All,
Question regarding the plastic coolant bleeder valve: Would that cause a intermittent "low coolant" warning?
Reason I ask is my LR3 (2007 w/139k owned since 59k) coolant bleeder valve just disintegrated spraying me with very hot coolant. This past weekend drove 500 miles rnd trip up to NJ from Alexandria VA with no issues (save for intermittent coolant warning though the coolant was full and no visible leaks or smell). I drove it again yesterday and it seemed to be running a little rough. I cleared faults and issue went away. Today, went for a short drive- it was running a little rough and was showing the low coolant warning. Got home and the engine seemed hot, no leaks coolant full, I started poking around foolishly, and the T-Valve just disintegrated in my hand spraying the coolant all over. I was quite surprised. Just ordered the replacement bleeder T-valve from Atlantic British.

I hope I can bleed the coolant system my self and add additional fluid. It seems a bit challenging from different posts. I am planning on attending the Mid-Atlantic Rover Rally on the 26th of Sept. Timing sure is great!

So- would a brittle cracked Bleeder valve cause a low coolant warning (never signs of engine over heating either) and the engine to run rough?
Thanks!
James

 

There's a float in the reservoir that gets saturated and no longer floats triggering a false "low coolant" warning. You'll need to replace the reservoir to fix this. There's a reed switch that snaps into the bottom of the reservoir. I recommend getting a new reservoir that comes with the new switch or buy both parts if needed. The old switch will not likely survive a swap, they're snapped in pretty tight. I have the MAHLE / CLEVITE reservoir in both my 07 and 06. This is a bare tank, no cap/no switch. I'm happy with the quality of the tank.

I have had to replace virtually every plastic cooling system part on both of my LR3's. Both had the bleeder T deleted already when I bought them. These parts get brittle!
07 - 145k miles (bought at 105k)
06 - 182k miles (bought at 164k)

I use a cheap vacuum bleeder to refill the system. It works great, but you need an air compressor to run it.

 

Cool-
Well I will get a replacement Coolant reservoir as well. It happens to my RRS (07 79k miles) the intermittent low coolant warning. I will get two-
Thanks for the tip!
James

 

If you swap tanks, uses your old cap if you want to play it safe. The aftermarket tanks almost almost come with pressure caps for the LR4 or such. The LR3 is low pressure, around 16psi which is common for many vehicles. The pressure cap for the LR4 is set much higher.

 

I've had that happen to me, so if you catch a whiff of coolant wait until it cools off to check that T. They really do explode!

 

Yea it was a hoot- I had read about the bleeder valve disintegration, but you know "it wont happen to me" -learned that lesson!

 

Got the bleeder valve yesterday evening and installed this am. Got the temps up to 200 and seems to be running fine. I used the bleeder screw on the expansion tank to bleed out some of the air (spitting when up to pressure running the engine at 3k rpm). I am not sure when the air is all released. I assume when its a steady flow of coolant from the bleeder on the expansion tank?

 

would Air in the cooling system cause engine performance degradation, like a hesitation when accelerating, causing the check engine light to blink?

Currently, trying to bleed it, and I am not sure if working. The original issue to cause me to poke around, was this hesitation when accelerating and the check engine light to flash. I just cleared it. it came back, which is why i handled the t-valve causing it to crumble.

 

Not, it should not on the 4.4 unless you are overheating. So for bleeding I really found that once you have as much in as practical the best method was to drive it around, high RPMs here and there. Then check the tank again. You should have coolant in the upper chamber of the tank right were a small hose enters. Coolant should stay there even after cool down. If you have it there then there is a really good chance you worked the air out.

As for check engine.... stop clearing codes and actually check them? Can not help if the codes are not known. Hesitation on acceleration can be caused by a few things. One common issue is a dirty throttle body plate. I clean mine every year or so.

 

A blinking check engine light often indicates further damage can be caused by continuing to drive. Severe misfires will cause a blinking light and could also damage the catalytic converters if ignored. But, yes, need to know the codes.