Fuel consumption increases, engine power decreases

Hi everyone, I'm starting to get desperate. My Galaxy 1.9 TDI with 90 horsepower and 261,000 km is currently consuming about 9.5 liters, and it has almost no power anymore. It drives great in first and second gear from 1300 to 2200 rpm, but it's terrible from third gear onwards. The maximum speed is 150 km/h after driving for a while. The fuel filter, air filter, and error memory are all okay, and the idle speed should also be correct (according to...). (Okay for VW dealers), AGR is deactivated.
Data: Galaxy, 1Z.
Does anyone have any ideas or suggestions?

Sure, no problem. Here's the translation:

'Thank you in advance.'

Best regards, Mike.

...........It pulls well in the 1st and 2nd gears, from 1300 to 2200 RPM, but it's done after the 3rd gear.

It might sound silly , but it kind of sounds like the intercooler is completely blocked... (with leaves, etc...).
It's just an idea...

With 261km on the odometer, unfortunately, a technical defect is also not unlikely.

Regards,
Michl.

'No, unfortunately, that's not it either. I only washed it with a pressure washer a few days ago. What's a bit strange is that it's not always the same; sometimes it's better, sometimes it's worse. When I accelerate from 130 to 140 km/h on the highway, it takes me at least 15-20 seconds. I'm aware that I have a Porsche weighing almost 1700 kg. But when I bought it, it was running at almost 190 km/h and consuming about 6 liters per 100 km.'

Best regards, Mike.

Hello Michl and Mike,

MichlM wrote:

It might sound silly , but it kind of sounds like the intercooler is completely blocked... (with leaves, etc...). It's just an idea...

Once, a bumper was incorrectly installed on my car without the cutout for the license plate lamp. So, he wasn't getting any wind resistance at all anymore.
The effects were less pronounced than I expected; the car felt somewhat sluggish to drive, and the top speed decreased by less than 5 km/h.

Mike, does your car emit excessive exhaust when you accelerate fully? Somewhere, that 9.5 liters per 100 kilometers has to go.
Are the fuel hoses leaking?
Are several brakes (including the handbrake) sticking severely, or can all the wheels spin very freely?
What is your oil consumption? Given your vehicle's mileage, mechanical damage to the engine is also a possibility.

Best regards, Rainer.

How does your Galaxy start? When was the timing belt last changed? Does the car smoke? 'If so, when and what color?'
The answers here would be important for further troubleshooting, imo.

P.S. Doc also brought up an interesting point regarding the timing belt: a misaligned camshaft could also be a possible cause of the problem. However, I don't know whether the valves will close more forcefully, or whether the performance will drop as much as it did for you.

Okay, the engine performs very well in the lower RPM range (1300-2200). It's a bit rough below 1300 RPM. The timing belt was replaced about 1500 km ago (by a VW dealer), but the problem existed before that (the crankshaft pulley bolt came loose, and the engine wouldn't start). There's absolutely no smoke.

Here's the translation:

'Another question: Regarding the fuel injection amount (using VAG-COM), I'm seeing a maximum of 35.2mg/stroke, and it seems like that's too low to me...?'

Best regards, Mike.

Hello,

mhernach wrote:

Another question: Regarding the fuel injection amount (VAG-COM), I'm seeing a maximum of 35.2mg/stroke, and it seems like that's too low to me??? MFG Mike

It should actually match the table of target values.
Here's another possibility: someone might have sprayed expanding foam into your exhaust pipe... or is your catalytic converter crumbling and clogging the exhaust system? Have you already checked the catalytic converter and listened for any rattling noises?
On my G2 diesel, the pre-silencer collapsed internally. This caused the car to perform noticeably worse, although there wasn't a complete blockage, but rather the exhaust pipe was misaligned within the silencer housing.

Best regards, Rainer.

I can't say for sure right now that it's okay, but I don't hear anything when I tap on the catalytic converter, and if it's clogged, I would have to remove it.
Construction foam?!? No... definitely not. When my wife lets one go, you can already feel it in the back seat, and you know it's a big one.

Sure, here's the translation:

'MFG' is an abbreviation for 'Mit freundlichen Grüßen,' which translates to 'Sincerely' or 'Best regards' in English.

The funny thing is, it doesn't produce any black smoke, either at full load or partial load. The fuel lines are okay, and the oil consumption is also fine (0.5 liters for about 7000 km). At 178,000 km, the crankshaft, bearing shells, and timing belt were replaced (the crankshaft bolt was loosened once). And the brakes aren't really sticking. (The handbrake on the left rear wheel tends to stick a little, but I don't use it).


Sure, here's the translation:

'MFG mike' translates to 'Best regards, Mike' or 'Sincerely, Mike' in English.

mhernach wrote:

The funny thing is, it doesn't produce any soot, either at full load or under partial load. The fuel lines are okay, and the oil consumption is also fine (0.5 liters for about 7000 km). At 178,000 km, the crankshaft, bearing shells, and timing belt were replaced (the crankshaft bolt was loosened once), and the brakes aren't really sticking. (The left rear brake remains slightly engaged, but I don't use the handbrake). MFG mike

Okay, a fuel consumption increase in a diesel engine without any visible smoke is unusual. Unlike a gasoline engine, such a significant increase in fuel consumption would be noticeable with a lot of black smoke. Since you've already invested a lot in your engine, I'd also suggest investing in your brakes. First, you should remove all the brake pads and check their ease of movement. With that kind of mileage, they're often rusted and constantly dragging. Even if you don't use the handbrake, braking presses them against the brake discs, and they may then not release properly. If they are difficult to move, remove them and use a grinder to smooth the sides. Then, use a screwdriver to scratch the surfaces of the brake caliper guides and remove any visible debris. Finally, apply Plastilube or copper paste.
That should last for the next 260,000 kilometers.
I am certain that your increased consumption is not due to just one cause, but selective problem-solving will eventually lead to the desired outcome .

Sure, here's the translation:

"Best regards."

So, in a diesel engine, an increase in fuel consumption without any visible smoke is unusual. Unlike a gasoline engine, such a significant increase in fuel consumption would be noticeable with a lot of smoke. Since you've already invested quite a bit in your engine, I would also suggest investing in the brakes. First, you should remove all the brake pads and check their ease of movement. With such a high mileage, they are often rusted and constantly rubbing. Even if you don't use the handbrake, braking presses them against the brake discs, and they may then not release properly. If they are difficult to move, remove them and use a grinder to smooth the sides. Then, use a screwdriver to scratch the surfaces of the brake caliper guides and remove any visible debris. Finally, apply Plastilube or copper paste.
That should last for the next 260,000 kilometers.
I am certain that your increased consumption is not due to just one cause, but selective problem-solving will eventually lead to the desired outcome. Best regards.
I do that with the handbrake every year; unfortunately, it's a problem with this model series...

Best regards, Mike.

Correction:

1. Engine power: optimal range 1300-2600.
2. Soot only appears briefly during cold starts.
3. Transition from 130 to 140 in 17 seconds.
4. Starting is no problem; it's ready to go about half a second after you start it.


Note: Tire size 225/45 R17 (approximately 0.5 liters/100km higher fuel consumption).

Best regards, Mike.

Hi,

What RPM does your tachometer show?
If you're driving at 140 km/h and full throttle in 5th gear?

Best regards, Rainer.

If I watch it today, I can only write about it tomorrow.

Best regards.

mhernach wrote:

Hello everyone, I'm starting to get desperate. My Galaxy 1.9 TDI 90 HP with 261,000 km is currently using about 9.5 liters, and has almost no power anymore. It drives great from 1300-2200 RPM in 1st and 2nd gear, but it's over after 3rd gear. The maximum speed is 150 km/h after driving for a while. The fuel filter, air filter, and error memory are all okay, and the idle speed should also be fine (according to...). (Okay for VW dealers), AGR is deactivated. Data: Galaxy, 1Z.

Hi Mike,

Here's the translation:

"Just to reiterate, in general:"

Squealing brakes cause the wheel hubs to get extremely hot after just a few kilometers of driving. If there's nothing to feel, I think you can rule out the brakes.

Have you calculated the high fuel consumption based on the overnight fuel level, or is it only displayed on the MFA (Multi-Function Display)?
Regarding the latter, I believe it is fundamentally possible for the pump to experience extreme leakage, where the diesel "counted by the MFA" returns to the tank and is missing from the cylinders -> resulting in no power and no soot.
However, I cannot provide a specific estimate of the potential damage to the pump and injector area.

I would rule out a loose starter ring gear, because in most cases, that would manifest as starting problems first.

Perhaps it's just the camshaft that's twisted in the motor winding wheel.
I would definitely check that as soon as possible, before it potentially gets any worse and we end up with a situation where the pistons and valves are all mixed up...