Where is the #1 cylinder?

I would like to know if the #1 cylinder is on the right or the left when I am facing the engine.

Just signed up for this site and have found it to be excellent, great info!

it is probably on your left, but you did not show what type of engine (or car/year) you have.

edit: from your profile you have an ALH and the #1 is closest to the cam sprocket (to the left looking into the engine from the front).

The lift sensor is on the #3 injector, so 2 and 4 should be on the sides of that. The only one left is #1, correct? IIRC, VW numbers theirs opposite the Japanese, but I spent entirely too much time building rotaries to recall.

Not opposite ...

As with any in-line engine, the cylinder numbering starts with #1 at the front pulley and goes up towards the flywheel end. It's the same for a Honda as it is for a VW ... the diff is that on a Honda, the front pulley end of the engine is on the left side of the car, and for everything else including VW, the front pulley is on the right side of the car. Find the front pulley, and you've found #1 cylinder. Honda engines spin "backwards" and are facing the "wrong" side of the car compared to everyone else, but still, #1 is the cylinder closest to the front pulley.

Keep in mind also, that "right" and "left" by convention are in the orientation as seen by the driver sitting in the driver's seat facing forward ... NOT as seen by you staring into the engine compartment from the front of the car.

GoFaster,

I couldn't remember why they were different, but I knew they were. I haven't turned a wrench on a Japanese piston engine in years, and it was rare when I did. The only Japanese cars I had didn't have pistons.

Don't the glow plugs follow a different pattern? #1 being on the drivers side and #4 closest to the pulleys? Does this hold true for all TDI's?

JB05 said:

Don't the glow plugs follow a different pattern? #1 being on the drivers side and #4 closest to the pulleys? Does this hold true for all TDI's?

Click to expand...

Glow plugs follow firing order.

"GP's follow firing order."
I always had that sneaking suspicion, but your's is the first mention that I can recall.
So this means when I get a P0674 for GP #4, this would indicate that
cylinder #3 is the culprit. FO:1-3-4-2 IIRC.
Thanx Jetta2001, and my apologies to the OP for the high-jack.

^^^^^^ JB05 and Jetta2001tdi -

I just had my MIL pop on this past weekend, pulled the code at AutoZone and came running here to search Fred's for answers about my P0674 code.

Appears to be "Glow Plug #4". If GP's follow firing order, and we're FO:1-3-4-2, wouldn't GP#4 be located on cylinder #2?

ps: Wingnut's Glowplugs 101 is an EXCELLENT tutorial.
pss: I also apologize to the OP for continuing a hijack....

sammerdog said:

^^^^^^ JB05 and Jetta2001tdi -

I just had my MIL pop on this past weekend, pulled the code at AutoZone and came running here to search Fred's for answers about my P0674 code.

Appears to be "Glow Plug #4". If GP's follow firing order, and we're FO:1-3-4-2, wouldn't GP#4 be located on cylinder #2?

ps: Wingnut's Glowplugs 101 is an EXCELLENT tutorial.
pss: I also apologize to the OP for continuing a hijack....

Click to expand...

As JB said, it's cylinder #3. It is the last fired cylinder, GP fault is 4, thus the last cylinder.

Is on your left by the timing belt as you face the engine. Cylinder no.1 by design convention is always by the timing drive, be that belt, chain or gear (nose of the engine) except the odd engine i.e W8. Cylinder no.4 is at the rear (tail) of the engine. However, the glow plug wiring sequence is reversed. So, gp wiring no.1 corresponds to cyl. no.4, GPW no.2 to cyl. no.3, GPW no.3 to cyl. no.2, and GPW no.4 to cyl. no.1.

If in doubts, unplug one GPW. Connect a VAG-COM, then scan the engine for DTC w/o having the engine running. This will throw an engine fault
code. Compare the fault code to the following codes

SAE / VAG / DESCRIPTION
P0670 / 17054 / GLOW PLUG MODULE CONTROL UNIT
P0671 / 17055 / GLOW PLUG CIRCUIT 1 (Q10) ON CYLINDER 4
P0672 / 17056 / GLOW PLUG CIRCUIT 2 (Q11) ON CYLINDER 3
P0673 / 17057 / GLOW PLUG CIRCUIT 3 (Q12) ON CYLINDER 2
P0674 / 17058 / GLOW PLUG CIRCUIT 4 (Q13) ON CYLINDER 1


I hope this helps

Okay - looks like we all may have been wrong except for Wingnut. Code P0674 shows GlowPlug #4. We all over thought this trying to match up GP's and firing orders, etc......

After checking ohms with the ol' tester, it was plain and simply the Glow Plug in the #4 cylinder.... closest to the driver's side of the car.

Replaced it and got my CEL cleared at Advance and have been trouble free ever since!

sammerdog said:

Okay - looks like we all may have been wrong except for Wingnut. Code P0674 shows GlowPlug #4. We all over thought this trying to match up GP's and firing orders, etc......

After checking ohms with the ol' tester, it was plain and simply the Glow Plug in the #4 cylinder.... closest to the driver's side of the car.

Replaced it and got my CEL cleared at Advance and have been trouble free ever since!

Click to expand...

Are you sure about this? Please see post no.11. GP no.4 firing order (P0674) is on cyl. no.1 by the timing belt. and the GP no.1 firing order (P0671) is on cyl. 4.

The only reason I could think of, why the firing order is backward, because VW/Audi has been using the flywheel for timing, 1st seen on the VR6, which gives more accurate timing, then if using the crankshaft pulley. Cyl no.4 being the closest to the flywheel, so it gets assigned as the 1st firing order for GP no.1 on cyl. no.4.

Congrats though that you fixed the probs.

The cylinders in most vehicles is indeed numbered in sequence starting from the front of the engine. So in a 4 cyl TDI, 1 would be the timing belt side and 4 would be the transmission side.

In regards to the glow plugs, it has been my experience that in SOME models, the wiring was backwards. Specifically some 2002-2003 ALH TDI's. If you get a code for a glow plug in Cyl #1, its usually Cyl # 4 that threw the code. I have diagnosed in the neighborhood of 60-70 GP faults on ALH cars and only ONCE did the code match the actual bad plug. All BEW engines I have checked were all correct in their GP sequence.

So to sumarize, there were just a select range of cars that had the GP wiring reversed from the traditional cylinder sequence. The best way to find out for sure is to perform the test mentioned above to confirm how your actual car is wired.

Thanks Wingnut for your confirmation.

This GP wiring sequence is also true with PD BHW. I now this because I had to work on the GPW on my wife's car. To some people it's backward, but it makes sense since VW/Audi uses the flywheel for the timing, 1st seen on the VR6 engine.

The easiest way to figure out the GPW sequence is to unplug a GPW. Connect a VAGCOM, then VAGCOM will throw a GP fault code. Re- connect the GPW that was unplug then disconnect another one. Repeat the previous procedure. From there one will be able to figure out the
wiring sequence.

Only Three Glow Plugs Working 2002 Jetta

Tyring to remove the # 3 glow plug, the casing broke. I completely broke it off and tried the extraction method shown on this site. It is really seized/welded. Finally broke off an extraction tool in it. Now has to go to shop to take head off to get it out.

Question - should it crank and run on three glow plugs okay until fixed?

Thanks

timestar said:

Tyring to remove the # 3 glow plug, the casing broke. I completely broke it off and tried the extraction method shown on this site. It is really seized/welded. Finally broke off an extraction tool in it. Now has to go to shop to take head off to get it out.

Question - should it crank and run on three glow plugs okay until fixed?

Thanks

Click to expand...

People have driven their TDI for years with a broken glow plug.