Hot answers tagged

8

We have a Mk4 TDI Jetta that makes a sound after startup that might be described as a sneeze. I'm fairly confident that it's the starter motor's overrun clutch. As soon as the engine "starts," it begins turning faster than the starter can turn. For this reason, starters have a one-way clutch, called an overrun or sprag clutch. This permits the starter to ...


7

As a vehicle technician for BMW I can assure that it is good for your engine to get rid of EGR. EGR systems are there to improve the exhaust gas quality and slightly win a few miles on a tank (in theory). What really happens is quite different. Your oil will become polluted quicker, your manifold / intake will get clogged by excessive amounts of soot and ...


6

Hi I'm a VAG mechanic 20 years experience, all the TDI engines need to be serviced every 30.000 KM if you are using 5w30 iso 500 to 504. DSG every 60.000 KM. Fuel filter, air filter, and cabin filter also 60.000 KM or 2 years. Its your choice if you want to pay us more. Most of my customers have more of 600.000 KM on tacho.


5

To a certain extent it depends on the type of usage you do, but for an average driver doing average miles (i.e. a mixture of highway, country and urban driving), I'd say to stick with the manufacturer's recommendation - but make sure you also stick to the recommended specification of oil. Remember that oil technologies and manufacturing tolerances have ...


5

tl;dr: Your radiator cap might be working as advertised and releasing a bit of overpressure. The difference is points one and two is telling. In point two, you're explicitly staying out of boost on the turbo. Steady state cruising really doesn't require the turbo to spin up. In point one, you're explicitly relying on the turbo quite a bit. This is going ...


5

A little research leads me to believe (aka I could be wrong) that reverse gear in this car requires you to depress the shift knob and move it far left-forward. It also seems that some, but not all '02 TDi Jetta owners have had complaints that the difference between finding first and reverse gears is vague. Seeing as the knob location for the two gears are ...


5

Some thoughts on how to verify if you have... an intake obstruction Disconnect the air filter (keep the MAF in place) to expose the compressor inlet and log boost values with the car at idle and under load. If the boost numbers are close to what the engine computer is expecting then this would confirm that something upstream the MAF is obstructing the ...


5

Is there any way that the vane actuator could be moving and yet not actually moving the vanes, or is it a positive linkage? There is a positive linkage, but it doesn't mean it isn't working right. However, if the linkage is moving freely, the vanes inside the turbo exhaust housing should be moving. The vacuum can (actuator) is where the problems lie most of ...


5

Will changing to the 5w-40 hurt the engine? Most likely not. Should you change to it? I my humble opinion, no. Here's the thing ... the manufacturer has said 5w-30 (assuming that is correct) is the proper weight oil for the engine. This means all of the tolerances and how the engine runs is setup to match the 5w-30 weight oil. By using the heavier oil, you'...


4

If you take it off of the engine, your best bet is to clean it with carb cleaner. Don't submerge it in anything, as you can cause damage to any diaphragm seals which may be present (if vacuum operated) or in any electrical motors which do the work. Also, when you clean it, don't forget to clean the ports in the intake manifold. They will also be clogged. ...


4

Get a bunch of carburetor cleaner and some oil picks Really, it's not a big job but it's a little nasty. Having some metal mixing bowls to put the EGR into when you spray it down will help to contain the mess into a nice consolidated little package. Using some glovers as well is not a bad idea. How I've done it and I've only done one. Remove it Visually ...


4

I'm biased based on my experience, but perhaps it might be helpful. I spent time in the Army troubleshooting (and teaching mechanics to troubleshoot) vehicle electrical systems. After that job I worked for a US automotive manufacturer, first as a design engineer and then as a new model launch person, including countless hours spent troubleshooting ...


4

Fundamentally the engine is a pretty robust unit - but something to check thoroughly is whether it as affected by the "Dieselgate" scandal, cars that have had the recall "fix" done have significantly poorer driveability and the change to the injection cycle means they chew through EGR valves like there's no tomorrow! And replacing the EGR is not exactly ...


3

So what ended up working for me was to cut a piece of 1x2 lumber (I couldn't fit a bigger piece from above) about 24" long and I braced it against the pump drive cog and pounded on it with a five pound sledge. Once I saw it start to move a bit I crawled under the car (which was up on jack stands with the front wheels, fender skirts, skid plate and side ...


3

According to the 2013 TDI maintenance schedule for US market (PDF, via tdiclub.com), oil and filter changes occur every 10 000 miles (synthetic only, which allows for higher mileage between changes), same with tyre rotations; fuel filter replaced every 20 000 miles. This would be covered under 30 000 miles US Carefree Maintenance program included with ...


3

Old topic, but just had the exact same problem on a 1.9tdi 110. The problem occured only under load, and certain driving conditions "pushing" the engine harder. We changed everything, cap, thermostat, resevoir, radiator!(someone suggested i could be clogged), oil heat exchanger, pipework, watter pump, and the heater matrix was eliminated at one point because ...


3

You may find that the throw-out bearing is the culprit, based on your description. As you've noted, slight pressure on the pedal causes the bearing to seat in the races, creating quiet. When that pressure is gone, the bearing should not be spinning, but it might be. The spinning without load means there is contact somewhere. The slight contact load is ...


2

I just starting having this trouble with my 2008 Golf 1.9 TDI. Had to call NRMA service but when he arrived checked the battery and all was fine. Couldn't find an ignition fuse to get the ignition up again. After some stuffing around the car started fine. NRMA said that it can be that the ECU has lost the key encryption and some cars have a port (hidden ...


2

You may need to have the key reprogrammed. I believe that if the vehicle does not recognize a key that has been inserted into the ignition, because of the immobilizer, it will not allow the key to activate the ignition even if the key has been turned. The immobilization method varies between makes and models but this is the general principle. On older ...


2

Watch out to not have oil in the coolant or vice-versa. Check the oil level and coolant level and their quality. Usually a head gasket could be a cause of this. Combining this with "no acceleration speed" this could mean a timing issue too. Maybe the engine timing is not well set and the combustion is not done properly. This means unburned fuel and lots of ...


2

You might find this post about Dynamic EGR Control for TDIs on the TDI Club forums by Mark at Malone Tuning interesting. Mark reports on his experiments with the EGR system on a 2006 TDI. He reports that the stock EGR settings resulted in a faster warm up (less wear on the engine) and better fuel economy than he got with the EGR deleted or dialed back. The ...


2

Since no one has chimed in, I will at least give it an answer. I don't think that it would. The control unit for the diesel injection can limit fuel through the unit injector solenoids directly. The N109 takes a signal from the J491 crash control unit, although it also takes a signal from the J248 diesel injection control unit as well. It would seem to ...


2

First I would establish actuator movement. The failure of the actuator to move properly is the leading cause of VW turbo failures. With a vacuum pump, such as a Mighty-Vac, or the Harbor Freight clone, draw 30" of vacuum. You can access the line for the turbo on top at the solenoid on the firewall. 30" should sustain for more than 10 seconds to a vacuum ...


2

Before adjusting linkages, I would inspect your bushings. A missing or damaged bushing might cause this, and they are rather easy to replace. You will have to pull the battery and tray to get to the area of the bushings. If you adjust things first, it will be harder to get everything smooth and adjusted right after finding a worn or broken bushing. You ...


2

I found out what it is. It controls the air recirculation flap to the cabin. Nothing to do with the engine at all. Just above the input and output pipes to the heater core on the firewall is a little plastic nozzle. This is what this actuator is supposed to be connected to.


2

My B4 Passat 1996, suddenly, would idle but not respond to the accelerator pedal. It would not go over 5mph before it would quit. Answer: Bad N109 relay that was partially working and supplying a partial voltage to the shut-off solenoid on the injection pump. Just enough opening of the solenoid to allow idle. The solenoid has one wire to the top of it that ...


1

This is more than likely a vacuum switch which tells the computer something when it reaches a certain amount of vacuum (could also be a pressure switch doing the same thing when the turbo reaches a certain pressure, depending on which side of the turbo the "vacuum" line is located). This would be why you are only seeing the vacuum line and connection to the ...


1

For what it might be worth, we have a pair of Jetta Mk4 TDIs one with the ALH engine, the other with a BEW. Both are well over 200,000 miles (the ALH is pushing 300,000) and for the most part we do our own maintenance, using a local shop for thorny diagnostic issues and when specialized tools or a lift are required. Over about 200,000 miles the ALH has run ...


1

This is a noise typical to Volkswagens. It is the starter motor. The starter motor extends into the bell housing of the gearbox. The extension on the starter acts as a support for the front of the starter motor. It runs in a bushing which becomes dry over time. You can either ignore it, or remove the starter motor and with a long artists brush and put copper ...


1

If your TDI is a PD type then you're better off erring on the short/fast side. There were many cases of prematurely worn out cams on PDs due to oil. This means sticking to the oil norm and change interval specified by VW. If the engine is a non-PD TDI (such as ALH, AFN etc.) then you could try using oil analyzer (such as lubricheck) in order to determine ...


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