DeLorean Car Fires ...Numbers, Causes and Fixes

[Rich W]

<snip>
But if there are 3 DMC-12 fires amongst the estimated 2,500 running, 6,500 in existence (both estimates) I would argue that it is significant/relevant. Also, as our labors of love age characteristics may develop that we need to track and manage. As such I look at how the numbers play out amongst DMC-12's and not against similar era cars.

The fun part of statistics is that even though you may have only a .000001% chance of xxx it is a big deal to the person it happens to.
<snip>

As long as statistics have been mentioned here, I would like to note the 6,500 DeLoreans in existence quote is most likely a DeLorean myth
that will one day be true, but I think we are still a ways away from that day. I did a little statistical analysis with Knut around DCS 2006,
with the [6,500] number already in regular use since DCS 2000, and IIRC, based on an unkown actual amount of DeLoreans built, but using
some of the "best" estimated build numbers, Knut and I came up with estimates between 7,200 and 7,500 DeLoreans still in existence.

Even if you use the low end of the estimates, and you account for a dozen or so complete losses per year since 2006 (less is more likely),
it is more likely there are still well over 7,000 DeLoreans still in existence. Again, even our work was based on estimates, and I personally
believe there were much less losses than the 50-100 cars per year, for the first few years, gradually tapering off throughout the 1980's
and 1990's, so just looking at the numbers (and the multiple estimates) there may be well over 7,500 DeLoreans still in existence.

Within the last decade or so, there has been at least as many "part-outs" as there has been total losses due to collisions and fire damage,
so the numbers are decreasing, but statistically speaking, it may be a while before we actually reach the 6,500 car estimate, in the future.

[ALEXAKOS]

Vin Unknown,

Car was imported from Qatar to Germany in 1987.
Owner invested over 20.000 Euros in restoration in 2001 to 2006.
During a summer drive, white smoke came out of the vents. He turned the ac off. After a minute the car started loosing power. He pulls over, opens engine compartment and flames fly out.
Uses floor mats to kill the flames. Car burns on for 3 hours even with fire Dpt help.
At first nobody stops for help with extinguisher, they were to scared it would explode... (DAMN MOVIES!) Then 50+ people stop to take photos and videos.... Nobody is afraid the car will explode any more

Actual cause never found.

[David T]

Fuel fires most generally occur soon after a service. A banjo bolt breaks or is not tight enough, a crush washer is missing, a hose was bent, stretched, or kinked. In many cases there is a smell of fuel which goes ignored. Because of the higher pressures used in the K-Jet a tiny leak can be invisible because the fuel atomizes as soon as it leaks out. With a spark or a hot source it becomes a blowtorch. Typically a fire in the engine compartment is a fuel fire, not electrical, at least in the beginning. Electrical fires most commonly originate in the fuseblock area behind the passenger seat. The two most troublesome circuits are for the cooling fans and the fuel pump. There is usually some warning. There will be an odor and if you look there will be visual signs of overheating, discolored insulation or melted plastic. Regular inspection and upgrading the relays and circuit breakers can prevent any electrical fire. The other big problem area is the headlight switch but it usually just melts, not burns.
I do not see any reason to obsess over fire per se. The car is also subject to mechanical failure and that is much more likely. The answer to ALL of the problems is good upkeep, regular maintenance and inspections. As an example, if you drive on 10 year old tires you can expect them to fail! If you drive on new tires but never check the air pressure and you have a slow leak you can expect problems.
Regular inspection is the key. The big caveat is of course, you have to know what you are looking at and be able to spot a problem before it causes trouble. That is where experience becomes so important. Watch when you take the car for a Tech inspection. Most clubs have a tech session once a year. See what the Tech is doing and what he points out.

[DrJeff]

This thread (or a new thread/sub-topic) related to preventing fires or catastrophic failure in Deloreans is a great idea. If the goal of the discussion of causes is to get to a specific list of checks, parts, changes to the design, etc., then I believe we'll need to get as close as possible to specific causes (as opposed to the "it's usually fuel or electrical"). We'd need to get to the "wire X runs past sharp edge at position Y" level of detail if we're going to develop a set of preventative actions that go beyond "be careful and check everything". (Rather like the "place a split rubber hose between the rear door brackets and the torsion bar" type of guidance.)

Since the occurrences of fires is relatively infrequent and has the tendency to destroy the obvious evidence in the process, I think for fires we are going to have to list and rate the risk from 'likely failure points'. We might start by listing out the sources of risk (which is started, fuel lines - age and heat stress, electric wire runs, etc.) and then look for the places on the car where these occur (e.g. fuel lines in the engine bay, points of greatest heat stress or pressure in the lines, etc). Thought... any evidence of fire risk when the flexible fuel hoses go at the fuel tank?

"Thankfully" for physical breaks, like TAB failures or lower ball joints, there is a better chance of determining the cause, and thus working towards the corrective measures.

[DMCMW Dave]

The typical fuel line break in the engine compartment is at the end of one of the Teflon lines where it has been pressed onto the banjo fitting.

The most common one to break is the one to the cold start valve. I'm not sure why, but we sell that as a stand-alone replacement line much more often than any others. My pet theory is that is one that is more commonly twisted during removal and installation, and has a bit of force on it when installed (i.e. it is not formed exactly to where it goes). It is also the ONLY one of the small lines that is under full line pressure all the time.

A full set of stainless lines is a good idea.

BTW - we (and DMC Affiliates) do stock and sell that line by itself, and a whole set as well. It is braided stainless with a black outer jacket.

http://store.delorean.com/p-10631-br...-line-set.aspx . Ignore the photo.

[Mark D]

The most common one to break is the one to the cold start valve.

This was the exact line that was broken on my car (on the fuel distributor end of the hose.) The symptom that lead me to investigate was leaking fuel on top of the fuel distributor. The break in the line wasn't noticeable until I peeled back the rubber jacket and saw the hose was cracked towards the end near the banjo fitting. The crack was in the lengthwise direction of the hose, similar to how a drinking straw would commonly split. The rubber outer jacket was all that was holding back the fuel from spraying everywhere.

[djdogbone]

Can that auto fire extinguisher really work in a DMC- it looks like a great idea! But, it goes off at 175 degrees. Is that too low for the engine compartment?

[nkemp]

OK, here’s the ones I know about.

Only a few have causes, but maybe others can chime in with any known details.

Thanks for providing. Depressing but relevant. Hopefully those owners will chime in here.

This thread (or a new thread/sub-topic) related to preventing fires or catastrophic failure in Deloreans is a great idea. If the goal of the discussion of causes is to get to a specific list of checks, parts, changes to the design, etc., then I believe we'll need to get as close as possible to specific causes (as opposed to the "it's usually fuel or electrical"). We'd need to get to the "wire X runs past sharp edge at position Y" level of detail if we're going to develop a set of preventative actions that go beyond "be careful and check everything". (Rather like the "place a split rubber hose between the rear door brackets and the torsion bar" type of guidance.)

Since the occurrences of fires is relatively infrequent and has the tendency to destroy the obvious evidence in the process, I think for fires we are going to have to list and rate the risk from 'likely failure points'. We might start by listing out the sources of risk (which is started, fuel lines - age and heat stress, electric wire runs, etc.) and then look for the places on the car where these occur (e.g. fuel lines in the engine bay, points of greatest heat stress or pressure in the lines, etc). Thought... any evidence of fire risk when the flexible fuel hoses go at the fuel tank?

"Thankfully" for physical breaks, like TAB failures or lower ball joints, there is a better chance of determining the cause, and thus working towards the corrective measures.

DrJeff ...This is exactly what we need to do herein.

... "it's usually fuel or electrical"). ...

Generally these type comments come 2nd, 3rd, 4th ... hand. What we need is 1st hand accounts. The problems with fires is that they tend to destroy evidence. To compensate it would be great if the owners of the cars mentioned above could comment on what they may have done hours, days, weeks before the fire. Or if they did nothing maybe they could provide other clues they observed before the event. One occurrence of something may be coincidence. Two is starting a trend and three gets you well on your way. So any clues may become more helpful over time.

Also, if owners were aware of an effort to collect failure data, maybe more would take a critical look (photo) after the event and document it.

The typical fuel line break in the engine compartment is at the end of one of the Teflon lines where it has been pressed onto the banjo fitting.

The most common one to break is the one to the cold start valve. I'm not sure why, but we sell that as a stand-alone replacement line much more often than any others. My pet theory is that is one that is more commonly twisted during removal and installation, and has a bit of force on it when installed (i.e. it is not formed exactly to where it goes). It is also the ONLY one of the small lines that is under full line pressure all the time.

A full set of stainless lines is a good idea.

BTW - we (and DMC Affiliates) do stock and sell that line by itself, and a whole set as well. It is braided stainless with a black outer jacket.

http://store.delorean.com/p-10631-br...-line-set.aspx . Ignore the photo.

Dave, good input! The original lines are 30+ years old. Gas formulations have changed a lot, plastic type materials don't last forever, the engine heat is not keeping them young. And yes, heavy handed manipulation by all sorts of "mechanics".

[nkemp]

Can that auto fire extinguisher really work in a DMC- it looks like a great idea! But, it goes off at 175 degrees. Is that too low for the engine compartment?

The opposite may also be a problem... is that too high? There is a lot more air movement in our engine compartment than a boat engine compartment. Thus air temp may not reach 175 until it is well on its way to destruction.

[David T]

The opposite may also be a problem... is that too high? There is a lot more air movement in our engine compartment than a boat engine compartment. Thus air temp may not reach 175 until it is well on its way to destruction.

If you are that worried about fire you can install a fire suppression system such as they have in race cars. They are not meant to save the car though. The main purpose is to buy the driver some extra time to get out. With proper care and maintenance Deloreans are no more prone to fire than any other fuel injected car. Keep a fire extinguisher handy and make sure your insurance has the car well covered and is paid up. The hoses are no more prone to fire and leakage if they are well treated. In fact, the original hoses are better than some of the replacement ones some venders sell!