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Gurgling sound GS300 on start up.

Hi guys/gals,

I still drive my old 95 GS 300 (Mark I) and still love it. Have a Prius on order (company car, somehow would not let me get a LS600h or even a GS450h) but still want to keep and maintain the GS. I had the radiator replaced last year, after it left me stranded due to acute water loss. Well, after 12 years is not that bad, I guess. As of the last couple of months (not sure if it was from the start since the replacement or not, didn't notice anyway) I can hear a few seconds of gurgling when the car starts. I am pretty certain that there is some air in either the cooling system or in the heater core. It disappears after a few seconds, does not always happen and the temperature is always fine, as it should. When I had it serviced for it regular maintenance, I asked them to top up the cooling fluid, if needed and get rid of the air there. This is not a Lexus shop mind you, but they do service a couple of Lexi and other (relatively) modern Japanese motors. Have never had any complaint about them, seem to do an honest job, not over asking, not pushing any unneeded services or jobs. They did my tyiming belt and more. In this case howvere, they had to admit not being able to get the air out. Somehow they had been looking for a valve or something to release air from the system, but could not find any. Are they missing something? I also read somewhere that the best way to accomplish this task is to place the car on a slope, nose/radiator pointed to the highest point and then just let it run for w short while with the radiator cap removed. That should get all air to the top of the system and get it done. Is that correct? I mean, in that case, I could probably do it myself, right? Taking precautions that the engine should be cool, always making sure that the hot coolant does not spill where it shouldn't and such...

Thanks in advance,

Patrick

Reply to
Patrick
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It should not be necessary for the car to be parked on a slope to get the air out of the cooling system. First, set the heater temperature to full hot, remove the radiator cap, and start the car. Let the system warm up until the coolant starts to rise up to the top of the radiator neck and the coolant flows past the neck.. Replace the cap, and you should be good. If the radiator cap was not replaced with a new one when the radiator was replaced or if the radiator cap is aftermarket, try replacing the cap as well. Also make sure that the coolant in the overflow tank is at least to the cold mark when the coolant is cold, or the cooling system might suck air in as it cools.

Reply to
Ray O

The shop can do a pressure test for you. A pressure test is not foolproof but gives good indication of significant leaks. If this passes then check your reservoir return hose and radiator cap. When the engine cooled down it may be sucking air back instead of coolant. If the reservoir tank and return hose do not leak, then it may be the head gasket as you had major coolant loss before.

I prefer a radiator cap with a spring-loaded vacuum return valve. Not one of those "hang-loose" plastic valve. I think the hang-loose caps should not even be sold.

Reply to
johngdole

Typically every manufacturer has a method for bleeding the cooling system. But the easy way is to install a tire valve in the highest point of the sustem. Usually that's the top radiator hose. It's easy and makes bleeding the system a breeze. Phil Brown

Reply to
Phil Brown

Ray, John,

Thanks for your replies. Been busy so it may take a couple of more days to get around to the job, but it sounds easy enough. Will certainly chck the radiator cap as well to see what they put on there after the new radiator was installed. They did install a Lexus radiator (not enough 95 GS 300 around over here to warrant a large supply of other brands or aftermarket), but not sure what cap was put on, if a new cap was installed in the first place. I assume that a same size Toyota (duh!) cap will fit? Seeing that there are only a few Lexus dealerships and a lot of Toyota shops.

Cheers,

Patrick

Reply to
Patrick

Phil,

Not sure if I need to go as far as punching holes in any of the hoses, but if the problem persist after I bleed and then replace the cap, I will certainly keep it in mind. It sounds like a simple, yet efficient way to do the job, if needed.

Cheers,

Patrick > Typically every manufacturer has a method for bleeding the cooling

Reply to
Patrick

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