New '79 3.0 SC owner. Advice needed
New '79 3.0 SC owner. Advice needed
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SuperCarrera

Original Poster:

8,325 posts

281 months

Monday 21st March 2022
quotequote all
Hello there. I recently purchased a G series 911. I absolutely love it and find myself using it for every journey, no matter how impractical it is.

There's a few things with it that I wonder whether they are foibles of the car ("they all do that, sir") or whether I need to get some bits looked at.

1. After driving around for 30 mins or so, when idling in traffic it's around 1800 rpm rather than the 1000 when I first head off. Is this normal?

2. The first, second and third gears are a bit of a pig sometimes (especially first) and you really have to ram the stick into place or you get a god awful grinding sound. Is this normal?

3. At motorway speeds the air sound flying into the cabin is really loud. It feels like it wouldn't have left the factory this way, even in the 70's, so I think maybe some part is missing that blocks/channels this from the front of the car (the noise is coming from the bonnet area). Or, is this normal?

4. Can anyone explain to me how this heating control works? It seems to range from absolutely useless to barely usable. Once again, is this normal?


Koln-RS

4,051 posts

230 months

Monday 21st March 2022
quotequote all
1. No

2. It’s a a 915 gearbox - it needs to be set up correctly, and change gear slowly. And don’t be tempted to fit a short-shifter - it can make things worse.

3. Someone would need to look at it more closely

4.

Koln-RS

4,051 posts

230 months

Chemical Ali

951 posts

235 months

Monday 21st March 2022
quotequote all
Hi,

The throttle spring mechanism may be either clogged with dirt and is sticking or I found the carpets can get jammed in the accelerator. Try cleaning the accelerator area and the attachment to the throttle in the engine bay. WD40 and cloth. If you do need to go into a garage the idle is relatively easy to reset, so shouldnt be a big bill. Dont quote me though.

Gears, sounds like if all are difficult the clutch and or shifter need adjusting. Usually gear 1or 2 can be crunchy, but not so much all of them at once.Again, if its just adjustment this isnt usually a big job.

Wind noise-probably old rubbers. The doors may need adjusting and new rubbers. Again, not silly money if thats all it is.

Heater, renouned for being crap. Check hoses are attached properly to heat exchangers and under the dash and that the fan is working. Often hoses can become detatched or fans fail, fuses can blow etc. Failing that - suggest a coat.

Sounds like you need a good specialist and the car needs some pampering for a few hours by someone who knows their stuff. If they recommend big bills, get a second opinion from somewhere else before getting work done.








Wilmslowboy

4,574 posts

224 months

Monday 21st March 2022
quotequote all
Point 1 - No they should not do that - google Porsche 911 hot fast idle (it can be an endless list of items).

Point 2 - I have a 76 (2.7) same 915 gearbox - Mine is a delight, the only time it comes close to noise is going down from 5th to 4th when you have pause for a 1/4 of a second to let the reverse lock do its job. Yours mIght just need the gear linkages looking over, worse case a gearbox rebuild.



SuperCarrera

Original Poster:

8,325 posts

281 months

Tuesday 22nd March 2022
quotequote all
Thanks all. Very much appreciated!

BertBert

20,548 posts

229 months

Tuesday 22nd March 2022
quotequote all
Wilmslowboy said:
Point 2 - I have a 76 (2.7) same 915 gearbox - Mine is a delight, the only time it comes close to noise is going down from 5th to 4th when you have pause for a 1/4 of a second to let the reverse lock do its job. Yours mIght just need the gear linkages looking over, worse case a gearbox rebuild.
From experience 915 shift problems often require a gearbox refresh. But of course try the other things first

Caddyshack

12,935 posts

224 months

Tuesday 22nd March 2022
quotequote all
Could be the front blowers on the heater.

My 915 gearbox was a joy to use. I seem to think there might not be a syncro on one of the early gears but I may be talking out of my bum.

BertBert

20,548 posts

229 months

Tuesday 22nd March 2022
quotequote all
All forward gears have synchro I think. But they do wear. 2nd gear is often the worst

Caddyshack

12,935 posts

224 months

Tuesday 22nd March 2022
quotequote all
BertBert said:
All forward gears have synchro I think. But they do wear. 2nd gear is often the worst
Ah yes, it’s reverse that is non syncro.

The 1st can be fitted with a 2nd symmetrical syncro instead of assymetrical which helps down changes iirc.