Mrqng

Hi can anyone help, driving on the motorway for 20miles or so, come to a traffic light, reduce speed to gear 2 all sounds good no probs, turns green and off i went but within 10 seconds i hear a clanking noise very heavy, temperature increased a bit, so drove slowly into a lay by, turned it off and let it cool down, checked radiator, there's coolant, checked oil, there's enough. I don't know what else to check before i go to the stealers

Reginald.

Loki

iTrader: (1)

Possible a spark plug cable came loose? Possible you lost a belt? We'll need a lot more info that what's written here. Can you localize the noise within the engine bay?
"Temperature increased a bit" -- by the time that needle starts the move, the temperature has increased a lot. Has this happened before?

Does the clanking sound vary with engine rpm OR with vehicle speed OR neither of those?

Mrqng

Hi Loki, temperature moved slightly away from the mid position (normal position at operating temperature) the clanking sound seems to come from cat area travelling upwards towards centre of engine, soon as i heard the sound the power dropped and i eased off the acceleration simultaneously. After stopping to check all fluids, started the car without any problems, still with clanking noise and moved it closer to the front of the layby and left it there. A week or ago so my heatshield was a bit loose, so used a cable tie to hold it firm against a firm body part. It also sounds like something has been disconnected.
I hope this will help to diagnose further.

Mrqng

Clanking noise does slightly change under acceleration but not in neutral, i presume it will increase under load, but didn't want to take any chances. I have really looked after my 8, since i bought it two years ago with 83k miles on it.
I'm thinking would i qualify for 100k warranty as its 14 years old.

Loki

iTrader: (1)

The warranty is 100k OR 8 years, whichever comes first. So that's a negative, ghost rider.

One obvious thing that comes to mind is that your cat has shelled out. See if you can drop it for inspection.
The other options in my mind are clutch related. Unless something catastrophic happened in the engine, like a shattered seal, you wouldn't really get banging, and if you did shatter a seal, I don't think the car would start right up.

One trick you can use is take a 2x4 or some other stick of wood and apply one end to various engine/exhaust parts, and the other end to your ear. When you touch the part that is actually knocking, you'll hear it loud and clear through the stick.

Mrqng

So nothing for me on warranty
I'm ruling out broken seals, cos it starts one time on the money and idils fine, no misfires no check engine light. I will try pry it tomorrow as you advised Loki, then call the RAC out to tow it to a garage.
I don't really know the condition of the cat, but i know it was replaced by one of the previous owners 3-4 years ago. I had a brand new clutch, fly wheel etc replaced March this year and since then I have never had any problems with the clutch or gears.
But how can the cat just shatter like that, it passed its mot 2 weeks ago without any advisories on cat, exhaust or emissions.

​​​​​​

Loki

iTrader: (1)

Just don't let the garage throw parts at it without narrowing down the problem. Especially if they don't know rotaries.

Mrqng

Yeah, I'll make sure that doesn't happen, I'll only get them to inspect the cat and if they refuse I'll tow it down to my house until I'm ready to fix it. The stealers won't be getting my money any time soon, lol.

Thanks for your advice Loki.

Mrqng

Got my car recovered today, the RAC guy looked everywhere under the car under the bonnet and rear exhaust. The diagnosis is that the catalytic converter is broken and the metal bits is what's causing the noise. The car was drivable, just noisy. At least i know what's wrong with it before the stealers throw parts at it, lol.

Shaozhou Zhang

Hi Mrqng
Have you had your cat replaced/removed/gutted?
If the cat is damaged and the metal bits is making the noise, it can be clogged overtime, a clogged cat will localize the heat and overheat the sideseal and sideseal springs. Which is BAD. Especially as you have mentioned the temp gauge moved. Be sure to have a healthy cat on your 8, maybe not having on at all.

Mrqng

Hi Zhang, never had my cat replaced or gutted, again I'm ruling out cat converter and the exhaust system after close inspection and prying the cat to listen for pieces of metal noise, but no noise coming from underneath the car at all, temp gauge is working as it should, (travelled 80 miles return no overheating)
Here's what i think may be wrong, plugged in my diagnostic device and it tells me that the secondary air intake is inefficient and short, so my mind tells me the control valves on the manifold is faulty, possibly to change all three. See attached video let me know what you think.

Video would not attach, mp4 version, advice if known what other way i can attach it.

Regards
Reginald.

Loki

iTrader: (1)

Wait.. The mechanic diagnosed it as broken cat, yet you're ruling out, and you have diagnostic codes, but the description doesn't make sense. There is no code for secondary air intake being short. Do you mean secondary air pump? That is only really on for the first few minutes while the cat warms up and has no effect on power delivery.

What is/are the codes exactly?

Keep in mind that if it is the cat and you keep driving, you will destroy your engine.

StealthTL

iTrader: (1)

Sounds like you are misinterpreting the code for 'secondary O2 sensor'.....

Please don't mess with the engine if you don't understand what the secondary O2 sensor actually does.

S

UnknownJinX

So did they drop the cat and look at it? This is the surest way to check its condition.

Otherwise we are just running around in circles here. Also, make sure you post the exact code.

Mrqng

Hi Loki, the diagnosis on broken cat was done by the RAC guy who came to recover me, the main reason I'm ruling it out is because it passed mot on emissions shortly before this happened, no smoking, perfect idling, no spitting, only the clanking sound and slight loss of power.
The code is p2259 secondary selenoid, circuit B low. I have isolated the air pump and bench tested, it works perfectly, so ruled that out as well. So really the only thing i have not isolated to test are the solenoids and the cat itself apart from prying it.
The rx8 has not been used since Nov 2018, but will take it to my mechanic end of the month to have him inspect the cat properly and the solenoids.

I'd appreciate any input.

Mrqng

Hi Stealth, it's definitely not an O2 sensor code and i know what the O2 sensor does.
See my reply to Loki on the exact code and interpretation.

Thanks.

Loki

iTrader: (1)

Hmm if that's the only code then it's a bit of a dead end. The secondary air pump solenoid has no effect on power delivery. It's off under normal driving conditions. It's separate from the intake valves, those all have their own codes.

You keep saying "prying" but if that's referring to the stick method, there is no prying or force involved. You're just trying to locate the noise by touching various components until one makes the sound come through the stick. It wouldn't hurt to repeat that until you find the source of the sound.
​​
But passing emissions is a good sign.

Here's another test: does the sound frequency or pitch change with rpm OR with vehicle speed? Only in neutral or only in gear? There's a whole other set of options here related to cluch/transmission

Mrqng

Hi Loki, it's definitely not clutch, cos i changed clutch 18 months ago and i haven't really used it for a year now. I took it to my local mechanic, who took out and cleaned the ssv, but still the clanking noise remains. P2259 is the only code the car shows, but will find out from the mechanic tomorrow if any codes have come up since the clean.

thebubbadog

Check the cat under the car by taking it off, post video of it happening if you can or from your memory tell us if it changes tone/ starts making the clunking with Rpm as the car is sitting still and reving or only happens under driving conditions? enough said

Cosmo Canuck

Is the noise gone? Or does it come back after the engine is warmed up? The catalytic converter issue is not external that causes the problem. The material inside can fall apart with minimal warning. I even had one that crapped out just as the emission test finished and fortunately the tester ignored it because it failed two days later.
Many will rattle around pieces inside only after warm up, then suddenly clog off the outlet, which diminishes power considerably or stalls engines. Left to cool down it can weld into place and either stay clogged, fall over and be unclogged until hot enough to dance around again.

At this point it is assumed that the rotating external parts are checked (belts, fans, pulleys, alternator internals, etc) Same with clutches. If you romp on it, even a new clutch can only take so much.

Mrqng

Hi check out this link, no increase in noise with rpm, .

​​​​Let me know what you think.
https://youtu.be/4OY2VaZ3Gil

Copy and paste on your browser, it should work.

Mrqng

Hi check out this link, no increase in noise with rpm, [url]https://youtu.be/4OY2VaZ3Gil
Let me know what you think?

Cosmo Canuck

No video available?

Mrqng

Let me try again


Copy and paste on your browser, it should work.

Loki

iTrader: (1)

Video unavailable even in browser. Perhaps it hasn't been published?