Exhaust Valve Rattle with Dual Resonator Delete

[BJHNG]

I pulled the exhaust valve fuse within a day of ownership then got a front resonator delete a couple months after that. I made sure to test the valve functionality every once in a while to ensure proper operation. I never had this rattle until I recently deleted the larger middle resonator. The car only has 5k miles on it and live in a mild climate(no snow, hardly any rain). I am noticing rattle during cold starts and regular driving in all modes when the valve is 100% closed. I've read many others with aftermarket valved systems with rattle but mine is an otherwise stock system with no resonators. I'm surprised there aren't many posts on this due to the popularity of the resonator deletes. Anybody else experiencing this and possible solutions? I've read about resetting the valve to add tension or installing stiffer springs but want to hear about other's experiences before jumping into it.

Sponsored

 

[Han_Solo]

I pulled the exhaust valve fuse within a day of ownership then got a front resonator delete a couple months after that. I made sure to test the valve functionality every once in a while to ensure proper operation. I never had this rattle until I recently deleted the larger middle resonator. The car only has 5k miles on it and live in a mild climate(no snow, hardly any rain). I am noticing rattle during cold starts and regular driving in all modes when the valve is 100% closed. I've read many others with aftermarket valved systems with rattle but mine is an otherwise stock system with no resonators. I'm surprised there aren't many posts on this due to the popularity of the resonator deletes. Anybody else experiencing this and possible solutions? I've read about resetting the valve to add tension or installing stiffer springs but want to hear about other's experiences before jumping into it.

For what it's worth, I also have a dual-res delete and I have had no issues or rattles after 3 months or so. I have a similar climate to yours, no snow etc and warm most of the year. Could be an issue that a dealer needs to look at.

 

[gerryman81]

I've got the same rattle and am also running the dual delete. From what I researched its the valve spring that compresses and doesn't put enough pressure on the valve plate so it rattles during certain RPMs. We should be able to replace or modify the spring to get rid of the rattle but in the meantime I just pulled the fuse. When I called my local honda dealership they said that they can only sell the valve assembly and not just the valve spring which I'm not sure is really true. If anyone has replaced that spring could you send a part number?

 

[BJHNG]

I think replacing with the OEM spring won't resolve the issue since mine is basically new. I might experiment with an upgraded spring. I've read about a stiffer Mopar spring and Hyundai Veloster/Elantra Ns are also having valve rattle on their stock systems so there are options out there. It seems to be a direct replacement too.

 

[BJHNG]

@Han_Solo , have you pulled the fuse for the exhaust valve or still stock config? Also, do you have an upgraded RMM?

@gerryman81 , stock RMM or aftermarket?

I have Powerflex yellow inserts in my stock Rear Motor Mount so wondering if the additional NVH is a potential cause for the exhaust valve rattle.

 

[Han_Solo]

@Han_Solo , have you pulled the fuse for the exhaust valve or still stock config? Also, do you have an upgraded RMM?

@gerryman81 , stock RMM or aftermarket?

I have Powerflex yellow inserts in my stock Rear Motor Mount so wondering if the additional NVH is a potential cause for the exhaust valve rattle.

I run both exhaust setups from time to time, fuse trick and loud, or with the active valve. It depends on where I am and where I'm driving etc.

Stock RMM. How loud or noticeable is the rattle? I can try run the it with the fuse to double check. Any specific circumstance where it's very noticeable?

 

[BJHNG]

During a cold start is where I first noticed it. I can hear it in comfort mode with valves closed but you'd have to have windows down and speeds lower than 40mph since wind noise will just drown it out. My work has a parking garage and is noticeable putting around in 1st/2nd gear since the sounds echo from the ceiling.

 

[Jhatmaker]

I have dual res delete and prl rmm. My rattle is only on cold starts then goes away as idle drops. I figured it is the added NVH and dont use comfort mode so wouldn't know about that. Ive just been living with it but it does annoy me. Might retry the fuse pull and see if it makes a difference.

 

[BJHNG]

If I do the fuse pull to lock it open then I have 0 rattles from the valve at all and that's where I plan to keep it 95% of the time. There are very rare occasions where I would want the valves closed but the rattle defeats the purpose since the sound is quite embarrassing.

I've sourced a couple options for stiffer springs that worked for other FL5 owners on aftermarket applications as well as the Hyundai N crowd on their stock exhaust and seems to be a direct replacement.

Mopar Exhaust Valve Spring - Part# 68319331aa

Hyundai Exhaust Valve Spring - Part# 287a6ib100fff

 

[gerryman81]

I'm running the Cobb rear motor mount but I noticed the rattle before and after I installed the mount so I'm pretty sure it's the spring. Mine only happens more during the cold start phase when the engine is at a higher rpm. Not sure if its rattling while I'm driving but it might be and maybe I just can't hear it with the windows up. With the fuse pulled I don't get any rattle but would eventually like to try and fix the spring and see if that gets rid of it.

 

[BJHNG]

Thanks for confirming! I didn't think a RMM would affect the rattle since it's more RPM/load driven but didn't want to exclude it as a possibility. I'm not in a rush for a fix but also would eventually like to try something. I'm thinking pick up that upgraded Hyundai spring from a local dealer since it's only $5 to try it out.

 

[gerryman81]

Thanks for confirming! I didn't think a RMM would affect the rattle since it's more RPM/load driven but didn't want to exclude it as a possibility. I'm not in a rush for a fix but also would eventually like to try something. I'm thinking pick up that upgraded Hyundai spring from a local dealer since it's only $5 to try it out.

Let me know if you end of changing out the spring. From what I can see on the exhaust you would have to take it off the hangers to access the actuator on the topside of the middle exhaust. Curious how much work that would be or if you can access it without having to take things apart.

 

[BJHNG]

I've messed with it briefly on jack stands without taking anything apart. It's difficult but doesn't seem impossible. You'd have to be doing the removal and install of the actuator by feel. I ordered 2 springs from Hyundai for $8 so I'll give it a shot soon.

 

[T41WN.1]

Might just be a faulty spring, I've been on dual res delete with fuse pulled out for over a year now, i've put the fuse back in to use the valve and haven't had any rattles. Only rattle I get is the glovebox rattle lol.

 

[Han_Solo]

Popped the fuse back in for the morning commute today and no rattles here. Hope you manage to fix it with the new spring!

I'm always pleasantly surprised by how quiet the car is with the valve closed even after the dual-res delete.

Sponsored