Diagnose my problem

Mr. Presentable

04 Golf TDI. 200,000 km. Timing Belt changed at 175,000km. New injector at 190,000.

While driving a minor tapping started. Gradually it became louder under acceleration and braking until very loud and the engine became rough. Temp normal, oil OK, no engine light. Left it overnight to take to garage.

It started, lots of black smoke and very rough. Died out after 100m and would not start again. Battery OK, starter motor OK. Called tow truck and took to garage. Three days later they still haven't started the car and say the diagnostics show everything in full health.

WTF?

Any ideas?

mickdw

What colour smoke? Black, white, Deisel smell from it ?

Mr. Presentable

Black smoke, deisel smell.

craichoe

Gradually it became louder under acceleration and braking until very loud and the engine became rough.

Stop driving it ! ... could be a coil problem .. i'd get it towed to a garage to avoid damage.

T-Maxx

Take it to another garage. Really.

If they haven't even started it up in 3 days time... Not to mention the fact that the diagnostics would not pick up some mechanical failure like a bearing, broken ring, etc.

Henry Ford III

craichoe wrote: »

Stop driving it ! ... could be a coil problem .. i'd get it towed to a garage to avoid damage.

Pretty unlikely. Diesels use compression ignition, so do not have spark plugs, coils and the like.

I do hope I'm not horribly wrong on that


p.s. Problem sounds like a mechanical one. Tappet, valve?

Ferris

+1 on the tappets.

1.9 pd tdi's can suffer hydraulic tappet failure and premature cam lobe wear if the wrong grade of oil is used of if oil changes are neglected. Worst case is a new cylinder head, best case is new 'buckets' or hydraulic tappets. A friend was quoted 400euro to fix the tappets. Cylinder head is big money obviously.

Either that or the engine siezed and threw a con rod. Happens when the turbo fails and the engine runs on the sump oil. Would explain the sudden failure, black smoke, still not starting and no diagnostic warning.

Marcus.Aurelius

Henry Ford III wrote: »

Pretty unlikely. Diesels use compression ignition, so do not have spark plugs, coils and the like.

I do hope I'm not horribly wrong on that


p.s. Problem sounds like a mechanical one. Tappet, valve?

Diesels do indeed use compression ignition but also use glow plugs, which can become troublesome. This wouldn't explain the tapping, unless the glow plugs are coming on and off periodically and causing misfire???

I thought tappets myself, like the old Ford Fiestas, but would they cause the noise and rough movement?

If the temp sensor(s) for the glow plugs was misbehaving they might not be heating adequately to ignite the diesel. (Just a thought!)

EDIT: +1 on Ferris' Post, sounds about right.

Henry Ford III

Marcus.Aurelius wrote: »

Diesels do indeed use compression ignition but also use glow plugs, which can become troublesome. This wouldn't explain the tapping, unless the glow plugs are coming on and off periodically and causing misfire???

I thought tappets myself, like the old Ford Fiestas, but would they cause the noise and rough movement?

If the temp sensor(s) for the glow plugs was misbehaving they might not be heating adequately to ignite the diesel. (Just a thought!)

EDIT: +1 on Ferris' Post, sounds about right.

Glow plugs only preheat the fuel mixture don't they?

Once the engine is running they are no longer needed.

Marcus.Aurelius

Henry Ford III wrote: »

Glow plugs only preheat the fuel mixture don't they?

Once the engine is running they are no longer needed.

Yes you're right there, I just thought that maybe they were still on during driving, and might explain the starting issue since if they were gone. (Still the OP would notice the light not coming on before initial ignition)

Tappets sounds more convincing at this stage though!

Mr. Presentable

Just been told they are looking at the cam sensor as a possible cause. I thought tappets were from cars in the 1950's, had no idea they still existed (or what they do).

Dirty_Diesel

craichoe wrote: »

could be a coil problem

Ha ha, in a diesel???

craichoe wrote: »

i'd get it towed to a garage to avoid damage.

You mean get it towed to another garage

If you read the post properly you would see it was already in a garage......

Ferris wrote: »

1.9 pd tdi's can suffer hydraulic tappet failure and premature cam lobe wear if the wrong grade of oil is used of if oil changes are neglected.

Unfortunately with 200,000 on the clock thats a lot of oil changes which may not have been with VW 505.01 approved oil (which has additives to protect cam lobe wear).

The following picture shows the camshaft (left) taken from a PD-TDI Golf that gave up at 135,000 miles. The right hand side shows a brand new item.
This particular car had 21 oil changes to date, 7 of those with oil that was not VW 505.01 approved.

Ferris wrote: »

Either that or the engine siezed and threw a con rod. Happens when the turbo fails and the engine runs on the sump oil. Would explain the sudden failure, black smoke, still not starting and no diagnostic warning.

However, ^^^ may be a more likely problem as the were no CEL on the dash, or would there be for cam wear???

Mr. Presentable

Holy crap! That's some picture.

mickdw

If there is a fuel smell from it, I would guess at failed injector (can often cause a clicking sound) or something causing a malfunction in the fuel system from sensor to moved pump timing.

Ferris

Dirty_Diesel wrote: »

However, ^^^ may be a more likely problem as the were no CEL on the dash, or would there be for cam wear???

Don't know, speaking from a friends experience with a turbo emptying his engine of oil on the M1 at 70mph:(!

I'd imagine its the top end thats gone though, well known prob with the PD tdi's or indeed any engine that hasn't had the approved oil used in it.

stratos

A VW I was driving started making what I can best describe as a binking noise, then the power went, next an almighty bang. Dropped a valve. Banana shaped crank shaft anyone ?

Actually I had to add this edit. I went to the garage where the thing went to get my stuff out of the vehicle. I found two of the mechanics trying to jump start it, they couldn't understand why the engine wouldn't turn over. "probably a duff starter" one of them said to me. Hillarious.

Mr. Presentable

mickdw wrote: »

If there is a fuel smell from it, I would guess at failed injector (can often cause a clicking sound) or something causing a malfunction in the fuel system from sensor to moved pump timing.

Update. They have ruled out cam sensor/cam issues. Now they think a dead injector may have thrown out the timing. That's what they'll check next. Naturally they are not spending all day every day on it, but they will have it a week tomorrow and still don't know what's wrong.

Henry Ford III

How a "dead injector" could knock out the engine timing is beyond me.

Ferris

Its beyond me too, along with the garage concerned I suspect.

OP are you sure about this garage, they don't seem to be dealing with the problem very well.