After weeks of trying to diagnose the two codes, p087 and P089 we figured out that the High Pressure Fuel Pump was bad on my RL. Thank you "Robotech and Tomato Soup for your help. When we removed the old one there were no visible signs that it was bad. But a new pump at $650 seems to have been the cure. My RL was purchased new in 2008 by me, has 44,000 miles on it and other than some electrical connection problems with the GM power upgrade it has been problem free. Just wondering why this expensive fuel pump would fail with 44,000 miles, and what other "common" problems I might expect.
The four big ones it seems for our cars are the Water Pump, the Passenger Presence Sensor mat, the Rear Differential (though this seems to be relatively less common) and the HPFP (on the Redlines...2.4 NAs do not have them).
It was just a pain to diagnose even though there were codes to read they don't tell you fuel pump, and you have to go through process of elimination. With 44,000 miles I didn't expect the fuel pump to fail. I'm pretty sure I've only replaced 1 fuel pump on any of the cars I've owned. I've been told to quit leaving it in the garage to stay pretty and drive it every couple days. But I got this for my weekend car for me and my rider, and I'd like to keep it nice.
You'll look for signs of a coolant leak. These would be things like:
Rapid coolant temperature spikes (up to 230+ degrees) followed by rapid coolant temperature drops back to normal. (Indicates an air bubble in the system which can be generated by a leak in the system like at the water pump.)
Low coolant level in reservoir.
Low coolant warning light in dash.
Frequent refilling of coolant system.
The smell of coolant while driving (Kind of a sweet smell).
Puddle of water under car. This puddle would be in front of the front axle towards the center of the car slightly offset to the passenger side. (Basically under the water pump.)
Signs of coolant leaking under the water pump. This would be a redish brown stain under the water pump or even small amounts of water collecting in the recesses of the engine under the water pump.
For my water pump, the signs were very subtle. I had to refill the coolant level once in over a year (which is far too many times. It's a sealed system and should never require refilling until servicing). There were no puddles of water under the car (except for when I ran the AC which is normal) or smell of coolant. I could see a little staining under the water pump and a slight bit of water collected in the recesses of the block. My primary reason for changing my water pump was a) it was on it's way out eventually and b) I was going turbo and changing the pump allowed me to have the service techs replace some parts required for the turbo install.
Usually the leak is big enough that it is easy to see there is a problem. You smell the coolant and have a small puddle under the car that is reddish brown in an area where you shouldn't have a puddle. You'll be refilling the coolant overflow reservoir with some regularity too. Some are worse than others but the above warning signs are indicative of many coolant problems...its just with our cars the first culprit to check is the water pump as it is a known issue.
Also, just in case you don't know where the water pump is, here is a diagram. The diagram is of the 2.0L Turbo LNF engine but the water pump is in the same location on both the 2.0L LNF and the 2.4L LE5.