Team-BHP - Engine Oil pushing the coolant to spill

Hi fellow BHPians

Need an urgent expert opinion and diagnosis on my Creta 2017, 1.6 Diesel, MT

The car ran for 55000 kms till date, regularly serviced in the service center

Post the last service in September, in January, at around 50,000 kms there was excessive engine heating that we could feel, and there was coolant water splashed on the inside of the wheels and slightly on the front doors.

I took it to the service center and they said the engine oil and coolant were getting mixed, they cleaned the radiator for any blockages. They kept the car for 2 days drove it for 100 kms and checked through and returned the car

Yesterday, when driving around, there was a thud sound in the engine, so I immediately stopped the car as I didn't want any damage to the engine. I called in a local mechanic to check, and he said that the engine oil was low and not to start the car. I called in the service center and got the vehicle towed

Today got a call from the service center, below are the problems that they understood after topping up the engine oil and testing the car
1. Coolant is being pushed up and is spilling. So there is pressure being built up.
2. Could be a possibility of engine oil pushing the coolant up due to a valve failure in the water bed of the engine (which separates engine oil and coolant in the engine)
3. Head Gasket failure which could push the engine oil and lead to leak /depletion. The reason for this could be, as stated by the service team, is if the piston rings are worn which will impact the gasket (I doubt the worn-out happening, as the engine has run in just 55k km)

The resolution they are suggesting is to open the engine, replace the gasket, and change all the one-time parts, and water bed with an estimate of 1 to 2 lakhs

So wanted an expert opinion on the issue and how to proceed please

Your first over heating issue happened in January. The splashing of coolant on the wheels was because of overheating as that is when coolant gets pushed out. The ASC did not resolve the issue properly.

Now the problem is more severe as coolant is getting mixed with oil and this may have caused irreparable damage to the internals.

In such a situation, even after repairs, it is most likely that some problem or the other will keep recurring.

Usually when such major damage happens it is better to repair and sell the car because long term reliability will be affected as the ASC will not be able to completely resolve the issue.

Looks like a head gasket failure. The main reason why head gaskets will fail is due to low coolant levels due to a leak or faulty water pump or a faulty thermostat. The head gasket is the element which acts as a sealant between the head and block and as well as the outside of the engine. So if it goes bad, firstly there will be leaks in two forms, can be an oil leak to the outside of the engine, which may cause low oil pressures. This is because the gasket is blown near to the edge where it resides and leaking the oil out. So this could be a part of the explanation for low oil in your engine, there are other things as well, but let us not get into it until more factors dictate.
Other case if the blow is near the coolant gallery of the engine it will allow the coolant to seep into the cylinder and cause white smoke from the tail pipe, and cause irreversible damage to the internals, which can only be fixed by replacement.

And the ASCs statement is somewhat sketchy. The head gasket can go bad in only some cases but majorly if the engine overheats due to lack of coolant. This overheating cause can be from user end, where the coolant level is not maintained and checked, secondly, from an angle of gasket where it goes bad by self and leaks coolant and in turn destroys itself and other components as well. Piston rings go bad usually due to heat, age, low quality of oil. So if the ring is bad it will allow the combustion gases to escape into the crankcase, which is not a pleasant thing, and will cause numerous issues. However these are only speculations from my view and there can be many other things involved.

Best is to follow a guided flowchart to solve this:
1. Since the radiator was cleaned, make sure all the pipings are clean and are not leaking any coolant. Top up coolant and engine oil and check if the coolant level is stable, or any white smoke from the exhaust. This requires the car to run for about 15mins to reach coolant temperatures. One thing here is if its a blow head gasket then you most likely will find it in this test.
2. If you find the above, open and replace the head gasket, and if possible perform compression test to eliminate the piston rings to be bad. But most likely if you are running a bad gasket for too long then the internals would be damaged, so better to replace them once you open the engine.
3. After all the repairs, you will still be facing issues with the engine and there is no guarantee on its longevity, so better to get rid of the vehicle before it puts you in a even more unpleasant situation.

Hope this helps. Happy Motoring!