CX-9 Oil Issue

[justmazdas]

Hey

So I’ve got the 2.5T CX-9, with 91k miles. I bought it used at 56k miles.

I’m hoping someone here has had a similar experience or issues and can help me put together what’s going on.

I’ve been experiencing “rough idling” every now and then. Usually when I come off the highway. Usually it skips for a few seconds and then it’s good.

I’ve had high oil consumption. I noticed recently I’ve been running through oil. My VIN falls in the range for potentially bad Valve Stem Seals, so I’m thinking it’s that. I’m hoping that’s also the cause for the rough idling. I’m going to hope Mazda could replace them, but I’m past the 84,000 extended warranty for it.

Where I’m at a loss. I noticed initially that my oil dipstick had been pushed up during a drive and some oil had shot out. I took it to the mechanic and he said that during idle, the pressure in the crank case was normal. But I’m not sure if maybe there’s a pressure issue while driving. Has anyone had something like this?

 

[Lazy2.5]

I've never heard of an oil dipstick being pushed up. are you sure it was secured properly in the first place? I would double check and monitor that..

As far as the rest of your issues, i mean, you could start with a compression test, but obviously you have issues with the compression if you are burning oil.

You'd have to pinpoint whether it is indeed the valve stems causing the consumption and then decide (if that is the case) if you want to rebuild the engine and replace it.

In the meantime, I would try some stop-leak additives, with thicker oil, like 10w30 to help slow down consumption somewhat.

 

[Silly Wabbit]

What year? Spark plugs change every 40k? What is your oil change interval? How much oil you lose?

 

[Lazy2.5]

I mean, it's useful to know, but What does spark plug change frequency and OCI have to do with oil consumptiom

 

[Mazdiod2]

Hey

So I’ve got the 2.5T CX-9, with 91k miles. I bought it used at 56k miles.


Where I’m at a loss. I noticed initially that my oil dipstick had been pushed up during a drive and some oil had shot out. I took it to the mechanic and he said that during idle, the pressure in the crank case was normal. But I’m not sure if maybe there’s a pressure issue while driving. Has anyone had something like this?

I think it's possible that if you have excessive blow-by you can have that happen.
Have you noticed when you are using the oil? Does it smoke at particular times? What kind of oil have you been using?
I guess often oil consumption results from leaky valve stem seals or the oil rings.

 

[Silly Wabbit]

I mean, it's useful to know, but What does spark plug change frequency and OCI have to do with oil consumptiom

OP mentioned rough idle

 

[justmazdas]

What year? Spark plugs change every 40k? What is your oil change interval? How much oil you lose?

Spark plugs changed at 60k when I got it since I wasn’t sure if they were done. Not done again yet.
I was doing 7500, but now I’m going to start doing every 5k. I haven’t experienced high oil consumption until my last oil change at 87.5k. I noticed the light came on, checked the oil and it was a little low. Same thing this time now at 91k. I would say I’m missing at least a quarter of and a half.

 

[justmazdas]

I think it's possible that if you have excessive blow-by you can have that happen.
Have you noticed when you are using the oil? Does it smoke at particular times? What kind of oil have you been using?
I guess often oil consumption results from leaky valve stem seals or the oil rings.

My thought was initially blow-by and was thinking PCV valve or oil rings. But I’m just going to move forward thinking I must have not secured the dip stick back that one time and oil came up through it during a drive.
I’m leaning towards it being the valve stem seals because I’m in the range listed on the TSB. But I also haven’t noticed the blue/gray smoke

 

[justmazdas]

I had checked one spark plug, and didn’t notice carbon buildup. I’m going to check the others tomorrow.
I definitely don’t have an oil leak, so it must be burning off somewhere. Mechanic was thinking either the valve stem seal issue or maybe a leak in the turbo. Anyone have ideas to narrow it down?
FYI I’ll be bringing it to Mazda and see if they will cover the valve seals, but was hoping to narrow it down before I go in and get a full engine rebuild

 

[Silly Wabbit]

I think you should first try to quantify the oil consumption. How much goes in, how much you need to add, how much comes out.

For me (2016), the manual calls for 5.1qt but my oil light will definitely light up before my next oil change. So I usually add about 5.2qt and that works get me to the high side of the dip stick. When I drain my oil, I get close to 5qt at 5k interval. So my engine "burns" oil too but at least it's not at an alarming rate.

 

[justmazdas]

I think you should first try to quantify the oil consumption. How much goes in, how much you need to add, how much comes out.

For me (2016), the manual calls for 5.1qt but my oil light will definitely light up before my next oil change. So I usually add about 5.2qt and that works get me to the high side of the dip stick. When I drain my oil, I get close to 5qt at 5k interval. So my engine "burns" oil too but at least it's not at an alarming rate

I’m planning to change my oil this weekend, and will better be able to keep track of exactly how much is being lost. I can say I put in 5.1 quarts at 87.5k and have had to put an extra quart in to get it back towards the top dot. None of this was really on my radar before. When I saw I had gone through some extra oil last time I just chalked it up to the high mileage and put in high mileage oil last time.

I’ll be able to better track and quantify now that I know i could have a bigger issue

 

[Lazy2.5]

I think you should first try to quantify the oil consumption. How much goes in, how much you need to add, how much comes out.

For me (2016), the manual calls for 5.1qt but my oil light will definitely light up before my next oil change. So I usually add about 5.2qt and that works get me to the high side of the dip stick. When I drain my oil, I get close to 5qt at 5k interval. So my engine "burns" oil too but at least it's not at an alarming rate.

.2 qt could easily be what's left behind in the bottom of the oil pan, completely insignificant if it is indeed consuming it

 

[justmazdas]

This is the startup after 10 hours sitting. It’s 55 degrees outside. What do you guys think? Is this beyond the normal startup white vapor? To me, it’s not obviously blue but I could be convinced

 

[Lazy2.5]

View attachment 382761
This is the startup after 10 hours sitting. It’s 55 degrees outside. What do you guys think? Is this beyond the normal startup white vapor? To me, it’s not obviously blue but I could be convinced

looks perfectly normal. you exhaust tips don't look too dirty either.

 

[justmazdas]

looks perfectly normal. you exhaust tips don't look too dirty either.

So now the game is trying to figure out where the oil is burning, if I rule out the valve stem seals.

 

[Lazy2.5]

So now the game is trying to figure out where the oil is burning, if I rule out the valve stem seals.

Oil burning won't always show up as obvious smoke through the exhaust, especially not at idle.

 

[Lazy2.5]

But we obviously know the engine is burning oil. Because it's low.

Do you have any CEL?

If the dealer doesn't wanna cover the valve stem thing, go to a good mechanic to figure out what's up with it

 

[justmazdas]

But we obviously know the engine is burning oil. Because it's low.

Do you have any CEL?

If the dealer doesn't wanna cover the valve stem thing, go to a good mechanic to figure out what's up with it

No engine light. I think what I’ll do at this point is change my oil out, and see exactly where it is after 1,000 miles. I want to be able to go to Mazda and say this is exactly how much I’m burning per 1k miles. I know I could just bring it to them and let them troubleshoot, but I want it be as accurate as possible

 

[Lazy2.5]

No engine light. I think what I’ll do at this point is change my oil out, and see exactly where it is after 1,000 miles. I want to be able to go to Mazda and say this is exactly how much I’m burning per 1k miles. I know I could just bring it to them and let them troubleshoot, but I want it be as accurate as possible

If it's out of your pocket, don't waste your time trying to get them to troubleshoot anything.

Since you're out of warranty, worth a shot talking to the manager, but don't count on it

 

[justmazdas]

If it's out of your pocket, don't waste your time trying to get them to troubleshoot anything.

Since you're out of warranty, worth a shot talking to the manager, but don't count on it

I saw someone else noted the valve stem seal repair was increased to 96k miles. So I’m hoping it’s either covered or they goodwill it