1

Run a modern car (2010+ model) until all parts, oil and coolant has fully reached operating temperature. After driving for some time, shut it down at the gas station and leave it off while refueling (less than five minutes) and restart it. How long does it take for the engine to fully regain oil pressure? Is it ok to rev it quite hard after a minute or so?

3

A normally operating engine regains pressure almost instantly. Oil residual stays in the bearings and on parts for quite some time after the engine is turned off.

As soon as the engine starts turning the oil pump pressure begins to build. This only takes a second or so.

Unless there is something wrong with the engine, or the oil pump, I doubt there would be a lack of sufficient oil pressure to prevent you from revving the engine after a minute of running.

Note: this is a very general answer to a very generalized question. If there is some specific issue you are having, please add details to your question.

  • Very interesting. My car (2011 Audi A4 2.0 TDi) has hydraulic cam lifters, and the manual says that they require a small amount of times after startup to build oil pressure and that during this time, some engine noise might be heard. Do they also regain pressure after a pause of running, or do they require any longer time? And as an additional question, are they part of the same system as every other component being lubricated? – Erik Jul 13 '17 at 20:34
  • @Erik - What are you considering a "pause"? 5 seconds, 5 minutes, 5 hours? – Pᴀᴜʟsᴛᴇʀ2 Jul 13 '17 at 21:08
  • @Pᴀᴜʟsᴛᴇʀ2 5 minutes or less as written in the question - a typical stop for refueling – Erik Jul 13 '17 at 21:13
  • @Pᴀᴜʟsᴛᴇʀ2 No worries! – Erik Jul 13 '17 at 21:21
  • 1
    As stated, it was a very general answer. Your vehicles manual is referring to a cold start (after sitting for hours). It is never a good idea to rev an engine immediately after a cold start. After the the engine is warm, and is shut off for a short period (as you described), my answer still applies. In the future, please add vehicle specific information so we can give vehicle specific answers. – CharlieRB Jul 14 '17 at 11:23
0

Oil pressure may be built up within engine bearings but it does not mean that all components that use oil have sufficient amount such as hydraulic lifters and some timing belt tensioners so I would let it idle for a few seconds before revving the motor, no matter how short of a time span the motor had been off.

Also, I don't understand why you want to "rev it quite hard", are there other issues that need to be addressed?

  • No issues at all, I'm just very interested in the subject. I've got this one hill about 100m after the gas station where I like to rev it quite hard to launch up the hill - no other reason than fun. Before doing this it would idle for some 30 seconds and then I'd have to drive the 100m to get around the station to the hill. Keep in mind that the car would be fully warm before stopping for fuel. – Erik Jul 13 '17 at 22:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.