I’ve read this thread so many times due to issues with my F12 lazy start! I’m on my third battery in 15 months and up until May it had no resolve! Battery would deplete and not charge properly even on a trickle. Not sure if this will help anyone else but an eagle eyed engineer spotted two cables that were touching near the Starter motor Solonoid? They were taped up and separated and voila problem gone battery charges and starts like it should. The problem reoccurred last weekend and I called My local dealer as they had already said they would order the part and it would be a temporary fix. Got the car back Friday and all is good again. I will find the workshop sheet and see if it states the part as it was done under power warranty. Dan
Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login install lithium battery then problem solve no need starter cable.. anything just the battery can’t handle the heat from engine Sent from my iPhone using FerrariChat.com mobile app
Keep in mind that lithiums have PC boards and electronic components that dislike heat and heat cycles as well as mechanical vibration.
Yes, I know about that.. that why I made heat protection for it.. I know how to build lithium battery.. it not that hard... and 50% of Antigravity battery and use A123 battery.
It's very strange, that so many people have this problem with their F12s and there is still no definitive answer what causes this. The only thing, that is certain at this point is that nobody fixed the problem with replacing the battery or the starter motor.
I have had 0 issues with hot start in 110*+F ambient AZ heat using Interstate AGM battery. personally if I had to replace battery more than once in a year, I would never use that battery brand again, including OEM.
Others too have mentioned ground strap corrosion. Some of the components (straps/bolts/washers) are dissimilar to the aluminum chassis they bolt to and Ferrari has known issues with this type of corrosion especially in the presence of electrolytes. There have been of pictures of FF chassis ground straps posted that caused all kinds of hard to solve issues with starting and software. The starter cable is only the positive lead and the return is through connections to the chassis. If either can't handle the inrush of current you can have similar issues. There are several straps located throughout the vehicle. If I had the problem I would check for a weak ground and inspect all of them.
I'm a farmer and come across similar problems on my tractors with the exact symptoms. This was a few years ago but through many months of frustration and trial and error the problems were eventually traced to faulty/loose/rusty earth cables usually on the earthing side of the cable not the battery side. Its very frustrating that something so simple can cause so many engine cranking issues. On another note i was getting cranking issues on my old 458 which was solved by fitting an Antigravity 40Ah battery. When i sold my 458 i took the AG battery out and transferred it to my 991.2GT3 RS WP more for weight savings rather than cranking issues.
i wanted to update my testing 2016 F12 original battery with what i thought were hot starting issues. today i returned from 12 day trip car on battery tender, i watch the volt reading on dash cold start 11.7 started just fine lunch about 2 hours returned to car volt reading 11.5 started just fine parked in garage, popped the hood to vent heat, came back within 5 minutes volt reading 11.6 but when i pushed start button LAZY lazy cranking and volt dropped to 9.8 until it finally turned over and started after about 4 seconds it slowly cranked about 6 times. i'm thinking battery is my issue just curious why it has lazy restarts so close to when i just shut off the engine?
My thought is that it's the increased friction and resulting compression of everything being hot in the engine closing up the tolerances, there could be additional piston to ring to cylinder wall clearance when everything is cold.
If that was the case, the engine would be ruined upon startup. Normally the engine is looser when cold, not tighter. Only case where it gets tight, is when the block is cold and the piston is hot. But these are street engines, and the tolerances are nowhere near that tight. These are very advanced performance engines, but not race engines with super low tolerances. If that engine would crank slowly because of friction in the cylinder bore, it would mean that the bore would be torn up in short order. It is also worth noting that the rings used are going by the more modern way of thinking, where thin rings and low ring pressure is better. That's one major advantage of dry sump lubrication, you can run a pretty high vacuum. This means you can run super light and thin rings, and still get a good seal, especially if the pistons are gas ported. If the engine cranks slowly, it means a lack of power. It's that simple.
I stated the engine was looser when cold…. We are discussing a high compression engine with 12 cylinders of part interaction, other high compression engines of similar displacement use two batteries for starting (aka diesels), just throwing a different thought out there. Yes I understand a diesel is a higher compression engine than the F12.
I’m curious...since not all F12s suffer from this is there a correlation between this problem and F12s that also have the corrosion problem? Could it be some combination of flawed step in manufacturing coupled with hot/humid environments? Mr. Owen suggested corroded earth cable connection... Just wondering. (btw..I had both problems with my F12...paint corrosion and recurring hot-restart problems. Touch wood, my 812SF has been flawless over 6K miles.)
I had it once on my car in very hot weather (34 degrees Celsius). Car almost didn't start on the gas station. My car doesn't have any paint corrosion and has been in my town its whole life. The humidity here is very low. Battery is brand new - Bosch. I highly doubt it is engine-related.
I got a feelback from a guy he said that he had the dealer update the new alternator with bigger one then the problem solve.. Anyone one can confirm that Part no Alternator new : 322484 Crankshaft Pulley : 321956 Fixed mule pulley : 295763 Belt tensioner : 325416 Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
All the parts stated except for 321956 are for F12 tdf. Will this work? Sent from my iPhone using FerrariChat
Finally I can confirm.. my Ferrari problem solve with the new alternator kit. part no : 330767 the part include all the necessary change for F12 to a update version. The car run so much better, the voltage alway stay at 13.5 when running. to conclusion it is not to do anything with heat relate to the battery. All asian car which has battery in the engine bay and has same issue. It just the alternator is too small for the V12 to charge the Battery. I hope it help someone here.
Are the pullies and the tensioner the standard replacement parts for original setup that gets ordered? Some need that kit anyway and some have no issues with the OEM setup. Maybe just the alternator is different.
Yes it is.. I can point out the new alternator part no : 322484 the new one has clutch like mercedes benz so it won't throw the belt.. tensioner and new crankshaft pulley so u won't have any issue.. it is perfect fitment. I think it all depend on how people driving the car. U need to remember our car is handbuild so it is custom made order.. it can't be like production car.
V12 battery issues been discussed many times, only perfect batteries seem to work, be careful not to overcharge them too…see link below to another thread https://www.ferrarichat.com/forum/threads/812-superfast-battery-question.612006/page-2#post-147904422 Sent from my iPhone using FerrariChat
Hi, Has the “lazy start” issue been sorted out for your F12? I’ve not experienced anything yet but that’s also because I’ve not been using the car much. To recap, what parts did you change? Thanks in advance for your reply. Sent from my iPhone using FerrariChat
I've spoken with my mechanic about that yesterday. He said the ground cable of the battery doesn't seem strong enough in the first place. He said he will do some modifications to what he can to see if it will change anything.
