Engine Fire....
Discussion
While driving home last night I experienced a small engine fire in my S2, which appears to have done some lasting damage to the internal of the engine.
It appears that the air filter has caught alight, and in doing so, melted the intake trumpet to #3 cylinder. As this occured while I was driving, I suspect that some of the molten metal from the melted intake trumpet has made its way into the engine, in addition to burnt parts of the air filter.
We didn't hear any backfire from the motor, and we had driven about 1km when the problem first occured in the form of a stuck partially open throttle and a loss of power from the engine. I coasted to the nearest place I could safely pull over - a petrol station (I didn't know that anything was on fire at this stage!), and got out to investigate to discover lots of smoke coming from the air cleaner box.
The engine now runs, but blows a lot of steam out the exhaust leading me to suspect a blown head gasket, cracked head or other similar engine internal issues.
Has this occured to anyone else? Does anyone have any idea on what may have caused it?
cheers,
Ian...
It appears that the air filter has caught alight, and in doing so, melted the intake trumpet to #3 cylinder. As this occured while I was driving, I suspect that some of the molten metal from the melted intake trumpet has made its way into the engine, in addition to burnt parts of the air filter.
We didn't hear any backfire from the motor, and we had driven about 1km when the problem first occured in the form of a stuck partially open throttle and a loss of power from the engine. I coasted to the nearest place I could safely pull over - a petrol station (I didn't know that anything was on fire at this stage!), and got out to investigate to discover lots of smoke coming from the air cleaner box.
The engine now runs, but blows a lot of steam out the exhaust leading me to suspect a blown head gasket, cracked head or other similar engine internal issues.
Has this occured to anyone else? Does anyone have any idea on what may have caused it?
cheers,
Ian...
In my experience, air filters don't just catch on fire. There is usually a backfire event. In your case, it sounds like there was a problem with #3. I am not familiar with S2's, but I am thinking they are carb'ed, right? In that case, I would venture to say that a backfire occurred, perhaps with a fuel leak on the #3 choke, although the leak is not really necessary with all the gas in there, resulting in the melted horn and eventually the burned air filter. The normal state of side drafts has a cloud of fuel vapor (vapour) out by the horns anyway. Now, what happened to the motor side I can only venture to guess, but it does not sound good. Steam out the tail pipe is never a good sign. At a minimum, BHG (Blown Head Gasket), at a maximum, much much worse. Either way, the head is going to have to come off so you can have a look-see.
I really can't see how the fire out in the carb area could cause a BHG, but anything is possible. Oh, and you will likely need a new carbie too. Good Luck.
Dr.Hess
I really can't see how the fire out in the carb area could cause a BHG, but anything is possible. Oh, and you will likely need a new carbie too. Good Luck.
Dr.Hess
Hi,
Sorry to hear of your troubles. As mentioned, a backfire is likely the culprit, and in my mind is more the result of an engine malfunction than the other way 'round. Something in the engine let go and caused the backfire to occur, which intensified into the fire you experienced.
So far as the engine problem is concerned, get a leak-down tester and check out each cylinder, starting w/ #3. Absent that, or in addition to, do a cooling system pressure test and see if coolant is migrating past the head gasket. These tests will narrow the list of possibilities.
If I had to guess off the top of my head, I'd say you possibly melted the #3 piston, perhaps from running too lean or by an air leak in the intake system. This allowed blow-by to occur and could well cause a backfire. Better than a lot of possibilities, but without a thorough inspection, I am merely speculating. Good Luck! Happy Motoring! ...Jim'85TE
Sorry to hear of your troubles. As mentioned, a backfire is likely the culprit, and in my mind is more the result of an engine malfunction than the other way 'round. Something in the engine let go and caused the backfire to occur, which intensified into the fire you experienced.
So far as the engine problem is concerned, get a leak-down tester and check out each cylinder, starting w/ #3. Absent that, or in addition to, do a cooling system pressure test and see if coolant is migrating past the head gasket. These tests will narrow the list of possibilities.
If I had to guess off the top of my head, I'd say you possibly melted the #3 piston, perhaps from running too lean or by an air leak in the intake system. This allowed blow-by to occur and could well cause a backfire. Better than a lot of possibilities, but without a thorough inspection, I am merely speculating. Good Luck! Happy Motoring! ...Jim'85TE
Thanks everyone for the input....
With luck, it should be covered by insurance. It will depend on the post mortem and what damage was caused by the fire. I have already arranged for it to be dropped to a specialist for assessment. Needless to say the insurance company would not allow me to do the assessment!
Apparently there is a history of early lotii having engine fires from backfires or the carbs spitting fuel.
cheers,
Ian...
With luck, it should be covered by insurance. It will depend on the post mortem and what damage was caused by the fire. I have already arranged for it to be dropped to a specialist for assessment. Needless to say the insurance company would not allow me to do the assessment!
Apparently there is a history of early lotii having engine fires from backfires or the carbs spitting fuel.
cheers,
Ian...
Let us know the results.
The first thing I did with my car when I got it going was to take it to a tuning specialist I know as I need to run it on the 96 octane unleaded we have in NZ. The 96 sold in NZ has a tendency for carbed cars to run lean (Ford Falcons and Toyota Hiaces were particularly affected and needed to be rejetted to run smoothly).
If the fuel in Oz is the same rubbish that we get, it may have been making your run lean.
BTW after retuning I was getting 160bhp on the dyno which is what Lotus quoted for that motor, so I am happy with that.
Hope the damage isn't too serious.
Graeme
The first thing I did with my car when I got it going was to take it to a tuning specialist I know as I need to run it on the 96 octane unleaded we have in NZ. The 96 sold in NZ has a tendency for carbed cars to run lean (Ford Falcons and Toyota Hiaces were particularly affected and needed to be rejetted to run smoothly).
If the fuel in Oz is the same rubbish that we get, it may have been making your run lean.
BTW after retuning I was getting 160bhp on the dyno which is what Lotus quoted for that motor, so I am happy with that.
Hope the damage isn't too serious.
Graeme
scoots said:
Thanks everyone for the input....
Apparently there is a history of early lotii having engine fires from backfires or the carbs spitting fuel.
cheers,
Ian...
Hi,
Agreed that there have been numerous engine fires in early Esprits. The primary cause is neglect.
The dellorto DHLA carb has it's accelerator pump on the underside of the carb body. Consequently, when the accellerator pump diaphram fails, it leaks fuel directly over the starter/distributor electronics (ignition source). A simple splash plate installed by Lotus would have mitigated this to a great degree, but none was forthcoming.
It behooves every carb'd Esprit owner to frequently reach to the underside of the carb bodies and feel for some leaking fuel. The accellerator pump diaphram is made of a thin 'live' rubber surround with a steel/zinc coated plunger at it's center. This plunger corrodes with time and compromises the rubber on it's edge. Also, the 'live' rubber hardens from it's constant flexing and exposure to fuel and eventually splits. Either of these eventualities will cause fuel to spill out the bottom. If this happens you have about a 100% probability of a fire.
The fix is simply a carb rebuild, pretty simple, cost for both carbs <$100 and it takes less than an afternoon to do. You could simply replace the accellerator pump diaphram, but with limited access etc., it's better to simply do a full rebuild every 5-10 years or so.
If you are not sure how long it's been since your carbs were rebuilt, it would be prudent to inspect the carb undersides regularly and plan a rebuild in the near future. Either that, or keep a fire extinguisher very close at hand.
Not to be alarmist, but this is probably the most serious risk of fire on the entire car. The fix is so relatively cheap and easy, it is foolhardy to ignore it. Happy Motoring! ... Jim'85TE
kylie said:
For the rebuild Jim are you referring to all Carbed cars or just for the earlier ones?? A full rebuild is on the list but its running excellent at the moment so I havent put this as a high priority. Well least I have a fire extinguisher mounted in the car
Kylie,
No one would call you a negligent owner. Nor did I mean to imply a negative connotation to that description. But carbs are a mystery to many people and on the Turbo Esprit, they're buried deep under lots of intakes, balance tubes, plenums and the like and many people just don't realize how serious it can be to leave them until they actually fail.
Fact is, long before they may start to leak, their performance will have decreased due to normal wear and tear anyway. The materials used, given the environment they are employed in, really only have about a 5 to 10 year lifespan (upwards of 10 if driven regularly, closer to 5 if stored for extended periods such as for the winter).
A varnish is a by-product of the gasoline and over time will build up on the carb interior and minute passages restricting flow and also causing chaos to the fluid dynamics at work resulting in lowered performance, harder starting, poor idle etc. Additionally, these by-products accelerate the deterioration of all the rubber 'O' rings and gaskets inside. A rebuild involves cleaning all the parts in a solvent which dissolves this varnish restoring the nominal performance once again.
The Turbo carbs are slightly more susceptable due to the fact that they are Dellorto DHLA 45 M's which are pressurized and use butyl seals and gaskets to accomplish this. The Dellorto DHLA 45 used on the S1s, S2s (upgrades), and S3s use fiber gaskets. The Butyl gaskets are better at sealing and are reusable should you need to open the carb for Float adjustment etc., whereas the fiber ones are not. If I had regular DHLA 45's, I'd use the M rebuild kit, only about $15 bucks more. But, the all-important accelerator pump diaphram (the weak spot) is the same on both.
If you check the underside of the carb with your hand on a semi-regular basis, at least you're awareness to the problem is increased.
Btw, I guess I never realized your excellent car was carb'd, although when I think about it I did know that. Just another reason you're my kind of woman...
Happy Motoring! ...Jim'85TE >> Edited by Lotusguy on Monday 7th June 06:50
Hi,
Just a follow-up about rebuilding your carbs. While the safety aspect is certainly the overriding reason to do this on regular (every 5-6 years) basis, you also get the added benefit of greater performance, easier starting and smoother idling.
I was at a Wrentching Party last Saturday of our local club, the Lotus-Eaters. While my Esprit didn't need much work, my daily driver needed to have it's exhaust replaced, so I brought it. Also attending was a member with a Jensen-Healey, which uses the Lotus 907 engine. He had a pair of Weber DCOE 45 carbs. His problem was that liquid gas was leaking from the #1 air trumpet (you guessed it, right on the ignition electronics), and he wanted me to teach him to rebuild the carbs.
Anyway, with my exhaust system to do, and considering the Teach a Man to Fish theory, I got him started and then went to work on my Honda. Throughout the day, I spot checked his work and answered questions while lying prone under my car.
I assisted him in setting the float heights and once he had reassembled the carbs, I checked them over and found he had done a perfect job of reassembly.
We mounted the carbs back on the car and started it up to begin the tuning process ( a real b*tch on webers as opposed to Dellorto's). Anyway, the car started right up, but gas started leaking again from the #1 trumpet.
Thinking I had overlooked something, we took the carb to the bench and disassembled it step by step. Everything was correct. We even disassembled the other carb side by side as a comparison and found nothing, everything was identical. The only possibility left, to my mind, was that he had a minute crack in the casting of the front carb (this had happened to another friend of mine w/ a Caterham). Not having the tools to properly determine this, we dropped the carb off at a carb shop.
They called the next day to say the only problem was that the carb was still dirty, fuel passages were blocked causing a back-up of fuel which subsequently leaked. Mea Culpa for not checking the thoroughness of my friend's cleaning job.
We picked the carb up, installed it, started the car (no leaks) and tuned it. My friend was overjoyed, he stated the car had never run so well since he bought it 7 years ago. Idle was smoother than it had ever been, low-end torque was up considerably and engine response was near instantaneous. This despite having had the car professionally serviced since it's purchase.
The moral of the story (aside from ensuring that you thoroughly soak and clean your carbs) is that rebuilding your carbs, in addition to insuring against accidental engine fires, will bring new life and performance to your engine. Safety is still the major concern, but the enhanced performance makes it a very worthwhile task to perform on a regular basis. Happy Motoring! ...Jim'85TE
Just a follow-up about rebuilding your carbs. While the safety aspect is certainly the overriding reason to do this on regular (every 5-6 years) basis, you also get the added benefit of greater performance, easier starting and smoother idling.
I was at a Wrentching Party last Saturday of our local club, the Lotus-Eaters. While my Esprit didn't need much work, my daily driver needed to have it's exhaust replaced, so I brought it. Also attending was a member with a Jensen-Healey, which uses the Lotus 907 engine. He had a pair of Weber DCOE 45 carbs. His problem was that liquid gas was leaking from the #1 air trumpet (you guessed it, right on the ignition electronics), and he wanted me to teach him to rebuild the carbs.
Anyway, with my exhaust system to do, and considering the Teach a Man to Fish theory, I got him started and then went to work on my Honda. Throughout the day, I spot checked his work and answered questions while lying prone under my car.
I assisted him in setting the float heights and once he had reassembled the carbs, I checked them over and found he had done a perfect job of reassembly.
We mounted the carbs back on the car and started it up to begin the tuning process ( a real b*tch on webers as opposed to Dellorto's). Anyway, the car started right up, but gas started leaking again from the #1 trumpet.
Thinking I had overlooked something, we took the carb to the bench and disassembled it step by step. Everything was correct. We even disassembled the other carb side by side as a comparison and found nothing, everything was identical. The only possibility left, to my mind, was that he had a minute crack in the casting of the front carb (this had happened to another friend of mine w/ a Caterham). Not having the tools to properly determine this, we dropped the carb off at a carb shop.
They called the next day to say the only problem was that the carb was still dirty, fuel passages were blocked causing a back-up of fuel which subsequently leaked. Mea Culpa for not checking the thoroughness of my friend's cleaning job.
We picked the carb up, installed it, started the car (no leaks) and tuned it. My friend was overjoyed, he stated the car had never run so well since he bought it 7 years ago. Idle was smoother than it had ever been, low-end torque was up considerably and engine response was near instantaneous. This despite having had the car professionally serviced since it's purchase.
The moral of the story (aside from ensuring that you thoroughly soak and clean your carbs) is that rebuilding your carbs, in addition to insuring against accidental engine fires, will bring new life and performance to your engine. Safety is still the major concern, but the enhanced performance makes it a very worthwhile task to perform on a regular basis. Happy Motoring! ...Jim'85TE
Harking back to my original post, we have the engine apart and lots of people have had a look at it. The Post Moretom revelaed that we have a cracked cylinder liner. It's seems most likely that the cylinder liner crack, admitting some coolant to the combustion chamber of #3. This caused a backfire which ignited the air cleaner and buggered up the carby etc.
So I need another motor. If anyone knows of a sensibly priced NA 2.0 or 2.2 motor please let me know. Especially if it's in Australia. I have found one in Sydney, but it's out of an S1 and has the stromberg carbs, which means is prolly a low compression federal motor. I would prefer something with dellortos (since one of mine is stuffed) closer to what is currently in the car.
cheers,
Ian...
So I need another motor. If anyone knows of a sensibly priced NA 2.0 or 2.2 motor please let me know. Especially if it's in Australia. I have found one in Sydney, but it's out of an S1 and has the stromberg carbs, which means is prolly a low compression federal motor. I would prefer something with dellortos (since one of mine is stuffed) closer to what is currently in the car.
cheers,
Ian...
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