996.2 | Cracked head? Need help in diagnosis of video

[CarPlebs]

 

Hi all, 

 

(youtube results linked below)

 

Well here I am again with a quick diagnosis based on experience. 

 

(cap is new and expansion tank fairly new also)

(no intermix present)

 

I have noticed coolant disappearing, after which it was identified that some pipes were leaking and we proactively changed the water pump as well. Exterior leaks disappeared, however I have noticed that the coolant level keeps decreasing to MIN after longer (100km) drives. I keep refilling to the same effect. We checked radiators etc. and all seems to be fine. Pressure test as well. 

 

Mechanik stated it’s likely a cracked head. So I decided to buy the amazon head gasket kit to test. 

 

As for the results, I let the engine get to nearly operating temperature. I did some revving and there are both bubbles and apparent vacuum which I do not understand. 

 

In terms of the video. 

 

Cold (6 celsius, 42 fahrenheit)

 

the beginning is just the end showing that there are no bubbles in the liquid whilst at near operating temp. Also for sanities sake I put the blue liquid on my hand and next to the exhaust to confirm that it works. Fluid only changes a bit in terms of color, please compare start to end. 

 

6:55 1st rev

 

12:36 2nd rev

 

reaches near operating temp. 

 

17:10 3rd rev

 

Is the head gasket blown? Why does the fluid keep going to the min mark after the refill? 

 

Thanks! 

 

 

 

[judgejon]

Leak under pressure at a radiator hose connection?  But no coolant leaks… ?

Good luck. 

[JFP in PA]

Interesting test idea, but if you want to definitively evaluate the engine for cracks anywhere in the cooling system, the correct way to do it is with an cooling system pressure testing rig:

 

This tool will allow you to properly test ANY cooling system, using the correct adaptor, by pressurizing the system to 18-20 PSIG, and then watching it for 15-20 min to see if it drops.  If it does, first thing you check for is external leaks. which is done by adding a small quantity of cooling system YV dye, running the system, and then inspecting all possible leak points (seals, gaskets, hoses, etc.) in a darkened garage with a UV light source:

 

 

If there is even the slightest leak, the UV dye will light up like a Christmas tree; if nothing is found, the leak has to be internal to the engine.  At that point, a leak down test is in order to determine where (which head) is the problem:

 

 

Good luck.

[RFM]

On 11/23/2022 at 9:40 PM, CarPlebs said:

I have noticed that the coolant level keeps decreasing to MIN after longer (100km) drives.

If the car has a Tiptronic gearbox, an internal eak from the cooler can cause this phenomenon. Check the ATF oil for intermix with cooling water, the gearbox can be destroyed in a short time.

[JW89225]

I had the same symptoms but with a Manual transmission car. Eventually found intermix after a few months...

Edited July 5, 2023 by JW89225