Advice on Living with a 964 C4

[au-yt]

With the fear of not hijacking the 993 V 964 thread.
There appears to be plenty of 964C4's available however having read about the complexities of the C4 drive system is the fear justified?

or does C4 stand for C$ and why?

[Hamptonsam]

C4's are generally trouble free when it comes to the AWD system. There have been some issues that come up, however they seem very infrequent. There are are a few sensors that can be expensive new, but they generally just need cleaning or there is a source for solid state replacements.

[Newsboy]

The AWD system is complex, but works well. There are components, which are expensive if they need to be replaced, but the systems has proved to be reliable. If you search for 964 C-4 AWD problems here and on Rennlist. You won't find much. Buying a C-4 has more to do with the type of handling you want.

[au-yt]

. Buying a C-4 has more to do with the type of handling you want.[/QUOTE]

Interesting and if I may ask what is it the makes the difference as I believe from what I have read they have a large rear wheel bias in the setup, or is there something else ?

[iamtheari]

The 964 C4 understeers, in comparison with a C2. As a daily driver, it is a fantastic car. On the track, it is also a lot of fun but you would benefit from dialing some of the understeer out. Common tips for that include a larger rear antiroll bar, wider front tires, and shutting off the traction control before going out on the track.

The actual AWD system scares people because (1) it is complicated and (2) it is expensive to repair or replace parts. But that is only if they break, which happens very infrequently. As in I check this board regularly and in the 2-1/2 years I've driven my C4 I cannot recall anyone who posted to say that he had actually experienced a problem with the 964 AWD system.

The problems you will run into are present on the 964 C2 as well: The engine will mark its spot in the garage by dripping oil. Many leaks can be plugged without removing the engine, but it takes patience to do so. The steering rack will most likely develop a leak if it has not already, and you will get drips on the garage floor and keep proper Pentosin steering fluid on hand at all times until you get around to rebuilding the steering rack or having someone else rebuild it for you. The steering pump can also leak, but that seems to be significantly less common than the rack. The sunroof seals will probably need to be replaced after decades of exposure to the elements. Same with the carpet.

If you are going to drive at least 80% on the street, a 964 C4 is a good choice. Especially given the artificially depressed price at which you can find one. The only time I wish I hadn't bought my 964 C4 is when it understeers a bit on the track. But then I drive it home and realize I am at the track a maximum of 6 days a year and on wet, sandy, icy, or gravel roads the other 359 days where the AWD in these old cars out-performs every other vehicle I have driven except for a 2011 AWD Mercury Mariner (the exception being deep snow, for which my lowered 964 does not have enough ground clearance).

[porterdog]

Love my C4; it kills in the snow.

I reduced understeer by removing the front anti-roll bar; very happy with the street balance.

[65rsr]

What a blast. One of the most fun cars in the snow that I have ever owned was an '89 C4. You could dial out the understeer, to the point where you could drive it with the throttle pedal. I put Nokian Hakkapeliittas on it and a ski rack, full throttle early morning runs up to Killington and Stratton, bombing around the abandoned snow-covered dirt roads of Vermont during blizzards at warp speeds..... The C4 is a snowmobile with climate control and a leather stearing wheel.

[au-yt]

Originally Posted by 65rsr

What a blast. .... The C4 is a snowmobile with climate control and a leather stearing wheel.

Briliant comment..... only issue is snow ist common here in Aus.
Very interesting comments about oil leaks on the rack , pumps what sort of age/milage is this most common.

Graeme

[Busta Rib]

Originally Posted by iamtheari

The 964 C4 understeers, in comparison with a C2. As a daily driver, it is a fantastic car. On the track, it is also a lot of fun but you would benefit from dialing some of the understeer out. Common tips for that include a larger rear antiroll bar, wider front tires, and shutting off the traction control before going out on the track.

The actual AWD system scares people because (1) it is complicated and (2) it is expensive to repair or replace parts. But that is only if they break, which happens very infrequently. As in I check this board regularly and in the 2-1/2 years I've driven my C4 I cannot recall anyone who posted to say that he had actually experienced a problem with the 964 AWD system.

The problems you will run into are present on the 964 C2 as well: The engine will mark its spot in the garage by dripping oil. Many leaks can be plugged without removing the engine, but it takes patience to do so. The steering rack will most likely develop a leak if it has not already, and you will get drips on the garage floor and keep proper Pentosin steering fluid on hand at all times until you get around to rebuilding the steering rack or having someone else rebuild it for you. The steering pump can also leak, but that seems to be significantly less common than the rack. The sunroof seals will probably need to be replaced after decades of exposure to the elements. Same with the carpet.

If you are going to drive at least 80% on the street, a 964 C4 is a good choice. Especially given the artificially depressed price at which you can find one. The only time I wish I hadn't bought my 964 C4 is when it understeers a bit on the track. But then I drive it home and realize I am at the track a maximum of 6 days a year and on wet, sandy, icy, or gravel roads the other 359 days where the AWD in these old cars out-performs every other vehicle I have driven except for a 2011 AWD Mercury Mariner (the exception being deep snow, for which my lowered 964 does not have enough ground clearance).

+964. Well stated. I had a 964 C4 and it makes a wonderful daily driver. Never had an issue with the AWD system. That said, I prefer RWD cars for the driving dynamics. Did not like the understeer of the C4. If you don't mind the way it drives, don't hesitate to own/drive a C4.

[dporsche74]

964 C4 one of the BEST driving 911 in the whole line up .. drive it you will see

[Spenny_b]

Originally Posted by iamtheari

The 964 C4 understeers, in comparison with a C2. As a daily driver, it is a fantastic car. On the track, it is also a lot of fun but you would benefit from dialing some of the understeer out. Common tips for that include a larger rear antiroll bar, wider front tires, and shutting off the traction control before going out on the track.

The actual AWD system scares people because (1) it is complicated and (2) it is expensive to repair or replace parts. But that is only if they break, which happens very infrequently. As in I check this board regularly and in the 2-1/2 years I've driven my C4 I cannot recall anyone who posted to say that he had actually experienced a problem with the 964 AWD system.

The problems you will run into are present on the 964 C2 as well: The engine will mark its spot in the garage by dripping oil. Many leaks can be plugged without removing the engine, but it takes patience to do so. The steering rack will most likely develop a leak if it has not already, and you will get drips on the garage floor and keep proper Pentosin steering fluid on hand at all times until you get around to rebuilding the steering rack or having someone else rebuild it for you. The steering pump can also leak, but that seems to be significantly less common than the rack. The sunroof seals will probably need to be replaced after decades of exposure to the elements. Same with the carpet.

If you are going to drive at least 80% on the street, a 964 C4 is a good choice. Especially given the artificially depressed price at which you can find one. The only time I wish I hadn't bought my 964 C4 is when it understeers a bit on the track. But then I drive it home and realize I am at the track a maximum of 6 days a year and on wet, sandy, icy, or gravel roads the other 359 days where the AWD in these old cars out-performs every other vehicle I have driven except for a 2011 AWD Mercury Mariner (the exception being deep snow, for which my lowered 964 does not have enough ground clearance).

Great write-up, thanks....I was *so* close to doing a deal on an early C4 a few months ago, a non-sunroof example in GR, just crying out to be made into an RS homage.

Didn't go this route in the end; a very questionable engine rebuild (both the reason why and the extent, or lack of, the work done) and some corrosion meaning that being an unlaquered paint (as I understand it, not a paint guy) meant it'd be better and more cost effective to do a full glass out respray, meant I didn't pull the trigger and got a 1 of 50 Exige Cup 240 instead....but I have to say the prospect of having an all-weather 911 to compliment the Turbo once it's finally finished, was a tasty one. Possibly would've given me a headache as to which one to use on those sunny day hoons, but a nice problem to have.

At the time, everything I read both in the contemporary press reports and latter day buying guides, suggested that for road use, VERY little negative diff between AWD and RWD, with the advantage of better standing starts (!) and bad weather traction. As you say above, it's when you get it on track it becomes a little more apparent with C4 understeer....which wasn't going to be a problem for me at the time as it wasn't going to be a track toy.

Kind of regretting not going for it, but love the Lotus and don't have time for yet another project. One day maybe, probably once everyone gets wise to C4 under valuing and prices go skywards!

[au-yt]

Thank everyone for your comments, makes very interesting Reading.
The Hydralic system, I need to do more reasurch, however is it a traditional Hydralic system pump accumulators etc and whats the fluid?
Just found this article

http://www.adrianstreather.com/docs/PDAS%20Technical%20overviewR2.pdf

Comments any one?

Graeme

[porterdog]

std brake fluid

[umgang]

Amazing car. Designed off 953 platform that won Paris Dakar.
The best 4 wheel drive system of all 4 wd 911s.. 993 was lighter but could only put 40% to the front because of " simplification" of 964 system from clutch packs to torson drive.
Porsche dialed in a ton of understeer because that was around the time idiots who could not drive started suing car companies. If it slid off the road forward, that was ok; but if it slid off backwards it was the fault of the mfg. Add the bigger sway bar in back, and cut your air pressures to F: 35 R:36 and you will have no understeer.
The hydraulic brakes are better than any production car ever.
I try to make it step out at every corner and it won't. Dead on.
Admittedly it has a more planted feel and heavier nose compared to a rear wheel drive 911.
If you take out a hundred pounds or more the car really transforms.

[iamtheari]

umgang: Which 100 lbs or so do you recommend taking out? I want to lighten mine a bit without completely destreetifying it. It's a big nasty project but I'd like to pull the carpet and replace it with lighter carpet and sound insulation and replace the seats at least for track purposes. But I don't know a lot of front-end weight to remove that would really make up for the differential.

[au-yt]

The passion for these cars is inspiring, I have read lots of comments about the C4 and the service complexities so wanted to get first hand insight, plus the fact they are the cheapest of the series.

I have experience with cars with hydraulic systems as I have owned a Maserati Khamsin for 23 years and love it.
And yes I do all my own work except paint and trim.

https://www.facebook.com/photo.php?fbid=10151808233448445&set=a.10151788335158445.1073741839.161471148444&type=1&theater

I am quite a fan of Unusual cars with interesting Tech, how hard is it to get a Bosch Hammer for diagnostics and service?

Graeme

[Hamptonsam]

Don't worry about a Bosch Hammer. They are rare and expensive if you can find one. I just ordered a PDT999 for mine. Try google search on that. There are others out there but the PDT999 works to bleed the AWD actuators.

[au-yt]

Magic Tip thank you
oH amd Merry Christmas its 10230am Christmas Day

Graeme

[umgang]

the seats with power and heat weigh a bunch. I have comfortable but light Recaros.
Remove all the door bins, and bits and go with RS door panels.
Remove rear parcel shelf and put in lightweight carpet.

[umgang]

Originally Posted by Hamptonsam

Don't worry about a Bosch Hammer. They are rare and expensive if you can find one. I just ordered a PDT999 for mine. Try google search on that. There are others out there but the PDT999 works to bleed the AWD actuators.

Yup_ don't need the hammer or the price of it these days. Go with PDT999 from Paul
928-ecu-repair@hetnet.nl
Plugs right into the OEM port in passenger footwell.