sccadriver

I have a 08 40th. Second engine. I have had it since 2014. First engine went bye bye at 54k, after 2 mnths of ownership. She now got 130k on the clock, so 74k on the engine. So... it started a couple years back while taking a trip during the summer months. First is was on a hot day... above 95 degrees, she started like ticking, popping after driving for an hour or so during acceleration. Not hard but like I slowed down behind a car on the interstate then lightly accelerate to pass. The noise sounded like it was coming from outside but at the gear shift area. Now its progressed to above 85 degrees, worse if hotter, driving for 10 min. The popping is louder and seems to be coming from between the gear shifter to behind the radio. I.E. throttle body to the cat. I can feel a studder when it's popping. Also now I get a different sound from the engine..... for a lack of better words.... sounds like a infinity G35/7 wookie growl. Oh. I only have 1 mod... K&N Typhoon intake.
Any ideas, please help.
Thank You

Red line envy

If you still have the OEM intake put that back on. I only know of two good intakes for the 8. AEM and Mazda speed.

sccadriver

I only have the Typhoon. It was on her when I bought her. Just to add a little more... when it's cool outside, there is no problems. Full power. Driving to work, 5am, 30 miles on the interstate. But coming home, 95+ degrees.... horrible... I can set the cruise and when going up a slight incline, it sounds like a wookie taking a boiling bath... engine/wooki, boiling water from lower area. The CEL came on but that was for the intake manifold runner stuck open. Idle is good except an occasional bump. Starts great every time.

dannobre

iTrader: (3)

You should check your Cat.... it often is the first of a cascade that ends up with motor going bad.

sccadriver

I will definitely check the cat. I have seen both replacing and gutting the cat. No state inspection here, so what do you recommend. Luckily I am an O'Reilly Auto Parts store manager and I have most parts readilly available. Lol.
If anyone else knows what this issue is, let me know.

sccadriver

Update. New plugs, wires and coils. Cleaned the air filter. Cleaned the MAF. Seafoam before all was changed. No CEL. Starts fine and idles fine. But on hot days 10 minutes on the interstate and I get power loss and a droning roar from the intake. Plus sound like it has a misfire but no CEL. If I drive the back roads it takes much longer for the problem to show. If it's cool then even longer or I don't have a problem. Any ideas now?

dannobre

iTrader: (3)

Did you check the CAT?

furansu

Sounds like either the cat converter is partially obstructed or overheating, alternately heatsoak is setting in on the intake but the noises lead toward the former.

Do you have an OBDII reader that can log the IAT (intake air temp)? Cat will require a visual inspection (front midpipe inlet and through the secondary o2 sensor port) as the ECM only calculates the cat temp instead of using a sensor. You can still log the cat temp and see if the car is going into cat protection (requested rich AFR) during the periods where the noises and odd driving behavior is present. Also worth logging MAF (mass air flow), ECT (coolant temp), and the WBo2 against RPM to have a decent picture of what is happening.

40th8Jake

Well I would start with the simple solution first. Find a stock intake somewhere if you can, maybe check local scrap yards for Rx8s. Make sure either you grab the whole thing including VFAD or plug off the vacuum line that opens it. Then see what happens. Also Racing Beat makes a good intake but it’s pricey.

sccadriver

I took the CAT down today. It seem to be in mint condition. Nothing came out the back. Nothing down the rear mid pipe. No rattle in the muffler. Put everything back together and gave her a drive. Same issue. She was fine till I got her on the interstate. I did notice that after that drive, at idle, I could feel it more, but holding steady at 1 click below 1k... so 800 or so. But it also had rhythmic bump. Is that a misfire? After a few hours, I had to go to the store.. about 7 miles on back roads. She started fine, ran fine there and back. Back at home, idle at the same rpm, no vibration, no bump.
Also. I have had her since 2014 and the intake was already on her. 4 years of driving and never any problem.

40th8Jake

My guess is vacuum leak or failing coils. My understanding is that when coils are bad, heat really starts to affect them. Hard to diagnose something without looking at it. By no means am I a legitimate mechanic, but I have some experience. So no CEL?
My guess is coils. Just a guess. When is last time you replaced them?

sccadriver

New coils, new plugs, new wires. NGK plugs, import direct coils and wires. Possibly one of the new coils is bad. But is was doing this before they was replaced. Could this be a fuel pump issue?

40th8Jake

I read your initial post again and it sounds like it could be an exhaust manifold leak. It’s worth at least checking out. This would explain the new exhaust note. Also I’m not familiar with direct import as a brand of coils.

Do you live in a rust prone area in the county?
Try to get a decent video of the problem and post it here.

sccadriver

Definitely not at exhaust leak. But update. New code today. P2096 O2-2 reading lean at the in the cat. The noise is coming from the possibly the intake manifold. Only after driving for a period of time. I will be checking for vacuum leaks and a cracked intake manifold next.

Kiwiaudio

Following this as im interested in the result. If using a scan gauge, what would the expected intake temp (F) be on a correctly functioning engine ?
Ive read where the cat temp should max out in the 1600 - 1700 (F) range, but cannot find intake range.

Shaozhou Zhang

If there's no state inspection, you could get a midpipe, eliminating a potential failing point along with some horsepower gain.
Check out the private sale section for a used stock air box, the stock one is really good, most aftermarket intake will make you lose power.
I would also like to see you fuel trim data.
A very uneducated guess, the heat from the engine bay "melts" (Sorry I don't know how to say English is not my 1st language) part of the intake, once cool down it 's fine but after absorbing heat the hole melt and open again.

sccadriver

So far I have it narrowed down to the intake manifold and I think it's the ssv. When I switch off, I get a squealing noise from the ssv area.
does anyone know if the intake from an 04 will fit my 08.

Red line envy

I believe it would fit yes.

AMDguy

Yes, you have an series 1 car (series 1 was from 04-08, S2 from 09-11), and almost all of the major parts from the S1 cars are interchangeable. I think there may be a few exceptions, but yes, an 04 LIM (lower intake manifold) would definately fit your 08. Just make sure you get the correct manifold; ie. if your car is an automatic, then the LIM from a manual car would NOT fit yours, and vice versa, a LIM from a automatic would NOT fit a manual.

TullioRX8

This is as weird as it gets. I have no CEL on Key on position and engine won’t start.
It used to come on when I turn key to ON then it would go off when engine starts.
What is the most obvious reason for this?

Loki

iTrader: (1)

Please start your own thread. Check/charge battery and check all fuses.