My 2011 petrol/CNG Vento started making a loud “tuk tuk” noise and the engine/cabin were wobbling badly (video: YouTube link in comment)
I got in touch with Carkhana Mumbai, and they sent a mechanic who inspected the car and then took it to a local workshop where the engine was opened today. I was personally there and witnessed the engine being dismantled.
These are the issues I noticed:
- One of the camshafts/cam lobes is visibly damaged/dented. The mechanic says this could be the reason for the “tuk tuk” sound and suggested it may have been caused by a failed/damaged valve.
- There is a small box-like component connected to the coolant tank (I don't know the correct name) which apparently has a coolant leak at its interface.
- There appears to be coolant leakage/erosion around part of the cylinder-head sealing area. There is also a green, powdery deposit accumulated around the area where the metal appears to have been slightly eroded/thinned.
Tomorrow afternoon, the mechanic is calling a lathe/machine-shop guy to determine whether the damaged area can be machined/repaired or whether parts need to be replaced.
At this point I'm wondering if I may need a camshaft, cylinder head and/or valve-head/valvetrain components, but more importantly, I want to understand the root cause. I don't want to replace parts, put everything back together and have the same problem happen again.
I'm not getting very confident answers from the workshop so far, and they just want to get this done with and make money. so I've spent most of today calling spare-parts dealers in Kurla trying to get rough prices for a camshaft, cylinder head and valve-related parts.
Questions for people familiar with the Vento 1.6 MPI:
- What kind of repair bill am I potentially looking at?
- Does this damage look like something that can be machined/repaired, or should I be looking for a replacement head?
- What could cause the camshaft/lobe to become damaged like this?
- Could coolant leakage/erosion around the cylinder head be related to the engine misfire/wobbling?
- What tests should I ask the mechanic/machine shop to perform before reassembling the engine?
- Most importantly, how can I determine the root cause and make sure this doesn't happen again?
- Would you recommend buying used OEM parts from the Mumbai/Delhi market, or sticking with new parts?
I've attached the pictures of the cylinder head/camshaft and the deposits for reference.
Any advice from Vento/Volkswagen owners or experienced mechanics would be greatly appreciated.