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View Full Version : Taking our other car into the shop, looking for thoughts on the issue...



johnsnownw
June 22nd, 2014, 10:12 PM
Our 2013 Mazda 6 has 12,000 miles, and has 1500 miles left before the scheduled oil change. Anyway, we took a trip down to my parents and while driving I noticed that between 3000-4000 rpm the car would have a power drop, or hesitation, or just not a smooth acceleration (I'm not sure exactly what to call it, or how to describe it well). The burp, or whatever the hell one might call it, happened in every gear, but seemed to happen at slightly different points, between 3 and 4k in each gear.

So...WTF?

Wagoneer
July 1st, 2014, 09:55 PM
Nowadays with VVT engines are extremely sensitive to oil viscosities. I found the exact same thing with the SX4 when I still used regular oil. Whenever I pushed the car or on a long highway trip the car would lose a bunch of torque in the low and mid-range, it felt like the car was pulling timing. I really think was caused by the oil thinning out with higher temps and screwing with the VVT (it's electronically controlled but oil pressure activated). After the engine got up to temp it would idle like a diesel and it would search for a consistent idle speed. The problem got worse the longer I went between oil change intervals.

Now that I switched to synthetic the problem went away completely. I think all newer engines, whether they say it or not, are designed around synthetic oil that holds a constant viscosity whether it's hot or cold.

johnsnownw
July 1st, 2014, 09:59 PM
Nowadays with VVT engines are extremely sensitive to oil viscosities. I found the exact same thing with the SX4 when I still used regular oil. Whenever I pushed the car or on a long highway trip the car would lose a bunch of torque in the low and mid-range, it felt like the car was pulling timing. I really think was caused by the oil thinning out with higher temps and screwing with the VVT (it's electronically controlled but oil pressure activated). After the engine got up to temp it would idle like a diesel and it would search for a consistent idle speed. The problem got worse the longer I went between oil change intervals.

Now that I switched to synthetic the problem went away completely. I think all newer engines, whether they say it or not, are designed around synthetic oil that holds a constant viscosity whether it's hot or cold.

Yeah, I took it to the dealership and couldn't reproduce the issue. They had no idea when I described what was going on. I got the oil change, and we're going on a longish trip toward the end of the month. I'll see if it starts acting up again, but I suspect you may be right and I won't see it again until further into the life of the oil.

midnightsx4
July 1st, 2014, 11:37 PM
Second oil change?
Mineral oil or synthetic?

johnsnownw
July 2nd, 2014, 07:17 AM
Second oil change?
Mineral oil or synthetic?

This is the 4th oil change. Whatever the dealership puts in there. It's the wife's car, and she doesn't care what goes in it.

twistedcherokee
July 2nd, 2014, 07:19 AM
Was it more on a hill? Wide open throttle or moderate throttle. Since it is online, the more info you give us the better. Is it just a short burp (100-300 rpm's) or longer? Hot out or on the cool side? Wet or dry? Good luck

Toby

johnsnownw
July 2nd, 2014, 11:14 AM
Was it more on a hill? Wide open throttle or moderate throttle. Since it is online, the more info you give us the better. Is it just a short burp (100-300 rpm's) or longer? Hot out or on the cool side? Wet or dry? Good luck

Toby

Short burp (really short, I'd say less than the span of 100rpm), wide open throttle, moderate temperature (low 80's), both dry and wet.

Samus
July 4th, 2014, 01:25 PM
Im at around 21000 km with mine and I still have mineral oil... When I asked to get full synthetic at my last oil change (15000 km) they told me wait at around 20000 km because it will mess-up my garantee... With my 2011 it was the same situation with the delearship. Its a world of difference having a vvt engine with synthetic oil. Often during idle after a long drive my rpm varies from 500 rpm to 600 rpm back and forth for a few seconds until it settles to 500 rpm.

midnightsx4
July 4th, 2014, 07:46 PM
Fair analogy would be comparing recent oil change for my bike. Last oil change decided to use Mobile 1 racing4T oil. From day one the engine sounded different, wet clutch engagement was also affected. It was too sensitive, like trigger on a sniper rifle.
Since I've gone back to Rotela T6( btw it is diesel oil 5w40 full synthetic), things have become normal. I got back smooth shifts, engine has quieted down.
So oil does play crucial role how engine performs, especially with VVT valve train.

Cheers. . .

Pete the Pirate
July 5th, 2014, 07:07 AM
And it is all mineral oil. Synthetic is just more accurately refined.