Ideas

[Doubeleive]

it has to be going somewhere I would get under the truck with a flashlight and take a closer look

 

[Nelson Camilo]

Every step you mentiones I did, also. Check coolant odor by the exaust.no odor, nothing wrong with the oil .
The reservoir was replaced because due to age working almost imposible to see on the inside, new cap comes.toguether with the tank. Amount of coolant loos in 5 miles like a litre, but on my way back nothing was lost.

My time experiencing this is from 7 months ago but due to the amount replace was once a month like 1/2 pint of coolant.
Now is the problem.the amount.is to much.

 

[wjburken]

I already check the. heater on the inside , no smell, no coolant, also the pressure check on the engine was perform up to 17 psi and he drops to 15 psi and stay there , oil was change 2.months ago but no indication of contamination yet.
The reservoir was changed because to check the level was to hard to see, also the new reservoir comes with a brand new. Ac delco cap for 15 psi.
This problem I notice from several months ago, now is the point when is required to watch.
The consuption of coolan yesterday was a litre of coolant in 5 miles and on my way back nothing was lost.
No coolant odor by the exaust.

Let me see if I got this right.

You stated that you get no odor of coolant in the vehicle, under the hood or out the exhaust. If you put your hand in front of the tail pipe while holding a white paper towel after the motor is warm, do you get any residue in it?

You have pressure tested your coolant system and it held 15 psi. Was that with the motor running or off? How long ago was the pressure test done?

You said that when the oil was changed 2 months ago there was no sign of contamination. Did you change the oil or did a local shop do it? Did you see the oil yourself? Have you looked at the oil on your dip stick recently?

You said that the problem has been going on for several months but it is now to the point that you need to check it regularly. You went from 1/4L a month before to 1L of coolant in 5 miles now? That is a significant change.

Your symptoms indicate that the fluid loss is when the vehicle is running as you are not getting any signs of fluid on the floor. This leads me to look at a leak that is opening up when the motor is hot as I am guessing the pressure was tested with the motor off. It could be spraying onto a hot surface and evaporating, but that would create an odor under the hood. It leads me to believe the leak is internal and is either going out your exhaust or into your oil, or both.

I would repeat your pressure test and as @Doubeleive said, it has to be going somewhere so get a flashlight and look all over and under your vehicle with it running.

My gut is saying you have a headgasket that is failing but need more information.

 

[Nelson Camilo]

Let me see if I got this right.

You stated that you get no odor of coolant in the vehicle, under the hood or out the exhaust. If you put your hand in front of the tail pipe while holding a white paper towel after the motor is warm, do you get any residue in it?

You have pressure tested your coolant system and it held 15 psi. Was that with the motor running or off? How long ago was the pressure test done?

You said that when the oil was changed 2 months ago there was no sign of contamination. Did you change the oil or did a local shop do it? Did you see the oil yourself? Have you looked at the oil on your dip stick recently?

You said that the problem has been going on for several months but it is now to the point that you need to check it regularly. You went from 1/4L a month before to 1L of coolant in 5 miles now? That is a significant change.

Your symptoms indicate that the fluid loss is when the vehicle is running as you are not getting any signs of fluid on the floor. This leads me to look at a leak that is opening up when the motor is hot as I am guessing the pressure was tested with the motor off. It could be spraying onto a hot surface and evaporating, but that would create an odor under the hood. It leads me to believe the leak is internal and is either going out your exhaust or into your oil, or both.

I would repeat your pressure test and as @Doubeleive said, it has to be going somewhere so get a flashlight and look all over and under your vehicle with it running.

My gut is saying you have a headgasket that is failing but need more information.

 

[Nelson Camilo]

Let me see if I got this right.

You stated that you get no odor of coolant in the vehicle, under the hood or out the exhaust. If you put your hand in front of the tail pipe while holding a white paper towel after the motor is warm, do you get any residue in it?

You have pressure tested your coolant system and it held 15 psi. Was that with the motor running or off? How long ago was the pressure test done?

You said that when the oil was changed 2 months ago there was no sign of contamination. Did you change the oil or did a local shop do it? Did you see the oil yourself? Have you looked at the oil on your dip stick recently?

You said that the problem has been going on for several months but it is now to the point that you need to check it regularly. You went from 1/4L a month before to 1L of coolant in 5 miles now? That is a significant change.

Your symptoms indicate that the fluid loss is when the vehicle is running as you are not getting any signs of fluid on the floor. This leads me to look at a leak that is opening up when the motor is hot as I am guessing the pressure was tested with the motor off. It could be spraying onto a hot surface and evaporating, but that would create an odor under the hood. It leads me to believe the leak is internal and is either going out your exhaust or into your oil, or both.

I would repeat your pressure test and as @Doubeleive said, it has to be going somewhere so get a flashlight and look all over and under your vehicle with it running.

My gut is saying you have a headgasket that is failing but need more information.

 

[Nelson Camilo]

You are right I.m kind of. Driver who like to maintain the best shape my Tahoe, I dont move whike the oil is change and monitor at least 2 times a week the oil level and color.
Your last test out the exaust pipe I didnt yet.
I m think that there is the posibility a cyl.head gasket leak
Only thing that I got in mine,
Test on radiator press was 13 days ago, eng.off.
Also the kind.of oil I use is Mobil 5w30 synthetic.
And I always check the color or contamination on the replace oil.