Sound of water for few seconds when starting IS250 RWD
02-02-20, 09:26 AM
#1
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Thread Starter
Sound of water for few seconds when starting IS250 RWD
When starting my IS250 RWD I hear the sound of water travelling for few seconds. It's usually completely gone within 10 seconds. Usually it's only when engine is cold. But a few times on warm engine I heard it too. Does this mean I have air in the system? Not having any overheating issues or anything. Water pump was change many years ago.
02-02-20, 10:27 AM
#2
Could be... I had a rented ford fusion that did that and it also did it even when fully warmed up, when I would put it in neutral and smack the throttle; you'd hear the water flowing around. Try that.
02-02-20, 10:47 AM
#3
I'm not sure what your skills are, but a mistake people make is looking at the coolant reservoir level, seeing it full and assuming everything is OK! The coolant in circulation in the engine block can be very low as you suspect. Low means it has air in it and the coolant is being aerated which makes it louder. Like walking up to a waterfall or the beach and hearing the water crash.
When the engine is cold and you can easily squeeze the larger coolant hoses, open the cap on level ground. The coolant should be flush. If not, your system likely has a leak somewhere and IS LOW on coolant even though the reservoir is full. This can ruin the engine!
When the engine is cold and you can easily squeeze the larger coolant hoses, open the cap on level ground. The coolant should be flush. If not, your system likely has a leak somewhere and IS LOW on coolant even though the reservoir is full. This can ruin the engine!
Last edited by 2013FSport; 02-11-20 at 01:41 PM.
02-02-20, 11:18 AM
#4
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Thread Starter
I'm not sure what your skills are, but a mistake people make is looking at the coolant reservoir level, seeing it full and assuming everything is OK! The coolant in circulation in the engine block can be very low as you suspect. Low means it has water in it and is being aerated which makes it louder. Like walking up to a waterfall or the beach and hearing the water crash.
When the engine is cold and you can easily squeeze the larger coolant hoses, open the cap on level ground. The coolant should be flush. If not, your system likely has a leak somewhere and IS LOW on coolant even though the reservoir is full. This can ruin the engine!
When the engine is cold and you can easily squeeze the larger coolant hoses, open the cap on level ground. The coolant should be flush. If not, your system likely has a leak somewhere and IS LOW on coolant even though the reservoir is full. This can ruin the engine!
02-02-20, 11:53 AM
#5
I'm not sure what your skills are, but a mistake people make is looking at the coolant reservoir level, seeing it full and assuming everything is OK! The coolant in circulation in the engine block can be very low as you suspect. Low means it has water in it and is being aerated which makes it louder. Like walking up to a waterfall or the beach and hearing the water crash.
When the engine is cold and you can easily squeeze the larger coolant hoses, open the cap on level ground. The coolant should be flush. If not, your system likely has a leak somewhere and IS LOW on coolant even though the reservoir is full. This can ruin the engine!
When the engine is cold and you can easily squeeze the larger coolant hoses, open the cap on level ground. The coolant should be flush. If not, your system likely has a leak somewhere and IS LOW on coolant even though the reservoir is full. This can ruin the engine!
02-02-20, 02:25 PM
#6
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Thread Starter
I changed the water pump about 50k miles ago myself and drained most of the coolant and refilled. Drained the coolant from one side of the engine block drain plug too. The other side of the V was difficult to release the plug but I thought most of it was done anyway this way. I bled the system with one of those yellow funnels that connect to radiator cap section filled with coolant and then just let car warm up and rev at 2k rpm etc for about 10-15mins and let it all burp out. I think maybe I didn't get it all out? Because i'm sure i've been hearing this sound for a very long time. I may try and re-burp it by adding more coolant to the funnel to raise the coolant height, then burp it and plug the funnel and close the cap. I'm also due a coolant change as it's been 50k since last change. So maybe I should just do a coolant change and burp at the same time.
I just noticed while I was parked up, when I rev it after letting it idle then i hear something that sounds like water near the footwell area for a split second and then it stops while i'm revving it. Then if I rev straight away it's not there. If i let it idle for a bit then rev again then i hear it. Can air cause this? What is in the footwell area? because the noise sounds like it's around there and behind the dash
I just noticed while I was parked up, when I rev it after letting it idle then i hear something that sounds like water near the footwell area for a split second and then it stops while i'm revving it. Then if I rev straight away it's not there. If i let it idle for a bit then rev again then i hear it. Can air cause this? What is in the footwell area? because the noise sounds like it's around there and behind the dash
Last edited by lexus-is2; 02-02-20 at 03:10 PM.
02-02-20, 04:03 PM
#7
Then if the reservoir doesn't help the coolant level, what's it there for? When coolant heats it expands into the tank, when it cools, it contracts. If there's too little coolant it contracts into the engine/radiator and leaves the expansion reservoir low. If it only goes one way, that means that every time it expanded it would fill the reservoir, but every time it contracted it wouldn't suck any more out, leaving the reservoir fuller and fuller every time... that would make zero sense.
With the block and reservoir full on a cold start the engine heats the coolant and the coolant expands as you stated. If it exceeds the caps rating, it is forced into the reservoir.
If the block was low on coolant; as it heats the coolant, it may steam or not and may push steam and coolant into the reservoir. Upon cool down; if and only IF the engine blocks coolant system is air tight, as the block cools, the coolant contracts and forms a vacuum in the block. If all this are correct, the coolant is pulled into the block through the radiator cap from the reservoir and the block is filled.
Here is where things go south. Any leak in the block, any debris in the cap, and the system can not form the vacuum needed to pull coolant from the reservoir. BUT - often times people ONLY CHECK the reservoir even when things are behaving strange! That is what I'm talking about.
What people do not see is the function of the radiator cap. It has three (3) sealing areas. One keeps the cap sealed to the block so no coolant is lost. The second is the pressure sealing ring that vents to the reservoir when the caps pressure rating is exceeded. The third is the vacuum ring. When the block cools, this ring retracts allowing coolant to be pulled from the reservoir to the block. That vacuum ring often gets a tiny bit of debris in it and doesn't seal. From here, the block heats and pushes fluid to the reservoir. A spot check says all is well (res is full) and there are no leaks. However, the block is now running low on coolant.
I'm just saying, if it seems wrong, it likely is. Like IF, the coolant reservoir OVERFLOWS! Your CAP IS BAD and very likely the engine is low on coolant!
Make sense?
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02-02-20, 11:09 PM
#8
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Thread Starter
What would you suggest I try? You mentioned to squeeze the hose with radiator cap open when everything is cold. Any particular hose and should fluid come up the open cap when I squeeze? If not then it's low on fluid?
02-03-20, 11:29 AM
#9
Hose squeeze test is to confirm system is not under pressure before removing cap. If the hose is hard; DO NOT REMOVE CAP!
That said, a another squeeze should reveal coolant at the cap level. Is that not the case?
As you used the funnel, maybe it is normal but I never hear that on my 350. You try filling it with the nose slightly elevated and heater on?
At least verify the reservoir volume moves slightly from cold to hot.
Last edited by 2013FSport; 02-03-20 at 11:41 AM.
02-03-20, 02:38 PM
#11
All good points. The problem is the smallest leak wrecks the whole function and this what gets people into trouble. Especially if the failure is the cap itself.
With the block and reservoir full on a cold start the engine heats the coolant and the coolant expands as you stated. If it exceeds the caps rating, it is forced into the reservoir.
If the block was low on coolant; as it heats the coolant, it may steam or not and may push steam and coolant into the reservoir. Upon cool down; if and only IF the engine blocks coolant system is air tight, as the block cools, the coolant contracts and forms a vacuum in the block. If all this are correct, the coolant is pulled into the block through the radiator cap from the reservoir and the block is filled.
Here is where things go south. Any leak in the block, any debris in the cap, and the system can not form the vacuum needed to pull coolant from the reservoir. BUT - often times people ONLY CHECK the reservoir even when things are behaving strange! That is what I'm talking about.
What people do not see is the function of the radiator cap. It has three (3) sealing areas. One keeps the cap sealed to the block so no coolant is lost. The second is the pressure sealing ring that vents to the reservoir when the caps pressure rating is exceeded. The third is the vacuum ring. When the block cools, this ring retracts allowing coolant to be pulled from the reservoir to the block. That vacuum ring often gets a tiny bit of debris in it and doesn't seal. From here, the block heats and pushes fluid to the reservoir. A spot check says all is well (res is full) and there are no leaks. However, the block is now running low on coolant.
I'm just saying, if it seems wrong, it likely is. Like IF, the coolant reservoir OVERFLOWS! Your CAP IS BAD and very likely the engine is low on coolant!
Make sense?
With the block and reservoir full on a cold start the engine heats the coolant and the coolant expands as you stated. If it exceeds the caps rating, it is forced into the reservoir.
If the block was low on coolant; as it heats the coolant, it may steam or not and may push steam and coolant into the reservoir. Upon cool down; if and only IF the engine blocks coolant system is air tight, as the block cools, the coolant contracts and forms a vacuum in the block. If all this are correct, the coolant is pulled into the block through the radiator cap from the reservoir and the block is filled.
Here is where things go south. Any leak in the block, any debris in the cap, and the system can not form the vacuum needed to pull coolant from the reservoir. BUT - often times people ONLY CHECK the reservoir even when things are behaving strange! That is what I'm talking about.
What people do not see is the function of the radiator cap. It has three (3) sealing areas. One keeps the cap sealed to the block so no coolant is lost. The second is the pressure sealing ring that vents to the reservoir when the caps pressure rating is exceeded. The third is the vacuum ring. When the block cools, this ring retracts allowing coolant to be pulled from the reservoir to the block. That vacuum ring often gets a tiny bit of debris in it and doesn't seal. From here, the block heats and pushes fluid to the reservoir. A spot check says all is well (res is full) and there are no leaks. However, the block is now running low on coolant.
I'm just saying, if it seems wrong, it likely is. Like IF, the coolant reservoir OVERFLOWS! Your CAP IS BAD and very likely the engine is low on coolant!
Make sense?
It does. Thank you for that explanation. Most wouldn't have been able to articulate that like you did. Thanks again.
02-08-20, 12:00 AM
#12
Intermediate
Hose squeeze test is to confirm system is not under pressure before removing cap. If the hose is hard; DO NOT REMOVE CAP!
That said, a another squeeze should reveal coolant at the cap level. Is that not the case?
As you used the funnel, maybe it is normal but I never hear that on my 350. You try filling it with the nose slightly elevated and heater on?
At least verify the reservoir volume moves slightly from cold to hot.
That said, a another squeeze should reveal coolant at the cap level. Is that not the case?
As you used the funnel, maybe it is normal but I never hear that on my 350. You try filling it with the nose slightly elevated and heater on?
At least verify the reservoir volume moves slightly from cold to hot.
02-10-20, 02:18 PM
#13
I would suspect this, yes. I've had the 350 for 40,000 miles now and have never heard that. When I have heard sounds like this on other cars, it is because the coolant is low and what you hear is the air and water gushing as air is displaced by water.
External signs of a bad cap are an overful coolant reservoir or one that has coolant stains/residue dribbled out from its overflow hose.
When cold, do as stated above and verify the block is full by starting the car cold, heater on, and pull the cap. Is the block full on level ground.
Let us know if it is low....
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ncatona (02-11-20)
02-17-20, 02:43 PM
#14
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Thread Starter
If my coolant in my expansion bottle has run low could air enter the system that way? I've got one of those burping funnels that connect to the radiator cap. What is the best step by step procedure to fill up the expansion bottle and burp the system? With a cold engine, should I first fill up the expansion bottle to the min or max mark, then connect the funnel to the radiator top, fill the funnel with coolant high up to make the highest point of the water higher than everything else then start the car? And then how long shall I run the car for and what should I do and look out for and when should I stop and put everything back?
02-17-20, 03:09 PM
#15
If my coolant in my expansion bottle has run low could air enter the system that way? I've got one of those burping funnels that connect to the radiator cap. What is the best step by step procedure to fill up the expansion bottle and burp the system? With a cold engine, should I first fill up the expansion bottle to the min or max mark, then connect the funnel to the radiator top, fill the funnel with coolant high up to make the highest point of the water higher than everything else then start the car? And then how long shall I run the car for and what should I do and look out for and when should I stop and put everything back?
Yes you have everything covered pretty much. Fill the reservoir tank to the cold mark. Attach the funnel add some coolant to the funnel enough so when it drops it doesn't engulf air. Idle the car with max heat on, and lowest fan setting. The fans should kick on a couple of times. Run it till the water in the funnel is still, and no air bubbles. It will depend how much air is present. That's the way I do it until the next fan cycle the water is still, and no bubbles coming up.
Then I normally just let the car cool down. At this point the water in the funnel will receded as well. Put the stopper in, the funnel, and put the unused coolant in its container. Cap off the radiator.
Check water level at the radiator cold next day. It should be full. Add coolant needed to the reservoir to meet the cold mark as needed.
It make take a day or so to see the reservoir stable at the cold mark. Meaning it's not needing to replenish any lost fluid.
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lexus-is2 (02-18-20)