Camry V6 Transmission Issues

[Antharro]

My 2002 Camry V6 auto has developed what I believe is a transmission fault. When it's cold, it's fine, no problems. It shifts smoothly, it's a pleasure to drive. When it's hot, it's a different story.

When pulling away with very light acceleration, or when using the barest amount of right foot to maintain a speed between 40 and 55mph, there is a noticable surge in power. The RPMs stay constant, but the power fades and returns very quickly. It is not dissimilar to someone dipping the clutch in a manual car. When pulling away from standing, this problem is exacerbated if I am turning. I have noticed that often, the RPMs are around 1500. I have tested this throughout the speed range and it can also be replicated at 80mph.

When the problem manifests at 1500rpm, I can press the O/D button to switch off the overdrive, which increases the RPMs to around 2200 and the problem immediately goes away, while the speed has not changed.

Under hard acceleration there are no problems, it pulls smoothly up to high RPM. There are no odd noises or clunks at all.

I have also noticed that there is a loss of power sometimes - not a sudden loss, but I will notice it when I need to accelerate on the motorway and have to force it to shift down hard before it will pick up speed. So I have had to be creative with my use of the O/D button to get the power out of it. Which I don't think I should have to do with a 3 litre V6!

Last problem is I think something that's more by design than a specific problem. If I'm in very slow traffic, the transmission will quickly shift to second gear at walking pace. If the traffic suddenly picks up speed, I have to use what I think is a disproportionate amount of right foot to force it to shift down, otherwise the acceleration is almost enitrely lacking. It will eventually pick up speed but takes longer than I would like. And when I do put my foot down, it feels like it lurches through a gear change before it takes off.

Many hours of Googling have revealed this may be a torque converter problem. So I took it to a transmission specialist near Portsmouth who initially agreed with me. However once they had tested it further they were not so sure. They first thought it was an exhaust problem - blocked exhaust - which would match the power fade problems. They thought they had proved it when the car failed to maintain 2000 rpm at idle; it slowly started to lose engine speed. They eventually discounted that as they couldn't find a fault with the exhaust system other than there didn't seem to be much coming out of the tail pipe, which doesn't surprise me in a Japanese car with a huge back box!

I picked up the car this morning. They had replaced the spark plugs, checked over every filter, the EGR valve, and cleaned the MAP sensor, but the problem still persists.

Any help would be appreciated!

[Antharro]

71 views, no replies? Someone must have some idea?

[EP914AGE]

Do you have a code reader? When was the gearbox last serviced?

[Antharro]

Mod edit: bump removed as against terms and conditions of TOC.

Since my original posts, the problem deteriorated. The judder became much worse until it was reproducible at any speed above 35mph, and became more pronounced, eventually to a point where I stopped driving the car for a while. It went in to a local "transmission specialist" who sent the torque converter away to be rebuilt. When I got it back, it was initially better (they had manage to break other stuff on the car but that's not for this thread!) but quickly deteriorated again. Neither of my two local garages could replicate the problem and told me it was just the car "getting old".

Eventually I found another place in Weymouth who were able to reproduce the fault instantly, within a minute of driving the car. They diagnosed it as the torque converter not locking up correctly, probably due to bad seals in the valves that control lockup. Given the age of the box and its mileage (216,000) they didn't want to rebuild the box and advised me to find a replacement.

Got one from a Japanese parts importer on eBay. 27,000 miles, with a torque converter. Found another local place to do the work, recommended by one of my mechanics. They fitted the box with the newer torque converter, new oil, etc, etc. I've just received the car back tonight and ... with a different box, different torque converter, IT'S STILL JUDDERING!!!

The symptoms are easier to explain now. Engine must be at running temperature. Drive up to 45mph, ease off so only the minimum amount of right foot is being used to maintain speed. Car will judder - almost like a misfire, but it's not - no engine check light, engine speed constant, no odd noises from the exhaust, etc. No codes to read off the ECU either. Also reproducible if I get the car up to speed, ease off completely, then add just enough right foot to keep the speed constant.

The only good thing that's come of this replacement transmission is the MPG has shot up, from late teens to late 20ies!

At this point I've sunk a considerable amount of money into this car and I'm really not happy! What's the problem here? CV joints? Engine problems? It's had plugs, oil change, filters, EGR and MAP sensor cleaned... no luck. Any advice appreciated!

[RUToyota]

It seems you've been very unlucky in that the Camry has a great rep. for reliability/longevity etc (providing it's been looked after by previous owners of course)....you have the 1MZ-FE engine I assume.?..(as in my V6 Estima)...a great engine and thought to be virtually bomb proof. (and 200k miles + is not a massive mileage for these engines)

It would normally throw an EML if anything is amiss of course...and if you have had the codes read and nothing showed then it's a bit of a mystery....otherwise I'd be looking at coil packs/MAF sensor etc.

I can understand your frustration..sadly I can't give you clear answers. Hope you are able to sort it.

 

Neil

[Antharro]

I don't think there's anything wrong with the engine - the car had 212k on it when I bought it and it was running pretty sweet for its mileage and age. Didn't have this problem at all. So I don't question the reliability - I would expect any Japanese engine to last for at least this long, especially a V6.

Today I did the following:

Checked the front three coil packs - two of them had identical resistance readings, one was slightly higher. Swapped that one to the middle of the three just out of curiosity to see if would have any affect. Didn't check the rear three as that involves removing the manifold, air intake, probably the strut brace etc.

Disconnected the MAF sensor to check the resistances. Seemed to be a bit out of spec. Online research showed it should be showing around 2.2 to 2.6 kOhms at 20c and 0.49 to 0.67 kOhms at 60c - it was reading 1.7 at around 20c. Left it disconnected and went for a short drive - the symptoms were greatly exacerbated. Half way around my test route I stopped and reconnected it - symptoms were immediately reduced.

Question - is the MAF sensor faulty, not badly enough to cause the car to stall, but badly enough that under certain conditions, it causes problems? Or is the MAF sensor helping the ECU/engine etc manage the problem which actually lies elsewhere?

The fault has now moved; rather than exhibiting when maintaining a speed, it is now more obvious when barely maintaining a speed and very slightly dropping speed - not braking, but not giving it enough right foot to properly maintain a speed. Possibly because of the moved coil pack?

Also found a rather nasty leak of some sort of fluid sitting on the lower chassis arm - couldn't identify it by smell or colour. I am tempted to throw it at the main dealer and have them check the MAF and o2 sensors and fix the fault. (My local dealer is generally pretty good so I don't mind using them, and they can get me in faster than my regular mechanic). I can also have them check the driveshafts as that's been suggested elsewhere.

[RUToyota]

Given what you've said I think I'd certainly be investigating the coil pack/MAF/sensor areas..though I would have thought the system would be throwing a CEL/EML light and show up on a code read.?

The fluid leak ?...it can only be ATF/Oil/coolant and any of those should be identifiable....I'd be getting that checked PDQ.

 

Good luck.

[Antharro]

Did some further testing today, found out a few new things.

When the car is at normal running temperature, if I rev it hard in neutral to over 3000rpm, when the revs drop naturally, there is a "clunk" or "knock" at 1500rpm. This is repeatable. It feels very similar to the judder, like it's coming from the same place.

Shifting into drive can also produce this clunk sometimes.

When hot, if I try to pull away from standing but don't give it enough revs, the judder is there and very noticeable.

Moving the front three coil packs around produced very similar results, but one particular configuration of the packs (i.e., which pack for which cylinder) seems to have eliminated the pulling away from standing problem. Dodgy coil packs perhaps?

The source of the leak has been found - I have a leaking pipe running from the steering fluid tank to the pump; is it possible this is in any way affecting or even causing the judder? (My thoughts are on "no", but I'm asking anyway).

The "dogbone" top engine mount is disintegrating. Is it possible this is contributing? And does anyone have a part number?

Main dealer can replicate the fault but don't know what it is and won't do further diagnostic work until the steering fluid leak is fixed.

EML hasn't come on and there are no codes to read (I checked).

[RUToyota]

Dodgy coil packs are a PIA.....and a possibility...depends what's in there.?

I would never use anything but the likes of Denso etc....PS Fluid leak needs to be fixed of course..and your dealer should be able to identify the engine mount part.... then I guess you take it from there.

[Antharro]

Believe it or not, five years later I'm still dealing with the same problem on this car!

Since my past post, the following work has been done:

- power steering pump reconditioned with some pipework replaced, fluid reservoir cleaned and fresh fluid supplied
- EGR valve removed, cleaned and lubricated
- both outer CV joints replaced
- alternator replaced (not related, it just happened to fail)
- air con compressor replaced (not related, it just happened to fail)
- routine servicing
- all four tyres replaced and balanced
- all brake pads and discs replaced
- four wheel geometry / alignment carried out
- all engine and gearbox mounts replaced
- all anti-roll bar links replaced
- exhaust fully replaced with stainless system from manifold cats back
- cleaned air intake flow sensor/meter
- cleaned air intake valve assembly

Of these, the only thing that made a difference was changing the engine mounts and having the exhaust fitted - they were done at about the same time and made the problem worse! I guess the excessive vibrations caused by this problem put extra load on the engine mounts; all of them were quite badly worn out.

With new, firm engine mounts, new tyres, suspension parts replaced and geometry set up correctly, the car drives like a dream. Handling has been transformed and with the exhaust, the average MPG has gone up a little bit - bonus! The main dealer also gave the car a check over and OK'd the coil packs and spark plugs. No fault codes stored anywhere either.

However - from 35 mph to 45mph (sometimes to 50), I still have this damn wobble/vibration/judder. I can replicate it on demand; get to about 40-45mph, and let off the accelerator, applying just enough to maintain the speed. It'll judder all day long. Put my foot down to accelerate faster and it goes away. Take my foot off completely and it goes away. And if the road starts to go up hill and I don't apply any extra acceleration, it will start to judder worse for about a second before either slowing down or shifting up a gear, both of which make it go away. Sometimes, very occasionally, I'll feel it when it changes up through the gears, usually 3-4 but sometimes 2-3.

Apart from this, it drives perfectly. If I floor it from standing it will shift smoothly through the gears right up to motorway speeds. If I ask for sudden hard acceleration it will shift down smoothly and take off.

After doing a LOT of reading up on this, I've reached the conclusion that I'm looking at a fault with one or more of the following:

- air flow valve assembly
- air intake flow sensor
- egr valve
- torque convertor
- gearbox

The gearbox was supposed to only have 27000 miles on it, and it doesn't show any other signs of wear that I can determine. The torque convertor was supplied with the box. I am wondering if the torque convertor is potentially at fault here - damaged or worn internal parts causing slipping when it goes to lock up at lower RPMs.

I would very much appreciate the forums help on this as I cannot believe I'm still dealing with this years on from my first post!

[RUToyota]

Sorry to hear this...your patience is to be applauded.

I think I would have given up on this ages ago.

The V6 1mz-fe engine is generally a peach though mine has only covered 96k now and both engine and gearbox perform as they should. (and have always done)

Even after nearly 6 years of ownership I'm still amazed with my V6 Estima and its smoothness and driveability.

You know more about this than anyone.!!!...but for me, it points more towards the gearbox/TC than anything else.

I can't offer any more than you have already investigated I'm afraid...I do hope you can find the solution.

[VientaV6]

Hi I am a new member and just by chance read your long running saga.

I had a not dissimilar issue with my V6 1mz-fe  a year ago. It had been behaving much like yours, rough running, but never stalling, it seemed like a miss-fire - very light throttle engine warm. Most noticeable at the 40-50 mpg range. I checked the plugs, wires, cleaned the throttle body, IAC valve and finally removed and cleaned the EGR. But still had the problem. I continued to drive it every day, and just got used to the poor running, Most of my daily drive is on the motorway so at 60MPH+ it was not really so bad, only showing itself as I slowed and often running very roughly when coming off the motorway. Roll on six months or so and around February 2021 after "google some more I began to think it seemed so similar to lots of EGR valve problems I had read on various other sites for various makes and models. So I disconnected the vacuum pipe from the EGR valve and plugged it with a Golf-T (one lunchtime while at work) Got in the car and drove home later that day not expecting anything and the engine ran so smoothly I literally couldn't believe it!  Its been running like this ever since. My average MPG went up from 21 to 26 MPG as well 🙂 

I thought about buying a new EGR valve but Toyota wants £300 odd for one and that's crazy. If it passes the next MOT then I think my "EGR Delete" will be considered a permanent fix. 

Just a thought..........

[Antharro]

@VientaV6 Thanks for taking the time to post that. I would LOVE to give it a try, however...

Well... unfortunately, I no longer need to troubleshoot this. Car was involved in an accident and the insurance has written it off. (Someone pulled out across my lane at a cross roads where I had right of way). I'm waiting to see what the insurance will do, but they've already said they're going to write it off. Unsure if I'm going to try and buy it back; it's not repairable but it has a lot of good parts including a near immaculate interior.

[Antharro]

For anyone still reading this, the insurance classed the car as a "Cat B" write off - it must be crushed, but some parts could be saved if the breaker wanted to. Knowing the scrap industry in this country, because it's old it'll probably get crushed whole, with the thousands of pounds of new parts still on it. What a Mod edit waste.

[Cyker]

I dunno, some scrap yards are quite canny and know that they can make a lot more money off the parts than they can from the steel; A lot of them salvage things like engines, gearboxes, exhausts etc. before sending what's left to the crusher 

Where I am they don't survive long due to lack of space, but in the USA where there is loads of land, many scrappers keep the cars around to pick for parts, esp. uncommon models; Might be like that for scrappers in the less populated parts of the UK too...?

 

[VientaV6]

What a shame, as you say, loads of useful parts that may be lost. Its the thing I dread the most - someone rear ending mine while texting/phoning.  She'll be 25 years old this year, the insurance would write it off in a heart beat 😞 I doubt I could get classic or agreed value insurance, its just not old enough to fit that category, its just an old car........ 😞