High Mileage Mazda 3, Engine clean, oil for long term

[Johnnyz2]

2007 Mazda 3, 2.3L engine. The car is at 185K miles with basic oil changes at the recommended intervals, or sooner occasionally, but with “nothing special” discount-coupon oil changes for most of them. Almost all of them non-synthetic. There is no noticeable oil loss between oil changes.

In the last 12 months or so, the car has become noticeably less “peppy” than before. In the last two years or so, fuel economy has decreased from 26.5 to about 25 MPG

On the non oil side…
Some scan tool use and testing shows that the various sensors seem to be working reasonably well; however, the car is adding about 6% positive long term trim; so, I’m planning to check fuel pressure and will probably replace the injectors regardless (they are at the end of their expected life). The scan tool analysis suggests that the engine trim strategy is working as intended; so, that may only account for a bit of the sluggishness.

Cleaning and New Oil…
Beside double checking fuel supply, a track racer friend suggested an additional path of an “engine clean” and switching oils. That suggestion and some online content about Valvoline Restore and Protect and I’m falling into the oil “rabbit hole.” That in turn lead me to posts about product like HPL EC and BG EPR, etc.

So, now I’m wondering whether I should do quick "clean" with one of the shorter term products and then switch to a new oil like Valvoline R&P or Pennzoil Ultra Platinum for long term maintenance and ongoing cleaning.

That said, this BITOG discussion suggests to leave it alone: https://bobistheoilguy.com/forums/t...ys-a-good-idea-on-high-mileage-engine.390274/

I don’t think I’d be considering a clean cycle it if not for the performance issue. As for a better long term oil, that seems to be prudent considering we intend to keep the car for some time.

I’d appreciate advice on doing a clean, on a what to do for a long term oil, and recommendations for which products might be best.

 

[JohnnyJohnson]

Two questions what's your tire pressure and how long has it been since it has had a tune up?

 

[SubieRubyRoo]

2007 Mazda 3, 2.3L engine. The car is at 185K miles with basic oil changes at the recommended intervals, or sooner occasionally, but with “nothing special” discount-coupon oil changes for most of them. Almost all of them non-synthetic. There is no noticeable oil loss between oil changes.

In the last 12 months or so, the car has become noticeably less “peppy” than before. In the last two years or so, fuel economy has decreased from 26.5 to about 25 MPG

On the non oil side…
Some scan tool use and testing shows that the various sensors seem to be working reasonably well; however, the car is adding about 6% positive long term trim; so, I’m planning to check fuel pressure and will probably replace the injectors regardless (they are at the end of their expected life). The scan tool analysis suggests that the engine trim strategy is working as intended; so, that may only account for a bit of the sluggishness.

Cleaning and New Oil…
Beside double checking fuel supply, a track racer friend suggested an additional path of an “engine clean” and switching oils. That suggestion and some online content about Valvoline Restore and Protect and I’m falling into the oil “rabbit hole.” That in turn lead me to posts about product like HPL EC and BG EPR, etc.

So, now I’m wondering whether I should do quick "clean" with one of the shorter term products and then switch to a new oil like Valvoline R&P or Pennzoil Ultra Platinum for long term maintenance and ongoing cleaning.

That said, this BITOG discussion suggests to leave it alone: https://bobistheoilguy.com/forums/t...ys-a-good-idea-on-high-mileage-engine.390274/

I don’t think I’d be considering a clean cycle it if not for the performance issue. As for a better long term oil, that seems to be prudent considering we intend to keep the car for some time.

I’d appreciate advice on doing a clean, on a what to do for a long term oil, and recommendations for which products might be best.

The MZR family engine you have is very good. Your “track racer friend” didn’t give you very good advice; don’t ever use a solvent-based cleaner in your crankcase. Restore & Protect is an option, along with HPL Engine Cleaner, but if you pop the oil fill cap and there’s not a bunch of varnish and scum it’s unlikely the oil is your problem, especially when it’s not using/losing anything.

I agree with Johnny at this point; check your tire pressures and put fresh plugs in. Also remember, “pep” is all relative when you’re only talking 160HP, and the butt dyno quickly acclimatizes to a given power level. It’s how the performance aftermarket keeps growing every year.

You didn’t mention, and likely should pursue along with plugs, a bottle or two of Redline SI-1 to clean your injectors. Dirty injectors can easily lead to sluggish response (liquid fuel vs. atomized fuel does not burn) and also contribute to a perceived loss in economy.

 

[kschachn]

In the last 12 months or so, the car has become noticeably less “peppy” than before. In the last two years or so, fuel economy has decreased from 26.5 to about 25 MPG

On the non oil side…
Some scan tool use and testing shows that the various sensors seem to be working reasonably well; however, the car is adding about 6% positive long term trim; so, I’m planning to check fuel pressure and will probably replace the injectors regardless (they are at the end of their expected life). The scan tool analysis suggests that the engine trim strategy is working as intended; so, that may only account for a bit of the sluggishness.

I wouldn't expect a peppyness improvement from any change to the oil.

 

[tig1]

I have the same engine in my 2007 Ford Fusion with 331K. My engine still remains very clean, shows no sign of engine wear, uses only 6-8 oz of oil in my usual 10K Oci. Only oil I ever used is M1. I use NGK plugs and change them ever 100K. Also I put 10 OZ of MMO in the fuel every 3-4 fill ups. This routine has worked great for me in my 2.3.

 

[TwoC400s]

My thoughts/questions in no particular order.

1) clean your MAF
2) when was the last EGR valve replacement/cleaning?
3) Has it ever had fuel system treatment?
4) Four Valvoline restore and protect oil changes might help, it might not
5) Save your money when it comes to the quick flush products
6) when were the spark plugs and ignition coils last replaced?

 

[addyguy]

The oil isn’t the issue to look at; on-interval changes with even bulk 5W-20 will not cause enough deposits to affect engine running. Those Mazdas run fairly clean.

 

[Johnnyz2]

Two questions what's your tire pressure and how long has it been since it has had a tune up?

Every month on tires. Replaced plugs about 30K back.

I also plan to check the ignition coils. No codes but it is possible that one or more are producing too little spark.

 

[Johnnyz2]

The MZR family engine you have is very good. Your “track racer friend” didn’t give you very good advice; don’t ever use a solvent-based cleaner in your crankcase. Restore & Protect is an option, along with HPL Engine Cleaner, but if you pop the oil fill cap and there’s not a bunch of varnish and scum it’s unlikely the oil is your problem, especially when it’s not using/losing anything.

I agree with Johnny at this point; check your tire pressures and put fresh plugs in. Also remember, “pep” is all relative when you’re only talking 160HP, and the butt dyno quickly acclimatizes to a given power level. It’s how the performance aftermarket keeps growing every year.

You didn’t mention, and likely should pursue along with plugs, a bottle or two of Redline SI-1 to clean your injectors. Dirty injectors can easily lead to sluggish response (liquid fuel vs. atomized fuel does not burn) and also contribute to a perceived loss in economy.

I do regularly run injector cleaner as well. However, the injectors are past their expected life and I'm planning to proactively change them.

 

[twX]

however, the car is adding about 6% positive long term trim; so, I’m planning to check fuel pressure and will probably replace the injectors regardless (they are at the end of their expected life).

Positive fuel trims mean that the ECM is needing to add more fuel. Worn injectors would cause negative fuel trims, since they would be flowing more than new injectors. Dirty injectors might flow less and therefore cause positive fuel trims. I'd use some PEA fuel injector cleaner to see if that improves the fuel trims. Even though the ECM is able to correct the fuelling, if some injectors are flowing more than others, either due to wear or deposits, it could affect engine performance.

Positive fuel trims could also mean that your MAF is reading low. This will advance the ignition timing and cause more knock, which the ECM will react to by retarding timing. If you can monitor for knock readings, I would do that. Otherwise I'd just clean the MAF sensor.

 

[Johnnyz2]

My thoughts/questions in no particular order.

1) clean your MAF
2) when was the last EGR valve replacement/cleaning?
3) Has it ever had fuel system treatment?
4) Four Valvoline restore and protect oil changes might help, it might not
5) Save your money when it comes to the quick flush products
6) when were the spark plugs and ignition coils last replaced?

1. Cleaned regularly. Seems to be reporting as expected (from scan tool graphs)
2. About 100K. Not since
3. Fairly regularly. Generally with techron sometimes with the on sale option. A few times with seafoam.
5. Glad I asked here. Everyone seems to agree.
6. About 30K back on plugs. Coils never. They too are getting to the end of their expected life. I will be testing spark length and color to see if any are underperforming. Will replace as needed.

 

[thastinger]

When was the fuel filter last changed?
That engine will outlive you.

 

[Johnnyz2]

Positive fuel trims mean that the ECM is needing to add more fuel. Worn injectors would cause negative fuel trims, since they would be flowing more than new injectors. Dirty injectors might flow less and therefore cause positive fuel trims. I'd use some PEA fuel injector cleaner to see if that improves the fuel trims. Even though the ECM is able to correct the fuelling, if some injectors are flowing more than others, either due to wear or deposits, it could affect engine performance.

Positive fuel trims could also mean that your MAF is reading low. This will advance the ignition timing and cause more knock, which the ECM will react to by retarding timing. If can monitor for knock readings, I would do that. Otherwise I'd just clean the MAF sensor.

I did check for retarded timing and that was not reported by the scan tool. Just in case, I'll double check.

The MAF has never been replaced but cleaned a number of times. I'll clean it again and check readings again.

 

[Johnnyz2]

When was the fuel filter last changed?
That engine will outlive you.

Never. I do plan to check fuel pressure etc. As I think about how old it is, that's a proactive change that makes sense.

 

[thastinger]

Never. I do plan to check fuel pressure etc. As I think about how old it is, that's a proactive change that makes sense.

At 185K on the original fuel filter I would bet the LTFT comes back in line once you change it out and reset the trims for the adaptive learning cycles (disconnect the battery).

 

[Johnnyz2]

For my engine and miles, what are the recommendations for a long term oil. Switch to a synthetic or should I stick with standard oil?

Before starting this thread, I had been thinking of Valvoline R&P or Pennzoil Ultra Platinum based on "The motor oil geek" videos. Are those good choices? Are there other good options?

 

[Urshurak776]

For oil, I would do a few changes with VRP. Refresh the fluids (transmission/coolant.) Clean MAF. For coils, I imagine those can be checked electrically (resistance or something? I don't know about that.) I don't think the fuel filter is serviceable? May be on those though. I don't know much about the 2.3

Sounds like a great car!

 

[WobblyElvis]

will probably replace the injectors regardless (they are at the end of their expected life).

Injector past their expected life?

I expect mine to last a million miles or more.
My cars run a long time and none of them have needed an injector.
Reading articles on "million mile cars" seldom do they mention changing the injectors.
I suggest you save your money.

 

[katnapped]

Never. I do plan to check fuel pressure etc. As I think about how old it is, that's a proactive change that makes sense.

You don't have one aside from what's attached to the fuel pump in the tank.

 

[buster]

VRP