AU Problems: 1995 Car, 240k Miles

Hello,

I had my Golf inspected today for the TÜV (technical inspection) and emissions test. I have the stickers, but the inspector told me that there were some 'complications' during the emissions test.

- About the car: Volkswagen Golf III, manufactured in 1995, 1.9 liter engine, 240,000 km mileage, I once had a 10% performance chip installed for about 10,000 km.
- Not yet replaced: Turbo, injectors, fuel injection pump.
- Maintenance: Regularly (at least every 15,000 km); I perform most of the maintenance myself, but the timing belt is done by a colleague.
- Oil: Shell Helix 10W40
- Annual mileage: approximately 40,000 km.
- Driving style: Always warm up gently, highway: full throttle, 200 km/h.
- Issues: None significant (slightly increased water consumption).

'The inspector said: 'We had to run the emissions test several times because we couldn't achieve the required values. The engine kept stalling despite being at full throttle, and a lot of black smoke was coming out of the exhaust. We still have soot stains on the ground.''

I was completely taken aback; my car is having these kinds of problems, which is completely new to me.

After a phone conversation with me, they also refilled (according to the invoice) half a liter of oil (after the inspection!!!) because the level had reached the bottom of the minimum range.
Normally, when I change the oil, I fill it to the middle of the maximum range. I usually check it regularly, and when the oil level reaches the bottom of the optimal range, it's usually time for another change (15,000 km). The last oil change was done 10,000 km ago, which is why I don't understand why the oil level is already this low.

My theory: I don't believe that they thoroughly warmed up the car before the test (including the oil), and how that relates to our TDIs anyway. Mine needs 20km of driving before the oil is 'warm' (warm, not full temperature). Due to the low oil temperature and high RPM, it may have consumed oil (in some way...) which then came out as soot at the back. That's why they noticed after the emissions test that it had too little oil.

Just a theory!!! Could there be some truth to it? I'm not an expert... What do you think might be wrong with it?

After properly warming up the Golf, I tried it out myself. With throttle inputs from low load (LLD) up to approximately 4200 RPM, I didn't notice anything unusual. I also checked the oil level, which is now above the 'Max' mark .

If this has already been discussed, please provide me with a search term so I can find the relevant information.

Thank you for your patience, and best regards.
Mathias.

I don't quite understand what they're doing, but I always follow along when they're messing with my stuff.
To avoid any discussion (which there never has been), I always come to work wearing casual clothes.

It's certainly not good to overfill the oil past the maximum level, but I would always make sure to arrive with a slightly warm engine and the oil level perfectly adjusted.

I find it hard to believe that 0.5 to 1 liter of oil is being burned in the AU engine, because if that were the case, you wouldn't be able to drive at full throttle and reach 200 km/h on the highway for very long.

Does the turbo force the oil out, and if so, into which turbine – the exhaust turbine or the compressor turbine?
Because at high RPMs with a naturally aspirated engine, you have very high rotational speeds, but very little boost pressure (which would act against the oil).
My turbo is leaking a little oil, which I notice especially on longer, fast highway drives (in those situations, the oil level drops more quickly than when I'm driving normally).

Otherwise, I can't think of anything else...

m;

Normally, the mechanic performing the emissions test MUST check the oil level and bring the engine up to operating temperature! The strong exhaust smoke occurs when the engine has been running at low RPM or driven gently for a long time; the soot accumulates in the exhaust and is expelled during full-throttle bursts. When I go for an emissions test, I first warm up the engine properly, then I drive onto the highway and accelerate with several full-throttle bursts until hardly any smoke comes out, and then I go to the emissions test station! If there is still too much smoke even though everything seems fine, adding 50% vegetable oil to the tank will definitely work!

Oh yeah, I bet the workshop was just trying to make some extra money by topping up the oil! It's not possible that a few full throttle bursts would use up a whole liter of oil! If that were the case, it would be smoking blue like crazy!

Hello,

First of all, thank you for the answers!

Does the turbo force the oil out, i.e., into the exhaust turbine or the compressor turbine?
Because with a naturally aspirated engine, you have very high RPMs, but very little boost pressure (which would act against the oil).
Unfortunately, I can't say anything about the condition of the turbo. I stopped working on it (because I don't have the time due to work and evening school), and I haven't taken the turbo apart yet. It's still the original one, and with 240,000 km on the clock, it's bound to have some wear and tear.
Which would actually support my theory...

The strong Russian exhaust smell occurs when the engine has been running at low RPM or driven gently for a long time. Russian accumulates in the exhaust, and is then expelled with a burst of acceleration.
'I'm actually getting relatively good fuel economy right now, but I can't imagine that so much soot is building up. Especially since I often drive at full throttle on the highway during my daily commute, and after school, the highway is usually clear, so I often drive 10 km at 200 km/h (according to the speedometer, of course) with my foot on the accelerator. The route from work to school (across Nuremberg) also stresses the engine because it doesn't reach operating temperature. Besides, that wouldn't explain the drop in RPM...'

Oh yeah, I bet the workshop just wanted to make a little extra money by charging for the oil refill!
I don't believe that. The bill listed €2.50 for half a liter, and they also paid for the phone call to my mobile, so it wouldn't be profitable.


I think I'm going to reschedule my doctor's appointment for the summer and take that day off as vacation, all for the sake of the engine (I still need to get it to 160,000 km).

Have a nice weekend.
Mathias.

Since your car can still reach 200 km/h, the turbocharger pressure should be fine; otherwise, it would go into limp mode. Do you perhaps still have the tuning chip installed? If so, that could also be causing it. Otherwise, the ESP injectors might be worn out after 240,000 km, which would mean they're not atomizing the fuel properly anymore, leading to excessive emissions.

Since your car can still reach 200 km/h, the turbocharger pressure should be fine; otherwise, it would go into limp mode! Do you perhaps still have the tuning chip installed? If so, that could also be causing it! Otherwise, the ESP injectors might be worn out after 240,000 km, causing them to atomize the fuel insufficiently, leading to excessive emissions.

Hi,

'The boost pressure is fine; I have an LDA installed. There's a slight overshoot, around 0.9 bar. I removed the '10-cent' tuning in October 2005, and it was installed for about 10,000 km (it was great), but otherwise, there's no other performance tuning.'

Zieht ein zu großes Lagerspiel gleich einen Ladedruckverlust mit sich? I don't think so!

I understand that the nozzles might not be the best anymore, but as I said, I haven't had any problems at all (the performance is still there, and I don't see any soot in the rearview mirror, only a normal amount if I have someone with Xenon lights behind me). Even at low load, it runs smoothly like a kitten (currently, the serpentine belt is making a bit of a whistling noise).

I still need to monitor my water consumption a bit, because I suspect the water pump (also, is this the original one? When did you last replace it?) might need to be replaced soon. Are there any potential indicators of this behavior?


The difference between the oil level when cold and the oil level when warm is quite significant. Could it be that the employee checked the oil level when cold (or after presumably warming up the engine or letting it idle), and then added oil until the oil level when cold reached the maximum mark. The oil then warmed up during the inspection, thus increasing its volume, and then entered the combustion chamber through ... pathways .

Is the car properly :?warmed up} in 'normal' (i.e., those who are primarily concerned with cost and don't really care about the car) workshops? }

Greetings from Wassermungenau.
Mathias.

Zieht ein zu großes Lagerspiel gleich einen Ladedruckverlust mit sich? I don't think so!

If the impeller were too large, the turbocharger would whistle or screech because the shaft would be rubbing against the housing, and it would generate less boost pressure.

I understand that the nozzles might not be in the best condition, but as I said, I haven't experienced any problems at all (the performance is still there, and I don't see any excessive soot in the rearview mirror; if there is any, it's only in normal amounts when I have a car with xenon headlights behind me). Even at low speeds, it runs smoothly like a kitten (although the serpentine belt is whistling a bit at the moment).

Okay, so on a 1Z engine, the V-BELT is tensioned by a tensioner pulley. The power steering pump and water pump (if equipped with air conditioning) are usually driven by a V-belt. If you experience a squealing noise when turning the steering wheel, it could indicate that the V-belt is too loose.

I still need to monitor my water consumption a bit, because I suspect the water pump (also, is this the original one? When was it last replaced?) might need to be replaced soon. Are there any potential signs of this happening?

Does the coolant hose become very hard when the engine is warm? If you open the coolant reservoir, does a lot of pressure escape? If so, have a mechanic use a CO tester on the coolant reservoir with the engine running to check if there are exhaust gases in the cooling system. If there are, the head gasket is likely blown. Otherwise, carefully check if everything is sealed properly (radiator, water pump, connections, heater core, etc.).

icon_idea.gif icon_arrow.gif The difference between the "cold" oil level and the "warm" oil level is quite significant. It's possible that the employee checked the "cold" oil level (or, more likely, the engine was warmed up or idled for a while) and then added oil until the "cold" oil level reached the maximum mark. The oil then warmed up during the inspection, increasing its volume, and subsequently entered the combustion chamber through... various pathways. icon_question.gif

Hmm, the difference between cold and warm oil levels is minimal for me, about 0.1 liters! Even if I add 0.5 liters too much, there's no increased consumption or blue smoke. However, if I add 1 liter too much, the oil foams up a lot and smokes like crazy!
Perhaps an apprentice who doesn't have much experience yet did that.

Do regular (i.e., those who are primarily concerned with cost and don't really care about the car itself) workshops properly warm up the car?

Due to a lack of time, engines are often not properly warmed up, or are only allowed to warm up in idle.

'Yesterday, I let my 1Z engine idle for 30 minutes while running a diagnostic check. Above 50°C, the coolant temperature only increased very slowly to 60°C, as if the engine wasn't warming up any further. If you're interested, I have the data logged.'

So, if the engine was only warmed up while stationary before the emissions test, as is often the case, then I'm not surprised if it fails the test.

You could try unscrewing the upper intercooler pipe; it's a quick job, and then you can see how thick the oil film is.

No more than about a tablespoon of oil should drip out on its own; anything more indicates a problem. If they are completely clogged, the turbo will consume oil.

Otherwise, for the next inspection: gently unplug the mass airflow sensor. You're guaranteed to pass the inspection with that.

Good evening.

You could try unscrewing the upper intercooler pipe, it's quick, and see how thick the oil film is there.

No more than about one tablespoon of oil should drip out on its own; nothing more. If they are completely dirty, the turbo will consume oil.
Okay, let's see if I have some free time on Saturday after school; if I do, I'll do it (and maybe change the transmission oil).

Yesterday, I let my 1Z idle for 30 minutes with the diagnostic system running. Above 50°C, the coolant temperature increases very slowly, only reaching 60°C, as if the engine doesn't want to get any warmer. If you're interested, I logged the data.
Yep! Regarding the efficiency of the TDI engine, there's no issue with warm-up idling. We have a hill nearby, and when I'm driving downhill in 'sailing' mode at -20°C with the heater on (fan speed 2, just before the red light), I can watch the coolant temperature drop.

To...
So, if the engine was only warmed up while idling before the emissions test, as is commonly done, then I'm not surprised if it fails the emissions test. ...and...
Otherwise, for the next inspection: Gently unplug the mass airflow sensor. You are guaranteed to pass the inspection with that...
I had my Golf inspected for the TÜV and emissions test today, and I have the stickers, but...
...it just tends to have problems that I'm not used to from my Golf.

Have a good evening.
Mathias.

Hello.

They probably let the engine warm up while it was stationary, or maybe drove it around the block at most.

Last Wednesday, I brought my B4 with a 1Z engine to a Citroen workshop located on our company premises (with extensive VW experience) for an emissions test. Shortly after, the master mechanic (a young man in his mid-twenties with no VW experience) came and said that something was wrong with the car, as he was getting turbidity readings of around 6%.

I got in the car, drove 10km on the highway, went back to the emissions testing station, and passed with flying colors.

This is what can happen when people lack experience.

The mechanic was trying to explain something to me about poor compression and faulty injectors.

Best regards, Rüdi.

Hi!

Actually, they should know that you can't warm up a TDI engine while it's stationary, especially not in freezing temperatures.
Besides, I'm even more cautious when it comes to a car with 240,000 kilometers on the odometer.

It's a Suzuki workshop that has also been providing Skoda service for about a year.

What can be done about such a problem? At which workshops can I be sure that they will treat the car properly? Only VW, and even then not 100%? Really take a day off and warm up the car myself?

Have a nice day.
Mathias.

MWeid wrote:

What can be done about such a problem? Which workshops can I be sure will treat the car properly? Only VW, and even then not 100% sure? Really take a day off and warm up the car myself??

"I'm generally always available when a car comes to the workshop for an emissions test or wheel alignment (I handle everything else myself). I don't take vacations, but I'll either do it on a Saturday or make about 2 hours available."

I usually go to my regular repair shop (or Dekra), but I tried the Citroen factory service center this time due to a lack of time.

Best regards, Rüdi.