Hi Honda Experts ,

I need your expert advise. I have 98 Honda Accord LX V6. I am experiencing two different problems (may be related):

1) When I drive the car with cold engine, then car moves itself without any need of pressing gas pedal. As if someone is pressing the gas pedal. This problem goes off when engine is warm and idle is normal. what could be the problem?

2) Car takes around 10 minutes to warm-up (temp gauge to middle, 800rpm) .... Is this normal?

I normally wait 30 seconds after starting the car and then drives the car.

 

A few comments:

• What you are experiencing is totally normal
• Most (all?) engines run at a slightly higher RPM for the first minute or so following a cold start
• You should never let an engine idle to warm it up
• Waiting 30 seconds is way too long; start the engine, wait five seconds (while you put your seat belt on), put it in gear, and drive away.

 

agreed ^

However I do disagree about 30 seconds being way too long. There is nothing wrong with letting your engine idle. I do understand and agree that 5-10 seconds is enough but in cold weather there is absolutly nothing wrong with warming it up for 30 seconds infact I'd recommend it.

 

I'm going to have to stick with what I said earlier; modern water cooled engines have straight bores and there is absolutely zero reason to let the engine idle for longer than five to ten seconds. Extending the idle time to thirty seconds, while probably not harmful (assuming the duration of the drive is sufficient to boil off the extra water which the extended idling will impart into the oil), isn't beneficial in any way shape or form.

 

I think 10 mins is too long to warm up if you're driving. I reach operating temp w/ my 4-cyl Accord w/i 2-3 mins running at 30-35 mph. Too long warmup usually indicates the thermostat needs replacing w/ new OEM thermostat.

Agree that it is normal for idle to go up to 1500-2000 rpm in cold weather. Quick warmup will mitigate this issue somewhat.

good luck

 

No mechanical need to idle & warm it up. But if you need to scrape ice off your windows, it doesn't hurt to idle while you do this. Maybe a waste of fuel, but it's not good to drive off when you can't see through the windows.

 

where is this water coming from? I have never heard of idling putting appreciable amounts of water into the oil pan on a car that is not blowing smoke. the combustion chambers are sealed so any moisture is sent out the exhaust, any blow by is sucked out of the crank case by the PCV. If this is a problem then that is a sign of much worse things and warming your car up is the least of your concern.

The only potentially damaging thing is doing 2-10 min warm ups over a long period of time as it forces crap into your cat. This happens because 1) the car is cold and running richer and 2) the cats are not hot - which can result in clogging the cat faster.

 

Water (a byproduct of combustion) and excess fuel are constantly being mixed with the engine oil and cold engine idling is where this mixing is at its highest point. Don't make the mistake of thinking that blow by gasses, liquid fuel, and water molecules on the cylinder walls don't constantly mix with the oil; they do, hence the need for many of the stability additives in modern oil which prevent acid formation and cloudy/milky looking oil.

The thing is, if, on a regular basis, one was to start their engine on a cold day, let it idle, and then say drive to the local bus or train stop and park the car (and then do the reverse on the way home), water and fuel contamination of the oil will grow to the point where the additive package can be overwhelmed and the oil can start reacting with the contaminates which in turn creates the aforementioned acids.

It's far better to start the engine and drive it (conservatively of course) almost immediately; this procedure accelerates engine warming terminates the rich cold engine air to fuel ration cycle earlier, and minimizes blow by gasses due to the faster heating/expansion of the pistons.

 

Fair enough, I understand what your saying. I am also aware of people having issues with their car and they come in to the shop saying "well I warm it up enough and only drive 2-5miles each day, why is it broken". So I get it, however I do believe the majority of people fall outside of that group. Therefore I will stick with what I said earlier and say that it is more dangerous to the catalytic converter than anything.

 

How is driving conservatively following a cold start even remotely damaging to a catalytic converter?