What mods would make the car more reliable?

[aludden]

I think it would be interesting to list in a sticky the mods that would make for a more reliable car. There are many of us that are not looking for performance or projects - we just enjoy driving the car :-)

[opethmike]

My thoughts:

Updated relays/circuit break kit
Stainless clutch line in case of manual transmission
Tighten down output shaft nut in case of manual transmission (I can't emphasize this enough. Mine backed off, cracked open my transmission end cap. Huge headache.)
Unplug stock door lock module
Starter wiring tech bulletin if applicable and not done

[Ozzie]

Digital RPM relay by Dave/BitSyncmaster.

This is a modern replacement to a high failure part. Many a D owners have had relay failures caused by overheated, or delaminating, original RPM relays on long/highway trips. If your relay goes bad on a trip, you can a) jumper it for a short return trip, b) have and plug in a spare, or c) get this digital one and never think about it again.

I've been running one now for a few years and many miles here is an older review that still applies.

[jawn101]

Replace all flexible fuel lines and any rubber that coolant flows through, to include the short junctions in the pipes under the car. Silicone vacuum lines. Trailing arm bolts!

[JIMJAM]

A few years ago after buying my D I tried to follow the "must do mods" which was rather lenghty. I simplified it and just replaced anything that electricity ran through, gas touches or any part that moves and / or has weight on it.

[aludden]

Replace all flexible fuel lines and any rubber that coolant flows through, to include the short junctions in the pipes under the car. Silicone vacuum lines. Trailing arm bolts!

As far as fuel, you mean all the fuel lines going from the fuel distributor to the injectors? I have been looking at that, but it is a bit pricey, so it may have to wait a bit.

I just finished changing all the coolant hoses, including the heater valve and hoses behind the engine :-) I'm also doing the vacuum hoses.
As far as the trailing arm bolts, I'm pretty sure I got them replaced years ago, but I do have a new set to put in. Mine is more difficult because it's an automatic, but it's on my list.

[jawn101]

As far as fuel, you mean all the fuel lines going from the fuel distributor to the injectors? I have been looking at that, but it is a bit pricey, so it may have to wait a bit.

I just finished changing all the coolant hoses, including the heater valve and hoses behind the engine :-) I'm also doing the vacuum hoses.
As far as the trailing arm bolts, I'm pretty sure I got them replaced years ago, but I do have a new set to put in. Mine is more difficult because it's an automatic, but it's on my list.

Yup, all the flexible lines. From the filter, to the injectors, WUR, CSV, frequency valve, etc.

With coolant, don't forget the side hoses, water pump, and the small collars at the radiator and under the tub.

[Kenny_Z]

The mods I've done or plan to do to increase the reliability of my D:

Relay upgrades (I still have the original RPM installed but I do have a spare)
Plastic coolant tank replacement (I've heard they rupture under pressure, I still have the plastic installed but will be replacing it when I can)
Stainless clutch line (replaced when I replaced my master and slave cylinders)
Upgraded fuel pump with external check valve (came with the car but I just bought a used spare off a local Porsche guy)
Grounding upgrades (can be cheap and easy or not as cheap and extensive, I went extensive)
Coolant hose replacement with silicon hose (planned for Spring)
Coolant active bleeder system (I bought Hervey's but haven't installed it yet)


The ones below are ones I've seen done that just sound like they are a good idea for upgrades:

Stock radiator replacement (I've seen 10 year old plastic ones crack, ours are 30)
Stock radiator fan replacement (lower amp fans take some of the load off your circuits)
Water pump replacement with one with a bolt on pulley
Upgraded alternator (could be just a better DMC unit or an upgrade from another car)


None of the stuff above will get you any extra power out of the engine but they will keep you off the side of the road.

[Kenny_Z]

My thoughts:
Tighten down output shaft nut in case of manual transmission (I can't emphasize this enough. Mine backed off, cracked open my transmission end cap. Huge headache.)
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Is there a document on how to do this? I haven't seen one when I search for it. I'd really like to check this on Red. I drove her a bit with a bad shift link bushing so I don't know how long the previous owner was driving like that.

[jawn101]

The mods I've done or plan to do to increase the reliability of my D:

Relay upgrades (I still have the original RPM installed but I do have a spare)
Plastic coolant tank replacement (I've heard they rupture under pressure, I still have the plastic installed but will be replacing it when I can)
Stainless clutch line (replaced when I replaced my master and slave cylinders)
Upgraded fuel pump with external check valve (came with the car but I just bought a used spare off a local Porsche guy)
Grounding upgrades (can be cheap and easy or not as cheap and extensive, I went extensive)
Coolant hose replacement with silicon hose (planned for Spring)
Coolant active bleeder system (I bought Hervey's but haven't installed it yet)


The ones below are ones I've seen done that just sound like they are a good idea for upgrades:

Stock radiator replacement (I've seen 10 year old plastic ones crack, ours are 30)
Stock radiator fan replacement (lower amp fans take some of the load off your circuits)
Water pump replacement with one with a bolt on pulley
Upgraded alternator (could be just a better DMC unit or an upgrade from another car)


None of the stuff above will get you any extra power out of the engine but they will keep you off the side of the road.

Big +1 to the grounds, radiator, water pump, coolant tank, alternator and cooling fan updates. The grounds, alternator and fan updates will make a huge difference in the car's behavior (at least they did in mine). Hervey's ground cables alone made an immediate and enormous difference - best 40 bucks and 40 minutes you'll spend. The other updates are great for long term reliability and safety.