Burning engine oil
2024 Mazda CX5 Mazda has replace valve cover oil pan seal and timing cover. Mazda suggested engine oil die. No signs of a leak when the issue started there was a pool of oil near the intake. Mazda experts have no work around just fills the cabin with burnt oil. Any suggestions
Last edited by Koconnor; Jul 1, 2025 at 04:08 PM. Reason: 2024 CX-5
If you can smell it inside there's Oil getting on the Exhaust Manifold. Spray that area with Simple Green Cleaner, let it work for 30 minutes then hose it off. Avoid Electrical components. It takes a while to burn off the residual oil from the leak.
I second the Simple Green idea.
Also, if you have a local "manual" car wash most have the "engine clean" option.
You can select this to "spray" clean your engine but be careful to keep spray away from the fuse box area and air intake.
And also make sure you dry the bay out afterwards by going on a long drive or leaving the hood up.
Also, if you have a local "manual" car wash most have the "engine clean" option.
You can select this to "spray" clean your engine but be careful to keep spray away from the fuse box area and air intake.
And also make sure you dry the bay out afterwards by going on a long drive or leaving the hood up.
The use of simple green to clean the engine is fine but DONT let it set on your engine, and other under the hood components and part for 30 minutes. The most is a few minutes or less then 5 minutes tops! Simple green does have negative effect on adhesive material and can also discolor many or the parts under the hood.
It is better or wiser choice to use car wash soap and wash and rinse with a simple hose attachment for car washing.
I would also at least caution using high pressure car wash booths because you could end up being stuck with a no start engine and or a lot of miss fire cylinders.
You have been warned!!!
This or similar;
It is better or wiser choice to use car wash soap and wash and rinse with a simple hose attachment for car washing.
I would also at least caution using high pressure car wash booths because you could end up being stuck with a no start engine and or a lot of miss fire cylinders.
You have been warned!!!

This or similar;
Last edited by Callisto; Jul 7, 2025 at 10:11 AM.
On the subject of oil burning. In New Zealand we have a lot of CX-5's on the road they're very popular here. Disregarding the 2.2 diesel, I'm finding that some of the 2.0 & 2.5 litre engines are starting to use oil between services. There are no leaks to be found. For example my wife's 2018 2.5 litre N/A with 220'000 kilometres is starting to use oil, currently using 5w-30. What's your thoughts on going up to 5w-40, 10w-30 etc but full synthetic? It is quite the debate over here.
Not unusual for vehicles with that many miles to burn/use at least some oil.
Engines don't last forever, and the rings valves and seals are always wearing down.
At some point even they need replacing.
Engines don't last forever, and the rings valves and seals are always wearing down.
At some point even they need replacing.
Maybe I've been lucky, but I never had an issue with Simple Green to clean my engines, including motorcycles and boats.
Directions say let set a maximum of 3-5 minutes and to cover certain areas with plastic. Granted that only applies to those who read directions.
The local car wash I use has adjustable spray settings and is far less harmful than all the road saline solutions and saltwater fog my engine bay is subject to much of the year.
Directions say let set a maximum of 3-5 minutes and to cover certain areas with plastic. Granted that only applies to those who read directions.
The local car wash I use has adjustable spray settings and is far less harmful than all the road saline solutions and saltwater fog my engine bay is subject to much of the year.
On the subject of oil burning. In New Zealand we have a lot of CX-5's on the road they're very popular here. Disregarding the 2.2 diesel, I'm finding that some of the 2.0 & 2.5 litre engines are starting to use oil between services. There are no leaks to be found. For example my wife's 2018 2.5 litre N/A with 220'000 kilometres is starting to use oil, currently using 5w-30. What's your thoughts on going up to 5w-40, 10w-30 etc but full synthetic? It is quite the debate over here.
The suggestion that changing the oil viscosity is an example of those that do not understand what happens when you change viscosity best suited for the engine operation environment.
If one thinks that if the engine is using oil i.e. "burning" oil then going to a higher viscosity will reduce that amount then they are mistaken. The same amount of oil gets consumed in the engine only now you are feeding the carbon build up in the combustion chambers more so than choosing the proper viscosity oil. Then there is the misconception of information between oil burning or consumption and if it makes a difference between using synthetic, synthetic blend, nonsynthetic or even nondetergent motor oils. The amount of burring oil in the engine by volume is the same no matter what engine oil is chosen to use. The cause of burning oil is related to a mechanical condition of parts or the chosen parts used in the engine i.e. rings that control the oil as well the machining finish of the cylinder hone and its current condition. Then there is the valvetrain and it parts that can relate to oil consumption. Did the valve guides or seal start to fail, or are just worn out from normal wear, lack of service or in the very very few cases a product defect which would have at least with MAZDA reported a TSB with VIN and or model year and engine size effected information?
So basically, in the HOT TOPIC debate areas of any given forum or platform for the matter with 90% or greater DIY or just plain average owners without any real empirical information or real data then that is all it is just another conversation filler on a forum.
Maybe I've been lucky, but I never had an issue with Simple Green to clean my engines, including motorcycles and boats.
Directions say let set a maximum of 3-5 minutes and to cover certain areas with plastic. Granted that only applies to those who read directions.
The local car wash I use has adjustable spray settings and is far less harmful than all the road saline solutions and saltwater fog my engine bay is subject to much of the year.
Directions say let set a maximum of 3-5 minutes and to cover certain areas with plastic. Granted that only applies to those who read directions.
The local car wash I use has adjustable spray settings and is far less harmful than all the road saline solutions and saltwater fog my engine bay is subject to much of the year.
Go look at parts painted or coated black (mostly chassis and suspension) if you don't wipe them down with a clean wet rag with water only rinsing alone does not remove all of the simple green residue that remains.

And then there is the little areas like wire looms that the simple green gets into and does not always rinse out. It will dry to a white powder and eventually could cause continuity issues with connectors.
Hey I use simple green all the time, I would say close to daily. So much that I buy the 2.5 gallon jugs.

Last edited by Callisto; Jul 8, 2025 at 09:58 AM.
After using Simple Green I also wash with detergent, rinse and then wipe down.
Living on the coast, well water here is very high in iron content, requiring some form of water system unless you like having everything turn the same orange color as certain leaders face.
All the treatment systems leave a white residue, because of the chemicals and/or salt they use.
I'd be hard pressed to determine, without a chemical analisys, if the residue is Simple Green, treated well water, saltwater fog, road deicing salt/chemicals or just stinky lobster bait...
Living on the coast, well water here is very high in iron content, requiring some form of water system unless you like having everything turn the same orange color as certain leaders face.
All the treatment systems leave a white residue, because of the chemicals and/or salt they use.
I'd be hard pressed to determine, without a chemical analisys, if the residue is Simple Green, treated well water, saltwater fog, road deicing salt/chemicals or just stinky lobster bait...



