Start-up wear - how long to wait

[LouDawg]

Since most wear occurs at start up, is there a rule of thumb for how long to let your engine run before driving? I usually wait about 60 seconds before driving off, and I'm *trying* to get my wife to do the same.

I know there are a lot of variables, such as type/size of engine, type/viscosity of oil, temperature, etc., but in general, is there a safe number that would cover most situations?

TIA!

 

[dima]

I wait 10 seconds, and than go easy for about 1 minute. Same in winter.

 

[GROUCHO MARX]

I let it run about 10 seconds.

 

[GoldenRod]

Everybody here at BITOG says that if you let it idle to long, you will get fuel dillution. Then after that, everytime you pull the dip stick to check the oil level, your oil will smell like fuel. You don't want that.

 

[LouDawg]

quote:

---

Originally posted by GoldenRod:
Everybody here at BITOG says that if you let it idle to long, you will get fuel dillution. Then after that, everytime you pull the dip stick to check the oil level, your oil will smell like fuel. You don't want that.

---

Can you explain how that would happen?

 

[GoldenRod]

Originally posted by sprintman. March 03, 2004

quote:

---

Start the engine and drive away SLOWLY. Idling from cold the fuel doesn't atomise and raw fuel washes the cylinders. Not inducive to good wear characteristics.

---

 

[pitzel]

Once the engine is started, the 'damage' is done. As soon as the engine stabilizes insofar as RPM's and instruments are concerned, put some load on it, and get driving.

5-10 seconds sounds about right, a bit extra in the winter. Just don't hammer on it if you can avoid it. Sometimes I don't even start my motor until the car has completely rolled out of the driveway and onto the road, just to save fuel.

 

[427Z06]

quote:

---

Originally posted by pitzel:
Once the engine is started, the 'damage' is done.

---

Correctomundo. Approximately half the wear is due to the engine not being at operating temperature. A light load after the initial stabilization will bring it up to temperature quicker. The other half is due to lack of lubrication. This implies that if you could prelube, you might be able to cut the cold start wear proportionally. This all assumes good, clean lubrication under "normal" running conditions.

 

[Volvohead]

All our newer vehicles go through a cat heating routine upon start up that takes about 15-20 seconds. Once that happens and the revs drop below 1,000, we usually take off.

In the older vehicles, we wait about the same: 15-20 seconds. 60 seconds seems excessive.

 

[Titan]

I crank the engine first, do any adjustments, put on the seatbelt, tap the accelerator to drop the rpm's down (especially if it is an automatic transmission), and drive off easily.

 

[rjundi]

Forget telling your wife. There are bigger battles in life.

Engines rarely wear out unless you go into the long haul(eg 200,000 miles+ range) usually the car wears out or has a major failure (auto tranny) causing it to leave an owners possesion.

My personal experience is no warm up in warm weather but easy driving. In cold weather the same unless scraping windshield required. This achieved no engine issues (perfectly running) to 225k/10years in Civic and 200k/10 years in 1988 VW Jetta. Both cars sold because I was just tired of them.

 

[AEHaas]

The rate of wear is very high for the first few minutes then tapers down to a steady state when the oil temperature reaches approx 180 degrees. This takes about 20 - 25 minutes of normal driving.

It is best to get in the car and go but easy for the first minute or two. An oil less thick when you start it up such as a 0W- oil will allow a little more spirited driving earlier on.

aehaas

 

[AEHaas]

It is possible to shut the engine off and keep the temperature of the engine and oil the same. This experiment has been done. It shows that when you start it back up again the wear rate is exactly the same as the steady state hot engine.

aehaas

 

[Iain]

I usually let the vehicle warm-up for no more than 2 minutes, then drive conservatively for next 15-20 minutes till completely warmed up. No WOT during this time.

This is my regular procedure, summer or winter.

 

[vad]

quote:

---

Originally posted by LouDawg:
Since most wear occurs at start up, is there a rule of thumb for how long to let your engine run before driving?
TIA!

---

Question: what exactly are you guys trying to achieve by letting the engine idle?

It takes no more than several seconds for oil pressure to stabilyze.
If you let it sit and idle after that instead of driving, you'll just prolong the engine's heat up cycle and increase the wear rate.

 

[Steve S]

I really wouldn't worry about cold start wear. When cold or not up to operating temps the pistons aren't round .The engine clearances are changing "metals expand when warm". A richer air feul mixture may contribute to some lube washdown in the upper cylinder. Oil protects better when the additives temps are up. Also the major cause is when the wrong viscosity oil is used for example if a 20w/20 oil is used a -10f think about sucking a thick milkshake through a straw.The oil has to travel from the oil pan to the pump. The engine running with outlubrication is what you have to worry about.

 

[vad]

quote:

---

Originally posted by Iain:
What's the point of this question?

---

What's the point of idling for 1 or 2 min in the warm weather?
You don't do your engine any good.

 

[Highroller]

hmm i'd think in 30 degrees and below, id wait at least a min. Anything above is 30 seconds or less. Drive easy regardless of temperature for at least 10 minutes (keep rpm below 3k). I'd say idling for over 5 min is excessive. Put on the emergency lights or give a salute if you have to if someone is tailgating or honking at you in the morning trying to get to work on time

 

[Highroller]

Oh and also, keep a constant speed for as long as possible. The short stops and goes during the first 10 minutes are not helpful.

 

[LouDawg]

My startup and morning drive routine is usually startup, wait a minute, drive off and maintain highway speeds for about 45-55 minutes, really never going over 3K rpm...sounds like that'll take care of my question. Think I'll just wait 10-15 seconds now though instead of 60...