Hi,

Some advice please if possible. 

I've just bought a Skoda pick up 1.9sdi.

The previous owner said it had a 'hot starting' issue and unplugged the temperature sensor.

That's fine as a temporary measure but where do I start to address this as a permanent fix.

I'm going to renew the coolant as there are a couple of leaks that I want to stop and it looks as though there's been a new temperature sensor fitted with a green band.

Thanks in advance. 

Hot start is temperature sensor related I would advise checking the wiring as well as measuring the resistance of the thermistor

Hi, thanks for the reply,  will try that and post results.

I'm going to overhaul the cooling system as it seems to have one or two leaks.

If your car is hard to start when warm, you can trace the issue to one or more several potential faulty components, for example:

• Clogged air filter
• Corroded or loose battery terminal or cable
• Corroded or loose engine ground connection
• Vapor lock in the fuel system
• Faulty fuel system
• Engine control system problems
• One or more electrical sensors

https://axleaddict.com/auto-repair/My-Car-is-Hard-to-Start-When-Warm

On 15/03/2022 at 12:10, westie606 said:

I'm going to overhaul the cooling system as it seems to have one or two leaks.

I would do a full drain and clean of the whole system including engine block, radiator, heater matrix.

 

As the vehicle is new to you and given the previous owners attention given to it my usual advice I think applies more, give the pick-up a full 36-60k-mile service or check over in stage in between driving it to get used to it and discover and iron out any issues.

 

The important areas are of course brakes, steering, suspension (all three include the tyres)  visibility and safety electrics, then you go on to the bits most start with the engine, drivechain, last is always cosmetics.

 

The hot starting issue may well be temperature sensor related but do not forget the basics as highlighted in the previous post and these would be covered in carrying out service or service checks.  As with the computers GIGO it applies to vehicles if they are dirty it's muck going in, cleaning parts and replacing filters can make a big difference especially with diesel as they are already SISO (sh1te in, sh1te out).

 

One of the first things I check is that the battery is in good condition and state of charge and that it's post, post clamps, cables, connectors and earths are all clean, secure and protected as a battery in good condition helps with staring and problem solving and diagnosis and a battery and/or poor connections will hinder starting and problem solving and diagnosis.   Again, poor quality electric going in gives poor quality to and from parts and components, and the computer programs can throw wobblies too, same as poor quality air and fuel delivery to the engine.

 

Be interesting to see what you find, let us know how you get on, photos can sometimes help a lot.

 

@westie606

Define hot starting issue.

No start at all?

Hard start but eventually starts?

Rough idle?

Hi, thanks for the advice.

I've renewed air, fuel and oil filter and charged the battery. From cold it will start after the glow plug light goes out.

That is with the temp sensor connected or disconnected.

However, yesterday after I had run it up and moved it, it would not start, even with the temp sensor disconnected.

Half an hour later it started fine.

My only observation was that I thought the starter seemed slow.

I do have a refurbished spare so was going to try that.

Any comments greatly appreciated. 

How about doing a diagnose with a VAG-COM interface to look for stored errors?

I think you will find concrete evidence for faults.

On 08/03/2022 at 09:32, westie606 said:

Hi,

Some advice please if possible. 

I've just bought a Skoda pick up 1.9sdi.

The previous owner said it had a 'hot starting' issue and unplugged the temperature sensor.

 

Not an uncommon issue on older cars, esp the 1.9. Do not leave the temp sensor unplugged - you might need it one day... cooling is pretty bomb proof on the 1.9 and may not need intervention, but your call.

 

1. Have a really good service. Even give the top end an old fashioned de-coke.

2. Make sure your glow plugs are good. Better, fit four new ones.

3. Look on ebay for 'Diesel hot start'. Often associated with Range-Rover or BMW. A simple little black box about a tenner. Install per instructions.

4. Buy and fit a High Torque starter.

 

All worth every penny. Each time you start - hot or cold, wait for the orange light to go out and hit the starter for an instant start.  Keep the engine well serviced, with especial attention to the glow plugs and use the best quality fuel that you can.

 

I did this six years ago and never looked back. I hardly hear the engine turn over before it starts.