Hey guys so basically i had the Mazda oil fully synthetic made for the rx8 dexelia 5w30 and went to the dealer to buy some more oil and he told me i should use some mineral oil non synthetic i filled my engine with this one ... a couple days later i felt a loss of power ( feels like a dead clutch when u accelerate ) i drive it REDLINE Everyday.

Can it be the oil ? or is it just the clutch ?

i didn't had ANY problem with the clutch before

Basically it take a extra 3 seconds every time i shift in redline.

No problems at low RPM's

Thanks guys

 

I am half tempted to close this before it gets out of hand.


The short answer is that synthetic oil will not harm your engine. I assume by "mineral oil" you mean standard dino oil. That will not harm your engine either.

The dealer is misunderstanding Mazda's statement about synthetic oil. They can not provide an active recommendation for synthetic, but they do not prohibit it either.

There is a very very very slight difference in power and mileage based on weight of oil, but not the type of oil.

What you are feeling is not related to your change of oil types.



However, could you describe the power loss more completely? When it happens, when it doesn't happen, etc... Not sure what you mean by a "dead clutch".


High RPM power loss is usually ignition failure, clogged cat, or a fuel delivery problem.


(Moved to Troubleshooting)

 

thanks for answer.

It feels like when i switch gears in high rpm's quickly the rpm's doesn't have time to lower so it makes a loud noise when i switch up then the rpm goes down and then goes up again normally so just feels like clutch is sliding .... if that's can't be oil then it must be the clutch... drove this rx8 10k km's and already had dead battery rear shock dead ( i guess ) starter almost dead clutch dead ( only high rpms ) . i love the car bought it used so ill have to deal with the old owners manners myself.

I can't describe it any better. i guess i would have to film it...

 

Ok, that is a bit clearer. It does sound like you are slipping the clutch. Do you smell something that smells like burning rubber, only more sulfur in it?

 

No it just don't grip like it use to ... u know when you switch gear and the tires spins it grips and stuff... now its just weak... slow ...annoying and take longer to reach higher speeds... ill try to take a small videoclip and post it here in a few hours to show what I'm talking about. no smell or anything and clutch seems FINE under 6k

 

Is your RPM staying fixed to the speed? Or can it move around when in gear without the speed changing? I don't shift like you are describing, so having trouble relating, though it might be a language barrier.

If it's staying solid, then it might be a clogged cat causing significant power loss.

 

See how rpm are slowly sliding down and not going straight down even thought i hit the gas ? feels weak

 

your dealership is full of idiots, Synthetic oil is NOT the cause. in fact, if they continue to bitch, show this to them to shut them up.



It doesn't look like your clutch is slipping, hard to tell from an internet video, take it to any garage out there, any mechanic who has drove MT car long enough will be able to tell if it's slipping or not in 10 seconds.

Check your cat, coils, wires and plugs.

 

ok thanks

0:05 in the video you can see it slip while I'm hitting gas.

 

Hmm, that "slipping" looks like you are engaging the clutch slowly. And when you are still hitting the gas the RPM is higher than where it would be if the clutch was fully engaged, the drivetrain will keep pulling the RPM down until the clutch is solid and not slipping, and then start climbing with the gas.

Try shifting a bit more deliberately. Clutch in, shift out of gear, into gear, then clutch out, then gas. See what happens. Also, in 2nd gear, cruise at 5,500rpm sedately and while keeping your foot off the clutch, let off the gas slightly to let the rpms start falling for may be half a second, then punch the gas to the floor. Does the rev needle act as it should? If you have a weakening clutch, the revs should bounce up as the clutch slips, then either pause their climb as the vehicle speed comes up to match, or drop back down to the vehicle speed.

The video seems to pull hard enough that I wouldn't point a finger at your cat right now.

 

i know i don't shift all the way down and no i don't **** slowly i **** fast... when i do it slowly it doesn't do that... but it wasn't like that before anyway.

on my old car i had to change the clutch i noticed it when the rpm's started to rise but the speed was stil the same... I'm afraid this will soon happen got this car since 2 months and already putted 4k in new parts for it -_-

anyway thanks

 

i dont see how that is relevant

 

Yeah, you are probably burning the clutch, getting on the power before the clutch is fully engaged With the RPM we run at, you can kill one faster than most piston cars.

If you slow down the shifts just a bit, you will find that the RPM falls to where it needs to be anyway, and you can save quite a bit of clutch wear.

 

ahahahaha **** i didn't see that sorry ! looool meant shift

 

Mmm so u **** fast ...

How do i missed that?

 

turned out to be the clutch as expected... did a 8k drop in 5th gear with Ebrake on... guess what... it DIDNT stalled... total costs : 1200$

i hope i didn't damage my flywheel doing some **** with the clutch...

 

Next time don't be so aggressive with the clutch, and it will last much longer.
Notice that it survived as long as it had until you started driving it as hard as you are since you bought it.

BC.