Transmission oil leak in a new Renault Duster Turbo CVT

The car's engine seemed to be revving fine but very little power was being transferred to the wheels in D or R modes.

BHPian aKrain recently shared this with other enthusiasts.

Posting this as I am trying to figure out the root cause for an issue with my recently purchased Renault Duster Turbo CVT.

On 15 May, I was travelling with my family from Noida to Uttarkhand in our 1 month old Duster. We drove for about 5 hours and made a stop at Rudrapur border to show our Covid e-pass. After doing the formalities, we started off but after driving a few kms, the car suddenly lost power and started to slow down. I quickly pulled the car to the left and brought it to a halt. The car's engine seemed to be revving fine but very little power was being transferred to the wheels in D or R modes. On engaging D, it just a moved a little bit and after that anymore revs didn't make the car budge an inch. The gear indicator was showing D and some weird characters in between.

Something seemed to be wrong with the engine/transmission and I immediately killed the engine. From the time the issue had surfaced, the general warning light (orange) had come up for some time in between and then gone off. The general warning light is the one with number 5 on this webpage.

According to the manual, it means that the car is to be driven with care to the nearest service centre.

After getting out of the car, we found that there was some oil leaking from the front left very close to where the battery is located. Opened the bonnet and found that there was a dip stick in front of the battery for some kind of oil (most probably power steering oil). The oil seemed to be leaking from around that area. As it was getting dark, it was hard to see where exactly the leak was. It was definitely not near the engine or the engine oil dipstick which are both located towards the centre of the bay.

Fortunately, I was able to arrange for a tow truck from Renault RSA as well as a cab for further travel within half an hour. Since the car was under warranty, the RSA arranged for the car to be taken to the service centre in Haldwani. This was a big relief as all showrooms/shops were otherwise closed due to the prevailing lockdown.

I have still not been able to understand what exactly happened. Since the lockdown is not going to end soon, I would like to know if any fellow BHPians have faced any such problems? Any insights into the possible root causes for the issue are welcome.

Here's what BHPian Indian2003 had to say on the matter:

Are you sure that this is the dipstick for the servo? It seems more logical that it is the dipstick for the automatic transmission which is to the right when looking at the car from the front.

Here's what BHPian aKrain replied to Indian2003:

That is what I assumed as well but the car's manual doesn't show the location of the transmission oil dipstick. It does make sense in case the transmission oil is also located there.

In case it is the transmission oil, how bad is the issue going to be?

Here's what BHPian Tgo had to say on the matter:

The power steering pump and reservoir unit is located below the LHS front headlamp. There is no dipstick for that. PS oil is red in colour for the Duster.

What you might have checked would be the CVT oil dipstick. I cannot be sure though. A look through the manual would explain or show an indication of where to find the transmission dipstick.

The symptoms you described suggest towards a transmission related problem. A CVT transmission relies on hydraulic pressure to shift the pulleys into the required gear ratio configuration. With low/no oil, there will be no fluid to carry the hydraulic pressure thus resulting in a malfunction. Malfunction could be due to air getting trapped in the oil galleries of the transmission leading to erratic hydraulic pressure. The oil which lubricates the gearbox also works as the hydraulic fluid. In case of low oil level, there could be damage to the gearbox components due to lack of lubrication.

It should be a simple case of:

  • Identifying the source of the leak
  • Residual oil quantity by draining it completely and tallying it against a full fill quantity
  • Assessing damage to transmission by checking the remaining oil for metal particles, and if no damage is inferred,
  • Filling it up with the correct oil and driving off.

NOTE: In case you find out that they diagnosed low oil, do insist on oil analysis and a gearbox replacement if the internals have been damaged. You don’t want to be haunted by the ghost later.

Leak from oil filling port or dipstick port is not unheard of and that might be what happened in your case.

Here's what BHPian aKrain replied to Tgo:

Thanks a lot for the detailed analysis. This does seem to be the most logical explanation. The oil was definitely not red in colour. So that also rules out the power steering fluid. It was more like greenish gray in colour.

What would be a good way to know whether there was any damage to the gearbox internals?

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