Power flat spot.......

[Anonymous]

Has anyone had this happen to them.........

Was driving up to sunny Sheffield on Saturday for a birthday party. Car was running sweet, as usual, but tried to overtake an old middle lane hogging dodderer. Accelerated lovely up to about 4500-4600rpm, then all of a sudden it was loke someone just cutting the fuel back and the power just halved for some reason (or at least it felt like it!). Now, before you all completely flame me for this, I wanted to try and see where exactly this flat spot had appeared, so I did a couple of acceleration tests in various gears to see if it wasn't just me reading too much into things, but I tried revving the engine in 3rd, 4th and 5th over 4500rpm (yes, this DID equate to over 100mph at a couple of points. Normally, I would NEVER do that!) and the flat spot was still there. It really struggled to get the car going forward over that engine speed, yet below 4500rpm, the acceleration was a vivid as ever!

This got me worried, but we were nearly at our destination and the car felt completely fine otherwise, so I carried on. The car then wasn't touched until relatively late on Sunday evening on the drive back. So, to see if the car was still doing it, I had another go at accelerating over 4500rpm and the car is completely fine! I just don't get it. It FLYS around the rev counter now.

I am going to keep an eye on it and give it a blat every now and then and see if there is anything wrong on long term, but does anyone know of anything like this happening on other peoples cars and is it worth me getting it to the dealer for them to have a look, even though the problem, touch wood, isn't there at this moment?

A little worried by this......any ideas?

[Slacey]

Almost sounds to me as the VVTi wasn't working correctly, ie the valves weren't lifting when they should, which is around the rev range you mention, IIRC.   s:?: :?: s:?:

[Anonymous]

Surely if that were the case though, the acceleration would be the same as it was previously... 'cause cars without VVTi certainly don't flat spot.

Only time I've had what you describe was when I bounced if off the rev limiter (oops).

Doesn't sound good though... did you get the engine warning light on?

[Anonymous]

I get this as well, thought it may be something to do with the air density as it was after some rain, guess i was wrong then lol

[Tem]

Isn't the powerloss above 4500rpm the first sign of broken precats...?

Check your oils...often.

[mph]

Check your oil. The ECU won't switch the VVTi unless you have good oil pressure.

[Anonymous]

Oh god! Bugger! None of this sounds good!

Well, the power loss isn't there at the moment. Just been out in it and its fine, for now.

Before I go on ANY journey over about 100miles, I always check the oil and the oil was nice and high and very clean, so I don't think there is too mich of a problem there. Will check it again later though, in case it has dropped since the journey.

And it did feel like the VVTi wasn't working correctly. It was a very weird sensation. Got to about the 4500rpm mark and the car felt like it had quickly had an eleastic band attached to the back of the car. It kept going, but without the pull that it had. Normally, (and I know this is bad), it would FLY to 100mph, but not this time. Really struggled over 4500rpm and took a while to get there.

I will continue to check on the oil and will also give it a balt every now and then to check that it is OK.

The Pre-cats. How can I get those checked to see if they are knackered and if they are, what are the consequences to the car and the engine? And almost as importantly, as my car is now out of warranty, how much are they toget fixed if they are knackered?

I am getting quite scared now........

[Tem]

Check your exhaust pipe...do you see tiny white particles on it? Those are pieces of the precats.

Some threads from SC...check if these sound familiar:
 m http://www.spyderchat.com/phpBB/viewtopic.php?t=46 m
 m http://www.spyderchat.com/phpBB/viewtopic.php?t=5961 m
 m http://www.spyderchat.com/phpBB/viewtopic.php?t=5944 m

Plenty more on the Maintenance section:
 m http://www.spyderchat.com/phpBB/viewforum.php?f=6 m

[Anonymous]

[Moved to Maintenance, Problems & Troubleshooting]

[Anonymous]

I'd agree with Tem...   s:( s:(

[Anonymous]

Tem, where am I supposed to be looking for these white spots? IN the exhaust?

Can you be a bit more specific?

Also, according to those links you sent for SpyderChat, this seems a VERY common problem to the point it seems inevitable that this is going to happen, not if, but WHEN!!! If my car is out of warranty, do you reckon MrT will note the problem if it is that common and at least PAY for some of the repair work cos the car only has 13500 on the clock!!!

I am getting really worried now......
  s:? :? s:?    s:cry: :cry: s:cry:

[Tem]

Tem, where am I supposed to be looking for these white spots? IN the exhaust?

Yeah, IN the exhaust. Just check the tip, you should see it if they are there.

[Anonymous]

Right, just had a look down the exhaust and I can't see anything that looks like white spots. Seems very clean to me. How BIG are these spots and are they actually "chunks" of the cat? Or is it more powdery?

And I have also gone to check the oil again and there is nothing wrong with it. Nice a full and very clean......

Ok, getting scared now...........

[Anonymous]

Most probably on the floor.

EDIT - sorry posted after your comments.  There will be some blown out of the pipe.  Try putting some paper under the pipe and starting the car and maybe leaving it running.  Then see whats on the paper, if you want to start the car that is...

Be warned your dealer is probably going to deny any kinda CAT problem.

[Tem]

They are very small particles...not quite powder though. There was a pic on SC, but can't find it now...

If you can't see them and you have oil, it could be that you run into something new...the powerloss just fits perfectly to all those blown engines  s:? :? s:?

[Anonymous]

Cheers Dummy!!!!  s:wink: :wink: s:wink:    s:lol: :lol: s:lol:  

Living up to your name I see!!!  s:wink: :wink: s:wink:    s:lol: :lol: s:lol:  (Joke!)

Mind you, you're probably right!
  s:shock: :shock: s:shock:

[Anonymous]

Could it have been a bit ot dirt/water in the fuel or dirt in the carb that was restricting the power?

[Anonymous]

like I said though, be careful with the dealer.  They just sit there and spout about this is a 150k engine and its just starting to seem like its not at all.  With more people on SC I guess they have and more problems.

What kinda fuel and oil do you use?

[Tem]

Be warned your dealer is probably going to deny any kinda CAT problem.

Funny you should mention that...I know for a fact that there has been (at least) two cases in Finland. When I asked Toyota what will they do if my engine blows some time after the warranty, mentioning those two cases from here and the several on SC...they just said they haven't heard of the problem and can't find any info on their db  s:lol: :lol: s:lol:

[Anonymous]

Be warned your dealer is probably going to deny any kinda CAT problem.

Funny you should mention that...I know for a fact that there has been (at least) two cases in Finland. When I asked Toyota what will they do if my engine blows some time after the warranty, mentioning those two cases from here and the several on SC...they just said they haven't heard of the problem and can't find any info on their db  s:lol: :lol: s:lol:

Yip same old Toyota crap.  Hopefully in this case its not the CAT and we are over worrying.

[Anonymous]

Ok guys, thanks for all the help. I will try the paper thing and also keep an eye on it generally. Like I said, the problem isn't there AT THIS MOMENT, but I was DEFINATELY not imagining it cos even my girlfriend said that she could feel it.

I am using the same oil MrT puts in it (not filled it myself and its only had one major service cos of the low milage) and I am using Optimax 95% of the time, but I am tempted to not bother with this fo a while and see if this makes a difference.......

Will report back and see what happens.

Still scared........  s:? :? s:?

[markiii]

To follow on from earlier comments. Too little oil pressure will mean VVTI won't engage. However don't oberfill it either as too much pressure will cause the seals to fail, which is contributary to cat failure.

[mph]

Doesn't this sound very much the problem Rogue was having? I never did hear whether that was fixed or not..

[SteveJ]

Doesn't this sound very much the problem Rogue was having? I never did hear whether that was fixed or not..

AFAIK, Rogue is still having problems with the MR-S. His is slightly different though - when you reach ~4500 rpm there is a very pronounced power dip (like hitting a brick wall), and if you repeat this 2 or 3 times the CEL illuminates.

[Anonymous]

John, when was the last time you did 100mph?

Not sure how to describe this but sometimes when the car is driven at low speed (i.e. town driving) the engine is not breathing very well.  

A good run makes the engine breath again...