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964 timeline of improvements / problem years?

Hi all

I'm looking for a timeline of 964 development that charts which years were affected by 964 unique problems such as the flywheel and oil control gaskets, in addition to any other mid-generation changes for the better/worse to look out for.

thanks
r

Quote:

Originally Posted by r-mm (Post 7116500)

Peter Zimmerman's 911 buyer's guide is VERY good at explaining the pluses and minuses of each and every 911 year (up to about 2005).

The book is worth every penny.

Not to send you to another site, but I have documented most of the stuff I have done to the car.

Pending projects and a few q? - Rennlist Discussion Forums

There are some specifics for the first year... different parts for the '89.

Then you have the heads on the early cars with not sealing rings. This was mid 91 year cars...

Updated clutch release fork.

Need to install a vent kit for the distributor to avoid the degradation of the belt that drives the second distributor.

Technical bulletin for the plug that goes into the airflow meter.

Quote:

1. Is the distributer vented? If so, how long did it run before it was vented?
2. What kind of flywheel is installed? Luk is good news. Original Freudenberg is not good news. (But I have one, and it's been going for over 100k miles.) If it's a single mass flywheel, watch for driveability, especially when the air conditioning is on in traffic. Of course, if it's a tiptronic, the flywheel is a moot point.
3. Oil leaks around the cylinder head? (Early 964's did not have a gasket, and it caused problems in SOME of the cars. Cars that exhibited the problem during warranty were fixed by Porsche.) (On the positive side, my car has over 100k miles, no gasket, and it's fine! Touch wood.)
4. Oil leaks in general? These can be expensive to get to, and replacing some of the hoses can add up.
5. How's the air conditioning? Does it need a recharge?
6. How's the power steering pump? Often there are leaks.
7. If it's a cabriolet, how are the seals, condition of the top, operation while lowering/raising the top (should be quiet and smooth)? If it's a Targa, what's the condition of the Targa top? Does it fit well, or is there leaking and wind noise?
8. How are the brakes? Do the rotors or pads need to be replaced?
9. How are the tires?
10. How does it drive, especially in comparison with similar 964's?

Between these questions, the checklist, and a PPI from a reputable Porsche mechanic, you stand a very good chance of purchasing a 964 that you will enjoy for years to come! Good luck, and happy hunting!

I will update with more as I remember more stuff...

If it is a cabriolet that you are looking at, check the bolts on the top's transmission... you have one on each side. These come loose with time and need to be tighten...

Cabrio Top Mechanism Problems - Rennlist Discussion Forums

Details on the Erratic idle due to a connector

Quote:

Originally Posted by JasonAndreas (Post 2947343)

Engine - Erratic Idle, Loss of Power, or Stalling

May 15, 1990
Subject: Engine, Inconsistent Performance
Model Group

911 C2/911 C4 2

Part Identifier Number

9750 9005
ATTENTION: Service Manager/Service Technician

This bulletin replaces Technical Bulletin Group 2, Number 9005, dated April 6, 1990.

Models Affected: 911 Carrera 2 and 911 Carrera 4, Model Years 1989 (K) and 1990 (L)

Concern: Inconsistent acceleration, erratic idle, loss of power or engine dies.

http://members.rennlist.com/jandreas/9005-1.gif
http://members.rennlist.com/jandreas/9005-2.gif

Possible Cause: The air flow meter wiring harness protective cover (Figure 1) contacts the engine ventilation hoses (Figure 2) causing current flow interruptions on the plug terminals.

Vehicle Information: The protective cover on the air flow meter wiring harness plug was discontinued from production date February 13, 1990.

VIN's 96 - LS 45 1659 Coupe 96 - LS 46 0409 Targa 96 - LS 47 1072 Cabriolet

Repair Information: 911 Carrera 2 model year 1990 and 911 Carrera 4 model years 1989 and 1990 prior to the above VIN's should be modified when the engine is removed or when working on the air flow meter, even if no engine performance problems are present.

Work Procedure: 1. Remove air filter housing cover and filter.

http://members.rennlist.com/jandreas/9005-3.gif

2. Push down locking spring on air flow meter wiring plug and disconnect plug (arrow in Figure 6).

3. To gain access to plug, pull wiring harness with plug between air flow meter and idle stabilizer towards rear of vehicle.

http://members.rennlist.com/jandreas/9005-4.gif

4. Pull back rubber boot and cut protective wire covering using side cutter or similar tool (arrow in Figure 3).

http://members.rennlist.com/jandreas/9005-5.gif

5. Heat protective wire covering with hot air blower to maximum 110~ C (230~ F). Pull off and discard protective wire covering (Figure 4).

http://members.rennlist.com/jandreas/9005-6.gif

6. Reinstall rubber boot on plug housing. Loop wiring harness along side of plug and tie wrap as shown in Figure 5.

http://members.rennlist.com/jandreas/9005-7.gif

7. Reconnect wiring plug. Make sure spring lock is engaged. Figure 6 shows wiring plug connected (engine removed).

Important: Do not use contact spray.

http://members.rennlist.com/jandreas/9005-8.gif

Work Procedure: 8. Check clearance between wiring harness and vent hoses. Distance should be at least 15 mm. If necessary, bend bracket on right shock absorber mounting slightly forward (arrow in Figure 7). Make sure vent hoses are properly installed on bracket at shock absorber mounting and on bracket in front of air flow meter. The small diameter hose must be routed below the large diameter hose, 9. Reinstall air filter and filter housing cover.

http://members.rennlist.com/jandreas/9005-9.gif

10. Mark air flow meter with a black paint dot as shown in Figure 8.
Parts Information: Tie wrap: PN 999 513 021 40

Labor Information:
Labor Operation: 97 50 19 OA
Damage Code: 97 50 40 000 1
Time Units: Engine installed - 80 Engine removed - 20

Also need to decide if you want a C4 or a C2... with the C2 being less complex than the C4.

Mine is a C4 and the system has been working fine so far. Only had one problem, I was using the car and had to make a sudden stop at a speed bump. The ABS came to play. Since it was the first time I had sense the system in action I decided to give it another try. It worked flawlessly. Close to my house I made a normal stop and to my surprise the brake pedal would not respond. I had to push it extremely hard to make the car stop.

The problem was solved by: Pressure Sensor replaced(US$247.55 - Part # 964-606-904-00), Relay replaced (US$33.81 Part # 964-615-135-00), Rubber O-Ring replaced(US$4.99 Part # 999-707-094-40). Labor US$147.90 Minus PCA discount.

But, like I said, you are exposed to more potential issues with the awd system. For example, the solenoids that activate the front drive are over 300.00 each... and I have not found a way to rebuild them...

Oh, another thing I forgot... AC blowers. Two in front, one on each side... bearings go bad and you need to replace them... another 4-500 for each blower... Also the evaporator is a b* to replace, ask me how I know... but it can be a diy task and avoid paying for the labor (very labor intensive).

Fuel smell from either a bad gas cap, bad fuel filler neck, or evap valve, or old hose under the front trunk...

Steering rack is another issue to look at... no updates that I am aware... and still waiting for a vendor to sell a rebuild kit specific to our 964... the ones that I have found are only for 993 racks... not the same.

Here is a good thread on rebuilding a steering rack, again, for a 993

993 steering rack DIY rebuild tutorial - Rennlist Discussion Forums