Low Coolant Level Warning
Member
Joined: Nov 2021
Posts: 50
Likes: 5
Hi Folks,
Hoping someone has run across this before on an X350. My 2006 XJR started showing "Low Coolant Level" in the dash with the red light several months ago. It only happens when it's been up to full running temperature for about 10 minutes (started more like 1/2 hr, but has shortened). At first startup when the engine is cold (or cool), it goes away. I replaced the coolant level sensor on the bottom of the expansion tank last weekend when I replaced the thermostat, but it made no difference. The coolant level is consistent at just over (1/16") the max - no leaks, temp sensor stays consistent at midpoint. I've checked the grounds to the vehicle body (had these rot through twice in the past - don't you love galvanic corrosion 101) - not those. Have wiggled the wires from the connector down to the main harness and banged on the expansion tank while I had someone watching the warning light to see if there was some sort of a corroded wire or stuck float. No change.
So, I've reached the point where I'm out of good ideas. Either something is sticking or the resistance is rising as the heat rises to the point where the car thinks the sensor has been tripped. I'm still thinking it's somewhere in the wiring, but can't find it.
Any advice or suggestions would be extremely welcome.
Thanks very much!!
Chris.
Hoping someone has run across this before on an X350. My 2006 XJR started showing "Low Coolant Level" in the dash with the red light several months ago. It only happens when it's been up to full running temperature for about 10 minutes (started more like 1/2 hr, but has shortened). At first startup when the engine is cold (or cool), it goes away. I replaced the coolant level sensor on the bottom of the expansion tank last weekend when I replaced the thermostat, but it made no difference. The coolant level is consistent at just over (1/16") the max - no leaks, temp sensor stays consistent at midpoint. I've checked the grounds to the vehicle body (had these rot through twice in the past - don't you love galvanic corrosion 101) - not those. Have wiggled the wires from the connector down to the main harness and banged on the expansion tank while I had someone watching the warning light to see if there was some sort of a corroded wire or stuck float. No change.
So, I've reached the point where I'm out of good ideas. Either something is sticking or the resistance is rising as the heat rises to the point where the car thinks the sensor has been tripped. I'm still thinking it's somewhere in the wiring, but can't find it.
Any advice or suggestions would be extremely welcome.
Thanks very much!!
Chris.
it might be unrelated - but this is how my extremely slow leak of the thermostat housing started. You could not notice coolant level to drop - initially the leak is so small that any amount of coolant evaporates, not leaving anything behind to suspect a leak. at some point I had to add coolant every 2months, then every month, 2weeks (over 6-7month period) etc. At ~2week top up I finally found my leak (still no drip).
Thread Starter
|
Member
Joined: Aug 2017
Posts: 62
Likes: 7
From: Ortonville, Michigan
Hi Everyone,
So, I've hopefully brought the fuel pressure problem to a conclusion. I changed out the fuel pressure sensor as Mark had suggested and............bingo! Problem solved. No misfires and the fuel pressure is holding steady under ALL conditions at 50psi, give or take a few. Interestingly enough, as I tried to (gently) take the vacuum line off the sensor, the little stub pipe on the sensor came clean off. Have to wonder if it was already part cracked and air leaking through it changed the pressure differential - causing all the faulty readings. Getting the end of the pipe out of the vacuum line took a little finesse, but with the addition of a thin layer of Permatex to make certain there aren't any more leaks, all's well. Hope it stays that way.
Thanks very much to everyone who's offered help with this, really kind of you. Hope this serves as a useful thread for anyone who has a similar issue.
Chris.
So, I've hopefully brought the fuel pressure problem to a conclusion. I changed out the fuel pressure sensor as Mark had suggested and............bingo! Problem solved. No misfires and the fuel pressure is holding steady under ALL conditions at 50psi, give or take a few. Interestingly enough, as I tried to (gently) take the vacuum line off the sensor, the little stub pipe on the sensor came clean off. Have to wonder if it was already part cracked and air leaking through it changed the pressure differential - causing all the faulty readings. Getting the end of the pipe out of the vacuum line took a little finesse, but with the addition of a thin layer of Permatex to make certain there aren't any more leaks, all's well. Hope it stays that way.
Thanks very much to everyone who's offered help with this, really kind of you. Hope this serves as a useful thread for anyone who has a similar issue.
Chris.
Thread
Thread Starter
Forum
Replies
Last Post
thunderwood
XJ XJ6 / XJ8 / XJR ( X350 & X358 )
3
Oct 22, 2021 09:39 AM
gmsclassics
S-Type / S type R Supercharged V8 ( X200 )
3
Aug 8, 2013 08:19 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)