Stuck in 3 or 4th gear

[polardesign]

Hi all,

The Car is a W203 C180 2002, auto

It's happened a couple of times over the past month.

The car gets stuck in 3rd or 4th gear.

The dash still shows its in drive but if I try switching manually to 4th it stays in drive.

If I stop, turn off ingnition and restart the cat all is well.

IS this a sensor problem?

Strnage

 

[BTB 500]

Sounds like the gearbox is going into 'limp home' mode, where it stays in 3rd gear. There are a number of things that can cause this to happen intermittently ... you need to get the fault codes read.

 

[polardesign]

I have no engine light etc coming up, so will there be any codes to look at

 

[BTB 500]

Yes, the gearbox stores fault codes (as do many other parts of the car).

 

[Dieselman]

As BTB500 has said you need the codes read. The gearbox has a separate ECU and loads of sensors to detect speed and slippage. Even apparent wheel slippage will cause this problem.
The fault could be the gearbox is slipping, a sensor fault at either the gearbox or rear wheels or even incorrect tyre size at the rear.

 

[polardesign]

My rear tyres need replacing as gettng low, could that be the problem.

 

[Dieselman]

My rear tyres need replacing as gettng low, could that be the problem.

Unlikely unless they are a different size to the fronts.

 

[polardesign]

I have just had brand new ones put on the front

 

[BTB 500]

On my SL it was the gearbox conductor plate that caused this problem at about 46k miles. £115 for the part and £150 labour to fit. Symptoms were exactly as you have described i.e. it only happened intermittently and turning off and on again reset it.

Any dealer or decent independant will read the fault codes and tell you what's up with your car.

 

[polardesign]

I still have the problem with dodgy shifts.

I have now noticed that it mostly happens around corners, I went around a corner prior to joining a dual carriage way, accelerated then the car jumped out of gear rev and I had to pull over (the car still would go along at 30-40 mph) turn of engine and restart.
Sometime sluggish pulling away and problem appears when first started going around roundabouts etc

Any ideas

Going to get codes read next week by Prestige Cars Southampton who do all my servicing

 

[polardesign]

I have just had a look at a my previous service chit and says that there was a Slight Dampness around the gear box Sump pan...

Could this cause a problem for a W203 C180 gearbox

 

[Dieselman]

It could be low on fluid. That would cause it to fault particularly round bends.

 

[polardesign]

Hi can I check my gearbox fluid easily, I can't seem to get a haynes manual.

 

[Dieselman]

No, you need a service dipstick, your car doesn't have one.

 

[polardesign]

Can I buy a dip stick or use something else to check.

Where would the tube be to top up

 

[Dieselman]

You can buy a dipstick from the dealer, about £20.
The tube is at the rear o/s of the engine.

 

[polardesign]

I have just had a look at the underneath of my car and noticed oil underneath the car and on the underside of the floor pan.

Having checked the engine oil which is fine I suspect this is Gearbox oil.
What does anyone think the leak may be coming from (I know the gear box) but is it an easy to get to seal.

If fluid is low then the gear box will play up. Its a pain I can't just put a small amount of fluid in for peace of mind for travelling to the garage. I see the tamper proof cap

Car is being booked into Prestige Motors southampton next week to be investigated.

 

[polardesign]

Can someone please confirm the gear box dip stick position for a W203-c180

Is it at the rear, centre of engine bay, black cap with red tab.

 

[Dieselman]

Yes.
The ATF is probably leaking from the main electrical connector.

 

[polardesign]

The oil was leaking from the electrical connector slightly and the main Gearbox oil cooler attached to the main radiator. As it had a crack so have had new radiator fitted etc, only £312 inc vat

Gearbox now fine, but had coolant warning so will have to check level