A4 problem

mfceiling

The oul lads a4 (jan 2002 1.9 tdi 130 sport) is starting to give a few problems.

Last week he changed the back brake pads and discs but the dash still comes up with the brake symbol when he starts up.

Also it is fairly hard to start when warm but not when cold.
He says it also has a little hesitation or miss when it's being driven.

He changed the diesel filter last week and cleaned out the "breather"...his words not mine!!. He also put a bottle of diesel treatment into it.
Using the same diesel garage for the last 7-8 years.

There's 183,000 miles on it and to be fair it has been trouble free up til now and very well specced and looked after.

Any ideas?

Cheers.

George Dalton

Which brake warning is showing on startup? The red one or the yellow one?

Tropheus

The light you're seeing on the dash is either for low brake fluid or worn front pads. There is no sensor to detect ware on the rear pads.

The starting problem sounds like the coolant temperature sensor. They're a common problem on VAG cars. Do a search online and you'll find plenty of info. They're not expensive to replace.

The temperature sensor could also be causing the hesitation while driving so trying changing that first to see if is solves the problem. Another common problem is the MAF. Again, do a search.

I presume the diesel filter is the fuel filter? They should be changed at every service on a diesel. A good oil and air filter service could help too. When was it last done?

AeroEng1

Ya the temperature sensor is very common in relation to the problem you described. I replaced one a few months ago, only cost €20 and took 5 mins to replace. Its well worth trying at that price.

mfceiling

Thanks lads.

George its the red light. Comes on sometimes and not others.
He changed pads and discs a couple of weeks ago on the back and discs and pads on the front last year so they are all fairly good.

He likes the car and doesn't really want to change it as its a miser on juice and he likes the electric seats and the bit of poke that's left in it!!


Sorry George it's the yellow light that's comes on...and a little buzzer comes on.

George Dalton

Check the brake fluid level though I would imagine it is ok.

The red light warning flashing on briefly when starting the car first thing in the morning (especially a cold morning) is a very common problem on those A4s. Most people just ignore it.

George Dalton

The yellow light is the brake pad warning light. The wear sensor is on the inside pad on each of the front wheels. So check the inside front pads and make sure they aren't worn. If the pads are ok then there must be a problem with the sensor wiring.