VW Specialist

Tropheus

Hi,

Can someone recommend a VW specialist in the Dublin area? My father-in-law's 2001 2.0l petrol Passat is running badly and a scan has shown that it's running lean. Fault codes are:

16555 - Fuel Trim: System Too Lean: Bank 1
P0171 - 35-10 - - - Intermittent
16885 - Vehicle Speed Sensor: Implausible Signal
P0501 - 35-00 - -

At this stage, the lambda sensor, speed sensor, fuel filter, coolant temperature sensor and MAF have all been replaced to no avail. All bar the fuel filter are genuine VAG parts.

It was with a VW dealer last week as our local mechanic has drawn a blank. The dealer ran a few tests including measuring fuel pressure and found everything within tolerance. They said they could run deeper tests and replace more parts but would question the outlay given the age of the car.

Advice seems to suggest that there is a vacuum leak somewhere between the MAF and intake manifold. However, there is definitely nothing obvious.

It would be great to get someone with experience and knowledge who would have an interest in sorting this.

Thanks,

Nissan doctor

Has anyone done a vacuum test on it?

Main dealers will always just replace parts rather then spend time diagnosing the problem properly.

What's the exact symptoms?

Tropheus

It difficult to start from cold, usually needs 2 or 3 turns. It's also slow to pick up in low revs (below 3,000 rpm).

I'm not sure if a vacuum test has been done. I suppose that could be done on the manifold itself? Would that show up a lead in the injector seals - someone mentioned that as a possible problem.

The only other thing I considered was to renew all the seals on the injectors and manifold. I could probably do that myself and it wouldn't be expensive parts-wise. However, I could still be disappointed after doing it.

The other thing that worries me is a leak in the throttle body. That's an expensive part to replace.

Nissan doctor

ksimpson wrote: »

It difficult to start from cold, usually needs 2 or 3 turns. It's also slow to pick up in low revs (below 3,000 rpm).

I'm not sure if a vacuum test has been done. I suppose that could be done on the manifold itself? Would that show up a lead in the injector seals - someone mentioned that as a possible problem.

The only other thing I considered was to renew all the seals on the injectors and manifold. I could probably do that myself and it wouldn't be expensive parts-wise. However, I could still be disappointed after doing it.

The other thing that worries me is a leak in the throttle body. That's an expensive part to replace.

If the fuel pressure was ok then injector seals should be fine. You;d also get a smell of petrol of they were leaking bad enough to cause running issues.

Has anyone done an internal check on the engine? Compression/leakdown etc?

Tropheus

Nissan doctor wrote: »

Has anyone done an internal check on the engine? Compression/leakdown etc?

Not that I'm aware of. The VW dealer only charged us €29 so I doubt they did much beyond a VCDS scan.