Mazda SkyActiv DI engines have deposit problems ?

[Mr Nice]

Do Mazda SkyActiv DI engines have deposit problems ?

I've searched and get mixed info whether these DI engines (2.0L and 2.5L) have problems with deposits on valves.

 

[Speak2Mountain]

Can't say categorically yes or not, but it is the nature of beast. I have a 2007 2.5 Lexus w/DI and have had no CBU issues. But, I do try to prevent by:

1) Top Tier Gas
2) Low NOACK and SAPS oil
3) Limit stop and go
4) No lugging in too high of a gear
5) Run this pee out of it on the open roads (not Italian tune up though)
6) Fuel conditioners w/PEA

 

[skyactiv]

My wife had a Mazda3 with the 2L Skyactiv engine. Oddly, it got better fuel mileage new than it did as she put more miles on it.

 

[Eddie]

Several UOAs suggest that it is not an issue. Ed

 

[PimTac]

I haven’t heard of the deposit issues on SkyActiv engines compared to others. That’s not to say they are clear of the issue. Fuel dilution seems to be less compared to other manufacturers as well.

 

[Dyusik]

Mazda says they avoid that by designing intake valves to remain >400(?) degrees during operation. My MIL just got a 2013 3 with 70k on it, and plan to take a peek at the valves as soon as I have free time. Really curious myself.

My 07 IS250 does suffer from the deposits, even after the TSB work (pre catch can). Using an oil with Noack @ 4.7%, there is a discernible amount accumulated over 20k mi time. Adding things to the fuel does absolutely nothing for the valves, though the injectors do need it, even using top tier. For my car though, it only takes half hour or so to tear off, and put together the manifold, and using CRC DI cleaner spray works wonders. Just not through the vacuum line, that's just a waste of time.

 

[Trav]

I have seen some injectors from these with burned out filter baskets, literally incinerated. No in the tank or rail cleaner will clean that, they must be removed and done professionally.
I cant say if it happens to just a few or many as I have no idea how the engines were operated. Some other engines also have this issue, it has to do with the timing of the injector by the ECM. From what I see it seems as the injector pressure drops off there is still combustion taking place with the injector still slightly open.

I did an Audi that looked like someone took a blow torch to the filters, there was no filter left just the brass ring that holds it in. the burned filter material partially clogged the injectors.

 

[Mr Nice]

Trav,

You're talking about Lexus ?

 

[Trav]

No, they seem to be okay. As they all age I will know more.

 

[Mr Nice]

I do know SkyActiv engines have a high compression ratio and designed to have higher cylinder temperatures.