Johnny_Cracker

iTrader: (1)

SE

Help guys, just installed RB RR header and PP presilencer and now the car sounds like a lawnmower! I torqued down the header and the presilencer but it sounds really loud, almost like the header isn't bolted down all the way... Maybe I have a leak or something? It also smells noticeably more rich in the cabin, while before I never had a problem with fumes...


Is this how it's supposed to sound at idle standing by the passenger side wheel with hood closed?:

I'm hoping it's just an exhaust leak since I'm not too fond of how it sounds. I checked the header several times and tried tightening bolts more but nothing changed. I DID NOT use any RTV or copper spray on the new gasket I got from RB w/the header.

I like the way it sounds when running thru the gears, but I need to mute/muffle/fix the farting airplane/lawnmower sound. It just seems way too loud from under the hood..


I'm running the stock catback fwiw.

G-man

iTrader: (2)

I'm running the RB Street Header with pre-silencer and it definitely doesn't sound like that. There must be a leak..especially since you're saying it smells in the cabin. I didn't have to use anything other than the supplied RB gasket. Good luck.

t_g_farrell

iTrader: (1)

You have an exhaust leak for sure. Check your connections.

Johnny_Cracker

iTrader: (1)

Okay good thanks guys... that's what I was hoping to hear.

Will likely remove and see what the story is tonite.

Jeff20B

iTrader: (13)

One thing RB recommends on header installs is to tighten the nuts evenly. Did you? The flange is big for backwards compatability with thermal reactor engines, and if you tighten one nut all the way down, the opposite end will tend to lift away producing an exhaust leak.

The other posibility is a warped flange. Check it for flatness.

I assume your gasket is decent (new or good used).

rx7lives

1) You're right, it does sounds like a lawnmower.

2) You've got a bad leak somewhere. If it backfires, at night, make it backfire with someone watching (obviously at a safe distance) and find out where the leak is. It's either:
1) header to rotor housing
2) Header to pre-silencer.
3) You forgot to put the O2 sensor back in.
4) Between the pre-silencer and the stock pipe to the stock rear muffler. Was the system rusted out, maybe the back pipe was paper thin and moving it opened up an existing hole or made a new one. should be easy to find the leak.
Fixing, a little m o r e work...

Johnny_Cracker

iTrader: (1)

So yeah it was a leak at the header.. the cause: carelessness

The lock washer I thought I had lost was still on the lower rear mounting stud, so the header could never sit flush. Take a look...

Here's where I confirmed where it was blowing-by:




Here's where I noticed the divot left from the washer:


So tonight I put it all back together WITHOUT the washer and it's great! No leaks, sounds fantastic. Was gonna take her out but it's raining now of course.

Jeff20B

iTrader: (13)

Congrats! This is one of those things you'll never do again.

Cookboy

iTrader: (10)

Never let the rain stop you!!

Johnny_Cracker

iTrader: (1)

Thanks Jeff, yeah you're right-on lol.

@Cookboy, yeah I wussed out. I have the heat shields still off and didn't want to get all the shiny new parts mucked up. This morning though I brought it, regardless of forecast hehe. She needs a good washing to get the garage-dust off of her anyway.


So it drove in fine and dandy to work today. 30 minutes of mostly country roads... It's apparent now that stock muffler is gonna have to go soon, kinda "buzzy" and ricy, a bit too noisy for me at this stage in my life

The newest challenge is it smells really rich while at speed. The cabin got really funky and I had to pop roof and the windows a bit to help it air out. I was permeated with the stench that finally wore off my cloths about an hour ago.

I don't think this is the signature stink that a 7 can produce, especially in the cabin like that. Over the winter I had the LIM/UIM off and I sent the injectors for serviced, fuel rail pulled, cleaned, reinstalled. New fuel lines which have been tested and checked, driven a few hundred miles w/no issues/leaks. The pulsation damper was checked and looks brand new no signs of leaks or degradation. So I don't think it's a fuel leak. The smell appearing simultaneously with the exhaust upgrade reinforces my "no leak" hypothesis.

So what I'm thinking, based on other "stinky" threads is I need to spec. the water temp sensor, air intake temp sensor, and the O2 sensor. I forget anything???

FWIW the coolant temp gauge never even gets to mid-way "warm". I thought this was due to driving w/out the undershield on the engine and it getting more flow, but now I'm wondering if the temp sensor has been shot all along? Previously the improper AF ratio was unnoticed as excess fuel was burning off in the thermal reactor so it didn't smell at all. Now with the new header and presilencer, that excess fuel isn't burning off. That's what I'm hoping is the case.

I can't comment on mileage since it's only a good-weather car and mileage wasn't a big factor. I'll start keeping track to see if my mileage is **** too.

Johnny_Cracker

iTrader: (1)

New thermo sensor will be picked up tomorrow after work.

Guess I know what one of this weekends projects will be! I'll post my results after I try the new sensor out.

t_g_farrell

iTrader: (1)

Check the seals on your hatch glass or the seals around the rear lights. They can suck in the
exhaust fumes really well if leaking.

Cookboy

iTrader: (10)

Having just replaced hatch and door seals I can attest to that.

Johnny_Cracker

iTrader: (1)

Well after 30 minutes of spirited driving here's how high the temp gauge got:


I popped the hood to recheck for leaks and found some fuel under the fuel rail, so I gotta pull the UIM and see if it's the lines or injectors.

Johnny_Cracker

iTrader: (1)

FIXED (again)!

Fuel leak fixed. It was the new fuel lines. One was kinked and developed a pin-hole leak. I was expecting them to be melted/heat damaged as I found today they aren't "autonmotive" grade like the site I bought them from claimed. They're helix solid yellow fuel lines, which are good to 350degF. The heat didn't seem to be the issue though as they looked and felt fine. The problem is they kink much more readily than the thick OEM steel-reinforced rubber hoses!

I squashed a fuel lines under the UIM with the coolant bypass hose (thermowax delete) causing a fuel line to kink and apparently leak. I re-ran the coolant bypass hose UNDER the (replaced to OEM) fuel lines from the water pump to the back inlet and then the UIM bolted down solid.

I left the yellow Helix lines at the firewall run to the spider by the dynamic chamber. They look absolutely new with no feeling of weakness, so I'll let them stay, but will keep an eye on them. I don't expect them to get very hot there.

Another thing, the new thermo sensor did absolutely nothing! It climbs to about 1/4 and stays there just like before. Ambient temps tonite in the uipper 60s. Questions remain... I've already tested the thermostat on the stove and it opens around 180 as per the FSM. Maybe it just DOES run very cool? Anybody else run w/out the "under-shield" or whatever it's properly called under the engine? I also run w/out the fan shroud...

Could altering the oil cooler setup cause a drop in temps like this? I had 10AN bungs welded on to the oil cooler for in and out to fix a cracked oem input bung. Nice stainless Earl's hose to accompany the new bungs.

It still backfires too, or is this normal w/RB exhaust? I don't want to detonate my presilencer or anything. **** the muffler though, let it blow for all I care hehe.

Amazing difference in response. It feels correct now... she just doesn't run out of power, it's nuts! Loud only when I want to be too. Only riddle left is minimizing the backfiring.

t_g_farrell

iTrader: (1)

Yep, just new oil cooler lines willl do this. Most of the cooling is done by the oil
cooler in a rotary. You should be good to go now, thats about where my temps
sit all the time.

The under tray will make a slight difference but it does make sure that hot air
doesn't recirculate out of the engine compartment and back through the oil cooler.

The RB system will keep the noise to a reasonable level. Get the new muffler and
you will be good to go. The backfiring is normal for a carb because its just not
as accurate on fuel delivery as EFI. You should be able to tune that out better
with fuel injection but I'm no expert there.

P.S. You are probably shooting flames as well!