DeLorean Dirty Dozen

For potential buyers and new owners alike, the 12 most serious issues on a DeLorean.

Introduction

The DeLorean is often panned as “unreliable” by those not in the know. The truth is that a well-maintained car — and in particular addressing the items mentioned here — can be extremely reliable. Many cars take long distance trips or are daily drivers.

There are multiple solutions to the following, and multiple vendors — this guide will only touch upon some possible paths.

The List

1. Frame, frame, frame

Any advanced rust will be immediately obvious by looking the front frame extension, engine cradle and fuel tank closing plate. In very advanced cases, the treatment is to do a frame off and repair or replace with another frame — either an original, or (very expensive) stainless offering from some of the vendors.

In mild cases, treatment with POR-15 etc on the car is entirely practical.

There are a number of spots of note that might not be immediately visible without removing wheels, or use of a flash light and are almost never consider in sale photos:

  • Inside the engine cradle extensions — these are hard to reach or even see in. Internal frame treatment is possible here though.
  • In the cross member under the cradle extensions — this doesn’t always have epoxy all the way through, and even when it does, it may be lifting.
Rust in the rear support under the engine cradle.
  • Inside the front frame extension — again seeing in here is tricky, and requires getting under the frame with a flashlight, and is hard to reach with the steering rack in the way.
  • Other spots like the sidewall where the fuel filter mounts — this is somewhat thin and can collect moisture.

Also don’t forget to remove the fuel tank closing plate and examine its inside, as well as the frame sections it’s covering.

2. Fuel lines

The are a total of 22 lines on a DeLorean (some cars might have one additional if a valve is fitted to the fuel pump lines):

102318 Injector Line #1
102323 Injector Line #2
102327 Injector Line #3
102331 Injector Line #4
102335 Injector Line #5
102339 Injector Line #6
102348 Control Pressure Line
102357 Primary Pressure Line
102370 Cold Start Injector Line
102400 Longer Frequency Valve Line
102395 Shorter Frequency Valve Line
102365 Supply Line
102359 Return Line
106979 Fuel pump feed/return/accumulator (x3)
106997 Accumulator
106983 Fuel feed front
106998 Fuel return front
106989 Fuel feed rear
106995 Fuel return rear
106287 Fuel pickup

The final 5 lines listed here are metal and don’t need to be replaced except in severe cases of corrosion, although we’ll talk about the fuel pickup in the pump section.

All the vendors offer braided replacement lines (for the first 13 items) , although it can be confusing since the kits offered only have a limited number of the lines, so you need to make sure you get all of them. It can also be worth replacing the elbow fittings — especially the one feeding the fuel filter.

Braided lines installed.
Fuel filter elbow has seen better days.

Regularly overlooked are the 4 shorter lines — 2 from the fuel pump (accessible in the trunk under the cover) and 2 accumulator lines under the center of the car. The original lines have 3 layers — a black plastic/rubber coating, which is often flaking or completely gone, a white fabric second layer, and an internal hose, which is typically yellowed and very hard from age. If you are seeing white hoses, it’s well past time to replace. You need to use the correct fuel line clamps here (they should come in a kit from a vendor), not the typical hose clamps.

Cost for all items is about $500.

3. Vacuum lines

Original aging vacuum lines.

Replacing the full complement of 11 lines can be done for about $45 from vendors. However, getting to everything requires a visit to the valley — see the next section.

4. Valley of Death

Accessing the valley is not difficult, but it does mean removing a number of engine components, which can be a bit overwhelming for a new owner.

VoD being cleaned.

A “trip to the valley” is particularly important, because collecting coolant/water can cause block rot. Running through the valley is the heater return pipe, which is known to rust out, but is relatively easy to replace. With that is the Y pipe, which can also corrode, especially its bolt holes into the engine.

And as noted, above, replacing the full set of vacuum hoses requires this — 3 of the hoses terminate in the valley. Also, a tune up (spark plugs, wires, distributor and cap), are easier to access if the intake is removed, but not required.

There’s some debate over whether the valley should be painted (in high temperature engine paint), or just left after cleaning.

5. Roofbox

The roofbox is clearly lifting here.

Sometimes it is obvious by looking at the fit of the T-panel on the roof, but can otherwise be examined by removing the finishing plate above the rear window, where any lift will obvious. Over time, not fixed, this can lead to torsion bar failure. A boroscope is suggested also to look inside the roofbox access panel, especially the front area.

The repair is somewhat involved, but kits can be had from vendors for about $40. The repair involves resealing inside and out against further rusting.

In more extreme cases, especially in cars that have been sitting for any length of time, the roofbox will need replacing — this is a very involved repair, and stainless steel replacements are $1600 or more from vendors.

It is almost certain that any DeLorean will need one of these two repairs in the near future if it hasn’t been done, so this is an important thing to know about any given car’s history.

6. Fuel pump

However, what can be more concerning is the rubber boot around the pump — this can perish over time, especially with use of fuels with ethanol in them. It’s also worth examining the fuel tank for debris, which can cause havoc with the K-Jet system. Finally, check the fuel pick up line; sometimes it’s missing or jury rigged.

Finally, and very important, as mentioned earlier, the 2 lines here from the fuel pump — these are the easiest of all the fuel lines to replace, so there’s no excuse.

Fuel lines to the fuel pump. These are clearly original, deteriorating lines.

7. Fuse box and Relays

Fuse box area with a number of updates.

Dave McKeen sells a number of solid state relays and other items which can significantly reduce the current load (and therefore heat) of many items, and several of these are highly recommend for any car, especially the RPM relay, Lamba relay and also a fan relay to monitor the fans, above:

https://dm-eng.weebly.com/

8. LEDs

There are a couple of drawbacks to installing LEDs, and the battery light in the dash can’t be replaced, however, this guide covers everything apart from the headlights:

One caveat about replacing bulbs in the dash is that sometimes the original flexible PCB does not survive removal of the connectors due to its age. Replacements from vendors can be had for about $40.

7. Tires

At present in the United States, the only tire brand available that has front and rear matching are Hankook Kinergy, which are available from a number of retailers. Some European owners have found matching Nangkang tires. Since the Hankook tires have only been available for a couple of years, a car fitted with those will be in good condition.

That said, mismatched front/rear tires are not unusual to get the correct sizes, or sometimes the sizes will be varied to get a matching brand.

Front tires are 195/60R14 and rears are 235/60R15.

Hankook tires ready to be fitted.

8. Trailing Arm Bolts

On a manual transmission car, this is straightforward, if a bit involved, since it requires a number of steps, and other parts are often replaced in the process, including the trailing arm bushings and mounts.

Original trailing arm bolts after removal. One was so badly bend, it had to be cut out.

On an automatic transmission, the clearances, especially on the driver side, are very tight, and the process can be extremely time consuming, involving either loosening the transmission mounts or removing the trailing arm altogether, and is ideally a two person job with a lift.

9. A/C

Hamster cage, ready to be cleaned.

The A/C flap is prone to rust, and is NLA from vendors, but can be reached by removing the glovebox and refurbished.

For the rest of the A/C system, a rebuild of the heater box is sometimes necessary — this is a particularly involved job, as much of the dash has to be removed, the box resealed and broken items on the aging plastic repaired. In addition, typical A/C car items like the compressor and hoses may need to be replaced and the system possibly upgraded.

10. Radio and speakers

DIN-sized faceplate and original-sized faceplate.

One thing of note when updating the headset is that the grounds on the speakers need to be split — the original wiring uses shared grounds to the speakers, which results in awful sound if you do not do this.

The front speakers themselves may be OK, and but are easy enough to replace — one recommendation though is to use brass standoffs to get the screws back in. Rear factory speakers will in almost all cases have suffered rot, and will need to be replaced. Doing so is somewhat involved, since the rear interior panels have to be lifted from the door frame. Replacing the speaker wire is an option here too.

Typical rear speaker condition with dry rot.

11. Seat rails and carpet

Seat rails that have been better days.

12. Steering

Steering assembly. Bushing is seen right at the end.

Without this, the steering will be sloppy. Another possible wear item here is the upper universal — over time, the joint may wear, making steering less precise.

13A. Bonus round — Automatics

Also make sure automatic transmission filter is fresh.

13B. Bonus round — Manuals

This is what can happen. Photo courtesy Mike Guy.
And this is what it should look like.

Forthcoming topics

  • Brakes
  • Battery and grounds
  • Fluid change schedules
  • Binnacle and instrument cluster

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