Hello I have 2018 hyundai tucson 2.0L AWD automatic with 142000 klm
Recently my car has slow acceleration & higher rpm before changing gears. No engine codes or check engine light on the dash. And I have to add 1.5 litres of oil between changes.
Took it to the dealer and was presented with a $4500 repair quote, new spark plugs and coils packs along with a new catalytic converter. I was told that adding 1.5l between changes is within spec for my year and kilometres.
Do you think the dealer is correct with there
diagnosis?
Thank you,
Hi,
The results of the dealer's "diagnosis" seem bogus.
Many things can cause an engine's performance to degrade so it'll require a bit of trouble shooting.
The Hyundai-Kia Nu engine is known for a few issues in particular - namely: scuffing due to poor lubrication and cooling of the cylinder walls (rare on the 2018 model year, damage appears as metallic/black vertical scuff marks on the cylinder walls), damage to the upstream ceramic catalytic convertor causing pieces of it to enter and damage the cylinder walls (damage appears as white vertical scuff marks on the cylinder walls)
In addition to that, most of those sold in North America are the GDi engines (is yours?) - being GDi, the typical issues you'd expect to find on those are: Carbon buildup on the intake valves, and Clogged PCV valves.
Also, out of curiosity, how frequently was it serviced?
The way I'd troubleshoot it:
- Plug in an OBD2 scanner and see if the O2 sensors seem to be functioning correctly (upstream should bounce, downstream should stay constant once the Fuel system mode reading goes into "CL" / "Closed Loop")
- How do the spark plugs look? replace spark plugs.
- Take out and inspect if the PCV valve moves freely, although I recommend replacing it anyway - they should be a few bucks.
- Perform a wet/dry compression test.
- Borescope the cylinders.
- Check if the engine's intake ports are full of carbon.
- Check the CATs using Scotty's method
Depending on the findings, the route may be different - but if you find it's low compression / severely scuffed cylinder walls, just sell it.
Thank you Dan,
Time and life got away from me & the last major service was at 95k with an oil change at 120k.
The last oil chance was at 120,000 and now you’re at 142,000 - as in a full 22,000 km ago??
Sadly yes , I know I messed up.
the last major service was at 95k
Driving with dirty oil is like putting 100x more miles of wear on an engine. Especially weak engines like Hyundais.
