Oil buzzer, no light, shaky tachometer, dies when hot - 1.9 TDI ALH

[$hitblast]

Hello again . I bought me a Caddy; a 2002-model@155000 km, just over a week ago. It came with these errors: 1. The tachometer wobbles +- 100 rpm around where it is supposed to sit; sometimes more, sometimes less, but constantly wobbles to some degree. 2. The oil-buzzer goes off on acceleration. The harder one presses the pedal, the more buzz. The buzzing is independent of engine speed, varies instantly with throttle, and usually ends at operating temperature. The oil-light does not come on. There is no buzzing on idle and really slow acceleration.

The first trips went smoothly, with no surprises, but today, as I was taking my longest trip yet with it, ut sputtered out and died on road after about 30 km in the middle of a rather long, steep incline. It started back up before I lost too much speed, but was losing power intermittently while still in gear. It got me to the top of the hill, and ran a little better for a few hundred meters, before it died completely again, and had to be restarted. A couple of hundred after that, it would not start whatsoever and stranded me by the road. I popped the hood, got out, and heard a rapid ticking-sound from the injection pump, which lasted a few seconds.

While waiting for the tow-truck, it idled nicely for fifteen minutes or so, before it sputtered out again. The engine starts within a second or two when cold, and runs smoothly until it reaches operating temperature. Then it coughs and dies. There were lots of bubbles in the diesel-delivery hose, and the filter turned out to be full of air. The filter looked many years old. I filled it back up again, and the bubbles disappeared, but the engine would still shudder and die. I sucked on the delivery from the tank, but there seemed to be no restriction from there.

I suppose this may be a clogged fuel filter, causing restriction and air to seep in. I've ordered a new filter, and new O-rings for the thermal T. Then again, I've read about faulty engine speed sensors shorting out, causing the ECU to cut the engine. I'm not sure I've found it, but is it one of these two?

Edit: When standing in front of the car, this is to the left of, below, the oil-filter. Picture should have been rotated 90 degrees left.


Edit: This is deep down in the engine bay, at the proximal end of the gearbox.

[Bora Sport]

I presume you checked to ensure that it actually has the correct amount of oil in the engine?

[feenix74]

Does the oil light work at all?

Might want to check it is the correct specification of oil as well?

[gldgti]

Blocked fuel filter sounds plausible, and in line with your description.

Oil buzzer.... well you should definitely ensure there is enough oil in it if not already. it the level is OK, I would think of adding an oil pressure gauge next to give you some real data. Otherwise you're guessing.

If oil pressure is OK, then your buzzer and tacho issue might be caused by the same problem... like a bad earth for the dash cluster or something like that.

[Bora Sport]

Definitely shouldn't be driving it with the buzzer blaring.

[$hitblast]

Bora Sport:

Feenix 74: I don't know if the light is working or not. The service manual indicated an oil change about 10000 km ago, by memory. The guy selling it said he'd last put oil in it a year and a half ago, but I didn't ask him which kind.

Gldgti: I'll figure out where the earth for the cluster is, and check for corrosion or other failure. Then I'll install the new filter, when it arrives, and then I'll consider getting an oil pressure gauge.

In any case, I measured the resistance to the crank shaft speed sensor, as I seem to have the symptoms to match a faulty one: 0 rpm on cranking, flaky readings and engine shutdowns. Then there is the ticking from the IP, which I guess could be the fuel valve being mismanaged due to a faulty rpm-signal. I don't have any problems when the engine is cold, and these sensors typically get in trouble when they're old and warm, I've read a few places. It just now happens to be summer in Norway as well.

On cold engine the sensor measured 1125 Ohms between second and third pins, when counting from the bottom, as the socket is normally placed sideways in its bracket. No continuity between 1-2 and 1-3. I warmed it up, and let it run until its first hiccup, and then measured again: 1363 Ohms between 2-3, and still no continuity between 1-2 and 1-3.

Edit: Here's the connector to the crankshaft speed sensor, behind the oil filter. It has three pins.


Edit: Anyone know what the resistance in the crankshaft speed sensor should be? - I figured it out. According to https://www.youtube.com/watch?v=MJIA0AsxASQ about 900 Ohms when cold. I'm not sure if 1125 is too much or not, but more resistance should equal a weaker signal.

[$hitblast]

While waiting for the correct e-torx-tool to un-screw the crankshaft-position-sensor, my new VAG KKL-cable arrived. I pulled the following codes:

17958 - Charge pressure: Control Deviation P1550 - 35-00- -
00668 - 27-00 Supply Voltage Terminal 30
17656 - P1248 - 35 - 10 Start of Injection Timing Regulation: Control Deviation
17569 - P1161 - Manifold Temp Sensor (G72): Open or Short to +
18008 - P1602/005634 - Power Supply B+ Terminal 30: Voltage too Low

Then, I deleted all these codes, fired up the engine and let it run for about two minutes. After that, I shut it down, and read the codes again:

No codes.

I did change the battery recently, as the old one seemed to be quite old. I measured the charging voltage at idle to be 14,45 V, with a recently calibrated multimeter.

Next time, perhaps I should run the engine till it stalls again, and see which codes it produces.

Edit: And I forgot to mention that I changed the filter and O-rings. I filled it up with new fuel, all the way to the top. There were still a few bubbles afterwards, but less than before. It lasted about seven minutes before coughing out on the first go. On the second run, today, it ran fine on idle for 100 minutes, and didn't die. Now there's a bubble maybe once every minute or two, which is much less than before.

[gldgti]

you havnt told us what engine this actually is... is it an ALH? 1Z?

[$hitblast]

gldgti: Yes, I did. In the heading. ALH

Edit: And I haven't been able to find the earths for anything but but the starter thus far.

Edit 2: So, I ventured out for a six km spin, after it had idled for a hundred minutes with no problems a few days before. There were no problems for the duration of the trip; no oil-buzzer-like sound, and no engine-cutoffs. I noticed the engine also made less noise. There used to be a sharp engine beat at lower revs before the diesel-filter was changed.

[$hitblast]

So, the saga continues. It started and ran without problem since my last post, up until yesterday. As I turned the key, all the usual lights came on except the glow plug indicator. The starter spun the engine at good speed, but it would not fire at all. I tried for a few seconds three times more, but it would not show the glow plug light, and just spin with no fire. I switched the battery with a known working one, but it made no difference. The tachometer did not register the rpms when cranking, and this made me think it might be the crank posistion sensor acting up.

I let it sit until the next day, and tried to bump start it, but to no avail. I hooked it up to VCDS lite; however, it would not read anything but the airbags. It could not get the engine to answer. I sat there for a while, switching the ignition on and off, trying to get it to read the engine, until the glow plug light suddenly came back on again, flickering on and off two times, with a sort of click from somewhere in front of me. I hurried to turn the starter, and it fired right up and ran normally. I let it run for a few minutes, before turning it off, and then restarted it a few more times.

The same thing with the GP-light and the clicks happened over again. There would three or four clicks and blinks, or just one or two. The engine would start and run nevertheless. VCDS would now read the engine module too - 17656 - Start of injection timing regulation - control deviation - because of the bump-start maybe?

[gldgti]

I would seriously check your ignition switch! Sounds like you have a circuit that is flaky.

[$hitblast]

Ok. Will the steering wheel have to come off to do that? I took off the plastic covers, and wiggled the contacts, without making any difference.



I also steel-brushed all the contact points atop the battery, inside the terminal shoes, the first negative ground connection below the battery and the connection on the diesel solenoid. They all looked fine, with no rust or crud at all. That didn't make any difference. Edit: The portion of the main ground cable, under the battery, where the ground-connector bites into it, was visibly green from copper-corrosion. I wasn't sure if that mattered any, and guessed it would be cleaner under the biting clamp.

Then I checked the air-intake valve by the EGR-regulator, to see if it was open and could move freely. It moved freely and was in open position. Not much slag in there either.

Then I checked the 109-relay; which seemed to be working fine:

Edit: BTW, I read somewhere on TDI-club, that the ignition-switch must signal the ECU through fuse 29 (not 100% sure about the number), for the ECU to wake up and open ground to 85 on relay 109, so it can close and send more power to ECU. The relay is working, so is there anything else the ignition switch is supposed to do, but not doing already now?

[gldgti]

Just FYI on your fault code, this is copy/paste from ELSAWIN:

Output on the fault reader -V.A.G 1551- printer Possible fault cause Possible effects Fault elimination
17656 P1248
Injection commencement regulation
Control difference t Defective commencement of injection valve -N108-
t Needle lift sender -G80- defective
t Fuel tank empty
t Fuel supply not OK., lack of fuel
t Start of delivery not OK.
t Engine runs rough
t Reduced performance
t Increased exhaust emissions
t Poor cold starting
– Check commencement of injection valve -N108- → Chapter, Final control diagnosis
– Checking needle lift sender -G80- → Chapter
– Fuel filter or fuel line blocked
– Checking and adjusting

[gldgti]

How VW Ignition Switches Fail - YouTube

[gldgti]

in your video, I notice that you dont have any glow plug light on the dash when you switch to on.
(Sounds like you need a new throwout bearing on the starter motor too