Starting Problems VAG 1.9 TDi

[kevinday]

Any help would be much appreciated. I have a 2001 Skoda 1.9 TDi with about 65K miles on the clock and since the weather changed to be a bit colder and damper I have problems with starting in the mornings. I turn on the ignition and press the accelerator once, wait for the glowplug symbol to extinguish and then turn the starter. The engine turns over fine but will not catch. After a couple of attempts it starts to catch and dies. It may take 5 or 6 attempts before the engine catches. Needless to say there are a lot of visible fumes behind the car by then!

Any ideas?

[nel]

I would bet that your glowplugs are knackered - just coz the light comes on to show glowplug operation, that doesn't mean they're working. Change the glowplugs. Had similar symptoms on a Citroen turbodiesel - this sorted me out.

If that doesn't work I'd be surprised, but would then look into getting my injectors reconditioned/replaced.

Best of luck.

[deltaf]

Could also be the pre/post start relay that fires the glow plugs.

[kevinday]

Thanks, I will look at the glowplugs first.

[nel]

As Deltaf says, it could be the relay that fires up the glowplugs. I'd hazard a guess that glowplug light just shows that power is going to the relay, but is no absolute indication that the contact to power the plugs is being made.

Easily tested - take the wire off a glowplug and stick a 12V light bulb between the wire and an earth ( i.e. the engine block). When you turn on the ignition the bulb should light up....it's christmas time hooray!

[350zwelgje]

Not to be the devil, but in the worst case: cilinder head gasket on it's way out, or even cracked cilinder head. Why? Because as soon it gets colder the engine needs all the compression to achieve the temperature in the cilinder to ignite the diesel (the glow plugs have a supporting function in this process). If not able to achieve enough compression, the engine won't start. So if changing the glow plugs doesn't help - the devil is at work.

Rob

[nel]

350zwelgje said:

Not to be the devil, but in the worst case: cilinder head gasket on it's way out, or even cracked cilinder head. Why? Because as soon it gets colder the engine needs all the compression to achieve the temperature in the cilinder to ignite the diesel (the glow plugs have a supporting function in this process). If not able to achieve enough compression, the engine won't start. So if changing the glow plugs doesn't help - the devil is at work. Rob

Seems unlikely to me that all 4 cylinders would be down on compression in this manner without worn piston rings and bores, etc. So she would start on 2 or 3 cylinders immediately. My money's on the glowplugs...

[wolves_wanderer]

nel said:

I would bet that your glowplugs are knackered - just coz the light comes on to show glowplug operation, that doesn't mean they're working. Change the glowplugs. Had similar symptoms on a Citroen turbodiesel - this sorted me out. If that doesn't work I'd be surprised, but would then look into getting my injectors reconditioned/replaced. Best of luck.

Def glowplugs, I had exactly the same problem on my old Xsara every autumn/winter when it got cooler. Easy and fairly cheap to sort though

[350zwelgje]

nel said:

350zwelgje said: Not to be the devil, but in the worst case: cilinder head gasket on it's way out, or even cracked cilinder head. Why? Because as soon it gets colder the engine needs all the compression to achieve the temperature in the cilinder to ignite the diesel (the glow plugs have a supporting function in this process). If not able to achieve enough compression, the engine won't start. So if changing the glow plugs doesn't help - the devil is at work. Rob Seems unlikely to me that all 4 cylinders would be down on compression in this manner without worn piston rings and bores, etc. So she would start on 2 or 3 cylinders immediately. My money's on the glowplugs...

As mentioned before, yes glow plugs is the first to be checked. But, a cracked head affecting only one cilinder can cause bad starting. When it starts (and the 'old' indirect diesels wouldn't - the modern type is more likely), the clear sign would be with a lot of smoke (unburned diesel).

Rob

[kevinday]

Thanks all,

Been too busy this week to take a look, but will check the relay and the glowpugs this weekend.

[kevinday]

Thanks all,

Three duff glowplugs appear to have been the problem.

[kevinday]

Problem recurred after a week or so. Eventually ended up not starting at all. Got a local garage to look at it and they discovered the cause:

A small fracture in the fuel line upstream of the pump causing the pump to suck air. When left overnight the pump drained of fuel and did not reprime properly. No visible leak of fuel, just air into the system. New fuel line and it seems OK now.