5th gear pulls? Pulsing? Need thoughts at this point.
5th gear pulls? Pulsing? Need thoughts at this point.
Hey Guys,
I have asked a few Porsche Technicians and some knowledgeable Porsche guys on this and cant get an answer.
When I do a 5th gear pull (engine under load) I hear a lot of swirling wind noise but, I still have power. It feels like the car has a slight pulse now. (I cant describe feelings or noises well) 1st - 2nd are fine but gets worse incremental with each higher gear.
Initially, I thought an open Recirculation valve but had them check and they move freely. Then was instructed that it may be pinging (4 tanks of 100 Octane didn't help) Plugs were changed 3000 miles ago.
The cars tach also pulses and the car jerks at 2100K with sport mode off. With sport mode on, its fine.
Has anyone had a similar issue? Heading to the track on Friday for the first time and would love to know what is going on.
I have asked a few Porsche Technicians and some knowledgeable Porsche guys on this and cant get an answer.
When I do a 5th gear pull (engine under load) I hear a lot of swirling wind noise but, I still have power. It feels like the car has a slight pulse now. (I cant describe feelings or noises well) 1st - 2nd are fine but gets worse incremental with each higher gear.
Initially, I thought an open Recirculation valve but had them check and they move freely. Then was instructed that it may be pinging (4 tanks of 100 Octane didn't help) Plugs were changed 3000 miles ago.
The cars tach also pulses and the car jerks at 2100K with sport mode off. With sport mode on, its fine.
Has anyone had a similar issue? Heading to the track on Friday for the first time and would love to know what is going on.
How about doing a datalog (rpm,maf,iat) in 3rd gear wot? I found it helpful for diagnosing an odd power delivery. I compared to stock power curve. In my case it turned out to be vtg arm had not been reconnected after indie did plugs.
Thanks Steve, I can do that. My issue is, I don't have anything to compare it too as the car is flashed. I have the Durametric Pro.
Forgot to mention, I had the 2K RPM issue prior to taking the car in before the flash. The shop made it better but, it was still there.
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If you want, send me the excel file and I can compare to my curve. I've tracked my curve from stock to ep2 + softronic 93. After finding a safe place do a 3rd gear wot from 2000-6500.
Thank you. I also have the EP2 on my car with the 580evt flash.
Vtg arm wasn't sticking. It was not reconnected by indie after they changed my plugs. Symptoms were different sounding exhaust and peakier power delivery. Lag lag lag BOOST. In actual fact after reviewing plotted datalog (power proxy) power down low was below norm but at high rpm it was back to normal. The disconnected vtg arms made one turbo behave like a large turbo. Lag down low but after it got spinning it was game on.
It's easy to check your vtg arms, which are visible on the front side of the turbo. Give the arms a poke and they should move all the way forward then smoothly spring back.
For pic, search my post re "mixed bag after flash".
It's easy to check your vtg arms, which are visible on the front side of the turbo. Give the arms a poke and they should move all the way forward then smoothly spring back.
For pic, search my post re "mixed bag after flash".
Have you checked for boost leaks? Did you change the pressure plate when you put in the clutch?
The jerk at 2,100 rpm is odd though.
LP
The jerk at 2,100 rpm is odd though.
LP
Last edited by L_Perm; Apr 17, 2014 at 01:10 AM.
Vtg arm wasn't sticking. It was not reconnected by indie after they changed my plugs. Symptoms were different sounding exhaust and peakier power delivery. Lag lag lag BOOST. In actual fact after reviewing plotted datalog (power proxy) power down low was below norm but at high rpm it was back to normal. The disconnected vtg arms made one turbo behave like a large turbo. Lag down low but after it got spinning it was game on.
It's easy to check your vtg arms, which are visible on the front side of the turbo. Give the arms a poke and they should move all the way forward then smoothly spring back.
For pic, search my post re "mixed bag after flash".
It's easy to check your vtg arms, which are visible on the front side of the turbo. Give the arms a poke and they should move all the way forward then smoothly spring back.
For pic, search my post re "mixed bag after flash".
Thanks Steve, I will check the VTG arms. I have the severe lag problem also, Floor it and wait 3 seconds.
Havent checked for boost leaks but, my clutch came with a new pressure plate.
Is there a way to pin point a leak if there is one? I've heard of using smoke.
Not an expert here, but the first thing I would do is simply check all the boost hoses and connections. If nothing obvious, then I would imagine you'd need the car on a dyno to get the engine under load and re-create the pulsing. At that point, with rear apron removed exposing the hoses, I assume you feed some type of smoke into the air intake. What kind of smoke? Not sure how much it matters--cleaner smoke is probably better, if that makes sense. But, if you've gone through the trouble to get the car on a dyno, then you'll have someone around who knows more about it than I do. 
Good Luck,
LP

Good Luck,
LP





