I recently purchased a 2006 LR3 and love it except it has a weird problem involving the check Engine Light. If I let the car idle for over 15 minutes, sometimes the CEL will come on. It has done this twice in as many weeks. However, while the light may stay on for a couple of start cycles, after around the third start, the CEL is off.

I did have the codes checked the second time it did it and got the following" P0108 and P0406. But again. after a couple of start cycles, the CEL is now off.

108: Manifold Absolute Pressure/Barometric Pressure Circuit High Input
406: Exhaust Gas Recirculation Sensor "A" Circuit High

Other than consistent poor gas mileage, the engine seems to run the same whether the light is on or off.

Any thoughts as to what might be causing this and whether it is serious enough to do something about would be appreciated.

 

What engine do you have? How many miles on the car? It seems to me that these errors might be caused by the PCV valve failing in a "stuck closed" position.

If so, it's about a 30 second replacement on your part and $50 or so in parts, but hopefully somebody else with more knowledge can chime in and confirm or refute.

 

Thanks for the response. I have the six cylinder and it has 121,000 miles.

So do I understand what you are saying is that you believe if I replace the PCV valve, it might cure the problem?

Would you know where the valve is located?

TIA
Corstrat

 

Well, it sounds like the voltage being recorded by your MAP sensor/EGR valve is out of bounds. By "voltage too high", I assume it means the pressure in your crankcase is too high. There are probably multiple things that could cause the crankcase pressure to be too high, but the cheapest and easiest thing I can think of to fix is the PCV valve. And with 121,000 miles on the engine, if it has never been replaced, it is well overdue for it anyway. Do you see any oil/greasy spots around the PCV valve? Any oil leaks or weeping from the valve or around the valve cover seals? Basically, is there a lot of sticky crud built up on the outside of the engine by the PCV valve?

Of course, the problem could always lie in the MAP sensor/EGR valve itself if it is faulty, but the PCV valve is definitely worth a shot before that.

 

On the V8, yes, the PCV is a common issue, and good maintenance, however the one on the V6 is completely different, heated ball check valve vs rubber diaphragm.

The V6 MAP sensor and EGR differential pressure sensor are the same part, part of the EGR valve itself. Pretty easy to replace, and I've seen a number of them fail.

 

cmb6 Thanks for the suggestion. Will check

 

Roverguy. Thanks for the reply. Are you saying it is unlikely it is the PCV valve since I have a 6? And that it is more likely it is the MAP sensor?

TIA

 

Was this ever resolved? I now have the same exact problem with the same exact codes.