'01 Camry Hesitates w/ gentle gas applied
 

I am so frustrated, I've always had my car dealer maintained, and now after 3 trips to them, they cannot determine what is wrong with it.

My 2001 Camry LE V6 (146,000 miles) hesitates when the engine is warm after leaving a complete stop and only when low/ gentle gas is applied. It is a very noticeable falter, you can feel the car move back and forth like it is trying to pull away from something holding it back. Even when traveling at 40-50 MPH, when I apply the gas pedal gently just to maintain that speed, I can feel it hesitating.

However, when I take off from a stop with umph or give it steady and strong gas - no faltering. When going 60 MPH and I need to kick-it to murge into the quicker lane to go 80 it does so perfectly as always.

It has never stalled or not wanted to turn-over/start. It idles quietly and smoothly. There is no engine knocking or exhaust fumes.

What the dealer has done to date: cleaned the EFI twice Oct 11 and Mar 12; replaced the fuel filter; replaced the air filter twice Oct 11 and again last week Mar 12; top engine cleaned to include the throttle body; flushed the transmission fluid; repaired transmission cooler line (it was leaking).

The timing belt was replaced in 2009.

I purchased the car new. Other than this issue which only started last Sep, it is a great and reliable car. I hope to have it for another 150,000 miles.

Appreciate any recommendations! :)

The problem only occurs after the engine is warmed up?

What other maintenance has the car had since new such as new spark plugs, etc.

Hi Toyomoho,

It has been well cared for always by the dealership with regular servicing. Last time the spark plugs were replaced was 2008. They were just checked and appeared to be fine. But perhaps it would be worthwhile to have them replaced again.

It has never needed anything significant done to it until the hesitating started. Just the usual oil and filters replaced, brake pads, topped-up fluids, and the timming belt was replaced 2009 when it had about 124,000 miles on it. It now has 146,000.

It iddles smooth, always starts, shifts smooth (automatic transmission) and responds great when I give it hard steady force of gas, and has never stalled.

The hesitation usually starts after I have driven the car several miles then stop for 30-45 minutes. When I drive off slowly with just gentle gas applied it hesitates and continues to do so even tho it shifts into 2nd gear. The hesitation is quite noticeable - feels like it is trying to pull away from something holding it back.

It lets up a bit once I am in 3rd gear but sometimes even then while going 40-50 MPH I can feel it hesitating when I apply just soft - gentle gas in order to maintain that speed.

When I give it umph to get up to 80 MPH on the interstate it is fine. I imagine it is still hesitating at that speed when I apply soft gas to maintain that speed, its just harder to feel it.

Thanks for your help!

If you don't stop for 35-45 minutes the problem does not occur?

Plugs should last 80 to 100K miles, doubt this is the problem.

Every once in a while it will hesitate during the initial start up and drive.... um, like Friday when I picked it up from the dealership's service dept.

I changed where I tank-up a month ago, thinking maybe it was poor quality gasoline (Mobil to Shell). Since purchasing the car, I have always used supreme/premium gas. It got better for 2 weeks, no hesitation, and then it started doing it again.

Last night it hesitated again during the initial start-up. I left work and drove about 5 miles to get some groceries... about 3 blocks from the store it started hesitating - badly. A very dramatic hesitation so much so I thought it would actually stall. It didn't.

However, when I left the store, it was fine. No hesitation at all.

Sigh... very frustrating. :{

May be a problem with the throttle position sensor (TPS) or manifold airflow sensor (MAF).

Both tell the engine computer about how much throttle is being given.

Maybe a failing fuel pump.

The TPS and MAF are both items are monitored by the computer but if not totally failed may not generate a trouble code. The fuel pump is not monitored. All these systems, parts can be tested.

Replacing any of these parts at a dealer will not be cheap.

My advice is find another repair shop, perhaps an independent shop. The dealer does not appear to be doing much. If doing this suggest only providing symptoms along with what was done by the dealer in the past, not recommendations as shops may provide what you request at your expense even if not required.

These parts can be tested electrically.

The owners manual should have the required octane rating needed for the fuel. Typically there is no need to use a fuel with a higher octane rating.

I would also check for any vacuum leaks. Maybe after the engine heats up, a possible leak/gasket leak opens up just enough to cause hesitation.

Thank you SO much Joey & "allcam". I truly appreciate your time and help. I will definitely look for an independent shop, and offer just symptoms and things completed thus far.

I can't continue to pay costs at the dealer, which is like 90% just for labor. :{

Yeah, I would definitely not recommend the dealer. At the same time, make sure you Yelp whichever independent shop you take it to as well.

Sounds good.

EGR Valve
 

I've been meaning to post the cure to my Toyota's hesitation problem.

After having the EFI cleaned twice, the power steering fluid flushed, the transmission fluid flushed, and the other items listed in this forum checked, I decided to just put up with the problem - car was running great outside of the hesitation.

A few months later, it eventually turned out to be the "EGR" system. Sometimes the problem isn't bad enough to turn on the applicable check engine code (P0402). The computer system finally registered and identified the hesitation problem. Once the dealership replaced the EGR valve, all was good again. Hasn't hesitated since then.

My toyota and I are back in Germany and it is very happy to be able to run at 90MPH to and from work (autobahn). It doesn't care much for inner-city travel, although we have to do that, too (of course).

Sadly, the transmission is starting to show signs of aging. About a 2 years ago I noticed a high pitched noise when giving low steady gas to maintain lower speeds (40 MPH) or when coasting at lower speeds. Guess this is to be expected for an engine with 175K miles on it now!

Thanks for posting back with the fix.

If a trans problem say a bearing the whine typically gets worse.

If possible shift trans to Neutral when coasting and determine if the noise is still there.

Assume the trans fluid level is OK but might check.

Just wanted to pitch in with my experience - similar 2001 V6 with now 190k. Hesitating on light throttle in the 1700,1800,1900 rpm range at 60-70klms. I was convinced it was the throttle position sensor (which incidentally was showing odd resistance and something of a flat spot). Anyhow a way to test if it is an egr is easy. There is a vacuum tube (black rubber tube) going to the top of the egr valve. Remove this and block it so it is air tight, this will stop the egr activating - and causing the problem. I used the bottom of one of those little birthday candle tips, the spike put in the tube and electrical tape. You may want to also block the entry into the egr - stop anything getting in there. Now drive! Debateable if this a permanent fix, but at least you can relatively easily test the problem. I had cleaned and tested my EGR and all seemed ok except that it made no difference. On doing the above the result was clear ;).

Thanks for the input about how fixed your problem. How long have you driven it like this and have you noticed any issues?

At a guess I think it has been about 4 months, the engine does have a slightly different sound to it at times other than this no problems. As far a fuel economy goes on a recent country trip I had figures approaching 8l/100k!, around town things are pretty crummy, however Sydney is very start stop etc. I have read various opinions on egr and fuel economy, will have to assess as time goes on. I have probably done around 4000ks since blocking the vacuum tube, as soon as I reconnect the problem returns, a new egr here exceeds $300 AUD and that is just for the part...

A further update on the EGR, I have been tracking my fuel consumption fairly rigorously and it would seem the country driving figure is good - without the egr the round town is terrible. I am a bit of a feather foot and it would seem with the egr reconnected and not working as well as it should I am getting just over 10l per hundred k's in the city, with it disconnected this figure is at 13 - 14l. So while this is anecdotal evidence, it does show some example of how the egr isn't just for nox, at least in the case of the camry!