DeLorean Dirty Dozen


Any comprehensive guide about DeLorean issues would be extraordinary lengthy, and this does not attempt to be such. Instead, this is meant to be a reference for newcomers evaluating a car — especially in the case of a car you might be planning to purchase, or in one you’ve just obtained. Some of the items here may be problematic to check just from photos, and might not be obvious until you can spend some up close time with the car.

The List

1. Frame, frame, frame

It is a rare DeLorean indeed that has no rust whatsoever, and certainly the original mild steel frame is prone, especially to cars from colder climates. Unless the car has had a recent frame off restoration, frame replacement, etc, some rust is almost certain on the car and frame in particular.

  • 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.

2. Fuel lines

The original rubber fuel lines after 40+ years are aging badly, and prone to split and are a severe fire risk at worst, or at the least, leaving you stranded.

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

3. Vacuum lines

This is an easy one, but again often overlooked. The factory original vacuum lines are typically aging and leaking, and are one of the first things to consider when trying to make a car run smoothly, and especially address high idle.

Original aging vacuum lines.

4. Valley of Death

This refers to the region on top of the engine, below the intake manifold. It is known for collecting coolant, loose engine parts and tools and other foreign objects.

VoD being cleaned.

5. Roofbox

Like the frame, the original roofbox is mild steel, and prone to rust both inside and out. It is also prone to lifting at the rear — the exact reasons are not clear, but probably due to aging glue and continual flex — in any case, it needs repair by bolting down.

The roofbox is clearly lifting here.

6. Fuel pump

The fuel pump itself tends to be an incremental and obvious failure, although plenty of original factory pumps are still going. There are multiple options for replacement from vendors, or kits to install mainstream ones. Some options include integrated fuel senders, to replace the factory sender, which can deteriorate over time, and even fully working isn’t the most reliable in reporting. Also available is a separate sender MCU to improve this.

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

7. Fuse box and Relays

Fuses and relays have been known to melt and cause fires due to high current draw or shorts, so this is important to check regularly. In particular, aging cooling fans can have very large current draw, and updated, much lower draw fans are available from vendors. However, some owners advocate for retaining the original fans (which have higher air flow), and improving the wiring or refurbishing the fans.

Fuse box area with a number of updates.

8. LEDs

Replacing LEDs in the car significantly reduce current draw, which is important to the above. And in particular, the some or the bulbs can get quite warm, especially the one in the engine bay, so putting in LEDs can be important.

7. Tires

This one is obvious, but so often not done. Tires are good for about 6 years, and then should be replaced, whether driven on or not. Sometimes DeLoreans have the factory original Goodyear NCT tires, which are only good for show.

Hankook tires ready to be fitted.

8. Trailing Arm Bolts

These bolts are part of the rear suspension, and hold the trailing arms to the frame. This was a relatively weak part of the original design of the car, and these bolts over time bend, and eventual break, leading to potentially dangerous situations. A car with original trailing arm bolts will almost certainly need them replaced; vendors sell stronger ones.

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

9. A/C

Poor air flow from the vents can often by fixed by cleaning out the fan or “hamster cage” or replacing the motor — a full assembly can be had cheaply and is very easy to replace. Over time the motors corrode and may start to squeal.

Hamster cage, ready to be cleaned.

10. Radio and speakers

The original Craig and ASI radios often are faulty from age, but can be refurbished. It is however also common to fit a new style standard DIN radio (in which case, a new DIN panel needs to be fitted, or the original cut to size), or it’s possible to find modern radios which fit in the original space.

DIN-sized faceplate and original-sized faceplate.
Typical rear speaker condition with dry rot.

11. Seat rails and carpet

This is an easy one, but the seat wells can collect water from the evaporator drain, doors and other locations. This leads to obviously damp carpet, and the seat rails in particular can get rusty. Too far gone, they’ll need to be replaced. Carpet too can be replaced in pieces or as a whole set — also worth checking the rear parts for battery leaks.

Seat rails that have been better days.

12. Steering

The steering bushing is a typical wear item, and is easy and cheap to replace. Sometimes overlooked is the inner steering bushing, which can crack — vendors sell a strong version of this — the steering assembly needs to be removed to fit this.

Steering assembly. Bushing is seen right at the end.

13A. Bonus round — Automatics

The original factory automatic computers aka governors, are well beyond their best before date, with failing components and connections. Vendors will rebuild these for around $400 with a core exchange. Also check the operation of the WoT microswitches and cable adjustment. A poorly adjusted automatic DeLorean does not drive well.

13B. Bonus round — Manuals

There are two nuts inside the end cap of the transmission housing that are known to have not been properly tightened at the factory. It’s possible to get to these without removing the transmission from the car. Left unchecked, a hole can be drilled in the housing.

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

Forthcoming topics

Future topics for this list:

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



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Peter Naulls

Peter Naulls

Vegan, IoT, Coffee, Lego and DeLoreans