Loosing coolant from somewhere

[NICAT]

Hi.
Head gasket was replaced. Both heater core and radiator were replaced replaced too.
Still loosing coolant. Not very much. 1l per each 1500km city driving (or 1 Litr per month).

Any idea how i can find the source ?
May it be from coolant reservoir cap ?
Regards

 

[StevieC]

Are they any spots on the driveway? If not see below questions.

Have you checked for milky oil?

Have you pulled the spark-plugs to make sure that it's not burning it even though the HG was replaced?

 

[demarpaint]

No disrespect intended, but with all those parts replaced the odds of a defective part being installed, or a part being installed incorrectly is always a possibility. It could also be leaking from something that wasn't addressed.

I'd pressure test the system and see if you can find the leak that way.

 

[Nick1994]

What kind of car?

 

[NICAT]

Originally Posted by StevieC
Are they any spots on the driveway? If not see below questions.

Have you checked for milky oil?

Have you pulled the spark-plugs to make sure that it's not burning it even though the HG was replaced?



No spot on the driveway,
No milky oil.

Quote
Have you pulled the spark-plugs to make sure that it's not burning it even though the HG was replaced?

Not pulled spark plugs, But it will be the first thing to do tomorrow. Thanks for the idea

By the way, what do you mean "make sure it is not burning ?" How should or shouln't they look if there is leak?
Sorry for poor english.

 

[skyactiv]

Do you know if the cylinder head was resurfaced and checked for cracks?

 

[StevieC]

Sparkplugs will indicate if the coolant is being burned in the combustion chamber (white in colour at the tip versus a nice brown) because the head gasket is leaking coolant into the cylinders, or a cracked head or cracked block. The later 2 is not as common today, more likely the head gasket unless the vehicle was severely overheated at some point then a cracked or warped head is a definite possibility and a gasket replacement would not cure this.

Is it hard to start or does it stumble during start-up after it is at full operating temperature and shut down for say 15-20 minutes and then restarted?

Do you see white smoke out the exhaust other than a slight amount during warm-up?

Also can you smell coolant when the engine is warm anywhere around the engine?

 

[mk378]

If there is a leak into a cylinder, that spark plug will look a lot whiter and cleaner than the others.

The coolant reservoir should be only about 1/3 full when the engine is cold. If you are overfilling it, the excess will be pushed out when it warms up.

 

[NICAT]

Originally Posted by demarpaint
No disrespect intended, but with all those parts replaced the odds of a defective part being installed, or a part being installed incorrectly is always a possibility. It could also be leaking from something that wasn't addressed.

I'd pressure test the system and see if you can find the leak that way.


Not sure if there is anyone who will do a pressure test here for me. Do we need special tools for it beside an air compressor ?

Originally Posted by Nick1994
What kind of car?


Daewoo Nexia 2006

Originally Posted by skyactiv
Do you know if the cylinder head was resurfaced and checked for cracks?


Good point. Once head gasket was burnt. The mechanic told i should had the head resurfaced. He had just done some visual tests at that time.
Then i changed his desicion, and decided not to resurface it.

 

[StevieC]

If you don't have access to a pressure tester you can just heat the vehicle up to full operating temperature and then shut it down and the pressure will build. Albeit not to the level you can achieve with a tester but enough that you should be able to see visible leaks and do the snift test all around. At the rate you are going through coolant it should be quite apparent if it's external and not going through the engine.

 

[StevieC]

Originally Posted by NICAT
Originally Posted by skyactiv
Do you know if the cylinder head was resurfaced and checked for cracks?

Good point. Once head gasket was burnt. The mechanic told i should had the head resurfaced. He had just done some visual tests at that time.
Then i changed his desicion, and decided not to resurface it.


Hmmmm. Sounds like the head isn't level then. This would be the cause for sure if that mechanic ran an edge across it to check for level.

 

[NICAT]

Originally Posted by StevieC
Sparkplugs will indicate if the coolant is being burned in the combustion chamber (white in colour at the tip versus a nice brown) because the head gasket is leaking coolant into the cylinders, or a cracked head or cracked block. The later 2 is not as common today, more likely the head gasket unless the vehicle was severely overheated at some point then a cracked or warped head is a definite possibility and a gasket replacement would not cure this.

Is it hard to start or does it stumble during start-up after it is at full operating temperature and shut down for say 15-20 minutes and then restarted?

Do you see white smoke out the exhaust other than a slight amount during warm-up?

Also can you smell coolant when the engine is warm anywhere around the engine?


No hard start. Car starts immediately when i turn the key. I can't not even observe any cranking.
Can't smell coolant.
Not sure about white smoke. will look tomorrow.

By the way, thanks all for helps. You saved me from making tons of researches

Quote
Hmmmm. Sounds like the head isn't level then. This would be the cause for sure if that mechanic ran an edge across it to check for level.


In this case the head should be removed ?

 

[StevieC]

Glad to help in any way that I can... Good Luck.

 

[NICAT]

Originally Posted by mk378
If there is a leak into a cylinder, that spark plug will look a lot whiter and cleaner than the others.

The coolant reservoir should be only about 1/3 full when the engine is cold. If you are overfilling it, the excess will be pushed out when it warms up.


This is something that i have just learnt. I used to fill it up to 70%.
Thanks.

 

[madeej11]

In my Toyota owners manual it says to check coolant level when cold. First thing in the morning fill the reservoir to the full mark, between add and full lines is also okay. Just check when cold.

 

[demarpaint]

Originally Posted by NICAT
Originally Posted by demarpaint
No disrespect intended, but with all those parts replaced the odds of a defective part being installed, or a part being installed incorrectly is always a possibility. It could also be leaking from something that wasn't addressed.

I'd pressure test the system and see if you can find the leak that way.


Not sure if there is anyone who will do a pressure test here for me. Do we need special tools for it beside an air compressor ?

Originally Posted by Nick1994
What kind of car?


Daewoo Nexia 2006

Originally Posted by skyactiv
Do you know if the cylinder head was resurfaced and checked for cracks?


Good point. Once head gasket was burnt. The mechanic told i should had the head resurfaced. He had just done some visual tests at that time.
Then i changed his desicion, and decided not to resurface it.



You don't need an air compressor to pressure test the cooling system. There is a small tool with a pump and different size caps that go on the radiator. "Google cooling system pressure tester." I'd see if one of the local parts stores will lend or rent you one. Or go to a good mechanic and have him pressure test it for you. If you do it yourself do it to a cold engine!!

I have a feeling not resurfacing the cylinder head is the problem. My bet is the head is warped. Pressure testing will shed some light.

 

[Leo99]

My coolant leak was due to defective radiator cap. Inexpensive fix. Surprised how much coolant it lost due to defective cap.

 

[andyd]

For how many months has the car used coolant ? If only a month's time, then it may have finally " burped" the air out of the system. Also, check all the hose connections for drips. Monitor coolant levels and carry a jug in the trunk.

 

[maxdustington]

Originally Posted by andyd
For how many months has the car used coolant ? If only a month's time, then it may have finally " burped" the air out of the system. Also, check all the hose connections for drips. Monitor coolant levels and carry a jug in the trunk.
I'd be shocked if it took a month. Up and down a hill with the tstat open should do it. When your low coolant warning light comes on for the second time, it's going somewhere.

 

[LvR]

Originally Posted by mk378
.......................

The coolant reservoir should be only about 1/3 full when the engine is cold. If you are overfilling it, the excess will be pushed out when it warms up.
Sorry but you are plain wrong.

The modern cooling systems are designed to be a closed system and thus MUST be able to and DO handle the correct filling of the expansion tank to the correct max mark when cold............... your advice (i/3 fill cold) is only correct for older cooling system designs where the pressure relief cap was located on the radiator itself and the top of the expansion tank was open to the atmosphere - soon as you have a pressure cap on the expansion bottle it must and should be filled to the correct max mark.