Weird start up today

[YearOneOne]

So when I started up the car this evening after being in the garage for about 3 or 4 days she started right up but it sound like a cammed v8. The temperatures have dipped hard in the past few days and I wonder if that played a role.

Has anyone else ever experienced this? It didn't sound normal but it did sound good I must admit!

[Dackelone]

Check for shadow codes...

IF I had to guess I'd say it was your HPFP starting to go out or maybe a bad/leaking injector? Did you smell any raw gas from the tail pipe ?

[YearOneOne]

Originally Posted by Dackelone

Check for shadow codes...

IF I had to guess I'd say it was your HPFP starting to go out or maybe a bad/leaking injector? Did you smell any raw gas from the tail pipe ?

Could be. I just turned over 47k on the clock so it's about that time huh. I will check for codes when I get a chance! Thank you

[desertman123]

Maybe someone dropped a cam'd LS in your bay!! Secret santa

[The Wind Breezes]

The colder it is the more gnarly these cars sound when starting. Not saying you don't have an issue, maybe get a sound clip next time?

[mr.fabulous]

Perhaps your exhaust flap is stuck open and you are not accustomed to the extra noise (it really makes a difference at cold start-up)? I hope that's all it is...

[ODU135]

hey there, I just went through a very bad case of leaky injectors and learned a lot in the process. I could be way off base here, but in my understanding of a leaky injector is that it will leak fuel onto your spark plugs and make them misfire for sure. At Least mine were misfiring very severely, and throwing codes.

If you have no misfires at idle, I doubt its injectors. Fingers crossed for you tho

[tock172]

The N55 135i is quite loud on cold start, but if it's misfiring, I can definitely see how it can sound and feel like a cammed pushrod V8.

[YearOneOne]

It's only did it for a couple of seconds of cold start then was fine but since it has started cooling off the idle has been similar to a heart murmur but from my understanding all of our cars do it? It doesn't seem like a misfire.

I actually did record it but forgot to save it. I'm gonna try it again tomorrow and see what happens I will also look for codes. Thanks for the input everyone.

[HyeWarrior]

Mines been weird lately too. It's really inconsistent. I'm getting more and more white smoke from the exhaust too lol

[Esteban]

My N55 (with PE) starts very loud when cold but calms down after a little while. I'm used to the sound and if it sounded different I'd know. The OP should know the sound of his own car and if it sounded different on cold start up.

[kprocivic]

Originally Posted by HyeWarrior

Mines been weird lately too. It's really inconsistent. I'm getting more and more white smoke from the exhaust too lol

Whats your mileage.

[YearOneOne]

Originally Posted by Esteban

My N55 (with PE) starts very loud when cold but calms down after a little while. I'm used to the sound and if it sounded different I'd know. The OP should know the sound of his own car and if it sounded different on cold start up.

It didn't sound different in the view of loud or soft. I have unplugged the flap and in my garage it's very loud and I'm fine with that it's what I was aiming for but the first couple of seconds during cold start the tone pulsed like a rotary or an old diesel that has sat for a while.

[YearOneOne]

Originally Posted by kprocivic

Whats your mileage.

A hair over 47k

[desertman123]

Have you cleaned your VANOS solenoids?

[Esteban]

Originally Posted by YearOneOne

It didn't sound different in the view of loud or soft. I have unplugged the flap and in my garage it's very loud and I'm fine with that it's what I was aiming for but the first couple of seconds during cold start the tone pulsed like a rotary or an old diesel that has sat for a while.

No, I get it: the rhythm (not the loudness) is what you're concerned about. What I'm saying is, I trust you to know the sound of your own car, just like I know mine.

[swagon]

Bad battery?

I remember that it did not crank up very nicely once, but that was after several weeks of sleep during the winter.

[AB M2C]

Originally Posted by Dackelone

Check for shadow codes...

IF I had to guess I'd say it was your HPFP starting to go out or maybe a bad/leaking injector? Did you smell any raw gas from the tail pipe ?

I think this nailed it on the head. My guess is the issue will continue to get worse and eventually throw a full misfire code.

[HyeWarrior]

Originally Posted by kprocivic

Whats your mileage.

65k

[STR8-6IX]

when was the last time you changed your oil?

[YearOneOne]

Originally Posted by ThatOneKid

I think this nailed it on the head. My guess is the issue will continue to get worse and eventually throw a full misfire code.

I think this maybe it too it. It did smell a little gassy

[mr.fabulous]

My flap is disconnected (electrical connector at the valve). And yet my car is quite loud and... I don't know... BIG CAM-y... the first few seconds of cold start-up. It's not the exhaust, something in the engine management at cold-start does this. It is clearly more pronounced since I disconnected the flap. I almost wish it sounded like this all the time, it's kind of muscle-car (and I'm old and I really don't want that, perhaps I'm just reminiscing).