View Full Version : Rough engine and poor throttle response


Manwe
11-01-2004, 01:54 PM
Noticed that recently my engine sounds very coarse and the throttle response for low gear(1-3 and sometimes 4) is very bad. When I step on accelerator, the engine sounds like it is gasping for air and pick up speed real slow...

I suspect that the oil is dirty as I currently have abt 2k clocked.... but stupid mm allocated the 1st service at 5k. I think my babe would not last that long... it is after all still a 1 week plus baby....

Should I just go and do an oil change myself???

Those from PI, when do you do your 1st oil change? Anyone from mm would like to give comment?

UG_8
11-01-2004, 05:38 PM
I did my first oil change at 1000 km. Than subsequently every 5000 km.

Manwe
11-01-2004, 06:57 PM
I did my first oil change at 1000 km. Than subsequently every 5000 km.
I am intending to do that too... but my SE told me that the recommendation from mazda corp is to do it at 5k. But the sound of the engine getting rougher and rougher.... sigh... wondering if it would become a permanent feature if i wait till 5k...

cuscorex
11-01-2004, 09:04 PM
hi man,
MM's 5k is juz a margin;meanin ur 1st service shld b done under 5k.u can by all means go 4 it now.
i did mine outside @ 500,then switch to syns @ 1.5k.din bother to go bk MM s i find it a hassle.gg to authorise wkshop is lesser hassle,but they dun allow u to use aft-mkt lubricants.

M-ster
11-01-2004, 09:19 PM
sounds like you've got more than just an oil change problem. i'd suggest you bring your car in to your dealer to check it out. with just 2k, the oil cant be that dirty til you can feels the difference of the performance and that rough engine. get it check.

EBS
11-02-2004, 01:45 AM
Yes think u shld just go down MM and get it check. Give u a piece of mind as well.

Manwe
11-02-2004, 03:36 AM
yea...think i would probably arrange for 1st service and get it checked.... seems reasonable today...only notice the problem when i am driving for a while and temperature is hot....

RedRocket
11-02-2004, 08:20 AM
Manwe,

I've called up MM last week and wanted to make an appointment to do a 1000km servicing but they insisted that I shouldnt waste money. They claimed that the first servicing should be done at 5k km, also said that the oil they used initially on the car is of very good quality fr Japan. Anyway, I'm a little confused too. If u want to do the oil change, let me know. I want to do it too.

Genesis
11-02-2004, 09:06 AM
I've called up MM last week and wanted to make an appointment to do a 1000km servicing but they insisted that I shouldnt waste money. They claimed that the first servicing should be done at 5k km, also said that the oil they used initially on the car is of very good quality fr Japan. Anyway, I'm a little confused too. If u want to do the oil change, let me know. I want to do it too.
Interesting thead for us new MM 8 owners. My 8 has 800 clicks on 'er and runs like a beauty. Have done three Mobil 8000 octane top-ups. Last one did 300 km on a 50 L fill up so that's approx. 6 km/L or 3.7 miles/L or 14 mpg. A bit below the average US pull of 17 mpg. I'm hoping as she gets broken-in, will get slightly better gaz mileage. My engine oil is down one notch, needs about 0.5 L to top up according to the manual. Will top it up tomorrow with Mobil 20w50 dino. MM uses Shell 20w50...big diff over the Mobil? Dun think so...dino is dino. Will keep the oil topped up at full with regular inspection until either 5k km is on the car or three months go by since I got 'er, then will hit MM for an oil change.

Ok, I've never owned a Rotary before, but I've been doing what I describe above with many other cars over the years without a single incident. Sure, you can decide to change the oil at 1k "cause it's a rotary" and even use syn oil if it makes more sense, but I'm sticking to the tried and true that works for me...just my two cents :)

Manwe
11-02-2004, 10:01 AM
the funny thing is that the response is only bad after long driving and the next morning it is alright again....

Strange....but did something though... today i was driving using 2nd, 3rd and 4th gear only for all speed range up to 170km/h(no aircon/no audio/but DSC on) and i noticed that the car drives like a babe....first time i am pushing the car....gives a fantastic feeling and the response from the steering is extremely precise and only a slight jerk would complete a overtaking manouvre... I also noticed that our padels were perfectly build for heel-toe...especially with the slight chamfer at the throttle padel....perfect... was a good experience.. I'll try without DSC next. (Think the good response is due to the high RPM I'm at. Never drop below 6k. I was using 5th and 6th gear and the poor car drives just like ahem..a normal car) But cannot speak for FC though...

I calculated the FC...gotten 7.5 on my last tank of Shell 98. Better than V-Power.

Manwe
11-02-2004, 10:03 AM
Manwe,

I've called up MM last week and wanted to make an appointment to do a 1000km servicing but they insisted that I shouldnt waste money. They claimed that the first servicing should be done at 5k km, also said that the oil they used initially on the car is of very good quality fr Japan. Anyway, I'm a little confused too. If u want to do the oil change, let me know. I want to do it too.
I was thinking of going down to autobacs to use the trust re oil. Saw a few bottles there the last time i went. Drool~

I'll monitor the situation for a short while to see if it require a quick fix...

Genesis
11-02-2004, 10:38 AM
I calculated the FC...gotten 7.5 on my last tank of Shell 98. Better than V-Power.
Interesting...will try Shell gaz and compare, thanx.

Genesis
11-02-2004, 10:52 AM
Strange....but did something though... today i was driving using 2nd, 3rd and 4th gear only for all speed range up to 170km/h

Must be a typo dude....170km/h :confused:

Genesis
11-02-2004, 10:56 AM
Hi.

I'm new to this forum and the car as well. I've clocked about 1300km on my 8. On Shell 95 only so far, I've had a consistent average of 8.6 to 8.8 km/l with lostsa stop and go traffic jams.

I'm pretty satisfied with the consumption. :)
Hi Mugo...that's almost 20 mpg! You dun shift over 3k rpm? Jest kidding....I'm going to switch to Shell and re-post later.

Genesis
11-02-2004, 11:12 AM
Not bad mate...about 5k is where I shift too, yet your FC is much better. Guess I'm getting a Shell card over the Smiles card :)

EBS
11-02-2004, 11:56 AM
Yes the shell 98 suits me as well. Getting around 8.2 to 8.5 km/l so far.

M-ster
11-02-2004, 12:17 PM
the funny thing is that the response is only bad after long driving and the next morning it is alright again....

Strange....but did something though... today i was driving using 2nd, 3rd and 4th gear only for all speed range up to 170km/h(no aircon/no audio/but DSC on) and i noticed that the car drives like a babe....first time i am pushing the car....gives a fantastic feeling and the response from the steering is extremely precise and only a slight jerk would complete a overtaking manouvre... I also noticed that our padels were perfectly build for heel-toe...especially with the slight chamfer at the throttle padel....perfect... was a good experience.. I'll try without DSC next. (Think the good response is due to the high RPM I'm at. Never drop below 6k. I was using 5th and 6th gear and the poor car drives just like ahem..a normal car) But cannot speak for FC though...

I think i might have just figure out your problem mate....

Well as everyone know, the rotary is prone to churning out alot of heat!
Its quite normal/common that when the engines are warmed-up and not enought cool air gets in the engine, the car would runs like its underpower/sluggish. Thus what you experienced up there; with that kind of speed, alot more air are forced in to the radiator, oil coolers and even the intake itself, plus the second pot are opened most of the time at that rpm, so the engine wasn't under any heat stress.

So, you'd get sluggish performance when the car travel slowly, but as speed builds up, your 8 would sings like an angel.

That sluggish performance is due to the heat, and it happen to most cars in our weather here, but probably more pronounce to the rotary due to its nature.

Manwe
11-03-2004, 02:24 AM
Must be a typo dude....170km/h :confused:
Err...no typo...i did go up to fifth occasionally but that was when i was at ridiculous speed already.... yes.. I was speeding(shhhhh)...testing out the car.... and i did a brake test too...can really feel the abs working... hear it release and break...very little wobbling...good....

Manwe
11-03-2004, 02:27 AM
I wasn't shifting at 5 k...I was maintaining above 5k even after shifted...meaning shifting at 7-9k.

M-ster...I think the sluggishness is real bad....it is like trying to move the car from 6th gear when i am in 3rd or 4th(maybe i am exaggerating a bit but it definitely is slow). Moreover, I have very coarse sound coming from the transmission and gear box....sounds so awful...

wootwoot
11-04-2004, 09:32 AM
ok.... after completeing 1.5k... i hear this noice under the car driver's side... the sound goes twick twick twick or tick tick tick.. something like that... b4 that drive over a high hump without braking & the car drag over the hump.. any1 experince this kind of sound b4? will be bringing the car to MM tml on friday

EBS
11-04-2004, 10:17 AM
My friend's 8 has something (rattling) at high rpm so went to MM to check. apparently some type of screw loose below which was tightened.

wootwoot
11-04-2004, 10:32 AM
ok thanks for the info... will be bringing the car down later this morning

rockstar
11-08-2004, 10:07 PM
Manwe / Red Pocket

Spoken to one of the dude in Mazda, he says they will only change our oil with Shell mineral 20W50. And only at around 5k. I drove my car up to my mechanic and get it changed at 1k. U ll be surprised by how much metallic deposits they are in the used oil. That probably cause the "coarse-ness" in your engine. My mechanic recommended me mineral to continue running in the engine. I use FK Massimo (5W20) super mineral, from Japan. Engine runs smooth and sounds sweet. And I change again at 3k and still there are metallic deposits. The car now has 4+k. I suggest U change your oil for the added performance and peace of mind. +, your engine will repay U with sweeter note.

Jus my 2 cents worth.

Yum Seng

RedRocket
11-09-2004, 07:44 AM
Manwe / Red Pocket

Spoken to one of the dude in Mazda, he says they will only change our oil with Shell mineral 20W50. And only at around 5k. I drove my car up to my mechanic and get it changed at 1k. U ll be surprised by how much metallic deposits they are in the used oil. That probably cause the "coarse-ness" in your engine. My mechanic recommended me mineral to continue running in the engine. I use FK Massimo (5W20) super mineral, from Japan. Engine runs smooth and sounds sweet. And I change again at 3k and still there are metallic deposits. The car now has 4+k. I suggest U change your oil for the added performance and peace of mind. +, your engine will repay U with sweeter note.

Jus my 2 cents worth.

Yum Seng

Thanks for advice. My engine sounded quite rough so i went down to MM this afternoon and realised that that my engine oil level is low so they topped it up with 1/2 litres. After that, feels slightly better. I checked with the advisor again on the servicing but he told me not necessary. My mileage already 2k, will find time to change oil.

RedRocket :)

Genesis
11-09-2004, 08:02 AM
Have over 1k on my 8 now, have topped up the oil (0.5L) with Shell Helix dino, car is running better than on day one. It's looser, more responsive, and sounds better than ever :)

Manwe
11-09-2004, 11:18 PM
I checked my oil level and it is still fine....so dun think it is the oil level. But I am very very concerned abt metalic deposits in the oil. If the oil is too 'coarse' due to them...wonder if they will create 'holes' and scratches everywhere....

Genesis
11-10-2004, 10:05 AM
I checked my oil level and it is still fine....so dun think it is the oil level. But I am very very concerned abt metalic deposits in the oil. If the oil is too 'coarse' due to them...wonder if they will create 'holes' and scratches everywhere....
Manwe, you have a new car. Metalic deposits in the oil causing holes and scratches in the rotor housing? Yikes, I kinda doubt. So would it matter if the oil was dino or syn? Even if you change the oil/filter at 1k (i.e. before 5k) based on what you said then metalic deposits would appear again and scratch cause holes in the housing? You're doomed! I dun think it's that mate.

UG_8
11-10-2004, 11:17 PM
I checked my oil level and it is still fine....so dun think it is the oil level. But I am very very concerned abt metalic deposits in the oil. If the oil is too 'coarse' due to them...wonder if they will create 'holes' and scratches everywhere....

Usually the metallic deposits will sink to the oil sump at the bottom. Guys don't worry too much. If it really unsettle you, do a change at 1K and subsequently do it every 5K. Oil as said b4 is very important, I have used FUCHS b4 and it sucks...tried Castrol seems ok...tried HKS my comments is good and lastly on Trust which i find it is good so far...

As for the grinding sound in your gear box...again you can change your transmission oil.

RedRocket
11-11-2004, 09:49 AM
I suppose you're driving a red from your nick. So that means you were the one turning out when I was turning into MM. :o
Yes :)

Manwe
11-11-2004, 09:47 PM
Manwe, you have a new car. Metalic deposits in the oil causing holes and scratches in the rotor housing? Yikes, I kinda doubt. So would it matter if the oil was dino or syn? Even if you change the oil/filter at 1k (i.e. before 5k) based on what you said then metalic deposits would appear again and scratch cause holes in the housing? You're doomed! I dun think it's that mate.
It will indeed cos excessive wear and tear...that is why you have to change oil often especially when running in to prevent that as the metallic deposit is more initially. Dunno why mm does not recommend that....

Small amount of deposit is fine but a lot is no no.. it is like sanding your engine instead of lubricating

Genesis
11-12-2004, 05:14 AM
Yeah I hear where you're coming from. I guess in my experience these metalic deposits haven't been much of a problem and I've had many new cars before. So how is your ride now, still experience the roughness? Had the car looked at?

wootwoot
11-12-2004, 05:18 AM
ermmm pai seh ah sidetrack abit.... any1 have pinky RX-8 here?? in spore?

Manwe
11-12-2004, 10:55 PM
it is cranky...some days feels responsive and some days feels not so fine...especially after a hard drive it is always not so fine at lower gears... Will be doing oil change soon and will monitor.... but overall still great. I checked with Ah Lye with the oil cooler protector. $120 for the curvy one but only cover 2 holes. If you want it just flat then cheaper.... he said the big hole above the front air dam too big and difficult to cover and takes too long....so i KIV first.... maybe wait till i off on a real long trip then do it

tems900
11-13-2004, 12:51 AM
Hi roger if u really drive hard better check the oil level every week, when the oil level is low the engine get really rough, i had sport clutch in my car so when the oil level get low & engine get rough, that sport clutch will create more noise than usual at idle for me to take note.

Neon
11-13-2004, 01:35 AM
envy ur ATF....I want I want!!!!! :D

Naughty Boy
11-13-2004, 05:31 AM
ermmm pai seh ah sidetrack abit.... any1 have pinky RX-8 here?? in spore?

Apparently there is (at least) one. I haven't seen it myself though. Heard it's neon pink!!! :eek: But it's one HOT chick driving it! :D

wootwoot
11-13-2004, 06:13 AM
Apparently there is (at least) one. I haven't seen it myself though. Heard it's neon pink!!! :eek: But it's one HOT chick driving it! :D

kewl!!! nice nice... is she in this forum?

takahashi
11-13-2004, 06:33 AM
ok.... after completeing 1.5k... i hear this noice under the car driver's side... the sound goes twick twick twick or tick tick tick.. something like that... b4 that drive over a high hump without braking & the car drag over the hump.. any1 experince this kind of sound b4? will be bringing the car to MM tml on friday
wootwoot

Check your driver seat - the nut is loose and it is a generic problem. It happens in US, Australia and even in Japan.

Try to rock your seat when sitting down - see if this reproduce the noise.

Genesis
11-14-2004, 06:55 AM
Try to rock your seat when sitting down - see if this reproduce the noise.
But make sure you try that in a crowded location so that others can see what you're doing....disco in the 8! :D :D

wootwoot
11-17-2004, 01:08 AM
wootwoot

Check your driver seat - the nut is loose and it is a generic problem. It happens in US, Australia and even in Japan.

Try to rock your seat when sitting down - see if this reproduce the noise.

i dun think is the seat... guess have to call sgren to meet him & some fellow rx-8 owners that live in the west of singapore... to hear their engine sound to see any diffirence in it... anyway thanks for the info... still have the sound though

SGren pai seh bout yesterday night cant meet up with u guys coz still stuck at somewhere... its not that i wanna fly u "areoplane" coz i no fly a plane...

Manwe
11-17-2004, 02:58 AM
we who fly planes also never fly ppl aeroplane...only fly our own

Manwe
11-17-2004, 03:01 AM
hmmm maybe the tick tick sound comes from your signal or hazard light? hahaha...just kidding.

But do check it out. I haven't heard it and cannot comment. It could be some lose stuff...I had tick tick sound in my old car too...turn out to be some washer that was lying around getting knocks.... dunno how it got there but i just threw it away...hahhaa....