2005 Mazda3, Startup noise after synthetic switch

[bigcitrus]

I have a 2005 Mazda 3 with the 2.3 liter engine and 73k miles. Bought the car with 30k, and was using conventional 5W20 (factory recommendation) oil up until a couple of oil changes ago when I switched to 5W20 synthetic.

I then started to notice a split second of sewing-machine valvetrain noise at every startup. It went away almost immediately after startup--I never heard it while driving.

I mentioned this to my mechanic at my next oil change, and he went to a 10W30 semi-synthetic. The noise is gone (or less obvious, anyway), although I'm wondering if 10W30 is really the right choice.

Here's the conundrum for me--5W20 is a relatively lightweight oil, and it's my understanding that one of the benefits of lightweight oils is better protection on cold starts. Same goes for synthetics, which are theoretically slipperier. If all of that is true, why did my car develop the noise on 5W20 synthetic, when it's quiet on 5W20 conventional or the current 10W30 semi-synthetic?

My pet theory, which admittedly isn't based on any scientific fact, is that the 5W20 synthetic is TOO slippery, and all of the oil runs out of the head and lifters overnight, leaving everything dry the next morning. The lack of residual oil in those spots is what creates the noise. Meanwhile, the conventional 5W20 and the semi-syn 10W30 both leave enough oil behind to keep everything lubed for that split second before the pressure comes up.

I like synthetic for the extended change intervals, but now I have no idea what to go with on the next change. For the time being, I'm eliminating 5W20 full synthetic since that's what led to the startup noise. Past that, should I go with:

1. 5W20 conventional?
2. 5W30 synthetic or semi-synthetic?
3. 10W30 synthetic or semi-synthetic?
4. Something else?

And, I guess the final question is...the noise SOUNDS bad, but is it really hurting anything?

 

[SrDriver]

I had the same problem with a Mazda. Was caused by not using an OEM oil filter and not the oil.

Changed the oil filter and all was good.

Ran the same weight synthetic oil all the time.

 

[SigQAEngineer]

I encountered the same problem once when I switched to K&N oil filter, once I switched back to OEM filter noise went away.

 

[frank2009]

Yeah I think the above posters got it! I have an '08 Mazda 3 with a 2.0. I'm guessing the motors are similar. I'm not one for playing amateur tribologist. Stay with 5W-20, assuming that's what the manual says.

I run a motor craft FL910s, after all it's a Ford motor, and have no problems or funny noises.

 

[aquariuscsm]

Does your manual have a list of various recommendations of oil weight vs ambient temperature? Also,what brand synth gave you the startup noise?

 

[FZ1]

4. Try a 5w-20 blend and the oem filter.

 

[gaijinnv]

Go with an OEM filter - it's the filter, not the oil that is most likely causing your startup noise.

 

[901Memphis]

10w30 will produce more wear due to incorrect start up viscosity.

Noise is typically a filter issue.

Did you use different filters with each new fill?

Your theory about oil falling off the engine is just as common as it is incorrect. The lightest oil at startup should get back to the parts the fastest, the oil film left on the parts lasts years.

 

[RF Overlord]

^^^what 901Memphis said^^^

Although I'm not sure whether the oil film will last for "years", it will certainly last more than overnight, so your theory is busted.

There has been so much anecdotal info about different oils producing different sounds, that it may also be simply the change in brand. I have excellent hearing and there was a definite change in the "start-up" sound of my DD when I switched from MC 5W-20 to M1 5W-30.

As for your final question, no it isn't hurting anything, but why not switch back to the first oil on your next change and see it it goes away? No reason to use an oil that makes you uncomfortable.

You could also try switching out the filter for an OEM Mazda one and see if that makes any difference.

 

[Mark_Walk]

Does the car have the cartridge filter or spin on? If spin on use an FL400s if it will fit. Also, the Motorcraft 5w20 semi syn is a great oil for this car.

 

[tig1]

Try M1 0-20. I have the same engines as your Mazda and I have no engine noise at start. I also use MC filters.

 

[gregk24]

Both 5w20 conventional and 5w20 synthetic are just that...5w20! same weight. So like most of the posters have said, its probably the oil filter. I used a Fram Ultra on my Accord and it ticked on start up. Running an OEM now and no issues.

 

[J. A. Rizzo]

If it sounds best with conventional 5W-20, I would use that in whatever flavor meets Mazda recommendations at the lowest cost. Any noises you hear for a small amount of time are almost completely meaningless as far as the life of the engine. People will make a huge hubbub about it, but they are crazy. It's nothing. Drive it and enjoy it, and use the lowest cost oil in Mazda's recommendations you possibly can. You will be 100% satisfied with the car and it will last you a very long time.

 

[Clevy]

10w-30 is not the Mazda recommended grade. Tell your mechanic he is using an oil that no oem specifies anymore,and hasn't for decades.
He owes you a refund for wasting the good oil you had in the first place.
The Mazda 0w-20 oil is great,and I'd use it over all others. Its formulated for your Mazda.
The start up noise is the filter letting the oil bleed out of the top end. Use an oem filter.
And synthetic oil isn't more slippery than conventional. Its oil. Period. The additive package of the oil itself determines the slipperiness and that is usually dependent on the friction modifiers in the oil.
So basically all your oil beliefs are incorrect.
Use the Mazda branded full synthetic and an oem filter. The Mazda oil has a huge shot of moly and has a super high viscosity index.
And forget the 30 grades. 0w-20 is what you want. As Mazda how long you can extend the interval with their 0w-20 synthetic or do a couple of uoa to determine oil change interval.
And tell your mechanic about bitog and explain to him that his oil knowledge is extinct and he needs to look over the cliff notes from the past 30 years.

 

[OVERKILL]

Originally Posted By: Clevy
10w-30 is not the Mazda recommended grade. Tell your mechanic he is using an oil that no oem specifies anymore,and hasn't for decades.
He owes you a refund for wasting the good oil you had in the first place.
The Mazda 0w-20 oil is great,and I'd use it over all others. Its formulated for your Mazda.
The start up noise is the filter letting the oil bleed out of the top end. Use an oem filter.
And synthetic oil isn't more slippery than conventional. Its oil. Period. The additive package of the oil itself determines the slipperiness and that is usually dependent on the friction modifiers in the oil.
So basically all your oil beliefs are incorrect.
Use the Mazda branded full synthetic and an oem filter. The Mazda oil has a huge shot of moly and has a super high viscosity index.
And forget the 30 grades. 0w-20 is what you want. As Mazda how long you can extend the interval with their 0w-20 synthetic or do a couple of uoa to determine oil change interval.
And tell your mechanic about bitog and explain to him that his oil knowledge is extinct and he needs to look over the cliff notes from the past 30 years.


I believe Dodge actually specified (specifies?) a 10w-30 for one of their engines. I remember it because it was weird and has been mentioned on here a number of times

 

[killswitch83]

Originally Posted By: OVERKILL


I believe Dodge actually specified (specifies?) a 10w-30 for one of their engines. I remember it because it was weird and has been mentioned on here a number of times

This. My 99 Ram 1500 5.9L 360 calls for it in the FSM (IIRC) and OM, thus I run QSUD 10w30. I wonder though if it's back-spec'd for anything different?

Edit: Found the temp diagram on page 17 (or 0-4 of the FSM). 32F and under allows for 5w30, while temps 0F and above specs 10w30.

 

[CharBaby]

I would stay with the 5w20 but, no higher than 5w30( or 0w).
I believe the 2.3L has a cartrige filter as my daughters '06 Mazda3 2.0L has a spin on filter. I use either 5w20 or 5w30 and Puro Classic/PureONE in her engine without any startup noise issues.

 

[bigcitrus]

Thanks for all the great info, everyone.

I don't know what filter has been used in the past, although for what it's worth I assume that the same filter was used for both the 5W20 and the 5W20 synthetic, and the noise was only with the synthetic.

But, I think I'll take a crack at the 5W20 synthetic the next time around, but make sure I'm getting an OEM filter. If that doesn't do the trick, maybe I'll go back to good old dino oil.

 

[charmicarmicat]

Guys, the MZ3 2.3l has a cartridge filter. The ADBV is not in the filter. So I don't think the filter is to blame in this case.

 

[bigcitrus]

Just a quick update. I checked with the shop that did the original 5w20 full synthetic change that caused (maybe) the startup ticking. They confirmed that they always use OEM filters (which is indeed a cartridge filter for this engine. So, as far as I can tell, the only difference between ticking/not ticking is conventional vs. synthetic.

I made an appointment for an oil change on Monday, and I figure I have two options:

1. Go back to 5w20 conventional and resign myself to more frequent changes, but possibly eliminate the startup noise.

2. Go with 5w20 synthetic and ignore the startup noise.

Any thoughts/possible "option 3" ideas?