SJ350z Posted September 5, 2014 Share Posted September 5, 2014 So I was at work the other day and was having a moan to a friend about another friend that tried to rev my car from cold . I snapped at him and he looked fairly embarrassed and he should know better as he drives a performance car. Anyway while I was having my little rant , to my surprise the friend I was moaning to turned round and said revving a NA engine from cold won't do anything.. It's only FI cars that will suffer Can someone please clarify this? Was I being a big lairy ape throwing the toys out of the pram or is my friend very misinformed? 1 Quote Link to comment Share on other sites More sharing options...
Ekona Posted September 5, 2014 Share Posted September 5, 2014 He's wrong. No engine should ever be revved from cold. 6 Quote Link to comment Share on other sites More sharing options...
hawker1986 Posted September 5, 2014 Share Posted September 5, 2014 I have no technical reasoning behind it but I've always believed the same as you. Certainly with the oil pressure gauge that goes flying up when the car is cold and I can't imagine that's much good for it. I'm sure someone better informed will come and agree or otherwise with a proper reason! Ed Quote Link to comment Share on other sites More sharing options...
japcarsbrett Posted September 5, 2014 Share Posted September 5, 2014 you should never rev any engine from cold it should always be warmed up first doesn't matter what car/engine it is that's how it is and always will be, as your supposed to let your car warm up before you drive it or at least give it 30sec to a min if your in a rush i always let mine get up to about half way on the temperature gauge before i go for a drive as they the oil psi is down to near were it should be, i know you dont have to do this but its safer and it's a habit from having a turbo supra before lol Quote Link to comment Share on other sites More sharing options...
Ekona Posted September 5, 2014 Share Posted September 5, 2014 No, you don't leave modern engines to warm up. You start them then you drive off immediately, but with mechanical sympathy so basically keep the revs to under 3k until the oil (not coolant) is warm. Then go nuts 4 Quote Link to comment Share on other sites More sharing options...
GMballistic Posted September 5, 2014 Share Posted September 5, 2014 He's wrong. No engine should ever be revved from cold. This with bells, whistles and other noisy parts all over it. It can easily cause friction wear on the pistons, piston rings and cylinder walls. Also I believe from what I've heard it can also damage your CAT's. 2 Quote Link to comment Share on other sites More sharing options...
Floydbax Posted September 5, 2014 Share Posted September 5, 2014 It's not so much the 'engine' per se that needs warming up it's the oil, which needs to be at a certain temperature before it does it's job properly of lubricating between metal parts rubbing together and those metal parts have expanded due to the heat produced during the combustion process. All engines suffer from this except 2 stroke where some of the oiling process is partly taken care of in the fuel mix. 1 Quote Link to comment Share on other sites More sharing options...
SJ350z Posted September 5, 2014 Author Share Posted September 5, 2014 Thanks for the clarification , glad I had words with the guy. Think he's a complete tool now tbh.. prattles on about how he knows about cars and goes and does that. Wasn't to redline only around 4-5k but not the point at all. Thanks for the all the messages chaps ! Never letting anyone near my car again Quote Link to comment Share on other sites More sharing options...
Martinjj Posted September 5, 2014 Share Posted September 5, 2014 Poppycock.. ( feeling posh today ) ... The oil needs to be warm first throughout to reach it's correct viscosity, too cold and it's too thick Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted September 5, 2014 Share Posted September 5, 2014 It not the revving a cold engine thats a problem its revving it with no load, the same really applies to a hot engine as well, however the term revving needs to be clarified, just bringing the revs/blipping up to say 3 to 4K is no real problem, but i wouldn't hold engine revs at that while cold. The only real difference in todays engines is the clearances and the material's, which are designed around modern oil technology, so engines are designed to be worked from cold, and modern synthetic multi grade oils can support this with no problem. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted September 5, 2014 Share Posted September 5, 2014 Poppycock.. ( feeling posh today ) ... The oil needs to be warm first throughout to reach it's correct viscosity, too cold and it's too thick Errr poppycock! that why modern oils are mutigrade.. and so are capable of providing the correct viscosity at all temps. Quote Link to comment Share on other sites More sharing options...
JEMAN Posted September 5, 2014 Share Posted September 5, 2014 I must admit, I never rev my engine from cold and when I drive off I stick to 2k revs until the car is fully up to temperature. It's something I've always done. Not sure if it does any good, but makes my conscience clear lol Quote Link to comment Share on other sites More sharing options...
SJ350z Posted September 5, 2014 Author Share Posted September 5, 2014 Well this just kind of went back and forwards. I'd still rather not rev my car knowing what I know now due to the responses from our forum members. No harm in sensible driving for 15 minutes after all. The car has plenty of useable power up to 3k imo having good amounts of torque. Some people though eh... what kind of insensitive plank starts revving a friends car? 1 Quote Link to comment Share on other sites More sharing options...
Floydbax Posted September 5, 2014 Share Posted September 5, 2014 My FTO had a lock in the mapping that wouldn't let you go over certain RPM until the engine was up to temperature. Not sur if the Z has a similar system as I've never tried revving it from cold but it wouldn't surprise me if there was something there to prevent damage to the engine! (Not that you should test this!!) Maybe one of the real gurus could let us know, Alex, Mark?? Quote Link to comment Share on other sites More sharing options...
codders Posted September 5, 2014 Share Posted September 5, 2014 My FTO had a lock in the mapping that wouldn't let you go over certain RPM until the engine was up to temperature. My MR2 2zz engine was the same. The engine normally has the rev limiter at 8.2k but if the temp was below 65 ish it was limited to 5k. All car ownership manuals I've had say set off after about 1-2 minutes but don't load the engine until normal operating temp. I've also heard many times that worst engine wear is at cold start up. Quote Link to comment Share on other sites More sharing options...
KyleR Posted September 5, 2014 Share Posted September 5, 2014 Recently I had to walk away from a keyboard war with a member on another (mixed) car forum about super unleaded and how I refused to use 95 in my car. He was saying it was stupid because it makes no difference in NA cars, only FI. I felt like punching him in the face, but chose to walk away as I'm relatively green on that forum with less than 100 posts. 1 Quote Link to comment Share on other sites More sharing options...
hensh65 Posted September 6, 2014 Share Posted September 6, 2014 Recently I had to walk away from a keyboard war with a member on another (mixed) car forum about super unleaded and how I refused to use 95 in my car. He was saying it was stupid because it makes no difference in NA cars, only FI. I felt like punching him in the face, but chose to walk away as I'm relatively green on that forum with less than 100 posts. Another forum!!!!!! How long has this being going on! 2 Quote Link to comment Share on other sites More sharing options...
GMballistic Posted September 6, 2014 Share Posted September 6, 2014 Recently I had to walk away from a keyboard war with a member on another (mixed) car forum about super unleaded and how I refused to use 95 in my car. He was saying it was stupid because it makes no difference in NA cars, only FI. I felt like punching him in the face, but chose to walk away as I'm relatively green on that forum with less than 100 posts. Another forum!!!!!! How long has this being going on! Link: 1 Quote Link to comment Share on other sites More sharing options...
choptop Posted September 6, 2014 Share Posted September 6, 2014 Having seen what they do to new cars coming off the production line, it does make you wonder............... 1 Quote Link to comment Share on other sites More sharing options...
Mike_89 Posted September 6, 2014 Share Posted September 6, 2014 I had the same type of conversation with a Merc driver the other day. Drives me mad... He basically revs the nuts off his car as soon as he leaves work. I explained what I did which is drive steady until my engine is ran up to temperature, and he just laughed at me. 1 Quote Link to comment Share on other sites More sharing options...
Pete87 Posted September 6, 2014 Share Posted September 6, 2014 Isn't the idea to warm your car up slowly aswell to stop the metal heating up to quickly and cracking say a head that's what I've been taught. Kind of like you don't put boiled water on an icy windscreen for the same reason. 1 Quote Link to comment Share on other sites More sharing options...
Flex Posted September 6, 2014 Share Posted September 6, 2014 I always use the rule of thumb that if I can lay my love sack on the engine then it's not warm enough to rev. Must admit you get some strange looks using this method. 4 Quote Link to comment Share on other sites More sharing options...
Martinjj Posted September 6, 2014 Share Posted September 6, 2014 I always use the rule of thumb that if I can lay my love sack on the engine then it's not warm enough to rev. Must admit you get some strange looks using this method. brings a whole new meaning to "boiled eggs" 1 Quote Link to comment Share on other sites More sharing options...
Ekona Posted September 6, 2014 Share Posted September 6, 2014 And "hot rod". 1 Quote Link to comment Share on other sites More sharing options...
GMballistic Posted September 6, 2014 Share Posted September 6, 2014 I had the same type of conversation with a Merc driver the other day. Drives me mad... He basically revs the nuts off his car as soon as he leaves work. I explained what I did which is drive steady until my engine is ran up to temperature, and he just laughed at me. Yep I know exactly the kind of idiot he is ~ same as my old boss. My old boss who had a 2001 Audi S3 reckoned he knew a lot about cars & modding them. Takes me out one day in his S3 when we had to pick up some paint supplies and what does he do? Redlines his car in 1st, 2nd & 3rd from the first set of traffic lights we came to even though I could see that not even his coolant temperature gauge had started to move yet let alone the oil temp. Literally started 30 seconds earlier from cold (and it's a turbo car!). Think he was hoping I'd be impressed or something by this but I wasn't as.... The car was not warmed up correctly. We where on a public road & not a drag strip. My Zeds definitely quicker. 2 Quote Link to comment Share on other sites More sharing options...
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