[Closed] Diesel MK4 Golf starting problem

and full service

check connections and pipes to the (replaced?)fuel filter,sounds like air is getting in to the fuel system somewhere. ❓

1996 isn't a mk4. They came in 1998/9.

Sorry 99, typo. BTW 1997 they started....

Did have starting issue before the full service but will check the pipes as well

Mk4's started in 98 actually, first ones were on an "S" plate...

Anyway, does sound like fuel feed problems. Filter been cleaned out or replaced recently? All the fuel pipes in good condition and free of leaks? A blocked/clogged filter would normally cause the symptoms you describe.

Gas recirculating valve?

One of my golfs started doing that, they hunted around plugs, injectors, fuel etc. Turned out to be a very minor leak in the head gasket.
Hope it isn't that serious for you.

Thanks for the ideas. Can we settle the year as well now please.....

The Golf Mk4 was first introduced in August 1997, followed by a notchback version (VW Bora or, in North America, again VW Jetta) in August 1998 and a new Golf Variant (estate) in March 1999

It possible that the fuel is leaking back to the tank, a return valve could be the problem, try pointing the car downhill overnight & see if the problem goes away, if it does then Roberts your mothers brother.

Cheers was thinking that but it starts a bit crap outside work as well whne on the flat (ish) Day off tommorow so will try it nose down and see if that improves 🙂
Dosen't matter if the bugger dosen't start

The "no fault coming up on the computer" is often shorthand for garages not wanting to waste time chasing intermitent faults.
I would by a £20 fault code reader from E-bay, and google the resulting faults that show up.

chickenman - Member

The "no fault coming up on the computer" is often shorthand for garages not wanting to waste time chasing intermitent faults.

So obviously your happy to pay for a mechanic to spend hours on your car & find nothing then?

It goes both ways...

No better facing downhill either. Bloody thing! It's only the 1st start of the day it's never had a problem once i've started it that 1st time

A couple of other things to try,
1, try turning the ignition on until the glow plug light goes out, then turn it on and off a few times whilst waiting for the light to go out in-between, that would indicate poor glow plugs.

2, have the temperature sensor on the head & water bottle checked, if they think the engine is warm then the fuel mixture at start up would be wrong.

glowplugs or related control system . . . suggest double checking they are really working . . . regardless of what you think . . . grey smoke is unburned/parially burned diesel vapour which shows it's getting fuel (despite all the crazy advice above) but not igniting it when cold . . . next port of call if the glowplugs are actually working is a compression tester . . .

(unscrew a glowplug and mole grip it to the block to ensure it's earthed, connect it up to the supply cable and switch the ignition on when the engine is stone cold (morning), the glowplug should glow bright red/yellow at the tip . . . if it doesn't . . . you have your problem)

Fd

+1 on 2unfit2ride number 1 option, you'll rule out if its a glow plug problem then. I had a diesel astra which was difficult to start in the mornings fitted new glow plugs but it still took time to start first thing so did the 3 times heating glow plugs and it started first turn. It's a bit of a PITA but a lot cheaper than trying to find the underlying fault.

2unfit2toride: Definately not happy with paying for a mechanic to not do something. had an injector wiring loom problem on my PD engined Passat and ended up finding the fault myself with the fault-code reader because my usual garage just wasn't doing the business!
Engine temperature sensor would be a likely candidate in the Golf scenario, I would suggest.

You say it runs rough occasionally, does it feel like a "misfire"?

You could have one of your injectors on the way out, but the symptoms you describe do sound like a glow plug problem.

Other things the garage should check for a high mileage car with those symptoms: compression test the cylinders to see if there is a problem, pressure test of cooling system to check for head gasket leaks.

Diesels only need three things to run, fuel, compression and heat. Sounds like glow plugs to me.

Brand new plugs in the service and we tested the plugs were getting power. As said it's getting fuel just not firing properly.

Engine temp sensor would make sense but though that would have shown on fault finder? Glows plugs on for a while before going out, thought they'd be pretty warm! Will try 3 heats and see if that helps. Perhaps poor compression is the (expensive)answer

So, the plugs are definitely going red/yellow hot on a cold start in the morning ? . . . you need to be 100% sure as what you describe is classic glowplug failure . . . ignore the fact that you changed them . . . that is not relevant to them actually working . . . don't get sucked down the route of 'I changed it so it must be ok' . . . coolant temp sender could cause glowplugs not to light but that will probably NOT show as a fault code, you need to VAGCOM the ECU and have a look at the live sensor readings . . . if you understand engines anything out of the ordinary will be obvious . . . I have to say that VAG temp senders don't tend to fail like that . . . but hey . . . who knows . . . time to get the ECU diagnostics online . . .

Fd

As above, new plugs don't always mean working plugs, replaced some on a peugeot years ago (all 4) and starting problem remained, removed them & checked them, 1 still faulty. Should have started better with three working plugs, but it didn't, maybe the head gasket that subsequently got changed was to blame for that though!!!!!