I had to add about 1/2 gal of engine coolant to my 2001 Vanden Plas 4.0 non-SC. Ran engine with heater on, temp gauge got to mid range. I let it cool and opened expansion tank. Looked good. Got in car, and whammo, there is the Restricted Performance (amber). Anybody got an idea what happened? And, can I drive it. The manual says yes - to a Jag dealer!

 

Unless you poured coolant into he spark coil cover, I believe there is NO cause and effect relationship between coolant and your restricted performance. Idle for a while- maybe, but not coolant. Suggest you check for codes

 

The simple (but telling?) question is - where did that original half gallon of coolant go? That's a lot. If, after refilling, the assumed leak started spraying coolant all over the place, a restricted performance due to wet connectors/components could be self explanatory.

 

Thanks Guys, I don't get codes. I did spill some coolant when I opened the thermostat housing cap. I was told to do that at same time as opening the expansion tank cap, since my "car expert" friends suggested I had an air block from changing out the coolant previously. Didn't do anything else that could cause the restricted warning, that I know of. This happened yesterday, and today I still get the warning message after turning the key on/off about 5 times. May have to take it to the shop. All this started as a way to avoid changing the thermostat, which again my friends suggested was my original problem.

 

Yes, on your MY the coolant reservoir is directly over the #7, and #8 (or (2)3, (2)4) coils. Any liquids on the coil cover direclty under the reservoir end up right down the coils. Read the codes and see what you get.

 

Steve11, I'll check under the reservoir. I don't get codes on this car. But wouldn't any coolant evap or dry up within 12 hours?

 

What Steve is saying is get the car read with an OBD reader, this is the generic tool that pulls codes from your car, via a data link under the dash, which the reader is connected to via a cable.
If you have an amber/red light on, there will be a code, or a number of codes stored within the memory of the car, pointing a technician towards locating the fault.
What is also a concern, is coolant (and it only needs to be a thimble full) dripping into one or maybe several spark plug holes. These are located under the reservoir, under a cover. If you'd like to check, undo the 8? bolts, remove the cover, and remove the ignition coils. They have rubber boots connecting them to the plugs. Moisture in, around and about will certainly "throw codes"......I hope this shines a light on what above posters are telling you.