srmlexus

My 2008 LS460L blows cold air on cold days/nights when the engine is idling. Raising the RPM to about 1500 causes heat to start to flow out of the air ducts.
I also hear a gurgling sound behind the dash when accelerating normally from idle.
The water pump was replaced by Lexus in late April 2014.
I have checked the coolant reservoir (engine cold) and found it to be slightly below the "LOW" coolant level mark (not empty).
It would seem that since the feed from the coolant reservoir is on the bottom of the reservoir, as long as there is some coolant in the reservoir, the rest of the system should be full.
All things considered, are the two issues (no heat & gurgling sound) more likely to be caused by low coolant in the system, the relatively new water pump, or something else? Help !!

BTW, what is the proper method to top off the coolant in a 2008 LS460L? Are there any special bleed ports for eliminating air pockets?

Thanks ...

Tsmith1982

I have the gurgling noise when taking off as well. Has always done that in the 10000 miles I have put on it. Heat works perfect though.

fly_s2k

iTrader: (1)

Did you note if that happened when the coolant was up to operating temperatures?

Doublebase

You shouldn't be hearing any gurgling sounds...the coolant is low and you have a leak somewhere. Try topping the fluid off and if the gurgling noise goes away and you have heat...you definitely have a leak.

sktn77a

iTrader: (2)

You may have a full coolant level but an air bubble in the plumbing. Try bleeding the cooling system.

roadfrog

There is a bleed screw on the top of the upper rad hose. remove it and add coolant while the engine is cold and running. when the bubbles stop and coolant flows steadily from the bleed screw, replace the screw, tiighten it up and continue to fill the coolant in the reservoir until full. You may still have to add some more after a few hundred miles. Guaranteed your low on coolant which is causing the cold air.

course, the question becomes, "why are you low on coolant". Likely culprits on these cars is a weephole leak from the water pump (you'll see a build up of deposits near the top of the water pump.

srmlexus

Thanks all for your insights.

Turns out that the system was low on coolant. The technician at a Lexus dealer thinks that when they replaced the water pump in April 2014, they did not get the system completely filled with coolant. No leaks are apparent at this point. Great !!

BTW, no charge from the Lexus dealer !!

Thanks again,
Steve

Nospinzone

It's a Christmas miracle!

gtung99

I have the same problem but it's random. Sometimes i have heat and sometimes i dont. More often i do during idle. Water pump was never changed and I have 110k miles. The dealership said my coolant is not low and does not appear to be leaking. Can it be something else like the temp sensor inside the cabin in my case?

Devh

These newer cars need to be bleed after fluid replacement or component change.
What probably happened is that they never bleed the coolant system and there was a trapped bubble. When these bubbles find their way to the heater core then you will have a problem with circulation and have no heat in the cabin or worse it can overheat the engine if the bubble finds it's way to the water pump.
Sometimes the bubbles can start collecting from a small intermittent gasket leak during temperature changes that allow air in small amounts over time to come into the system. Bleeding the coolant system when this happens is the best way to solve this issue.
My other Toyota is notorious for having to bleed because it has very long hoses runs from the front to the rear and double the amount of coolant of most cars.

jbrittmart

had this exact issue in my 2008 LS recently.

It was an air gap in the system.

Works fine now.

MySc4fever

iTrader: (7)

I'm experiencing this exact same issue right now. My coolant was down to the low point, and no heat at idle when stopped. Funny thing is its been like that for about a month or two. Which leads me to remember noticing a puddle under the car after driving right before the weather got cold. I thought it was from the ac, But now I think otherwise. I'm currently have 75k on the dash and I'm under the cpo warranty. And have had every service done at the dealer since purchasing the car at 55k. Guess I have to make a trip this week to the dealer. No indicator lights sure gives you false comfort levels @nd makes you feel comfortable. I'll let you all know the outcome afterwards.

Devh

Coolant leaks with the Toyota red coolant is obvious. If you didn't see red it's probably just condensation.

is150

iTrader: (10)

While the bleed screw on top of the rad hose is open and the engine is running but cold, where are you adding the coolent into? The bleed screw/ radiator cap/ or overfill?

Doublebase

Personally I've poured coolant right down into the bleeder port you are talking about...why not? Yeah I spilled a little, but I was doing a coolant change at the time anyway...it's not like things weren't a mess already. But I want to make it clear that I filled the reservoir up first, I just added coolant in the bleeder port to speed up the process of getting the air out. It worked fine.