Low / unstable idle

Defiant · Aug 5, 2017

Got my new temporary ignition coil in and was finally able to actually start the damn thing. Now it has idle issues so I recorded a video about it. When I give it some gas the idle drops down like it wants to stall and then rises back up to normal.
[video=youtube_share;BS2bH0xmKXQ]https://youtu.be/BS2bH0xmKXQ[/video]

its dark out now so tomorrow im going to test/clean the MAF and clean out the IAC valve to narrow the variables. Anything else I should check?

Also that tapping sound is new (from last week), im suspecting it's a exhaust leak.

Rolltide1006 · Aug 5, 2017

Very odd for sure. Does the idle drop only when you give it gas and let off? Vacuum leak perhaps ?

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Defiant · Aug 6, 2017

Yes it's only after giving it some gas or when slowing down to a stop.

Defiant · Aug 6, 2017

So here's the annoying ticking sound that I finally got on camera. It happens at light throttle, you can hear it when I crack the throttle. It's much louder when driving, I think it gets louder under load. It sounds like it's coming from the supercharger area. Doesn't sound like it's coming from the exhaust.
[video=youtube_share;YeOkqJ-BFPE]https://youtu.be/YeOkqJ-BFPE[/video]

Also I fixed the idle with a combination of cleaning the maf, iac valve and fixing some vacuum leaks.

edit: I'll also add that it doesn't tick on decel. If I downshift and Decel from 4500 to 2000 Rpm it makes no noise at all. If I'm in 4th gear at 2k rpm and cruising it makes no noise, but if I give it some gas it starts ticking/chirping.

Defiant · Aug 9, 2017

I still haven't found the ticking noise, I noticed on cold starts it doesn't do it. It's after the engine warms up when it starts to tick, even then, it sometimes goes away while driving. I suspect it might be the pcv? I'm getting a lot of oil sucked into the TB I definitely want a pol separator asap. I tightened down a bunch of hoses and vac lines and the engine does run smoother and the tick is slightly less audible but still there.

evilcw311 · Aug 9, 2017

Defiant said:
I still haven't found the ticking noise, I noticed on cold starts it doesn't do it. It's after the engine warms up when it starts to tick, even then, it sometimes goes away while driving. I suspect it might be the pcv? I'm getting a lot of oil sucked into the TB I definitely want a pol separator asap. I tightened down a bunch of hoses and vac lines and the engine does run smoother and the tick is slightly less audible but still there.

My pcv got quite loud when it went bad. I'd forgot about that till you just mentioned it. It got especially loud when it blew itself out of the block.

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Defiant · Aug 9, 2017

Damn that crankcase pressure must have built up pretty bad. Did your dipstick pop out also?

ill go pick up a new pcv, they're cheap as chips anyway.

Defiant · Aug 9, 2017

Old pcv valve out

New one part number. The motorcraft pcv valve has two ports for some reason. This pcv210 part number is also wrong according to advance auto's website. But look it fits perfect. The part number pcv203 part says it's for our cars, but it has two ports as well. Confusing. Anyway it's not motorcraft but it is metal so I hope it's good.

evilcw311 · Aug 9, 2017

Did it silence the ticking??

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Defiant · Aug 9, 2017

The ticking is still there, could it be the secondary pcv valve? I'm at a loss. Only other thing I could think of is the egr, since it only operates under part throttle conditions.

The ticking has gotten a lot quieter since the first day I noticed it, and it comes and goes while driving. So maybe I've been doing something right by sealing all the hoses and vac lines? No clue honestly.

g36 monkey · Aug 9, 2017

Use a stethoscope and make sure it's not coming from under the valve covers

Defiant · Aug 9, 2017

The problem is it doesn't make the noise unless it's under load. You can see in that video when I rev it quickly it only ticks a couple times. I can't tell where it's coming from because of this.

g36 monkey · Aug 9, 2017

You are convinced it's not exhaust leak? I have had plenty of exhaust leaks with similar characteristics

Defiant · Aug 9, 2017

I'm not convinced but I am like 60% sure it isn't judging by the location the sound appears to be coming from. It sounds like it's by the supercharger area.

I suspect if if it was an exhaust leak it would be louder on one side than the other, but this sounds like it's coming from the middle of the engine bay.

Would an exhaust leak come and go within a 15 minute drive? Wouldn't it be louder at full throttle than part throttle? This ticking is only at part throttle under load.

g36 monkey · Aug 9, 2017

Defiant said:
I'm not convinced but I am like 60% sure it isn't judging by the location the sound appears to be coming from. It sounds like it's by the supercharger area.

I suspect if if it was an exhaust leak it would be louder on one side than the other, but this sounds like it's coming from the middle of the engine bay.

Would an exhaust leak come and go within a 15 minute drive? Wouldn't it be louder at full throttle than part throttle? This ticking is only at part throttle under load.

I have had one that sealed at WOT but was only audible under light loads