Hitting redline for a few seconds, bad for old engine?


#1

I have a 2000 Corolla CE (4-spd auto) and today had to merge in fast moving traffic…the engine hit about 4000rpm for about 2 seconds or so and then dropped back down to 2800 and eventually 2300.

Not sure what the redline is for the 2000 corolla, but I’m guessing that hitting it especially when under load is bad even for a few seconds?


#2

The engine should handle 4K with no problem while merging into fast traffic. Damage is usually done while racing the engine to redline in neutral to impress the neighbors.


#3

I imagine red line is more than 4000 rpm, more like 5000, maybe even 6000. And since it’s an automatic, it would have shifted if it needed to.

No harm done, for sure.


#4

Yep, here’s the tach for a slightly older Corolla. 6000+ rpm red line:


#5

No harm done, 4000 rpm is nothing. If that were my car it would hit 4000 on a daily basis.

I don’t think I’ve ever seen a modern day gas engine with a redline at 4000rpm.


#6

The red line is the red part of the tachometer. Did the needle get into the red part of the gauge? If not, you didn’t red line your car.

I’m willing to bet your Corolla has a rev limiter that makes it impossible to red line it.


#7

My corolla does not come with a tachometer so I use a ScanGuage which told me about the 4000rpm (short delay).

Good to know 4000rpm is safe and 6000rpm is the redline.


#8

I’ll offer up at least one caveat to the “no harm, no foul” drumbeat.
If the engine has a ton of miles on it where it has been basically driven gently, the cylinder bores will have a wear ridge at the normal extent of the piston/ring travel. With enough wear, this can make extracting pistons difficult without using a ridge reamer. When an engine in this condition is suddenly revved well past its historical limit, the rings can contact this ridge and end up cracking the top ring. Without knowing the particulars on engine history, it’s hard for me to say there was absolutely no chance of some harm…


#9

My 2002 Sienna has the same redline markings. I run over 5000 rpm as often as once a week. There are winding mountain roads near here, and at times there are slow trucks. With only short straightaways I punch it to get around in as short a distance as I can.

Car has 206,000 miles on it, so I’d say having done that for years it isn’t hurting it.


#10

If an engine is worn enough it’s also possible that it could just flat grenade at 4000 RPM. Red lines are for engines in top mechanical condition.


#11

True, but chances are they’re fine.


#12

I also think they’re fine; just pointing out that a high miles, worn engine might see 4K RPMs as valve float and blow up time.

Many years ago a friend of mine decided to get into dirt track racing. He set up every engine loose (the analogy being wear) so it would rev quickly.
I don’t think he ever finished a heat race. The engine would scatter every time and he blamed it on Ford. He went to a Chevy and really grenaded that one on his first Bowtie race.

Oil pan sliced in half, several rods out the top through the aluminum intake, the rear float bowl on a Holley double pumper sheared off, and the hood bulged up…
I didn’t see it happen but did get to see the carnage later. That was the end of the racing career…


#13

That’s absolutely true, TT, but I cannot imagine a Corolla engine living its entire life hooked up to an automatic tranny and never having gone over 4K.

I very seriously doubt that 4K is not common for the engine, even if the OP is normally unaware of it. Merging with highway traffic safely would be terrifying staying below 4K. Passing on the highway would be impossible. If it were a powerful V8, perhaps, but not a 2000 Corolla.


#14

Well, it was unusual enough for the OP to come here and ask about it so I assumed it wasn’t a regular occurrence but rather a first time in the life of the car type of event…

My '03 Camry won’t hit 4k in normal expressway merging but I do regularly exercise it through the rpm range, regardless :wink:


#15

Mine gets exercised too. I’ve never been one to baby my cars in their use. I baby them instead on their maintenance.

Perhaps I should have asked the question of the OP as to how long he/she has had the ScanGage, how closely he/she monitors it, and whether he/she is the original owner. I have a feeling that this is a normal operating characteristic that the OP was unaware of until now.

OP?


#16

I have an almost 73 year old engine (my heart) and I run it up to the red line once a day. My doctor says it is good for it. If my 73 year old ticker can run up to the red line, I am sure that hitting the red line for your auto engine didn’t hurt it.


#17

I run it up to the red line once a day

Right, that’s the point. It’s used to doing it. Try sitting on a couch for 72 years and then run it up to red line. What do you think might happen then?


#18

@TwinTurbo: “It’s used to doing it. Try sitting on a couch for 72 years and then run it up to red line. What do you think might happen then?”

In this case, I think the analogy of comparing a car engine to a human body is inappropriate. A heart or body that gets regular elevated heart rates from regular cardio workouts can better withstand hard use. Conversely, a car that has been driven hard from day one is less likely to withstand abuse after years of punishment and metal fatigue. A car that has been driven gently is more likely to withstand hard use than one that has been abused its entire service life.


#19

@Whitey
You’re forgetting about my original point. The cylinder bores are worn to a point of their piston’s historical travel limit. Now hammer it such that the piston travel is increased beyond that historical limit and you have a ring that must traverse the ridge. Being a relatively brittle material, it doesn’t handle that kind of stress very well…


#20

Given that I haven’t seen a question here linked to ring breakage caused by over-revving a worn engine, it looks like the chances are very small. Not zero, but small…