At 73,000, car runs fine. I have a coolant leak I can smell but cannot find. When doing extended idling, I get codes P1000, P0171 and P0174. (no sign of loss of power), I removed plastic engine and radiator toppings in search of coolant to no avail, and no sign of leakage on garage floor. Car never overheated, but coolant sensor lets me know it's low to help avoid the overheating. No coolant in crankcase, no sign of oil in coolant. No noticable smoke from exhaust. Both coolant loss and codes appeared for first time at the same time.

 

Check for vacuum leaks and correct them before catalyst damage occurs. Under no circumstances is the vehicle to be operated if the MIL is flashing.

Check the vacuum line that goes from the inlet manifold to the brake booster as this is a common source of vacuum leaks. If the leak isn't obvious, have a smoke test performed by a Jaguar specialist.

Ignore DTC P1000 for now.

 

Given the age of the vehicle, the plastic coolant system parts can only withstand a finite number of cold to hot to cold cycles before failing. After a cold soak, preferably overnight, pressurise the coolant system to 1 bar and check for leaks. If the system loses pressure after fifteen minutes, there is a leak in the system that must be found. Typically, the water outlet is the culprit. Replace the water outlet, which contains a new thermostat and coolant temperature sensor. It carries a JLR part number of AJ811793.

 

I agree... vacuum leak and when it comes to the coolant leak go for a drive and then in a non-wind area park, engine off, and pop the hood. You should be able to see/hear/smell where its strongest.

If the radiator is leaking it can be a tough one to figure out because the coolant gets evaporated before drips can hit the ground. And the large surface area makes it hard to pinpoint the leak. Long life coolant will leave a reddish / whiteness marking where its leaking. And like mentioned pressure testing when cold is a good way to help find it.

Also, don't use any pour in radiator stop leak. And if you do only use the barrs leak tablets. DO NOT use anything else as it'll only plug up small passages and create other problems.

 

Check closely at the plastic radiator header seam near the DCCV.

 

Is there any place the coolant leak and vacuum leak could be at the same place, e.g. intake manifold or somewhere? I find it ironic that both issues occurred simultaneously.

 

Following a cold soak, preferably overnight, pressurise the cooling system to 1 bar and check for leaks if the pressure drops off. Usual places for leaks are the coolant reservoir, DCCV and radiator expansion tank(s) as Norri mentioned above.

 

yes sir that is where mine was...did not really show up until it blew the seam...the foam insulation was soaking up the minor coolant leak

 

I finally did a pressure test for leaky coolant system, and nada! Pumped system to 10 lbs psi and it didn't drop in an hour and a half. Could it be a bad cap? Could I be smelling coolant fumes with some water evaporation from the coolant. Or should I take pressure to 15 lbs? The cap is identified as 120 kpa which is over 17lbs but...

 

Just tested cap to 18 psi, and it didn't release any pressure. One would think it should have opened at 120 kpa (17.4 psi)...
Does anyone know the normal operating pressure at normal operating temperature?

 

Just tested cap to 18 psi, and it didn't release any pressure. One would think it should have opened at 120 kpa (17.4 psi)...
Does anyone know the normal operating pressure at normal operating temperature?

 

Pressure test the system again at 1 bar (100 kPa or 14.5 psi) and look for leaks. If the system reaches 1.2 bar (120 kPa or 17.4 psi), the cap is designed to release the pressure. Under normal circumstances, the system operates around 1 bar.

If you find no leaks, replace the cap with one rated at 120 kPa.

 

Also, could be that with heat.. material is expanding and then exposing a crack.

 

Concerning the codes you can check them by using the fuel trims

https://youtu.be/5WnM_NsOtd8


P1000 means that the car has not completed the emission tests since somebody cleared the codes. You will see p1111 when this has occurred.

 

Pumped 15 lbs into system and coolant ran out bottom pan at rear. Removed cover to find slow drip off oil filter originating from back of water pump pulley. It took more than 10 psi to start the drip, apparently early stage of leakage. 15 psi found it, because 10 didn't lose pressure overnight.
Thank you!