1979 911 SC - problem

[Pc007]

Hi guys,

I´ve got this problem in my 79 SC Targa (euro), and I´m almost giving up and just sell the car!!..

car had a refurbish with all mechanic parts revised, inclusively the clutch and flywheel, that where replaced because the car was vibrating and whobbling/shacking when it took of in 1st gear, thinking it was the clutch, I decided to replace it. but the symptoms didn't stop even after the new clutch:

1 - vibration/ whobbling/shacking when in first gear
2 - vibration/whoobling/shacking when in other gears and low rpm and accelerating

after the clutch and flywheel we tried the engine mounts and gearbox mounts...but it still does the same vibration/whoobling/shacking...so now the mechanic is saying it could be engine related....can this be true?...it "sounds" mechanic to me, like something "shaft" related...

what's your opinion in this??

thanks guys

[Bicykiller]

Big vacuum leak?
Chain Tensioners?

Only suggesting these because those caused similar symptoms for me.

[Pc007]

[QUOTE Bicykiller;10900985]Big vacuum leak?
Chain Tensioners?

Only suggesting these because those caused similar symptoms for me.[/QUOTE]

thanks for the feedback Bicykiller, when they pulled the engine for a refresh I actually checked that one side of the engine had the new type sensor upgrade but another side didn't... could this be it?

where did you had the leak?

[Locker537]

Do you have any videos of the symptoms?

[pmax]

Originally Posted by Pc007

after the clutch and flywheel we tried the engine mounts and gearbox mounts...but it still does the same vibration/whoobling/shacking...so now the mechanic is saying it could be engine related....can this be true?...it "sounds" mechanic to me, like something "shaft" related...

Sounds like the only "shaft" related issue is your mechanic stringing you along.

Checking for proper engine operation should be the first order of business ! That it happens in all gears indicates to me it's probably not tranny or clutch related. A video or more details will help. Did this problem suddenly appear ? My guess is the CIS system has a vacuum leak leading to what I call the "bucking bronco" syndrome.

[Pc007]

Originally Posted by pmax

Sounds like the only "shaft" related issue is your mechanic stringing you along.

Checking for proper engine operation should be the first order of business ! That it happens in all gears indicates to me it's probably not tranny or clutch related. A video or more details will help. Did this problem suddenly appear ? My guess is the CIS system has a vacuum leak leading to what I call the "bucking bronco" syndrome.

...I´ll try to post a video about it. the car has had this since I bought it 1 year ago, I almost don't drive it, as I have several other 911´s. I always thought it was the clutch and therefore I would change it and solve the problem...but now its really bugging me because I really would like to make it my daily driver during the summer.

its more noticeable in 1st and reverse.... car shakes and woobles like when you have a bad clutch....

[porsche930dude]

Hard to pinpoint if there is no sound associated with it. What about the cv axles

[Pc007]

Originally Posted by porsche930dude

Hard to pinpoint if there is no sound associated with it. What about the cv axles

For what I remember there’s actually no sound associated...that’s why I always thought it was mechanic...I’ll try to Make a video this weekend so I try to hear something.

Would cv joints do this?

[porsche930dude]

I thought about it a bit more and rather than the cv's its probably more likely a bad tire. Without seeing it myself its hard to say. But do you know how old they are?

[Pc007]

Originally Posted by porsche930dude

I thought about it a bit more and rather than the cv's its probably more likely a bad tire. Without seeing it myself its hard to say. But do you know how old they are?

tires are new...not the tires..I think...its to much vibration and usually only under acceleration, and more noticeable in 1st and reverse...
its very noticeable at very low speeds....5km/h etc...

[Jonny042]

So it only does it when you are slipping the clutch? Or you are lugging the motor so much its below idle... I'd say there is a good possibility there is no problem whatsoever?

[boyt911sc]

Take the car to another mechanic/shop for a second opinion. Or find someone who is familiar with 911 cars. It is quite difficult to diagnose your problem over the Internet. Get someone to look at it. Observation should be done with the car stationary, moving, in neutral, and in gear. Keep us posted.

Tony

[Pc007]

Originally Posted by Jonny042

So it only does it when you are slipping the clutch? Or you are lugging the motor so much its below idle... I'd say there is a good possibility there is no problem whatsoever?

??? The car shakes in 1st gear and reverse when accelerating to move...also in low rpm when pressing the gas ...it’s not suppose to do that...At least not in my cars

[Pc007]

Originally Posted by boyt911sc

Take the car to another mechanic/shop for a second opinion. Or find someone who is familiar with 911 cars. It is quite difficult to diagnose your problem over the Internet. Get someone to look at it. Observation should be done with the car stationary, moving, in neutral, and in gear. Keep us posted.

Tony

That’s happening this week, just checking the net for people with similar issue...I’ve gathered some helpful feedback

[356911930]

Firing order not correct is a possibility. Double check your spark plug wires are correctly installed on the distributor and going to the correct cylinders. Also not if your distributor is counter clockwise or clockwise rotation.

Best of luck,


Rahl

[Larmo63]

I doubt that it is CV joints or tires. Probably not firing order either, it would not run right in all gears and sound really funky.

Get it to a good professional Porsche shop and have them diagnose it.

[Pc007]

thanks guys! will take all advices in consideration, today it will go to a Porsche specialist to check for everything! will let you guys know!!

[pmax]

Originally Posted by Pc007

thanks guys! will take all advices in consideration, today it will go to a Porsche specialist to check for everything! will let you guys know!!

Don't wait another year

79 SC targa - shacking clutch

[Pc007]

Originally Posted by pmax

Don't wait another year

79 SC targa - shacking clutch

sad part is that the car still has the problem and nobody knows how ti fix it.. now we can add the engine getting warmer at high speeds...so definitely there's no way I will buy another SC...ive had 2 and both were ...lets say...challenging.

[john walker's workshop]

You still haven't found a GOOD 911 mechanic, is all I can say.