Passat PD woes

Nekarsulm

Hi all, I have a 2001 Passat 130 bhp.
It suddenly began to behave in the following manner. Starts from cold perfectly and you can leave it to idle and it will do so indefinitely. Turn it off when warm and will not start.
Drive it normally, and after five or six miles it will cut out and not restart if revs are allowed to drop below 3000 .
Local mechanic (VW trained ) says that it seems to be flooding itsself. Never heard of a diesel do this.
He reckoned it must be an injector problem, so I removed a set from another 130 hp passat that was running properly and he fitted them.
No improvement at all. He removed them again and says the seals seem damaged in the few miles it has driven since fitting them.
Now he wonders if the diesel return pipe is blocked? Or if the head itsself is worn/damaged. If so it's a death knell for her, and I really can't afford to change at the moment!
Getting fed up with VW rapidly!
Was thinking about going diesel Honda, but they have issues too!

dieselbug

Sounds like your mechanic is guessing and changeing parts in the hope he will get lucky, at your expense.

Have the basics been checked. Has the car been checked for fault codes? Fuel supply? Fuel filter condition?

Nekarsulm

Fuel filter is new, supply is OK. He checked codes first. The guy is a full time VW mechanic. Puzzling to say the least.

_Brian

How about the air flow meter. I've had a few of those passats and a dodgy air meter will cause funny behaviour.

Nekarsulm

Could be Brian. I'll ask him, but you'd imagine it would throw up a fault code.

I have a 91 Jetta in a shed, might be back on the road sooner than expected!

Seth Brundle

Had something similar on an old Open Omega (petrol) whereby the coolant temp sensor to the ECU was shot and it caused the engine to flood and have symptoms similar to yours.
A check of all fault codes should reveal if this is the case.

_Brian

Bring the mechanic and scanner for a spin. No idea what systems these lads use but my mechanic runs the scanner while driving to watch what's going on.

Nekarsulm

Right, called over to him. He admits he never came across such a case before.
He says no codes were showing when first checked. But that when he went into the "value blocks" (???) two injectors were showing far higher readings than normal. He changed those two but couldn't get the replacements coded.
That's when I got four replacements for him that were working fine in another car. Even with those its still doing the same thing.
He seems convinced that it's somehow connected to the diesel return line, which runs to a heater at the top of the filter and then back to the tank.

selectamatic

Could well be a fault in the injector loom it's a common-ish problem usually leads to misfiring and a jerky/juddering idle though however perhaps it's symptoms extend to your problem? might be worth swapping in a different one if ye have another passat handy. As a matter of interest is there any different colour smoke from the exhaust when idling or driving? (White/grey/blue)

Nekarsulm

Hi Selactamatic, I would have thought a loom problem might show a fault code?
Can't tell you about the smoke when driving, but it's fine when idling.
Losing faith in this mechanic fast!
If he dosnt come up with something by tomorrow night, I'll take it from him.

jca

When it stops how do you get it started again? Do you have to wait until it's cold before it'll restart? Air mass meter can be troublesome in them without ever throwing up a code but it will usually show as lacklustre performance rather than out and out stalling. Is the temperature gauge getting up to 90° and staying there steadily? It could be a faulty thermostat or temperature sensor where the ecu thinks the engine is cold.

selectamatic

Nekarsulm wrote: »

Hi Selactamatic, I would have thought a loom problem might show a fault code?
Can't tell you about the smoke when driving, but it's fine when idling.
Losing faith in this mechanic fast!
If he dosnt come up with something by tomorrow night, I'll take it from him.

In theory it should throw a fault code however I've heard of them not showing codes before, a tell tale symptom is the injectors showing varying values hence causing misfires or lumpy running and eventually cutting out however since your only experiencing one of those symptoms there's a good chance this isn't the issue although with these types of problems all avenues need to be explored when searching for a fix especially when dealing with unusual issues so I would give your mechanic plenty of time. Is he sure its "flooding" that'd be overfueling in my book resulting in lots of black smoke. to me it sounds more like fuel starvation. will it hold a rev while idling?

Nekarsulm

Well guys, he got it sorted. Contaminated fuel. Someting in the diesel, didnt smell like either petrol or kero, some kind of chemically smell, like a "sharp varnishy" smell he says.
You'd change a lot of parts before you cured that one!
Drained the tank and he says you can see whatever it is separating from the diesel in the bottom of the bucket.

jca

Nekarsulm wrote: »

Well guys, he got it sorted. Contaminated fuel. Someting in the diesel, didnt smell like either petrol or kero, some kind of chemically smell, like a "sharp varnishy" smell he says.
You'd change a lot of parts before you cured that one!
Drained the tank and he says you can see whatever it is separating from the diesel in the bottom of the bucket.

Where did you get your diesel? Any chance of the garage sorting the bill?

Seth Brundle

jca wrote: »

Where did you get your diesel? Any chance of the garage sorting the bill?

At this point it would be near impossible to prove the source of the issue!
Any accusations towards a retailer is likely to end the OP in trouble.

Nekarsulm

Yeah, impossible to prove at this remove. More than likely a station slipping a tankerfull of "washed" diesel into their storage tanks.
Mechanic did say I was lucky I dont drive a new Ford or Renault, or the bill would have been ten times as much. Only paid him for four hours labour.

Nekarsulm

Jca, missed your post. It would start again when cold, no problem, and idle for ages no problem. Seems the foreign liquid separated to the bottom of the tank quite quickly, but if you were driving on the road it mixed up again with the diesel. So in reality it wasn't that the engine was hot or cold that made the diffrence.

jca

You were very lucky... You should definitely buy a lotto ticket.

Nekarsulm

I suppose thats a good point about the PD system of unit injectors, no pump to feck up.

OldMrBrennan83

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Nekarsulm

Pat, how did you get the loom in? Looks like rigid plastic and with the engine running front to back on the passat there is no room?

OldMrBrennan83

This post has been deleted.