Diesel Prices Soar, Impacting Food Costs

Hello specialists,

I've been browsing this forum for quite some time now, and I've learned a lot of interesting things.

Now I've also signed up here because I really need help.

I drive a Chrysler Voyager, manufactured in 1996, with a 2.5-liter turbocharged diesel engine.

'This car won't pull properly anymore; it's okay up to around 1800 RPM, but then, when the turbocharger should really kick in, nothing happens. You can only push the car to about 3000 RPM in the lower gears.'

Starting in the year 2000, a distinct whistling sound can be heard from the turbocharger. It sounds like a healthy turbo, as I remember from before.

Here are the tests I have already done.
1.) Checked the check valve on the boost pressure regulator for smooth operation.
2.) The turbocharger boost pressure regulator was removed and tested for functionality.
3.) Various hoses were inspected for cracks.
4.) Air filter replaced.
5.) I performed a test run using a Scantool, and the following results were obtained.
5.1) The air mass value is approximately 150 mg/s at idle and does not exceed 280 mg/s, even at 3000 RPM.
5.2) The throttle valve position display operates smoothly and accurately, ranging from 0% to 100%, depending on the accelerator pedal position.
5.3) The intake air pressure is consistently showing 0 bar, with no negative or positive values. However, I'm unsure if this is due to the software and whether it's actually reading the correct value. At the very least, a negative pressure value should be present in the intake manifold when the engine is idling.

What are the potential error scenarios, and how can I check for them? :-nix
'Does anyone happen to have a workshop manual for the III series Voyi, especially one that covers the engine? Everything else available seems to be only for the gasoline models.'

Regards,
Horst.

Hi Horst,

"Values of 5.1, 5.2, and the charge air cooler piping strongly indicate a leak in the boost pressure system. Therefore, it is essential to thoroughly check the intercooler, the hoses from the turbocharger to the intercooler, the air intake path from the air filter to the turbocharger, and the path from the intercooler to the intake manifold!"
Does your car emit black smoke or no smoke at all when you accelerate fully under load?

Best regards, Rainer.

It only smokes when the engine is cold, at the very beginning. Once the engine warms up, it doesn't smoke at all, neither under light load nor under full load.

I guess I'll have to check the air ducts again.

After the turbocharger, there shouldn't be any leaks. If the turbo is working, but there's a whistling sound somewhere near the intercooler, then enough air is initially being drawn in, and the mass airflow sensor (MAF) should be registering a higher value, right?

Regards,
Horst.

Horsty wrote:

If the turbo is working, but air is escaping somewhere near the intercooler, then initially enough air is being drawn in, and the mass airflow sensor (MAF) should output a higher value, right?

Hi Horst,

At least with the TDI, that would be exactly the same - if the mass airflow sensor (MAF) is working correctly.

I'm not familiar with Voyi.

Hello, I can think of two possible causes:
'Mass airflow sensor (MAF) failure or, possibly, the exhaust gas recirculation (EGR) system being constantly open, which inevitably also leads to low readings from the MAF sensor.'
The best way to modify the AGR (Abgasrückführung) system is to cover it with a metal plate.
Then you can see from the higher LMM values whether it was the right thing.

hiho

'Is that definitely the same VM Motori engine that's also used in the Jeep?'

Okay, please check all the intercooler hoses after the turbo. In our Jeep, the hose leading to the intercooler has burst twice because the oil from the crankcase ventilation system somehow dissolved it.

'Well, in our case, the turbo failed once at 80,000 km (according to the workshop, but I'm not entirely sure I believe that anymore). Also, the exhaust and intake manifolds were damaged, or rather, cracked. And now, at 160,000 km, the gasket between the intake manifold and the cylinder head on the 4th cylinder failed. That's why it still ran normally up to 1800 rpm, but then, where the turbo comes into play, there was hardly any boost until 3000 rpm. And our car also made that whistling sound.'


And something different, is your engine also leaking from all corners? Or have you already replaced the cylinder heads? The people in the Jeep forums say that they usually fail around 110,000 km, but ours is about to reach 190,000 km and it's still bubbling coolant, not .


^^ This only applies to the 2.5 VM engine.