mazdaspeedwest

Well, much to my dismay my precious (and extinct) RMM header has some crackage! i put it on the rack tonight at work and saw 4 cracks 2 on the weld seem facing the block and 2 more on the backside, but below the weld seam...one is spider webbing too...i'm none to happy about it, but i can't argue the fact they have been on their for 12 years!!!!! and just now have failed.

Is this repairable? i know the cracks along the weld seam are, but the others that aren't, can that be fixed? If not i guess i'll seek out a set Pacesetter headers as i have a long term goal of re-building this engine for a 323 swap...as the Pro will be turbo soon.

Strange thing is, i see absolutely NO signs of carbon or any dis
coloration at the cracks??????

Another thing, my check engine light came on a few days ago, i did the trusty paper clip diagnosis test and got the code for the O2 sensor (15) bought a new one but have not installed it yet, as the light never came back on. I remembered from the last time, as the light would come on just after hitting normal temp.
Could the cracks have caused the fault code?

mazdaspeedwest

i happened to have a paper clip in the car. In the diagnostic plug (next to the brake resivoir) jump TN and GRD, turn key on and the check engine light will flash. First number of the code is a slow flash, the second number of the code flashes fast.

check your Haynes, it has the procedure and code listings.

the main thing i hope IS NOT the case, are the header walls too thin now....?

mazdaspeedwest

well, it happened today,....as i pulled out of the lot going home tonight, all of a sudden, BRAAAAPHHHT, BRRAAPPPHHHHTTT...i'm like DAMN!!! the crack has just turned into a hole.....i pulled over to see and sure enough, the cracks widened...so until i find my OEM manifold or i get this welded up, my ride's outta commish...i don't want to run the risk of dropping a valve...the leaks are on the cyl 1 & 4 tubes...

ehhh, life kinda sucks today...tomorrow will be better

protejay

sorry to hear 'bout it Darryl

would 'team duct tape' solution's help? (haha couldn't resist!)

mazdaspeedwest

ya ya, very funny

well i fianlly found my OEM manifold (it's been sitting outside for the last 12 years, can you say "rusty piece of ****!") put it on after work today. It was a 1.5 hour job to pull the RMM and out on the OEM. Most of the time was spent letting the bolts soak in a spray of lube and dremel cleaning the rust off the mating surfaces. Man that lift was sure nice too

So now my throttle response sux, i got nothing till 4500rpm, and then it's not all that much anyway...but i guess i have a tad bit down low and my exhaust is MUCH quieter. Oh, and since i've always had the header, i now finally hear that intake growl i've heard about....oh well, i'll live......amazing how much of a difference the headers make.

the RMM dosen't look too bad, a little patch and some new welds and it's all good.

mazdaspeedwest

Well, i got it welded up and re-installed it last night. Man did i miss that extra power...it's immediately noticeable. If you haven't got one yet, GET ONE! you'll really feel a difference.

Oh, i made a total rookie mistake and badly crossed threaded the O2 sensor threads on the header. I managed to get the sensor in there tight enough, as to not leak, but it's done for, no chance for it. I guess i'll cover it up and relocate it.