Gear stuck 4th

[kellogsj]

Hi everyone, after starting my car up tonight, the Rev counter was unusually higher than normal. It usually hovers nicely at 12 rpm but tonight is would shaking at 17 rpm. Then about 10 mins into my journey home the engine was stuck in 4th gear it while travelling I at 35 mph, also the the Rev counter needle was flicking up while the car was just rolling forward and the car was piling forward by itself without my foot on the accelerator. It's had a new Battery at the end of September plus service and spark plugs 4 weeks ago. Any help would be greatly appreciated. It's a IS 250 2011 reg.

 

 

Sent from my Iphone using Tapatalk

[Texas]

Sounds like unmetered air entering the engine that the ECU cannot account for or control and therefore the erratic revs which you have.

This maybe due to the recent spark plug job as this entailed removing the inlet manifold and disturbing the silicon gaskets/O rings beneath and if not perfectly sealed then the engine will draw air in this opening and cause erratic running.

paul m.

[kellogsj]

Sounds like unmetered air entering the engine that the ECU cannot account for or control and therefore the erratic revs which you have.
This maybe due to the recent spark plug job as this entailed removing the inlet manifold and disturbing the silicon gaskets/O rings beneath and if not perfectly sealed then the engine will draw air in this opening and cause erratic running.
paul m.

Thanks Paul, this only happened for the first time today. Also I had gaskets replaced when plugs where done. Should I take it back to the garage.


Sent from my Iphone using Tapatalk

[Shahpor]

Is the Check VSC and engine management light on?

Also, will it shift out of 4th if you try manually changing it?

[kellogsj]

Is the Check VSC and engine management light on?
Also, will it shift out of 4th if you try manually changing it?

No management light came on, I could try using paddle shifters to knock it up
To 5th if it happens again. I was on my way to get petrol when this happened. But when I started the car up again it was absolutely fine. I rang the mechanic who changed the plugs and he said because it was really freezing the transmission fluid could have been the problem because of the weather. He's a real good mechanic too. So I'll see what it's like today.


Sent from my Iphone using Tapatalk

[is200 Newbie]

When was the last time your coolant was changed?

Could be ?? an issue where due to the weather it was partially frozen if degraded too much or the wrong coolant used? No expert, just a stab in the dark...

 

[kellogsj]

When was the last time your coolant was changed?
Could be ?? an issue where due to the weather it was partially frozen if degraded too much or the wrong coolant used? No expert, just a stab in the dark...
 

I think it was changed at last service. 4 weeks ago.


Sent from my Iphone using Tapatalk

[is200 Newbie]

Could the system be air locked?

[kellogsj]

Could the system be air locked?

What does that mean mate.


Sent from my Iphone using Tapatalk

[Shahpor]

It means that there is air trapped in the system.  After a fluid change, it needs to be bled to get rid of any air that is stuck.

I can't imagine this being the problem though?

[kellogsj]

It means that there is air trapped in the system.  After a fluid change, it needs to be bled to get rid of any air that is stuck.
I can't imagine this being the problem though?

How could I do this, also when you say fluid change, what does this mean.


Sent from my Iphone using Tapatalk

[Shahpor]

As in coolant change, which you said you had done recently?

Well, if you want to give it a go, then following the bleeding instruction here:

[kellogsj]

As in coolant change, which you said you had done recently?
Well, if you want to give it a go, then following the bleeding instruction here:

I might mess it up. I'll ask the mechanic who done the service to do it. Thanks anyway.


Sent from my Iphone using Tapatalk

[is200 Newbie]

1 hour ago, kellogsj said:

What does that mean mate.


Sent from my iPhone using Tapatalk

It may or may not be the issue -

It used to be that if the system was not bled properly during/after a coolant change – a full drop of coolant – and topped up without leaving a hose open for the escape of air then the air that had entered the system when “empty” could get trapped and prevent the coolant from running through the system properly, trapped by the air.

A bit like the highest point in your central heating system – leave that pipe open or use as a bleed point on the system. Easiest way is to put the car on a slight incline (front of car on incline) and open the expansion tank. With the car on for a few minutes, see if the expansion tank coolant level drops, in effect you are forcing the air to the highest point of the system. If there is air in the system it will work itself out but you will need to top the system up if any air comes out.

If no coolant was getting to the box, rather than providing an ambient temperature it would remain colder longer? Hence you having issues in slow start up times?

 

Its just a thought but could be related to the recent coolant change? Its a good start to rule this out.

 

There is a small overflow rubber pipe coming from the expansion tank – first check to see if this is blocked as it wont allow any air out of the tank naturally. If clear then carefully open the tank cap BEFORE starting the car to prevent any hot coolant spitting out

Start the car keeping an eye on the bottle

 

BE CAREFULL WHEN OPENING THE EXPANSION TANK TOP – IT MAY SPIT IF IT DOES RELEASE AIR – TRY THIS WHEN ENGINE IS COLD TO PREVENT ANY HOT COOLANT SPITTING OUT WHEN IT GETS HOT. REMOVE THE CAP FIRST BEFORE STARTING THE CAR. 5 minutes should do to see if the tank level drops or until the car gets to temp.

[kellogsj]

It may or may not be the issue -

It used to be that if the system was not bled properly during/after a coolant change – a full drop of coolant – and topped up without leaving a hose open for the escape of air then the air that had entered the system when “empty” could get trapped and prevent the coolant from running through the system properly, trapped by the air.

A bit like the highest point in your central heating system – leave that pipe open or use as a bleed point on the system. Easiest way is to put the car on a slight incline (front of car on incline) and open the expansion tank. With the car on for a few minutes, see if the expansion tank coolant level drops, in effect you are forcing the air to the highest point of the system. If there is air in the system it will work itself out but you will need to top the system up if any air comes out.

If no coolant was getting to the box, rather than providing an ambient temperature it would remain colder longer? Hence you having issues in slow start up times?

 

Its just a thought but could be related to the recent coolant change? Its a good start to rule this out.

 

There is a small overflow rubber pipe coming from the expansion tank – first check to see if this is blocked as it wont allow any air out of the tank naturally. If clear then carefully open the tank cap BEFORE starting the car to prevent any hot coolant spitting out

Start the car keeping an eye on the bottle

 

BE CAREFULL WHEN OPENING THE EXPANSION TANK TOP – IT MAY SPIT IF IT DOES RELEASE AIR – TRY THIS WHEN ENGINE IS COLD TO PREVENT ANY HOT COOLANT SPITTING OUT WHEN IT GETS HOT. REMOVE THE CAP FIRST BEFORE STARTING THE CAR. 5 minutes should do to see if the tank level drops or until the car gets to temp.

Thanks for your help, but last night driving home the weather was a lot milder and again this morning, so the car seemed back to normal. From the advice given from you guys on here, the conclusion I've come to, is that the engine in particularly cold conditions will stay in lower gears for longer until engine and transmission fluid is up to the correct tempature. Fingers crossed it ok now. Thanks for your help anyway. [emoji1362][emoji1360]


Sent from my Iphone using Tapatalk