2023 Corolla Hybrid GR sport coolant ingress into engine

[Obsidian Estate]

 

[Kermit746]

I have an update on the possible coolant penetration into the engine causing a coffee cream like deposit under the rocker cover and oil filler cap, plus on the dipstick.

The car went in on the 23Jan2024 @ 08:00hrs and I collected it on the 25Jan2024 around 13:00hrs (long time as if I were doing he diagnostic work myself it would have been done in a day).

Anyway on the report that I quested, they performed two drain and refills of the oil with heat cycling, along with a coolant system pressure test to the rating of the coolant filler cap 86KPA for 20min with no pressure loss.

Basically from this nothing has been found, but if I were doing the diagnostics, I would have had an engine oil analysis performed ( I've used Millers oils in the past to diagnose a failing EGR valve on a T5 transporter from their results).

I guess now I need to keep an eye on things as I did before and insist that a oil analysis if performed next time. 

It's not the 7 mile trip to and from work five days per week (the engine gets up to normal operating temp quickly as the main percentage of the trip is motorway and fast A road) as I have been doing this for over two years in the 1.8 Corolla company car and now the other half uses it more that me covering far less miles per trip with no issues seen to date.     

The dealer also said that if the car isn't used for a period of time, it could cause this issue. Over Christmas and new year it wasn't used for a week and a half. Before this period, on inspection nothing was found, but after a weeks use after the christmas break I spotted it and flagged it in an email to the dealer. 

Concluding: I am not that happy with what diagnostic checks that were performed, plus the fact that I had to insist that a coolant system pressure test is performed, plus also having to chase them daily for updates, all of which seems a bit of a joke.

Further update to come.