[Ravi Parwan]

I think this thread is indicative of how the attitudes differ in India versus Overseas.

Jeroen, despite his age, continues to work on his cars with pride. I read all his threads with both admiration and envy. Here, in India, if you start even dusting or washing your car yourself, people look at you and wonder what's wrong with you.

Unfortunately, we in India are losing the drive to work with our hands, around the same time when skilled labour is getting expensive here. Anyone with enough smarts try to avoid working on machines themselves. Instead the actual manual work falls on the plates of the overworked workers, who have neither the knowledge nor the drive to do good work. I had once gotten fuel pump refurbishment done in my 2003 Indica as a solution to poor fuel efficiency and power. The lad in charge of refitting the steel fuel pipes to each cylinder tried to bend them to fit them with no regards to firing order! He did not even think that steel pipes would not have gotten out of alignment in the 30 min or so that they were off the engine. Thankfully I was standing there and stopped him in time, called the senior technician, who tried to smooth over the situation and installed them in the correct order with a little bit of fiddling and no bending!

The situation is worse in A.S.S., where the technicians of today are not bothered about the satisfaction of a job well done. Rather they are more concerned with fulfilling their quota for the day, punching their time and going home.

So while Jeroen is right in saying that head gasket replacement might be all that is needed and it is not that big a deal, the odds of that job getting done right in A.S.S. or outside mechanic are 50-50 or worse. Even if they get the gasket in correctly, chances are they will mess up the injectors or lines or any of the multiple sensors and connections on the engine head. The head gasket replacement bill will also get inflated in A.S.S. as they are in it for the quick buck and not for building reputations.

Having said all that, it would still be possible to get the engine fixed properly and with minimal impact to the wallet if the OP takes it to a trustworthy mechanic who knows his stuff. My advice would be to hunt for a good reputation mechanic in your town who has a track record of working on these engines. Once you get the right person to work on the engine, it should hopefully restore it to full glory and allow OP to enjoy his car to the fullest for a couple of more years, till 10 year old diesels get banned in his state!

[VijayAnand1]

An engine oil mixes at two places,

1. Head Gasket (blown)
2. Oil Cooler - in Diesel Engines.

With no visible oil leak from the head and the periphery, your prime observation point is to look further. Oil cooler has specially designed high-precision O ring inside. When this O ring fails, oil mixes with coolant and slowly yet steadily will degrade the engine. Internal oil cooler leak is harder to find. But a peek under the hood with a powerful torchlight will yield us of external leaks if any, which is a first sign of failure.

Good luck.

Cheers!
VJ

[jay26june]

On of my colleagues 2022 Venue 1.0 Turbo ODO 25000 km, had similar issue recently. Colant mixed with engine oil for no reason . No external damage was found , initially Hyundai denies warranty claim and after multiple follow up warranty claim was accepted . Total bill amount 1.5 Lakh.
Hyundai’s reliability is really questionable these days

[Maverick Avi]

Had the exact same problem in one of my Marutis a decade back. Went to MASS and they suggested the same thing that your service center is telling you. I pulled my car back and took it to a another garage where the diagnosis was same(head gasket failure) but they mentioned that parts replacement might only be required if damaged. On opening up the head nothing was damaged and only the head gasket was changed. No issues what so ever post that.

You can safely take your car to another trustworthy garage and let them open up the head and do a more elaborate diagnosis. Most probably it's just a head gasket replacement job that should not cost you a bomb. Getting engine replaced and all seems too far fetched an idea that most probably is not required in your case.

[V0id2003]

It is most likely worn piston rings.

I have confirmed form various sources that 1.6 CRDIs built between 2017-2019 used very thin piston rings that broke and caused issues like yours

My own 2018 Verna and my friend's 2019 Verna had engine failures at 65-70k KMs & had to get a complete overhaul with new pistons, rods etc.

The new piston rings they put in are much thicker and should last longer. But I didn't have extended warranty because I was so sure of Hyundai's quality with my last experience, so it was a hit of 1.5 lakhs.

[Jeroen]

Originally Posted by V0id2003

It is most likely worn piston rings.

How can worn piston rings cause these symptoms? Worn piston rings lead to poor compression. Worn scraper rings lead to oil burning.

Just one more thought about this very problem. Before you get somebody to pull the cilinderhead to replace the head gasket, make sure that it is the actual problem. Various members have pointed out the oil cooler as a potential problem area. It might well be, so you want to make sure which one is the culprit.

So to the point made by other members, you need to find a technician who knows how to test for a faulty head gasket versus a faulty oil cooler.

Jeroen
Jeroen

[reddyboi]

[Update]

Took the car to a known Hyundai Mechanic outside, and got the head gasket changed, the engine internal churn and cleanup, the cylinder head skimmed, (luckily no marks of piston rubbing against the walls in the block), changed the cooling bed and the rods

Took 3 days to source parts and to get it done

After all the changes are done, the engine oil is filled, the coolant topped up, and without closing the coolant lid, left the engine on for an hour to check for any further symptoms

Repeated the engine idling test another 2 times to see any pressure build up happening in the coolant tank

The vehicle seems alright now, now vibrations as of now, and the engine is running smooth and felt no loss of power

All the repairs costed around 40k overall

Thanks to everyone for sharing the diagnosis and suggesting on the line of action. Special thanks @Jeroen for the advice and for helping me to stay calm and explaining in detail

[reddyboi]

Originally Posted by Jeroen

So to the point made by other members, you need to find a technician who knows how to test for a faulty head gasket versus a faulty oil cooler.
Jeroen

The mechanic also had these 2 diagnosis for the same. But he was 90% sure it was the head piston ring because of how pressure is building up in the the coolant tank.

He checked the oil cooler first as it wouldn't require opening up of the engine head. He replaced the oil cooler first to see if the problem goes away, but the pressure buildup is still happening in the coolant tank. So he is sure about the gasket and went ahead to replace the same

[Jeroen]

Originally Posted by reddyboi

The mechanic also had these 2 diagnosis for the same. But he was 90% sure it was the head piston ring because of how pressure is building up in the the coolant tank.

He checked the oil cooler first as it wouldn't require opening up of the engine head. He replaced the oil cooler first to see if the problem goes away, but the pressure buildup is still happening in the coolant tank. So he is sure about the gasket and went ahead to replace the same

Thanks for sharing the final solution!

Good to see your mechanic did check out the oil cooler first. Sometimes replacing a part can be an easy way to the final diagnosis. I think he was right to try that first. If you have a spare one, it is a very easy thing to do and in this case it just confirmed the most likely cause of the problem.

Jeroen

[sanchari686102]

Hi everyone! I have a 2021 Hyundai Venue (1.0L Turbo engine). Recently I had given the car for my periodic 50k service at the authorised service center. At a time closer to the delivery of the car, I got a call from the service advisor mentioning that there is a mixing of coolant and oil happening. According to him the problem is due to a faulty oil cooler assembly. When the car came, I also checked the coolant area and it looked greasy. I never had any overheating issues before this and so this was kind of shocking. Is this a common issue in Hyundai petrol engines? How worried should I be about the future of the car? As the car is still in warranty (thankfully I had taken the extended warranty), the company is replacing the oil cooler assembly free of cost to me (but it took them more than a week to get the part from Chennai!). But how worried should I be about this issue? As I also have a long-trip coming up soon, do you have any specific suggestions for precautions that I should take for the drive after a repair of this nature?

[sanchari686102]

Wanted to provide a quick update and also seek an expert opinion: Authorised service centre replaced coolant assembly free of cost (car is still under extended warranty) and I have now driven the car around 1000km. Engine is smooth and no hearing issues. But even now I see a little bit of butter like presence on cap and inside coolant tank (please see the attached picture). But overall the coolant inside is looking transparent and smooth.

When I shared the pic with SA, he said it is normal. When I checked with another service centre, SA says either the entire unit will have to be dismantled and checked/ cleaned again or i should wait for 3-4 coolant flush outs to get it back to normal. I am now confused. What would be your advice on this? Should I just do 3-4 coolant flushing as part of periodic services over a couple of months or should I take the car to original service center and push for a more thorough answer? Or do you have any other suggestions? I would be really thankful for your suggestions.

Originally Posted by sanchari686102

Hi everyone! I have a 2021 Hyundai Venue (1.0L Turbo engine). Recently I had given the car for my periodic 50k service at the authorised service center. At a time closer to the delivery of the car, I got a call from the service advisor mentioning that there is a mixing of coolant and oil happening. According to him the problem is due to a faulty oil cooler assembly. When the car came, I also checked the coolant area and it looked greasy. I never had any overheating issues before this and so this was kind of shocking. Is this a common issue in Hyundai petrol engines? How worried should I be about the future of the car? As the car is still in warranty (thankfully I had taken the extended warranty), the company is replacing the oil cooler assembly free of cost to me (but it took them more than a week to get the part from Chennai!). But how worried should I be about this issue? As I also have a long-trip coming up soon, do you have any specific suggestions for precautions that I should take for the drive after a repair of this nature?

[sagarpadaki]

Originally Posted by sanchari686102

Wanted to provide a quick update and also seek an expert opinion: Authorised service centre replaced coolant assembly free of cost (car is still under extended warranty) and I have now driven the car around 1000km. Engine is smooth and no hearing issues. But even now I see a little bit of butter like presence on cap and inside coolant tank (please see the attached picture). But overall the coolant inside is looking transparent and smooth.

When I shared the pic with SA, he said it is normal. When I checked with another service centre, SA says either the entire unit will have to be dismantled and checked/ cleaned again or i should wait for 3-4 coolant flush outs to get it back to normal. I am now confused. What would be your advice on this? Should I just do 3-4 coolant flushing as part of periodic services over a couple of months or should I take the car to original service center and push for a more thorough answer? Or do you have any other suggestions? I would be really thankful for your suggestions.

Removing all the traces of oil in coolant is difficult.

Here is what I suggest - Pour a bottle of liqui moly radiator cleaner into the coolant expansion tank and radiator. Drive for a hundred kms. Drain the coolant from radiator and also drain the coolant tank. Fill with just distilled water and drive for a couple of hundred kms. During this period try what is shown in the below video for a few times.

https://www.youtube.com/watch?v=FH3seW8l_kA

You need to open the radiator cap and invert a bottle of half empty distilled water bottle into the radiator cap opening so that the mouth of the bottle is covered with the mixture in the radiator. Allow the car to warm up to operating temperature at idle. All the remaining oil in the distilled water will move into the water bottle there by leaving only the water in the system. Note - Start this procedure with the engine cold/warm to touch. Do not open radiator cap when engine is hot!

Then drain the distilled water and fill it with Hyundai pink coolant in 40% coolant 60% distilled water proportion. Few Hyundai service centers use an Indian oil branded coolant. Avoid that. Use only this
https://boodmo.com/catalog/part-engi...itre-51754384/


This is a time-consuming approach. But is the least invasive approach to remove the residual oil from the coolant system. With two flushes the coolant system will become clean. In future, change the pink coolant every 4 years irrespective of how many kms the car has run.

[Vmk1950]

Originally Posted by reddyboi

Hi fellow BHPians

I 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 is 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 55k kms)

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, I wanted an expert opinion on the issue and how to proceed

A cracked or burnt head gasket could be a possible cause. Once you remove the head assembly from the engine block, you can identify the issue. Worn-out piston Rings or worn-out Valves will give excessive smoke, as will smoke coming from the engine breather pipe/ oil cap. You can check this.

By removing the cylinder head, you will know whether it is just a burnt head gasket or something else.

Based on that, you can decide whether to keep the car or sell it.

[Vmk1950]

Originally Posted by sanchari686102

Wanted to provide a quick update and also seek an expert opinion:
Authorised service centre replaced coolant assembly free of cost (car is still under extended warranty) and I have now driven the car around 1000km. Engine is smooth and no hearing issues. But even now I see a little bit of butter like presence on cap and inside coolant tank (please see the attached picture). But overall the coolant inside is looking transparent and smooth.

I think the views of the second dealer is correct.
Since there was an oil mix in the cooling circuit / passages, some oil properties will be in the passages of engine block. Now that it is rectified, those residues ( greez / butter like substance) forms on the coolent/ radiator cap due to circulation. You can keep wiping them for few times when the engine is cool. It will stop after few cleaning.

Mean while keep a watch on over heating of the engine. No issue noticed for 1000 kms is a positive sign.

[sanchari686102]

Many thanks @vmk1950 and @sagarpadaki for the thoughtful responses. It's certainly relieving to hear that this issue may disappear over a period of time with some interventions. Will start with the simple suggestion of wiping them off for few times when the engine is cool. If it doesnt work, I shall also try the more complex solution suggested. Thanks again!