andrew964_123

About 9 months ago I bought a 1994 964 Turbo 3.6 with an X88 engine.
During low speed cornering with low engine revs and power off, I notice a knocking which (to my untrained ears) sounds like worn engine mounts. If I apply subtle power the knock disappears. It feels as though the engine is rocking on its mounts as it idles against the inertia of the decelerating car (except that it only happens when I'm cornering, not in a straight line).
It seems to get worse when tire pressures are low ie. when the tires are cold.
It also seems to be worse than when I first bought the car.

An earlier reading of the owners manual that came with the car (actually a Carrera 2 manual(!?)) indicated that some knocking on cornering was to be expected.
So I asked at my Porsche garage and got a couple of different answers - one was that it might be the dual mass flywheel and the other that it may be the differential (something to do with the friction coating used to transfer power in the diff). Both said that it was also unlikely that this was the case.

So, as I have no other car similar which I have had a chance to drive and compare, I'd like to know if it is really normal for this car to knock like this and if so, what is the acceptable level. Should I expect this to happen every time I corner?

The car still has about 3 months left on a Porsche Used Car Warrantee so I'm pretty keen to get to the bottom of it before I have to pay to fix something myself.

greg1234

Hi Andrew.

I'm by no means an expert but I believe it's normal, caused by the LSD locking up. My car clanks terribly on corners with power off.. and it also makes a loud growling noise sometimes (typically when reversing whilst cornering). From the last time I enquired about this, I understand it to be normal and not a cause for concern.

I'm pretty sure it isn't your flywheel though - it's the LSD. It doesn't happen when you decelerate in a straight line, right?

greg1234

BTW congrats on the car... <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

John McM

[quote]Originally posted by andrew964:
[QB]About 9 months ago I bought a 1994 964 Turbo 3.6 with an X88 engine.....as I have no other car similar which I have had a chance to drive and compare, I'd like to know if it is really normal for this car to knock like this and if so, what is the acceptable level [QB]<hr></blockquote>

Andrew,

Can't let the chance to catch up with another kiwi with a Turbo 3.6 go by. Albeit that I'm an expat kiwi until 9 November [has to be something auspicious about returning for good on 9/11!].

Tell me more about your car. So far I know of only three Turbo 3.6s in NZ. One Midnight Blue '93 model last seen in the South Island, another Midnight Blue '93 X88 for sale at Giltraps in Auckland, and mine an ex-Singapore Silver '93 model.

If Kevin Ross is right and there are only 7 Turbo 3.6s in Australia, one of which had the engine stolen, then we're fast approaching their number.

BTW: So far as I know, there were only 63 RHD Turbo 3.6s made; 46 in 1993 and 17 in 1994. Your's is a rare beast.

Jay_965

Andrew,

I'm no expert but I have owned my 911 Turbo 3.6 for over 2 years and have not experienced the knocking sounds you describe on low speed corners at low revs. If its getting worse then something must be wrong. If I were you I would try another getting another opinion from a different Porsche garage before your warranty expires.

Good Luck.

BTW: Big Mac.... Like your running reports on <a href="http://www.porsche964.co.uk" target="_blank">www.porsche964.co.uk</a> site. Where did you get the figures that only 63 RHD turbo 3.6s were made (46 for `93 & 17 for `94.) . I have seen quite a few people here in the UK quote these figures including Independent Porsche dealers but they are incorrect according to my information.
I have doubled checked with Porsche Cars Great Britain and the figures they gave me are: A Total of 74 units in RHD were imported for the 1993/4 model year. 36 for 1993 and 38 for 1994. (UK Market).

Of interest, out of these a total of 23 were in Midnight Metallic Blue. 10 for 1993 and 13 for 1994.


Jay
`94 Turbo 3.6

greg1234

Hi Jay.

You don't get the clanking sound and chugging sensation when going round a corner on a closed throttle?

greg1234

John - how about you? Do you get the clanking?

Jay_965

Hi Greg

No clanking sounds, does anyone else get this ...?
How loud a clanking noise do you get Greg, is it very noticable..?

greg1234

Funnily enough, I often think mine is getting worse too.

BTW sorry for the multiple posts - I wish there was some way to edit posts once you've made them but as far as I can tell there isn't... <img src="graemlins/c.gif" border="0" alt="[ouch]" />

I would be interested to get to the bottom of this as well. I had understood it to be normal but now I'm getting nervous..!!

greg1234

My God I'm stupid...

Thanks for the tip, Silver Bullet..

Jay - it's very, very noticeable. Can't miss it. It's a combination of a clanking noise and - perhaps more noticeable - a "chugging" sensation, similar to the feeling when trying to pull away in too high a gear. As soon as you add power, however little, it stops instantly - even in mid corner.

I'm sure this is exactly what Andrew was describing.

We discussed it on the 964 board a while ago - under the title "What's this chugging noise" - I'll try and put the URL here: <a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=4&t=001005" target="_blank">Chugging noise thread</a>

Reading it again, I'm not sure we came to any real conclusion... other than some people have it and some don't...

Jay_965

Greg - Thanks for the link. I will try tomorrow as Mike suggested and let you know the results. I've never noticed it before, maybe I've been subconsciously blocking it from memory in case it meant expensive repair
Anyway, I'll try some tests tomorrow and update you then.

JamesE

Gregg, don't worry it's your LSD. Mine growls whilst reversing. The diff will always lock 100% whilst you are not accelerating. I think the manual explains...

John McM

Greg,

I can't say I've ever noticed any clunks, but then again I've only had five weeks in total in the drivers seat. When I was in NZ I forgot to test the reverse and turn maneouvre to see if the LSD made any noise...it will have to wait another 132 days and 22 hours until I get another chance!

Jay,

Stuck on an island as I am, there are only two ways I could have gotten that info; magazine or Internet. The obvious magazine articles I have on Turbos don't mention it, so odds on the info came from the Internet, but I'm not sure where.

Nevertheless, the info would appear to be incorrect. Sorry, I have no intention to mislead the forum.

Unfortunately, I'm getting used to this. I quoted a magazine article to Kevin Ross in Australia about the number of Turbo 3.6s in Oz, and he came back with Porsche figures that were completely different.

Similarly, my friend with a 993RS quoted to me that 47 RHDs of his car were built and that figure is currently being blown out of the water on the 993 forum.

Maybe it's time for Rennlist to start a registry page so we can refine the data?

andrew964_123

Thanks for the feedback everyone - it seems that the jury is still out on whether the cornering knock is a problem - I'll definitely look up another Porsche garage for another opinion.

Also, now that you describe the growling noise in detail Greg, I also have that as well. I also get a decided clunk after the growling when reversing with power ie. up a hill. It scared the crap out of me when I first reversed and turned - I thought the diff was about to drop out of the car.

Anyway, I'll let you know what the outcome of further investigations are.

John - the midnight blue 3.6 turbo X88 you described is probably my car - as far as I know, there is only one of these in NZ. I bought the car in Dec 2001. The original owner picked it up from the factory in Dec 93 (hence the 94 rego I guess). He had the X88 mods done by the factory.

The guys at Giltrap tell me there were only 6 3.6 T's brought into NZ in total, one was rolled at some point - not sure whether it was repaired. Maybe I got that confused and there were 7 brought in and 1 rolled leaving 6 good ones.
I have personally seen 2 other midnight blue 3.6 T's Auckland - one of them was in Giltraps about a week ago, the other I've seen a couple of times around near where I live. I actually ended up parking next it and was fortunate enough to watch the owner of it as he returned to his car - talk about floored. He just stood there with his alarm remote in his raised hand, wordless! I've also seen a red specimen about as well.

Actually, it's only recently I discovered what the X88 designation actually means. I thought it was just a kit that added a lumpier cam but I know understand that it is the same basic engine as that in the 3.6 Turbo S. I'd actually be interested in getting it on a dyno knowing this as I'd really like to find out the real story w.r.t. the horse power generated by this engine. Porsche seems to be reckoned as conservative with their 388 hp rating - some sites on the web reckon its more like mid-to-high 400's (although I'd take that with a grain of salt).
The X88 kit itself consists mainly of cams, a different turbocharger and some other manifold type gear - a Google search on "Porsche Turbo 3.6 X88" will get you pages on it anyway.

Anyway, it's great to find a forum with people enthusiastic about this car (not a surprise really). It was pretty much an impulse purchase (admittedly fuelled by that teenage impression of the Porshe as THE ultimate sports car) but I have definitely fallen love with the car - not to mentions it's head turning ability. I also notice that your average punter just loves the car - I've had one guy in a WRX pull up alongside me (while still driving at 70 kph along a 2 lane stretch of road) and yell out 'That's just f*&&*ing beautiful, mate. Just beautiful' all done with a look of spiritual awe in his eyes!!

Anyway, this has turned into a monster post - so I'll sign off.

Thanks all,

Andrew

John McM

[quote]Originally posted by andrew964:
[QB]John - the midnight blue 3.6 turbo X88 you described is probably my car - as far as I know, there is only one of these in NZ. I bought the car in Dec 2001. The original owner picked it up from the factory in Dec 93 (hence the 94 rego I guess). He had the X88 mods done by the factory.

The guys at Giltrap tell me there were only 6 3.6 T's brought into NZ in total, one was rolled at some point - not sure whether it was repaired. [QB]<hr></blockquote>

Andrew,

The rolled car is probably the Midnight Blue one I did the PPI on in Christchurch before I bought my car. There is still another Midnight Blue X88 '93 model on sale at Giltraps, so with your car we have accounted for three NZ new cars. I've heard about the red car but never seen it advertised for sale. There is also a silver RUF BTR4 on the streets somewhere.

I'll be in Auckland in November and would be only too happy to compare our cars noises etc; e-mail me at mcmillan@vanuatu.com.vu to keep in contact.