Hi all,

I'm having an intermittent issue with my G35. 04, coupe, 6MT, 86k KMs. Tanabe Medallion Touring exhaust and Y-Pipe, everything else OEM.
Immediately after a hot start (that is, if the car has any heat registering on the gauge, not necessarily operating temp), the car shudders and shakes, even if i bring the RPM's up, It just shakes at a higher frequency following rpm. After about 10-20 seconds, it goes away after i give it some more gas (not driving, just at a stop). The car will try to idle, but will shake and shudder while doing it. It first happened a couple months ago, but now has been happening more and more frequently. I tried today to restart the car right after it shut off (within 10 seconds) and it fired back up no problem. So i'm rather confused right now. No codes.

What im thinking:
Original spark plugs?
MAF?
Dirty TB?
Vacuum leak?

Never seen anyone with this issue and I know the whole history of this car as my father purchased it new.

Any ideas?

 

I'd start with cleaning the MAF and TB for starters and see where that takes you, there are a few writeups and DIY'S floating out there that'll get you pointed in the right direction

 

Are you getting any check engine lights?

 

Yes that's what I was thinking, I'll clean the MAF and then TB, and I'll go from there. I'm not getting any check engine lights at all.

 

Cleaned MAF and TB at the same time, seems to be running great. Didn't get the dreaded idle issues. Cant say which one made the difference but either way it runs great.

 

Update. Car did it again today, for a good 30 seconds and then magically cleared itself out. At this point i'm thinking spark plugs, given that they are original and could be an issue. Any other ideas?

 

even if they're not the problem if you're at 85k miles on the car with original plugs

 

85k kilometers. Not miles. Significant difference. it's 52k miles.

 

It's not spark plugs. Shudder then stop, for short bursts, is sensor related. Could be one of the following..

TPS
IAC Valve
EGR Valve
Vacuum Lines

Quick and easy way to test, let the car run, and spray some Carb Cleaner on the vacuum lines (close up and slow bursts all along the lines) to see if it makes your engine revup. If that occurs, it's a vacuum leak. If not, it's one of those three sensors/valves.

(Might be a coil pack going bad, but unlikely, because its intermittent :/)

 

I'm sorry. I understand the difference but in my haste failed to see the km lol