the gauge, but there just seems to be a lot of heat soak in the back. Of course, it could be that it's been teasing 90 degrees here lately....and for the next five days, we're going to smash right through 90!

I'm really beginning to think this is operator error on my part...I've been driving it like a lazy person. I drove the car a bit yesterday and adjusted my take-off action and it was much better. Still, I'll have Ken look into it.

Thanks Ryan! I'll be sure to look into that. Might be cheap insurance to just buy a new one and see where that goes. But I'm hoping to get my car into Ken in the next week anyway...just waiting on my (delayed) parts from Pelican! :mad: ( ;) )

The difference in noise level could be attributable to he thermal reactors? If you are going from ssi's in your earlier car to the factory system on the 77, there is a huge dB difference.
There was for me.
By the way, once you get rid of them with a decent free flow sys, oil temps will drop 30+ degrees, and you will no longer have the possibility of boiling the fuel after spirited runs.
cis is a whole 'nother beast.
Have fun!

Backdating exhaust is on the list...but its down on priority. Should I move it up? The exhaust is stock from the factory. Could this be contributing to the amount of heat I feel around the back of the car after a drive?

yes, yes, and yes

move it way up on the list

thermal reactors are bad...... very, very bad
they are nothing but a 12lb(ea) cast iron heat-sink designed to burn off pollutants at super high temps towards Porsche's attempt to stay cat-free.

take a close look at the underside of your car to see the dictionary opposite of 'free flowing exhaust system'

Good to know, thanks!

OK, I really need to sell Foxy Brown so I can afford my cheap SC!! :(

Yeah well my friends SC was way quieter than my 74! SmileWavy Good to see you here Matt!

On the Decel valve, in the early CIS models this was an easy adjustment. The nut on top turns to make it drop quick or slow. Not sure if it is the same on the SCs?

Pat

Hey Doug, there are alternatives to selling old fauthful. I have most of the parts you need to convert to a euro exhaust sustem, dirt cheap. (2 heat exchangers, and the crossover pipe) that would not work on my short bellhousing 4 speed trans.
Bill K

PM'd you.

SmileWavy

PS. I still need to sell old faithful... :(

that day that 'old faithful' sells...i sense a premonition of the blowing of a 'mighty wind'.. ;)
ryan

My 84 oil pressure was pegging out also. I pulled the wire
off pressure sensor and the gauge went zero.. connect peg... I dont think it's good to have it pegged while driving. i'd probable disconnect if it's not reading at all.. then maybe not :) Mine was the pressure sensor unit. Here's the threads on replacing this if you have AC on the car (use a crowsfeet...)

http://forums.pelicanparts.com/porsche-911-technical-forum/149882-oil-pressure-sender.html

I had a small issue with getting into 1st gear unless stopped but got larger problems with a clunk... You should be able to get a R&R on the trans... syncho's etc for under $500 bucks LABOR... parts well depends where you buy these.

I paid for the parts below $1,230 shipped... last year.

So you looking at around $2k to address common wear items. If your looking at gears or heaven forbid bearing you better grab a chair when looking them up. Your bearing should last a long long time if you Do not run metal through them (hint your 1st and 3rd grinds.) I would attend to the trans pronto as it seems to be at a point that would really benefit you to get it done at a reasonable cost.

I did a small video of dropping a engine out of my 84 if
your interested. taking into account safety issues of a drop. ie. unhook the battery #1...

http://www.beams.com/porsche/


Good luck.


ALL OEM
item unit, cost unit, # units, cost

Gasket set 915-300-911-01, 42, 1, 42

Trans fluid swepco 201, 44.5, 1, 44.5

1st Syncro 915-302-301-06, 63, 1, 63

2nd Syncro 915-302-301-04, 62, 1, 62

3,4,5 Syncro 911-302-301-06, 57, 3, 171

Dog Teeth 1st 915-302-241-14, 106, 1, 106

Dog Teeth 2nd 915-302-242-00 105, 1, 105

Dog Teeth 3,4,5 915-302-242-03, 105, 3, 315

Guide Sleeve (spyder) 1st-2nd 915-302-401-02, 118, 1, 118

Slider 1st/2nd 930-302-411-02, 143, 1, 143

2nd brake band assmbly
Double Band Band 928-302-318-02, 29.71, 1, 29.71
Stop Block 915-302-315-01, 14.17, 1, 14.17
anchor block 2nd gear 928-302-322-00, 16.96, 1, 16.96

Parts Total 1230.34



:D

My grinding in 1st issues went away when I replaced the clutch. You have a 30 year old car and I bet the clutch is really old. People blame 915 transmission for being difficult but I think its old clutchs. The clutch takes almost no effort to push when new. If yours is hard to press it is old.

Get swepco 201, replace the shifter bushings and install a Seine shift kit ($150) and your shifting experience will be transformed.

Thermal reactors on an SC? I think those came w/the 2.7 not the 3.0.

The problem w/the SC oil temperatures is this stupid trombone "oil cooler" which isn't really much of a cooler at all. A Carrera cooler w/fan is the way to go as far as fender mounted units go. W/o the fan the car will still overheat in traffic.

Agreed on all the above, except (cynical me), I've got a carrera cooler + fan, and while it's much better, it's still not enough for track days.... But perfect for traffic jams !

I don't want to preach but if the tires are down to the wear bars be VERY careful when driving in the rain. When I bought my SC a few years ago I went on a short trip and it rained all the way back, I scared the heck out of myself even at moderate speeds. Ordered new shoes the next day. Enjoy

Bernie

Thanks Bernie. Fear not, I'm trying not to drive it in the rain. Although, Friday we had one of those humid days that is sunny until about 4:00 when the humidity creates pop-up storms. I got cought in one. I was very careful. The fronts are ok, the rears are the ones for me to worry about. So as long as I kept it "out of the power", I was pretty ok. Still, driving was very careful.

And the good news is my Targa doesn't seem to leak! :p

W/o records, I have no idea if the clutch is original or if it's been replaced lately. The action is easy and the pedal feels light(ish) and comfortable. Other than that slight juddering issue (which I'm pretty convinced is operator error) I have no reason to believe it's not a good clutch. But you never know... :(

I plan to move the cooling improvements up on the priority list. I don't know if the SC exhaust has thermal reactors like the 2.7 cars, but it does have a significant catalyst (3 way I believe) that looks to be creating a lot of heat. We don't have e-check anymore, so those will have to go. Then I'll look into the front cooler. Since this car won't see track action, I'm sure that's as far as I'll go.

rburn - thanks for the detailed info!

Still hoping to get the car to my wrench this coming week. I'm trying to drive it very little until then (with the bad tires and need of valve adjust). I'll have more info after the appt!