Question:

> I am a certified ASE auto technition…have been for over 10 years…and yes, > warm up is a good thing. As long as the cooling system is within spec, there > will be no harm in ‘over warm up’ at idle.

Why, then, do the Honda owner’s manuals specifically say something to the effect of "You should not wait to drive your car for more than 30 seconds, regardless of how cold it is"? And BTW, the harm in letting your car idle to warm up is that it is spending a longer period of time cold, which is where the most wear will occur.  Driving the car mellowly adds enough load to warm the engine up quickly, but not enough to add to the amount of wear.  Doing this minimizes the time spent with a cold engine. — Mike Kohlbrenner <kohlbren (-a t-) an dot hp dot com> sorry!

Response:

> My question is, well, pretty clear in the subject line. > I have a 96 Prelude VTEC and at 25k miles, I’m still babying the > engine.  After starting the car, I don’t drive it hard until the I’ve > got three bars on the temperature gauge (equivalent to the midpoint on > analog gauges) and the idle speed is below 1000rpm.  When these > conditions are met, then I consider the engine warmed up, and then the > fun can begin. :) > Is what I’m doing necessary or am I just being paranoid and too > overprotective of my engine?

Nope. You are ensuring the oil is properly distributed thru the engine, and that the engine will last a long time. Nothing’s worst than rev’ing the piss out of an engine with the oil still in the pan!

Response:

[...] >I have a 96 Prelude VTEC and at 25k miles, I’m still babying the >engine.  After starting the car, I don’t drive it hard until the I’ve >got three bars on the temperature gauge (equivalent to the midpoint on >analog gauges) and the idle speed is below 1000rpm.  When these >conditions are met, then I consider the engine warmed up, and then the >fun can begin. :)

An oil pressure or oil temperature gauge can be helpful in knowing if your engine is up to operating temperature.  I will not drive my car -hard- (above 2000rpm) until my idle oil pressure is 30psi… this roughly equates to the oil being at operating temperature – 200deg faranheit, methinks. >Is what I’m doing necessary or am I just being paranoid and too >overprotective of my engine?

No.  You’re doing the right thing.  Zinging your engine to redline before everything is up to proper operating temp is a "bad thing(tm)". >Albert

Wayne Edelen / Frederick, MD  -  96 Pontiac Firebird Formula BW T56 6spd – Purple/Graphite – AS&M Cold Air, GM 4.10 gears Hurst, HPP+, Borla Street / Strip Catback, Hypertech Airfoil 3ptSTB, SFC, Eibachs, PFCM pads, 160thermo, MBA Billet stuff

Response:

> Ok, all you guys who never warm up your engines in the winter: > How the heck do you keep inside of the windshield from fogging over? > I don’t think it’s safe to go anywhere until I’m getting some > seriously warm air out of the defroster, and that can be 10 > minutes if it’s really cold

This can well be a problem and obviously, safety should take precedence over engine longevity.  Just bear in mind that this is the tradeoff. > BTW, the "drive off slowly" idea doesn’t work too well if you live three > blocks from the expressway…

This is another issue.  I actually purposely drive to the next further on-ramp in the morning just for this reason.  Of course, the nearest ramp is actually a half mile in the wrong direction, so I’d end up going an extra mile or so to use it. Of course, on the way home, I have the same problem as you.  In the summer, the engine is pretty much warm by the on-ramp.  In the cold, I still get on the highway, I just don’t hammer it to redline to merge.  Mellowly accelerating to highway speed isn’t much of a problem when the engine is cold — it’s the pedal to the metal stuff that you should avoid. — Mike Kohlbrenner <kohlbren (-a t-) an dot hp dot com> sorry!

Response:

>Do you care to fill in with some facts and evidence?  The question is >why and how?  Seriously, I am interesting in hearing that too.  I have >been asking several people, some of them are licensed mechanics, and all >I heard was good things about warming up (one said 2-5 minutes should be >good enough).  I also heard something about oil contemination (why?).

 Because the engine warms up a lot faster under load, than just sitting idle.  I didn’t say you should drive away like a bat out of hell, but once the engine has started lubricating, your going to warm the engine up faster by driving away than sitting for several minutes.

Response:

> >My question is, well, pretty clear in the subject line. >  Your actually most likely doing harm to the engine.

How about idling the engine while going downhill? (putting it in neutral) is that harmfull too? and is it more harmfull than letting it rev at whatever gear you are on while cruising downhill? Rocket

Response:

– Hide quoted text — Show quoted text ->>Is what I’m doing necessary or am I just being paranoid and too >>overprotective of my engine? > Your actually most likely doing harm to the engine. > Idling an engine to warm it up is actually quite harmful.  Your >better off driving away nice and smooth. (i.e. don’t race right away) >    That’s right but I think that’s what the original post said. What >I understood is that he crank up his car and drive at relatively low effort >until the engine is warm and then he goes to those 7500 RPM shifts that are >kind of fun.  If that is the case then he’s following the right procedure. >Oil takes longer to warm up than coolant and clearances in the engine will >not be optimum until the engine is properly warmed.  

 Rereading the sentence.  I think your right.  Yes, don’t drive hard until the temperature gauge has reached normal operating levels.

Response:

– Hide quoted text — Show quoted text ->My question is, well, pretty clear in the subject line. >I have a 96 Prelude VTEC and at 25k miles, I’m still babying the >engine.  After starting the car, I don’t drive it hard until the I’ve >got three bars on the temperature gauge (equivalent to the midpoint on >analog gauges) and the idle speed >Just idling till you get 3 bars on the water gauge is too much. I do >agree warm-up is necessary to keep the engine for long miles. >But in my humble opinion what you do is hurting the engine. >The logic is this: >Combustion is less efficient when idling. Fuel residual contaminates >the engine oil. So the engine oil "gets dirty" faster. >What I recommend is to let the car idle for 5-10 seconds. Take the >time to wear your seatbelts, tune your radio, check the mirrors or >make a short prayer for safe driving.. >Then drive the car gently (never get close to the red line). >Once the water gauge reaches its usual position (3 bar in this case), >I regard that as fully warmed-up. Then rev your VTEC. >Reminder: I live it Texas. If you are in the north, take 20-30 >seconds.

Even a minute or two in sub-zero temps does not seem unreasonable. But I can’t see where you are reading that Mr. Wu is letting it idle until it reaches full operating temp.  He says he doesn’t drive it "hard" until it gets there, not that he doesn’t drive it at all.  His reference to normal idle speed seems to refer to stop light encounters along the way.  Of coure, it should be at normal idle long before it reaches full temp.

Response:

Ok, all you guys who never warm up your engines in the winter: How the heck do you keep inside of the windshield from fogging over? I don’t think it’s safe to go anywhere until I’m getting some seriously warm air out of the defroster, and that can be 10 minutes if it’s really cold (This may be less of a problem in larger cars, where the indoor humidity doesn’t rise quite so fast– I drive a CRX). I’ve also noticed that a couple of extra minutes beyond that can greatly improve the comfort factor, although I don’t usually wait that long. What I’d really like is a heated steering wheel– I don’t like driving with gloves on, but I often get to my destination before the steering wheel is warm enough to take them off. BTW, the "drive off slowly" idea doesn’t work too well if you live three blocks from the expressway…

Response:

>>Is what I’m doing necessary or am I just being paranoid and too >overprotective of my engine? >Albert >Too paranoid, unless you are planning to keep the car for  400,000 >miles. I got 150K on mine and never warm up the engine for more >than 5 seconds even on 10 degree days. >joe

The amount of milage you have accumed, is of no matter…I gaurantee you have shortend the life of your engine. Take care. __ Chris G. Not speaking for my employer.

Response:

>Too paranoid, within 20 sec. with grade 10-30W oil, your >engine is already protected.Considering the outside temp is >40-90F.

Untrue…the metal in the engine has not had enough time expand/contract. When an engine is not at operating tempature, tolerances are not at spec. While the tempature variation will have an effect, on the effect, it should be noted that if you would take off say…on a 25 degree engine…after just 30 seconds, you would be "scaping" hours and hours of life, off the cylinder walls…among other wear. Take care. __ Chris G. Not speaking for my employer.

Response:

- Hide quoted text — Show quoted text – >|>  Your actually most likely doing harm to the engine. >|> >|>  Idling an engine to warm it up is actually quite harmful.  Your >|> better off driving away nice and smooth. (i.e. don’t race right away) >|> >|> >|>  I usually let my car idle maybe 20 seconds in the winter, and hardly >|> at all the rest of the year. >|> >Do you care to fill in with some facts and evidence?  The question is >why and how?  Seriously, I am interesting in hearing that too.  I have >been asking several people, some of them are licensed mechanics, and all >I heard was good things about warming up (one said 2-5 minutes should be >good enough).  I also heard something about oil contemination (why?). >TIA >Steve

I am a certified ASE auto technition…have been for over 10 years…and yes, warm up is a good thing. As long as the cooling system is within spec, there will be no harm in ‘over warm up’ at idle. I heard another post about over-depositing because of weak combustion at low engine RPMs…but again…with a well working fuel introduction system, this would not happen. Take care. __ Chris G. Not speaking for my employer.

Response:

>My question is, well, pretty clear in the subject line. >I have a 96 Prelude VTEC and at 25k miles, I’m still babying the >engine.  After starting the car, I don’t drive it hard until the I’ve >got three bars on the temperature gauge (equivalent to the midpoint on >analog gauges) and the idle speed is below 1000rpm.  When these >conditions are met, then I consider the engine warmed up, and then the >fun can begin. :) >Is what I’m doing necessary or am I just being paranoid and too >overprotective of my engine?

 Your actually most likely doing harm to the engine.  Idling an engine to warm it up is actually quite harmful.  Your better off driving away nice and smooth. (i.e. don’t race right away)  I usually let my car idle maybe 20 seconds in the winter, and hardly at all the rest of the year.

Response:

>My question is, well, pretty clear in the subject line. >I have a 96 Prelude VTEC and at 25k miles, I’m still babying the >engine.  After starting the car, I don’t drive it hard until the I’ve >got three bars on the temperature gauge (equivalent to the midpoint on >analog gauges) and the idle speed

Just idling till you get 3 bars on the water gauge is too much. I do agree warm-up is necessary to keep the engine for long miles. But in my humble opinion what you do is hurting the engine. The logic is this: Combustion is less efficient when idling. Fuel residual contaminates the engine oil. So the engine oil "gets dirty" faster. What I recommend is to let the car idle for 5-10 seconds. Take the time to wear your seatbelts, tune your radio, check the mirrors or make a short prayer for safe driving.. Then drive the car gently (never get close to the red line). Once the water gauge reaches its usual position (3 bar in this case), I regard that as fully warmed-up. Then rev your VTEC. Reminder: I live it Texas. If you are in the north, take 20-30 seconds.

Response:

Have you noticed that you cannot bring the VTEC into play until the engine reaches a specific temperature? There is an electronic control that keeps the VTEC from kicking in until the engine is appropriately warm. On mine, that happens as soon as the first additional bar lights up. That’s my signal to GO FAST! Before that, don’t push the engine hard. The other advice here is correct in that waiting 10-30 seconds is sufficient to lubricate the engine, and idling beyond that point is a waste of time, fuel, and engine life. Get going. When it’s REALLY COLD (below -10