Land Rover Repair: SES light blinking & heater problems, spark plug wires, service engine soon light

Question
Hi John:

I replaced the spark plugs (they absolutely needed to be replaced) the spark plug wires, air filter, fuel filter as you suggested.  The engine is still running rough and the light still on (I am assuming I have to reset that?)  

Any suggestions why it would still be running rough?  

I do have another problem going on...the heat stopped working(yes, Im having all the luck) it blows properly but just cold air.  I noticed the antifreeze was low so I added more and you could tell the air was warmer but only for a day or two.  Then, the vehicle started running hot in the red zone.   We looked and the antifreeze was low again, but not that much.  I have ordered a thermostat...would that most likely to be problem for that?

Thank you for your help as I am on a budget and trying to do alot of this before I have to take it in to someone

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Followup To
Question -
I have a 2000 Disco II 87,000 miles.  The SES light started blinking last weekend and everytime I use the vehicle it blinks about 30 times and then remains on solid.

I have noticed that it is misfiring.  What could cause this?  is it ok to drive it?

I keep getting mixed information.  Im on a tight budget and in addition I live 2 hours away from a dealership.   I have found someone locally that does work on them.

But, Im trying to get past the holidays before I take it in.

Any advice would be great.
Answer -
Hi Christi,

the Service Engine Soon light is an emissions reset reminder.  You should have no trouble driving it.  The misfiring is another problem.  If you're in the states...go to an Advance Auto car parts shop and ask if they could look the OBDII code on your Disco.  Usually, Advance auto does this for free.  Nice guys.

The emissions light may be reset by such a reader.

As for misfires, when's the last time you had it tuned?  New plugs, new wires, new air filter, new fuel filter?

These are not very expensive and most auto parts stores carry them.  Hey, while you at Advance...why not inquire?

Best of luck, Merry Christmas and best wishes for 2006.

JohnMc

Answer
Hi Christi,

this is a tricky problem...I suggest you have your cooling system and radiator pressure tested for any leaks.  Also have the cylinders pressure tested.

IF you have a rough running engine AND you have coolant leaking, it's very possible that you may have a headgasket leak.  I hope this is all that is wrong.  

Don't let the engine run too hot...you can damage it beyond repair.

Sometimes its just a thermostat but in your case, I'd be very interested to know where that fluid is going.

Let me know what you find out,

JohnMc

NB:  as for the SES, find a tech that can reset your Service Enging Soon (emissions reminder).  If you need the instructions on how to do this, let me knwo.  I'll be glad to send what I have.