Avensis Sr 2.0 Vvti - Poor Preformance - Black Smoke

[RobJ1]

My girlfriend has an X reg Avensis 2.0 VVTI.

On cold starts you get a puff or two of black smoke out the exhaust and the preformance isnt that great on the car either.

She does a mixture of town and motorway driving and the trip computer is reading 30mpg does this sound about right.

Its recently had a new O2 sensor under warrenty and they put a new cat on it as well.

The car has only done 32k miles.

I would appreciate any advise about the black smoke and poor preformance.

Also, not 100% sure about the handelling either, when you go around a corner you all of a sudden seem to get a bit of over steer which you have to correct.... surely this cant be right on a front wheel drive car.... and when reversing and turning the steering coloumb makes a funny squeeking noise that sounds almost mechanical.

The car is still under Toyota warrentee so its been there a few times, they say there is nothing wrong with the steering and the car is fine.... We both feel differently... Again any advise apprciated. I this is my first post here so if i need to proved and further info please let me know.

Thanks

Rob

[RobJ1]

Could old spark plugs or HT leads cause this, just thought the car is now 6 years old but its probably on its origional Plugs as its only done 32k miles

[Steve84]

Steering noise is common problem. My dads had endless racks, columns, and power steering pumps, also new front subframe. Non have offerd a cure. Has for over steer issue i've got the mk2 avensis. My dads mk1 facelift on the x plate can not be driven has hard has mine. I've found the back end can be a bit twitchy when pushed hard. I've found it will give understeer first has you'd expect with a front wheel drive car but can wag its tall when backing off the throttle. This is only when driving the car hard tho, to be honest its not a car that you'd drive hard because of it twitchy nature on the limit and body roll. Black smoke issue can't help with. Poor performance i'm sure i've heard somthing about exhaust gas recirculation valves causing running problems. The engine is known for o2 sensor problmes has well.

[RobJ1]

Do the petrol VVTI's have a EGR valve? if so where abouts is it?

The Steering problem isnt when your driving the car exceptionally hard, its all the time around any bend thats more then just a slight band in the road. What can I tell toyota to check, they have test driven and say its fine.

Thanks again

[Ray99]

Hi Rob My feeling would be to check the air flow meter. I've seen several now where the hot wire gets covered in debris, built up over thousands of miles, often due to not changing the air filter frequently enough. The system will not light the MIL (malfunction indicator light) as it doesn't see a problem. I've cleaned a few, but they are easily damaged. Best just to replace it. About £100 plus fitting from memory. Regarding the noisy rack, there are several possible causes. The main one is a dry seal in the rack- the noise is transmitted up the steering column and sounds like it's coming out the steering wheel. Only cure is the modified rack from Toyota. Other possibilities are the gaiter at the base of the column- where the shaft passes to the outside of the car- that bearing can go dry and squeak. In extreme cases the noise of power assistance is transmitted inside the car by one of the pipes touching something it shouldn't under the bonnet. If you still have warranty then push for a repair, but at 6 years old any warranty will be fairly limited. Read the small print on your warranty form and make them stick to it. Let us know how you get on.

Rob, just re-read your original post. I agree it's most unusual to get oversteer on a front wheel drive car. First thing to check would be rear tyre pressures, then a 4 wheel alignment check. Hope this helps

[funkyg]

My feeling would be to check the air flow meter. I've seen several now where the hot wire gets covered in debris, built up over thousands of miles, often due to not changing the air filter frequently enough. The system will not light the MIL (malfunction indicator light) as it doesn't see a problem. I've cleaned a few, but they are easily damaged.

The early 2.0 VVTI's don't have air flow sensors. Mines a Y reg and doesn't have one, check out this thread.

http://toyotaownersclub.com/forums/index.php?showtopic=56814

Was also confirmed by the dealer.

Funkyg

[Penfold]

Call me old fashioned guys n gals but in the days before EFI/ECM a puff of smoke from the exhaust when starting from cold was a sure sign that the valve gear is b*ggered.

As the engine cools down the oil in the cylinder head seeps down the side of the valve stem and sits around the valve seat. Turn it on and the oil gets burnt off within the first few cycles.

The fact that perfomance is down as well would indicate a burnt valve. My guess is that the burnt valve is letting gas by and is making the oil seepage worse as time goes on. Out of interest - I bet the engine oil is filthy black.

[RobJ1]

Call me old fashioned guys n gals but in the days before EFI/ECM a puff of smoke from the exhaust when starting from cold was a sure sign that the valve gear is b*ggered.

As the engine cools down the oil in the cylinder head seeps down the side of the valve stem and sits around the valve seat. Turn it on and the oil gets burnt off within the first few cycles.

The fact that perfomance is down as well would indicate a burnt valve. My guess is that the burnt valve is letting gas by and is making the oil seepage worse as time goes on. Out of interest - I bet the engine oil is filthy black.

Yep the oil is quite black..... almost like ink black and its only been changed 2k miles ago..... hmm.... back to the dealers i think...

[RobJ1]

Could this problem happen if there is two much oil in the car, its about 1cm over the max mark on the dipstick

[Penfold]

it is unlikely if only over by that much. Even if you filled the entire crankcase up to the point where the valve gear was permanently covered (it would be leaking out of the exhaust or inlet by then anyway) the valve stem seals should hold up.

You need a compression test. This should indicate if it is just one cylinder at fault or all of them. If its just the one then you should get away with a new valve, seals and a decoke. If they are all shot then you'll need a reconditioned head. Think about changing the cam belt if the head is replaced as unless it is quite new it won't like the strain of the recon valve gear.

My 2.0 lean burn has just turned over 80k and the oil is just still showing a touch of gold/orange by the time it comes to servicing, which is every year and about 6k intervals.

Regarding the steering noise - this may sound silly but next time you clean the car squirt some Mr Sheen between the rear of the steering wheel and the shroud covering the stalks. and then work the steering from lock to lock a few times. Put a blanket over the seat and the floormat and pedals to stop them getting covered as well. Let us know if the noise persists.

[RobJ1]

The car has been into toyota now a few times.

They said they cant fault the stearing problem, its still seams that if your holding a corner in the car all of a sudden the steering get really light and you have to steer back slightly to keep it in line.

The also say the cant fault the black smoke, apparently its just carbon build up. How and Where is the carbon building up and how can we sort it out.

Thanks

Rob

[Ray99]

Hi Rob

I've been able to do a little research for you at work. You probably have the 1AZ-FE or 2AZ-FE engine. This is a D4 engine. That means it is 4 cylinders and gasoline direct injection. This type of engine uses a MAP (Manifold Absolute Pressure) sensor to measure engine load. It lives on the bulkhead fairly high up, it's black and has a small diameter vacuum pipe to it coming from the inlet manifold. It has a small mutliblock connector- only two or three wires. In Funkyg's pictures, pic 2 shows the throttle housing- electronically controlled. In pic 1 the MAP sensor is just out of shot in the top lefthand corner. Old spark plugs and leads could cause a problem, but the symptoms are usually a missfire in one cylinder. You have no leads on your engine as each spark plug has its own coil, but it's still possible that you would benefit from a plug change. The carbon build up mentioned by your dealer is in the inlet manifold and around the inlet valves. Because you have direct injection, there is nothing to wash the cabon into the cylinder to be burnt. In a conventional injection engine, the petrol is injected virtually onto the back of the inlet valve, keeping it and the port clean. You may need to leave the car overnight at your dealer for them to see the smoke and diagnose it. Hope this helps Ray

[Electric]

Hiya,

You may have already covered this but it's often over looked and it's a cheap fix, make sure you have a nice clean air filter in it, where its not getting air it could be over fueling giving crap economy as well.

Just a thought :)

(even if it's serviced check the dealer changed it)

[Ray99]

Hi Electric. This is a commom misconception, left over from the days of engines fitted with carburettors. The carb depended on the difference of atmopheric pressure and the manifold pressure to set the correct air/fuel ratio. A restricted air filter would make the manifold vacuum greater, thus delivering more fuel. In an injected engine, the sensors measure the amount of air going in to the engine and adjust the fuel accordingly. In extreme cases of a choked air filter the fuel economy would not suffer, but the performance would. As the volume of air drawn in would be less than normal, less fuel would be injected and so less power would be produced. Even given all of this, it's still good practice to change the air filter every 30k miles. Sooner if you live in a dusty area. Cheers Ray