I posted about my fan exploding and taking out my thermostat housing, a lower hose, the serpentine belt, the upper and lower fan shroud, and the lid to the air filter box. I fixed all that stuff, then posted about O2 sensors and Fuel Purge Valve. One thing I am pretty certain of is that if I experience some problem, someone else has experienced it before. So here's my story. In June I did the head gasket job. It is time consuming but not too hard when you have the manual, etc. Everything went together and worked after I discovered I had let the connector for the idle air controller fall behind the upper intake manifold and had missed it. I fished it out, hooked it up, and everything was fine.

Then I started experiencing intermittent misfires with different codes. Cylinder 2, cylinder 3, multiple misfires, P0154, O2 sensors code. last week I was driving and experienced multiple misfires and then the fan blew up. Or at least I thought the fan blew up. I think what really happened as I think back is that an amount of unburned fuel vapor collected under the hood and ignited. As I look back, there was a lot bigger KABOOM than if it had just been a mechanical failure of the fan. The hood arched up. The clear coat on the hood just above the location of the fuel purge valve has blistered. I feel pretty lucky that it was sudden and over without setting the whole Rover on fire. Saturday I replaced all the parts that had been destroyed by whatever happened. It seemed to run pretty well. Then I got the P0154 code. Then this afternoon I got the multiple misfires. The engine nearly stalled in traffic and I was really afraid it was going to be a repeat of the explosion. So I have four O2 sensors on the way and I just got a Dorman 911-800 fuel purge valve at AutoZone. It goes on tomorrow. The vacuum line seems pretty brittle so I'll replace it too. Could it have been unburned fuel vapor igniting?

 

I'd pull the upper intake plenum and check your injectors for leakage (o-rings). Could explain misfires and explosion issue. I'd not drive it until this is resovled. Next time, she may burn to the ground.

​​​​​​​ Brian.

 

 

If you're blistering paint then you have a very serious issue. Both previous responses are spot on. You may want to jump the fuel pump and pressurize the fuel rail to check for leaks before you try and start the engine again. I did exactly that this past weekend when installing an engine and luckily found this before I tried to start it. A brand new seal galled upon installation and fuel was misting out past the tear onto the manifold.

 

There's no liquid fuel leaking anywhere. Only unburned vapor. There is no gasoline smell. To further complicate matters, I'm sure the unburned fuel vapor is the result of the multiple misfires, which are very intermittent. I have inspected everything and am satisfied there are no liquid fuel leaks. With it being intermittent, I can only fix what I can per the codes and see if it never happens again. Not an ideal situation. The new fuel purge valve is on now. O2 sensors come tomorrow. The perplexing thing is that it runs great except when it drops into the misfire condition.

 

I did not have liquid leaks either. I had a fine mist passing by the torn seal and spraying out onto the intake, similar to what happens at the other end of the injector. Engine heat would have prevented it from condensing onto the manifold, however fuel smell would have been evident. Where do you suspect the source of the unburnt fuel vapor is? I will admit that I don't know much about the LR fuel delivery system yet but as far as I'm aware, the fuel purge valve is part of the vapor recovery system and used to regulate vacuum which draws vapor from the fuel tank into the charcoal canister. There is no vapor present from the engine side of the equation in this system, and this vapor is not intended to be combusted inside (or outside) of the engine. Any fuel vapor from the engine side of the fuel system is drawn into the cylinders unless there's a mechanical timing issue, and even then and backfires are usually contained in the intake tract. If the canister was bad then there would be no vacuum to draw the vapors unto the engine compartment. The fuel comes from the tank directly into the injectors and on into the engine. Any vapor present would be the result of some kind of a leak.

 

If you had vapor, you would smell the fuel. After all, vapor IS the fuel smell we detect.

It sounds a little far fetched. Is there any sign of singed materials in the engine bay? Plastic melts and deforms at a low temperature, the hood liner fibers would have melted too and shown signs of fire damage, your vacuum lines would show signs of melting or deforming, there would be some big obvious signs of fire damage in the engine bay before it blistered the paint on your hood.

I think you have a couple things going on, and the fan failure was a separate thing altogether from your poor running

 

It is not uncommon to not smell any fuel vapor. A lot of times, folks will just assume the vehicle is "running a little rich". Nine times out of ten...when you see a vehicle in flames along the road side...it is from injector o-ring failure...and...the driver probably had no clue...until it burst into flames. These rovers are getting old and rubber loses its ability to seal from the day it is assembled at the factory. Unlike me, it does not get better with age...lol.

Not disagreeing, you may have a couple separate issues...but, if you did have some sort of fuel ignition under the hood...you need to get this figured out.

Brian.

 

Also wanted to mention...just because you aren't smelling anything now...means nothing. You may not be duplicating the same exact conditions that exsited before (fuel temperature, ambient air temp, engine expansion qualities around injector o-ring, air/fuel ratio, etc).

​​​​​​​ Brian.