I really do not think the oil seal bulged due to the coolant and also thought the timing should not jump just because some amount of oil fell on it.
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Prelude: I have a preowned Renault Duster RXZ AMT 2016 model which was bought in June 2020 and at the time of buying, it had clocked 69,000 kms on the odo. All the services were carried out by the A.S.S itself. I got the annual service done at the A.S.S at 74,000 kms and the current ODO reading is 76,390 km.
I recently got the anytime warranty for 1 year for which I paid Rs. 29,165. I could not get the normal anytime warranty (costs about Rs. 19000) since the previous owner had missed two service intervals and got it serviced a little late. Hence, I had to go for Improper Service Anytime Warranty by paying Rs. 10,000 extra.
Recently, while driving, I noticed some engine noise. I took it to the FNG mechanic and had a test drive with him and made him hear the sound but he could not pinpoint the issue and he asked for the car to be left at the service center to take a look. Since I had an active warranty, I denied and took it to the A.S.S on 30th March. They checked and said that due to the engine heat, the crank shaft oil seal bulged causing some engine oil to fall on the timing pulley and thereby changing the engine timing itself.
Since I had warranty, I asked them if that can be repaired under warranty but they denied. The reason given – the previous owner had not agreed for the entire coolant to be flushed and fresh coolant to be added at 60,000 km as per the maintenance schedule and that the engine got heated due to this (car had max level coolant which was topped up) and bulged the crank shaft seal making the oil to fall on the pulley. Since this issue is related to coolant, they denied to repair under warranty.
It gets interesting here: When I spoke to the SA, he said if the coolant had been flushed and fresh coolant added, it would have retained its viscosity and ensured the engine temperature remained under control but since the coolant was topped up, it has lost its viscosity and could not keep the engine temperature under control which caused the crank shaft seal to bulge.
I asked him these questions:
1) If the engine temperature got so high, why did I not get a temperature warning or why was there no error code on the OBD for which his justification was that the temperature did not get so high to set up a warning on the Dashboard but got high enough to bulge the crankshaft oil seal.
2) How did he conclude that the topped up coolant had lost viscosity?, asked him if he had run any tests to prove that but he had no answer to that but said it is based on their experience they know it is due to topped up coolant.
The SA sent me the below images:
A gap can be observed as marked in the third image on the crank shaft which was never communicated to me.
I told them that I will take a look at the car and decide what to do next. Visited the A.S.S on 2nd April and to my surprise, I see that everything was closed and the car was out of the ramp. I asked them why they have closed it up when I clearly told them that I need to take a look but they said they cannot keep it like that. I got suspicious of their behaviour so got the car back.
After that, I dropped an email to the S.A and the service manager to give me in writing or in an email on what diagnosis was carried out and how it was concluded that it had happened due to the coolant not being replaced at 60,000 km, to which, till date, they have not given a reply and have been beating around the bush and asking me to visit the A.S.S.
I dropped an email to a few having top posts at Renault but even after two days, there is no call or even an email from anybody asking what is going on. Have raised two complaints from their website (case numbers) but nobody got back and if I call their toll free number, the customer representative says they are looking into it and somebody will get back.
I really do not think the oil seal bulged due to the coolant and also thought the timing should not jump just because some amount of oil fell on it (engine oil level is at max) and that just to deny warranty, they are linking it to the coolant.
Please comment if this could be a coolant issue or due to any other factors or if anybody has come across this kind of a scenario where timing itself changed.
Here’s what BHPian Jeroen had to say on the matter:
Sorry to hear about all of this. It is a bit messy I am afraid. I think you have asked some good questions.
Couple of thoughts/comments. Viscosity is completely irrelevant when it comes to old and new coolant. Maybe something gets lost in translation here?
The main reason for changing out coolant and a flush is to ensure any rust and debris in the coolant system comes out. Also, the coolant will, over time, loose it’s ability to prevent corrosion. So, yes, a coolant system needs to be flushed and re-filled with fresh coolant in accordance with the manufacturer’s recommended maintenance practice.
Yours went well over 10,000 km over the recommended interval. I would think it is unlikely for anything as dramatic as overheating to take place, but that will be difficult to prove. That’s unfortunate, but it will be difficult to argue.
The rust and other debris can settle in places within the engine and/or radiator. Which means that in certain spots, the cooling will not be optimal. Your Engine Coolant warning light measures the temperature of the coolant circulating through the engine. But that is sort of an average temperature. If say, one cylinder is partly blocked to scaling, that will simply not affect the temperature of the coolant.
Again, I think it is unlikely to be the case, given it is still a relatively low mileage engine. But you can see why your S.A. is adamant. He does have a point in terms of the coolant – it should have been replaced.
However, I am not so sure there is any correlation between the crank shaft seal failing and the coolant as such. Unless there was a massive cooling problem, this seal won’t fail. There is no cooling around the seal. The seals operate at whatever the engine casing/oil temperatures are. In order for it to fail, the temperature of the engine and oil would have to be sky high and you would have been looking at some very serious engine damage, not just a seal.
Additionally, I don’t understand how the oil leak can cause the timing to be off. It looks like the oil leaked onto the crankshaft sprocket. That is a toothed timing belt. It won’t slip, it can only jump a tooth. And it will only jump a tooth if the belt was not tensioned properly, or was stretching too much due to wear. Not sure when this belt needs changing?
I am not quite sure what this gap on the photo is supposed to be indicating? I am not familiar with this engine. Can the crankshaft sprocket somehow change its orientation (in which case the timing would be off too)?
I don’t understand why they claim the timing is off. Is that gap some indication as to how the sprocket needs to be aligned? Perhaps other members more familiar with this particular engine know?
Here is my take and summary:
- Viscosity in coolant is not a factor.
- Coolant flash and refresh not done, can cause engine cooling problems in due course. Not very likely to have caused any problems yet though.
- There is no solid explanation as to why the seal bulged
- There is no solid explanation as to why the timing would be off
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