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xzirri

Transmission (?) issues when cold

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I've had issues with low power combined with a weird noise and an RPM that won't go past 2K for a few seconds until I suddenly get the power back and the noise goes away. If I let the RPM drop to below 2K, this process repeats itself. This only happens when the car is cold though. When it's had a few minutes to warm up, everything is fine and I get a decent power delivery from standstill.

I've attatched a video, where you can hear the noise I'm talking about at 7 seconds, 13 seconds (I pushed the kickdown button at 16 seconds). I've tried to find videos or descriptions matching my issues online but I've had no luck. I've even been to a transmission shop twice, and they couldn't find any issues with the transmission. However, by the time I got there, the transmission was within operating temperature.

I did a transmission Oil change 9000 km ago and the Oil is still fine, so at least I know that the Oil isn't burning up. No burnt toast smell either. I'm wondering whether this could be sticky solenoids, torque convertor drainback, or maybe something else. Also, does anyone know what could be making that awful sound I'm getting? I'm not even sure what word to use to describe that sound, sounds kinda like a pump being starved.

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I know automatic transmissions are complex things and that people here might not know what the issue might be. Does anyone at least know about a forum of some sorts for automatic gearboxes?

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To me it looks more like a lazy turbo, but once it spools up, it goes fine. That would also explain the power being delivered fine if you dont drop below 2k, meaning turbo is always spooled up. 

You drop it below, it shuts down.  That is all assuming your turbo kicks in at that rpm?

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Thanks for your reply! I would have though the exact same thing if I had a turbo, but it's the 2.0 petrol, which does not have a turbo.

Today I also noticed that if I got up to 2.5k RPM on half throttle and then fully opened the throttle, the RPM would drop to below 2k with the lack of power and weird noise. I'm wondering if this could be either the pressure for the 1st and 2nd gear valves not being high enough for some reason, dropping it to 3rd gear, or that the torque converter clutch somehow engages when it isn't supposed to while cold... Any input would be appreciated!

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And the car revs fine in neutral?

There are no symptoms suggesting issue is on engine side, not transmission?

How about reverse, same symptoms?

Switch your car computer to show you current consumption, and when it starts to bog down, does the consumption to increase, and to which numbers?

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Car revs fine in neutral, no issues. Nothing wrong with the engine, as far as I can tell.

I have to say that I haven't tested this out in reverse. Thanks for the tip, that would actually help me narrowing down which parts of the transmission it could or could not be (if it is the transmission, that is)

Will have to test out these things tomorrow since the car isn't cold anymore as I have driven it today. Once again, thanks mate!

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I'm still inclined to think that it might be the engine who is at fault here. Have you changed the spark plugs recently, if ever?

Cleaned MAF sensor, put a new filter?

I know that those things would usually throw a code, but it's behaving so weirdly without any code, so anything is possible.

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I haven't cleaned the MAF sensor yet, nor changed the spark plugs. However, all filters except the fuel filter (since it's inside the tank) have been changed, yet the problem persists.

I'm skeptical to thinking it might be the spark plugs, as they either work or they don't. Even worn spark plugs don't hurt your performance more than maybe 1-3 % (as long as they don't misfire, which isn't the case here). I was planning on changing the spark plugs around next spring, as I've had a few expensive repairs done the last couple of months and I'm stretched thin at the moment.

Also, wouldn't a dirty MAF sensor cause issues regardless of whether the car is cold or within operating temperatures?

I also passed the MOT this week (after replacing a rear suspension arm) so there isn't any other issues with the car like increased emissions, which would be a typical issue with a dirty MAF sensor.

I'm worried that I might have to replace the solenoid packs, or maybe the entire transmission, as issues that disappear when the car is warmed up might mean some of the seals may have hardened. Weird thing is that I have done 14k miles without the issue getting any worse, and 6k miles after an ATF and filter change. The fluid still looks new.

I understand why you think it might be the engine and not the transmission, and I've been considering the same myself, but no mechanic has found any issue with my engine, apart from a water pump that I replaced about a year ago.

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You know what? I think I owe you an appology, because you might have been right about it being an issue with the engine and not the transmission. I stumbled upon this post:

This is basically exactly the same issue as I'm facing. He even describes the weird sound I'm getting a few posts further down. It doesn't seem like they came to a solution in that thread, but at least I have a starting point now!

If anyone knows anything about this particular issue I'd be happy for inputs!

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I'd try to write the guy a message. I see he has not been around for some time, but maybe he will get it in the mail.

This is just a guess, but have you checked the intake manifold? Maybe the problem is in air delivery, or flappers inside the manifold are somehow obstructing the air intake, but get cleared, or more open when warm?

 

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No, I haven't done anything major yet. Do you mean removing the intake manifold? Will I need new gaskets?

I'll try messaging him. I'm also thinking about cleaning the PCV valve, as the last post in that thread mentioned that as a possible solution. Would MAF cleaner work for cleaning that valve, and possibly also the intake manifold? I bought a can but haven't had time to clean the MAF yet.

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I do not know how good it will work on pcv valve, but since you will be taking it out, might as well give it a try.

I just mentioned intake manifold as a wild guess,  as the car might be struggling for air. As the intake flaps are on there, they could be restricting the airflow.

Do you have black smoke running out of exhaust?  This could indicate either running too lean, or starving for air. If the answer is no, i think we can drop the intake manifold thing.

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No black smoke, exhaust is normal. I guess I'll let the manifold stay on then 😜

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Going to clean the PCV valve today, do I need to buy teflon tape or something first? Saw a video of someone who wrapped some teflon tape on the threads before installing the PCV valve back. Or can I just put it back in without risking any leaks? And does anyone know the torque specs for the PCV valve?

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Update: Took the time to pull out the PCV valve today. First thing I did was the good old shake test and sure enough it was rattling. Then I looked at the engine side of the valve and oh boy, what a sight. It was clogged to the point where one couldn't even see that there was supposed to be a hole in the bottom! I did a function test by blowing into it from the engine side, then blowing into it from the hose/pipe side (no lip contact ofc as I don't intend on getting that nasty stuff in me). It seemed to be working so I installed it back.

Meanwhile I had taken out the MAF sensor and given it a thorough blast with some MAF cleaner. Installed it back as soon as it was dry, then drove to a place where I could rev the engine without receiving complaints. My initial issue was still present on the way there but idk if it was because I hadn't revved the engine enough to clear out the PCV hose/pipe. When I arrived at a suitable location I revved the engine to 4k for a minute. On my way back the issue was gone and the car felt more responsive.

The increased responsiveness might have been due to the PCV valve being cleaned or just my imagination. However, I'll have to wait until tomorrow to see whether or not this fixed it.

If not, I'll have a mechanic look do a scan from cold start to operating temperature to see what the issue might be.

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Issue is still present. I'm gonna take the car to a mechanic, let the car stay there over night and let the mechanic run diagnostics while the car is warming up.

Also, does anyone know what would produce the nasty sound when the car is hesitating? And what word would you use to describe that noise? I was trying to find videos of cars running rich and lean while accelerating but didn't find any videos that were helpful.

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On 9/26/2018 at 6:33 PM, xzirri said:

Issue is still present. I'm gonna take the car to a mechanic, let the car stay there over night and let the mechanic run diagnostics while the car is warming up.

Also, does anyone know what would produce the nasty sound when the car is hesitating? And what word would you use to describe that noise? I was trying to find videos of cars running rich and lean while accelerating but didn't find any videos that were helpful.

have you had any luck with your car?

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Not yet, been swamped with work and I'm still waiting for my payday. I'll keep you posted

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Hey, did you found solution? I have pretty much the same issue on my 2.0 petrol Avensis T25

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Hey, no, I haven't bothered taking the car to diagnostics yet.

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Anyone here who have any experience with carbon cleaning of intake valves and/or the entire inside of the engine? Having looked more into this matter I think it's related to the carbon buildup issues people have reported in New Zealand. One of the threads I stumbled over mentioned a noise sounding like paper touching the blades of a fan, which is a good description of the noise I'm hearing. See for yourself in the video earlier in this thread.

I'll try talking to someone about doing an internal cleaning of the engine (apparently they run some water mixture of some sorts through the engine while it's running at 2000 rpm). Tbh I think it sounds rather scary, with the risk of hydro locking the engine, bent valves and so on.

At the same time, if the procedure is completed without any issues I will end up with a cleaner engine. Even if this doesn't fix this particular issue I'll probably get better fuel economy and get rid of the idle dips (when warm the engine sometimes dips down to 650 ish rpm).

Not sure what to do anymore at this point... Others who have had the issue I'm having have fixed it by cleaning the PCV valve but it didn't work for me. The fact that my PCV valve was completely clogged has me thinking that the reason it worked for the others is that they had less carbon buildup than me. If anyone who's slightly less mechanically impaired than me reads this, I would appreciate any comment on whether or not my theories are reasonably sane.

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I have gained some more wrenching experience since last time I posted in this thread. So far I have done general servicing like Oil and filters for the engine, planning on doing transmission Oil and filter later this summer. I took off the throttle body and cleaned it up and the difference in throttle response is night and day. Idle RPMs are also super stable. I cleaned the PCV valve again as well, although it hadn't clogged up since last time. However, I suspect that there is a fair amount of sludge under the valve cover, so I will take it off later this week to clean it up, and measure the valve clearances while I'm at it.

The initial issue is still present, however, so today I admitted defeat and dropped the car off at the dealership with detailed description of the issue and how to reproduce it. I will update this thread tomorrow when I get the car back.

At this point, I am thinking about removing the intake manifold and cleaning the intake valves with an intake valve cleaner by closing the intake valves, soak the valves with the cleaner, then suck it out with a suction pump/extraxtor after it has dissolved the buildup. That way I won't hydrolock the engine and I won't have to pay for walnut blasting.

Next, I will try replacing the fuel filter, and if that doesn't work, I might have to do some research into how those fancy schmancy injectors work so I can clean them.

Here's to hoping that Mr. T will figure it out tomorrow so I can sort this issue out after 3 years and 40k miles of ownership!

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After that clean, take all the spark plugs out and turn the engine over a few times to be sure and clear out any liquid that got into the cylinders. Also handy to pull the fuel pump fuse or relay, first.

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Thanks mate, didn't think of the fuel pump fuse!

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I doubt it is your transmission. Seems like an engine fault. This engine has no EGR (in EU spec.) but does have high-pressure direct injection which can give problems at high mileages. Try to fault-find methodically...

1. Connect Techstream and check for stored codes. Clear codes and start the engine, watching parameters such as temperatures, fuel pressure and lambda switching as the car warms up.

2. Check compressions.

3. Check operation of VVT system with cold and hot engine.

4. I doubt a liquid solvent will clean the valves satisfactorily. You'll need blast cleaning.

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