Does anyone know what the target idle speeds are for the 458, A/C on and A/C off ?
I am having an issue with my car where the idle drops down to around 600rpm, and theres quite a bit of vibration/shaking, almost like the engine is lugging/missing a bit. Its not dependent on the AC On/Off, that still kicks up the engine 20-30rpm from where it is at Sometimes the engine will find its right balance and the rpms will return to 900 where they should be. We can't see any codes on the car either, but I am sure something is not working properly. The dealer has said this is normal in 458's, but I highly doubt this to be "normal" I don't think the 458 has an idle air valve like the 355 does, but rather controls air flow through the throttle bodies? If anyone has any input on what this could be, would really appreciate your feedback! Photos attached of normal idle and the lower idle. Image Unavailable, Please Login Image Unavailable, Please Login
I believe i have experienced similar issues. But the lower idle rpm seems right on line without the AC on, with the AC on it’s about 900-1 k rpm But there has been instances right after start up where it dips like you have described. The dealer also said this was normal for 458s.....
Does the engine respond as normal when stepping on the Excelerator no hesitation or stumbling???? If you have access to scan tool that can give you data look at the MAF sensor input both should read really close and look at short term fuel trim for both banks or try cleaning the MAF sensors and throttle bodies Sent from my iPhone using FerrariChat.com mobile app
Yes AC on or off, it drops to this level. Its not all the time, on start up it runs fine, until I accelerate a little bit and move the car, then when the RPMs settle, it will drop down. Sometimes it stays above the 900 level and the idle is very smooth. Sometimes it drops down... so strange! The engine responds perfectly, and no hesitation or stumbling with the accelerator at all. I don't have a scan tool, but I could see if I can borrow one from a friends shop and see if I can have a look at those values. Will have a look at the throttle bodies and MAF sensors as well, thank you!
Faulty TPS maybe. But the thing that worries me is that it is related to AC. Normally an EFI system has a specific feature that raises the RPM when AC is turned on. My concern is that it seems as if the ECU does no longer receive an input that asks the RPM to be raised as load is applied to the engine. This is why I don't think this has anything to do with MAF. I don't see how that relates to this issue. I'm thinking TPS, IAC or ECU. Not sure how the system in the EFI is set up. Some systems have the AC connected to the ECU via an Aux channel, and the AC-on idle RPM is a programmable feature in the EFI system. Other systems just work by raising idle RPM if they drop too much - a more simple solution. I think the car needs to be properly diagnosed, because this can be a few things. Oh a pet peeve of mine No such thing as RPMs. That would mean Rounds Per several Minutes RPM without the s, is by definition Rounds, so no s needed Sorry. Couldn't resist Sent from my SM-G930F using FerrariChat.com mobile app
Haha my OCD is in overdrive now! So I learned there is no IAC valve in this car, unlike the 355 which I had to replace. The AC On and Off still adjust the rpm up a tiny bit. If the engine is happy at 900RPM, the AC on request will bump it up a little bit to say 930RPM (guess, but I do see the needle move up) If the engine is lugging at 630RPM, AC on still requests the RPM to bump a little, so say 660RPM So overall the AC On and Off still works with the RPM going higher. Dealer said they cant find any fault codes, and that the California does the same thing and is even worse.. But I just can't see how this is "Normal"
I had a very similar issue develop. The car was seen by two different service center and they both had the same diagnosis which was faulty exhaust valve. It was replaced and the problem solved. A short and mild irregularity with the idle being otherwise steady (99% of the time) is normal for the 458 She is not a perfect machine.
You say that you do get a slight increase in RPM with the AC ON so the fuel map that is triggered when the AC button is depressed works. IMO i dare say Idle control valve if she has one and or sensor for the Throttle Body Valve.
That was the exact word from the dealer in Hong Kong. "This happens much worse in the California, and Ferrari states its normal" I pushed further and they said the car actually shakes when the idle drops... But I said this is a 458 not a California! So to your previous post, yes the AC triggers a jump in RPM, but that jump will happen wherever the idle is sitting to increase from that point by another 20-30pm or so. But wont bump back up to 900. Confirmed there is no Idle Air Valve in this car, just the electric throttle bodies... My OCD is on overdrive now!
With no CEL its going to be hard. The ECU is being triggered by something that wont open the TB a little more to get to the 900 rpm. Certainly a case for either Ferrari or a well versed mechanic that has experienced this before.
Resurrecting an old thread... I have a 2012 458 with 6800 miles. Everything runs good except when in idle, turning off the AC stalls the engine. I can reproduce this maybe 4/10 times. I have not reached out to my dealer yet but wanted to see if there's anyone here that saw this problem before.
Hi there ,recently my 2015 458 started Keeping the idle rpm between 1100 and 1300 and when on uphill in 1st gear is not going Neutral if I take my Foot off brake pedal , any advise ?
