Land Rover Repair: intake manifold gasket, intake manifold gasket, valve cover gasket

Question
Hi John,
  I own a 99 discovery sd I that has had some problems with a fluctuating temperature gauge.  The gauge starts moving to H after about 8 minutes of driving @ 40mph but will quickly return to normal at a stop light or if parked for a couple minutes.  A repair shop fixed the problem in February by replacing my water pump, thermostat, and flushing my radiator.  But here we are 4 months later and the problem has resurfaced.  They now say the problem is due to a leaky intake manifold gasket.  They said when replacing this gasket the valve cover gasket and thermostat gasket must also be replaced along with all inseals.  For this job they want to charge me about $1100.  My question is 1.)would this faulty gasket cause my gauge to act this way?, 2.) do I really need to replace all three gaskets?, 3.) isn't the price they are charging me a little steep?, and 4.) why would there now be a different solution for a problem I have already had and fixed recently?  Are they just moving down a list of things they think it could be?

Any input would be greatly appreciated.  Thanks in advance!
                                  
                                        Sincerely,
                                       Ricky Martinez  

Answer
If your truck leaks coolant it could act as you describe.  Do you add coolant regularly?  If so, it must be going somewhere.  If the intake leaks the procedure is pretty much what they said, and I am not surprised at the price.

The only caution I'd offer is that the heads may leak, and it can be very hard to tell the two leak sources apart in back.  So you could face doing it all over if the heads are indeed the culprit.

You ask if they are moving down a checklist . . . yes, they are, and that is often the reality of car diagnosis and repair.  I cannot speak to the qualification of that particular shop but often problems like this must be attacked in a step by step manner.