Rasp from engine...help!

Rotaryjon · Post by **Rotaryjon** » Sat Feb 16, 2019 4:14 pm

Hi guys,

Ok so I'm looking for some advice.

My 40th anniversary rex is making a nasty rasp noise when under heavy load (not when just gradually accelerating) I've searched the forum and I'm pretty sure it's not the marbles in a can issue.

Take a look at:

No error lights coming on and no real loss of power.

noise is less noticeable when running shell nitro or BP ultimate. Any other pertrol including Tesco momentum increases the noise sound.

Cleaned the MAF (was a bit dirty) with MAF cleaner (which actually made the noise worse!).

Got new spark plugs coming Monday (just incase).

I think It's had the leads done (blue in colour think racing beats) back when Tony had the car (sorry, can't find my old login details or old thread about my car so made new account).

Anyone come across this before?

Car starts hot and cold without issues. Revs can be a bit rough at startup but only dropping for a split second etc.

Any help would be appreciated.

P.s. I think the old thread on my car was called 'tonys 40th anniversary' or something similar but can't find it (prob been deleted as was old?)

13Black · Post by **13Black** » Sat Feb 16, 2019 6:37 pm

I'd say that's bearing failure I'm afraid.

I do hope I'm wrong though.

PeteH · Post by **PeteH** » Sat Feb 16, 2019 6:44 pm

It's got to be worth checking for loose heat shields, and getting the exhaust off and giving it a shake. I'd say it was exhaust resonance, but Nick's listened to more dead engines than I have.

Rotaryjon · Post by **Rotaryjon** » Sat Feb 16, 2019 6:47 pm

Thanks for feedback.

I'll try and get under it on Monday (local garage should let me use lifter for a bit).

Just to clarify, the noise isn't the 'packet of crisps' style noise in the video (that's just bits e.g dash cam rattling in the car), it's the deeper rough sound getting louder as rpm increase.

I hope it isn't bearings as that's sadly game over (rebuild would be more than value of car

)

Rotaryjon · Post by **Rotaryjon** » Sat Feb 16, 2019 6:52 pm

P.s. 67k on clock

Rotaryjon · Post by **Rotaryjon** » Sat Feb 16, 2019 6:54 pm

P.p.s would the fuel type make that much of a difference to engine bearing sound?

Post by **warpc0il** » Sat Feb 16, 2019 6:56 pm

Some 8s can be rough a noisy on cheap fuel. e.g 95 octane supermarket stuff.

Try some Shell V-Power or Tesco Momentum and see if it makes any difference to yours

Rotaryjon · Post by **Rotaryjon** » Sat Feb 16, 2019 7:03 pm

Hi Dave,

Yes, below is what happens,

Shell v power nitro etc etc = very little sound if anything
BP ultimate = same as shell
Esso premium = noise
Tesco mementun = noise
Any other pertrol 'premium' = worse noise

Noise has got worse since cleaning MAF.

Post by **warpc0il** » Sat Feb 16, 2019 7:09 pm

So the answer is....
.... stick with Shell V Power or BP Ultimate and she'll be happy.

Some 8s are just like that, while others don't seem to care.

My 8 isn't noisy on cheap fuel but runs noticeably smoother on 98+
There's no Shell V Power, BP Ultimate or Tesco Momentum in NI ;(
So she usually gets treated to Sainsburys Premium

Rotaryjon · Post by **Rotaryjon** » Sat Feb 16, 2019 7:14 pm

Sadly that's not really an option. Nearest shell and BP is a 40 minutes drive away. Also noise is new (over last few 5 ish months) getting gradually worse (Esso premium didn't used to make any noise).

Rather work out what was causing the noise.

Rotaryjon · Post by **Rotaryjon** » Sat Feb 16, 2019 7:33 pm

@13black, what are the other symptoms of bearing failure?

98of400 · Post by **98of400** » Sat Feb 16, 2019 8:20 pm

That's not dissimilar to the noise my 40th is making. Mine is only doing it when the engine is hot i.e. after a long drive or after it's being sitting a jam. Also only when I'm accelerating - as soon as take my foot of the gas it goes.

I checked my cat today, see my post, but ain't sure if it's clogged or not. While under there I did notice the heat shield in front of the cat (not the big shield around the cat), just before the pipe goes up, is rusty and loose, so it could be that resonating when hot and under load.

Our cars will be the same age so yours could be the same underneath. Might be worth checking.

Sent from my Moto G (5S) Plus using Tapatalk

GreySilver Beast · Post by **GreySilver Beast** » Sat Feb 16, 2019 10:00 pm

Hi Jon &

to the RX-8OC

Please put your Location here in the Profile Section

Please check out the EVENTS SECTION's - Events Team

Rotaryjon · Post by **Rotaryjon** » Sat Feb 16, 2019 10:11 pm

@98, mine does it when foot is flat down (hot or cold) but only when driving (not parked). Foot off and noise instantly goes.

Easier to reproduce on hills when accelerating.

My cat did go a while ago (got a new one put on). At first I thought a blocked exhaust but I've got no loss of power.

Do you have any power loss?

Try driving car hard at night then pull up and see if you can see any glow from cat (my old man swares by it as a way to confirm a cats blocked).

P.s. mines 2008.

Rotaryjon · Post by **Rotaryjon** » Sat Feb 16, 2019 10:13 pm

@greysilver, not a new member bud, just can't for the love of me remember my old username

(and old email address is long dead) and can't find membership email/PayPal payment

(was a loooong time ago though when I joined (back in 2013 ish).

Rotaryjon · Post by **Rotaryjon** » Sun Feb 17, 2019 5:56 pm

P.s. can a mod move this to "RX-8 Discussion"?

Post by **warpc0il** » Sun Feb 17, 2019 6:02 pm

Thread moved as requested.

Were you previously an RX8 Owners Club member or did you just have a guest account on the forum, as today?

MARKTHOMASBRAND · Post by **MARKTHOMASBRAND** » Sun Feb 17, 2019 6:18 pm

Rotaryjon wrote: ↑
Sat Feb 16, 2019 10:13 pm
can't find membership email/PayPal payment

Previous Club Member I'd say Dave

MARKTHOMASBRAND · Post by **MARKTHOMASBRAND** » Sun Feb 17, 2019 6:29 pm

Is this you ?

Give me a clue...location would be nice

Rotaryjon · Post by **Rotaryjon** » Sun Feb 17, 2019 6:34 pm

Not me sadly. Yes, was a member (back when u gave a tax window sticker and a clear plastic credit card). Was based in Sheffield back then.

There was a thread about my car on here at one point. A guy called Tony had it (he swapped it for a Subaru if I remember correctly). Did a thread regarding the changes he had made and I added to it. It was a while ago now so I suspect it's been deleted (?) as I can't find it. (Checked with PayPal but can't go back past 2016)

MARKTHOMASBRAND · Post by **MARKTHOMASBRAND** » Sun Feb 17, 2019 6:49 pm

Is this the Tony in question ?

MARKTHOMASBRAND · Post by **MARKTHOMASBRAND** » Sun Feb 17, 2019 6:52 pm

This must be you ?

Rotaryjon · Post by **Rotaryjon** » Sun Feb 17, 2019 7:07 pm

YEEESSSS!

Rotaryjon · Post by **Rotaryjon** » Sun Feb 17, 2019 7:12 pm

Sadly it's linked to my old email address so can't reset it.

jonathanp · Post by **jonathanp** » Sun Feb 17, 2019 7:21 pm

I'm in! Thx for your help mark

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