Replacement engine

[alexperkins]

I thought you had already checked that febi code, else i would've checked it was compatible

In front of cat after manifold - 030 906 262 K

After cat towards silencer - 036 906 262 D

Feb 36892 is the after cat lambda, rather than pre cat. You could use it if you wanted to...

[alexperkins]

https://www.ebay.co.uk/itm/NGK-LZA11-V3 ... SwevdaFvlt

Thats the cheapest one i could find, and its a very good price.

[littlepolo]

Thanks

[littlepolo]

While waiting for the correct O2 sensor to arrive I've been searching for more information on the failure modes and their effects on pre-cat O2 sensors. The voltages indicated seem to be well out of range (which is usually between 0 and 1 volt. Since the voltage is high (indicating a lean compensation) this might explain why there are no CEL's or codes (which are often concerned with emissions). Anyway, two things came up.

Before the exhaust manifold was removed a release agent was used on the nuts. There have been some reports, as well as TSB's, concerning the use of silicone based products in the engine bay since silicone can contaminate O2 sensors. It appears the main risk is related to induction and combustion of silicone which then passes through the exhaust system. Also, there could be a risk that silicone penetrates the O2 sensor ambient air (oxygen) sample. I doubt the former mode has occurred but the latter is a possibility. If there is silicone or fluid contamination it can be indicted by deposits on the sensor.

The other failure mode I found relates to high output voltages (example given was 1.2V) on the O2 sensor so this could be more interesting. There is a code P0138 O2 for Oxygen Sensor Circuit High. I do not have this code but I do have the high voltages (at least when the engine is cold or slightly warm). Apparently, if the output voltage is high it can be due to the catalyst being broken apart. The manifold was on the bench and the cat looked very clean on a visual inspection. Spark plug fouling is also an indicator. When the engine ran earlier (before I replaced the MAP sensor) the plus were slightly sooty, but I put that down to the cold start mixture. Another possibility is a leaky injector. I'll run the engine again from cold and pull the plus after to see if there is any variance between cylinders in terms of flooding, soot, etc.

Has anyone experienced either of the failure modes mentioned above?

[RUM4MO]

I've only ever had one failure of the B1 S1 sensor, and that was heater failure I think, I'll check through that car's records and confirm the exact fault code later.

Edit:- okay, the logged fault codes for that faulty B1 S1 sensor were, 17591 (P1183 - 35 - 10) and 17604 (P1196 - 35 - 10) replacing that sensor with a VW one sorted that out.

Another Edit:- by the way, if you are just using a general OBD2 scan tool you are probably not giving yourself the best chance to sort this out, I'd always use VCDS or another VW Group "optimised" scan tool as that find all possible fault codes.

[littlepolo]

Another Edit:- by the way, if you are just using a general OBD2 scan tool you are probably not giving yourself the best chance to sort this out, I'd always use VCDS or another VW Group "optimised" scan tool as that find all possible fault codes.

I'm using the VCDS software and cable which is how I'm getting data on trims, temps, voltages, etc. There are no codes other than the one (likely spurious) that I mentioned above. After checking the plugs I'm going to validate the trims again today. I can find very little info on excessively negative trims and the failure modes associated with them seem less likely. i'm wondering if they were swayed by the gas test (propane), but since they are STFT they should have swung back after.

[RUM4MO]

Hum, I should have worked that out from these facts about field/channel values, I'll try to keep up!

Edit:- I seem to remember for as long as I've owned VAG-COM then traded it in for VCDS, I have considered that having a "complete" set of channel values covering a very cold, cold, hot, very hot engine and ambient temperature, for each car I am running, would be handy to have as some reference values to spot the early onset of problems or aging of sensors - so far that has remained a very good idea, but only that!

[littlepolo]

Is any fuel rail pressure data available on the 1.4 BBY? Have looked at blocks 103 and 106 but no display.

Edit: The snow has put me off fitting new parts today but I did notice the camshaft position sensor on the donor head (fitted) has a part number of 036.907.601.D whereas the old sensor has a part number 036.907.601.B A Google search doesn't help much since they both look like generic VAG parts (VW, Seat, etc). Would there be any difference?

[littlepolo]

It was too cold to do any work but I ran the engine up and logged the data below (some rows are hidden) - apologies for the formatting.

Engine ran sort of OK from cold, seemed to be hunting a bit.

Engine load seems high at idle and O2 voltage fairly constant and goes high when stalled.

One other thing I noticed is the precat ex gas temp climbed after it stalled. Heat shield is off.

Can anyone make anything out of it?

Engine Speed Coolant Lambda Basic Setting Engine Speed Engine Load Injection Intake manifold Bank 1 Bank 1 Voltage
TIME Temperature Controller Requirements TIME Timing pressure TIME Lambda Control of Oxygen Sensors
Marker STAMP /min °C % STAMP /min % ms mbar STAMP % V

Order is: time, rpm, coolant, lambda controller, basic setting, time, rpm, engine load, inj timing, intake press, time, bank 1 lambda, O2 volt
0.49 1159 24 -41 10111110 0.95 1127 53.3 8 683.4 0.01 -42 0.446
1.96 1150 24 -40 10111110 2.46 1136 53.8 8 690.9 1.46 -39 0.448
3.49 1168 24 -38 10111110 3.99 1141 53.8 8 688.2 2.99 -42 0.446
5.01 1127 25 -39 10111110 5.52 1164 54.4 8 690.9 4.5 -40 0.45
6.54 1150 25 -39 10111110 7.06 1141 53.3 8 685.4 6.04 -39 0.446
8.1 1136 25 -40 10111110 8.59 1122 56.6 8 714 7.56 -40 0.446
9.64 1141 26 -39 10111110 10.16 1136 53 8 683.4 9.13 -39 0.444
52.55 2259 35 -23 10111000 53.05 2419 24.3 7 371.5 52.02 -25 0.444
54.05 650 35 -35 10111010 54.46 878 50.8 12 766.1 53.55 -31 0.468
55.5 1643 35 -26 10111010 56.02 1670 38 7 493.9 54.99 -39 0.434
57.04 2268 36 -23 10111000 57.54 2410 35.1 6 485.8 56.53 -28 0.43
58.58 1880 36 -34 10111010 59.09 1938 27.1 3 479.4 58.08 -31 0.454
60.13 939 36 -49 10111010 60.64 1422 41 11 619.8 59.6 -39 0.446
72.4 2235 38 -31 10111000 72.92 2448 34.9 6 489.6 71.9 -28 0.442
73.95 2489 38 -42 10111000 74.45 1989 37.4 4 504 73.44 -33 0.452
75.47 2277 39 -26 10111000 75.98 2470 33 5 461.8 74.95 -35 0.444
77.01 2560 39 -37 10111000 77.52 2560 31.2 4 436.9 76.49 -40 0.44
78.56 2530 39 -33 10111000 79.06 2560 31.2 5 438.6 78.03 -30 0.446
101.48 976 43 -55 10111110 101.98 1037 50.5 7 705.6 100.96 -57 0.444
103.02 1063 44 -50 10111110 103.55 1025 48.3 7 675.4 102.5 -51 0.446
104.55 965 44 -48 10111110 105.09 1020 46.6 6 652.8 104.06 -51 0.446
106.09 927 44 -50 10111110 106.61 911 45.2 6 645.1 105.61 -48 0.444
107.62 1067 45 -51 10111110 108.16 1008 46.4 6 650.2 107.1 -50 0.452
109.16 927 44 -53 10111110 109.66 900 49 7 688.2 108.68 -53 0.446
110.7 889 45 -50 10111110 111.2 1016 49 7 693.6 110.2 -53 0.444
259.26 735 55 -58 10111110 259.78 714 47.4 7 685.4 258.76 -55 0.448
260.7 794 55 -59 10111110 261.22 680 54.9 7 765 260.28 -60 0.454
266.86 875 55 -56 10111110 267.36 823 50 7 715.7 266.36 -60 0.444
268.39 833 56 -54 10111010 268.9 1155 50.1 7 695.5 267.87 -58 0.448
269.95 1530 56 -44 10111010 270.42 1235 34 4 459 269.43 -43 0.434
271.44 145 56 -52 10111010 271.86 0 0 0 975.4 270.94 -52 0.466
272.78 0 56 0 10110010 273.3 0 0 0 975.4 272.36 0 0.896
274.37 0 56 0 10110010 274.86 0 0 0 975.4 273.8 0 0.912
275.88 0 56 0 10110010 276.38 0 0 0 975.4 275.36 0 0.924

[littlepolo]

I've taken a step back on this problem to check over some basics. I found that when I unplugged the MAP sensor the engine load reverts to a 20-20% figure from cold and the engine runs OK, albeit rich. It revs fairly smoothly up through a few thousand RPM. When the temp gauge was up to normal (middle of the dial) I plugged the MAP back in. Engine was difficult to start and engine load figures went very high again. The coolant temp sensor was indicating around 72C at the time (after a period of fast idle), which is lower than it was indicating before. Hoses are hot. My plan is to swap the MAP and ECT sensors over the weekend and take some measurements thereafter. With the MAP unplugged as above the O2 sensor voltages were low but not sure what to read into that since it was not in closed loop. I have a new pre-cat O2 to plug in of the above fails to deliver any improvement. Nearly there?

[littlepolo]

Swapped the coolant temp sensor for a new one - no change.
Swapped the pre-cat O2 sensor for a new one - no change.
Reverted back to the old MAP sensor - no change.

As before, the engine catches first time from cold and will run albeit lumpy. It will run up to 30 or 40C before it becomes too lumpy and stalls. I cannot easily restart or keep it running once it's warm. Again from cold, if I unplug the MAP it will run up to 50 or 60C before it becomes too lumpy and stalls. From cold it does not run any better with the MAP unplugged - it's lumpy most likely due to the rich mixture. If I rev the engine (with the MAP unplugged) it revs cleanly. I pulled the plugs to inspect them. All are sooty, but not wet. I am far from an expert in these matters but if it was a fuel regulator pressure issue, or injector leakage I'd expect plugs to be wet.

Some more data:

Engine off:

Group 03: Engine speed 0, Intake manifold pressure 989.4 mBar, Throttle drive angle sensor 8.4, Ignition timing 0
Group 033: Bank 1 Lambda Control 0.0%, Bank 1 Voltage of Oxygen Sensors 6.225V (still not sure what this means)

Engine on (MAP unplugged):

Group 001: Engine speed 1020, Coolant Temp 37C, Lambda Controller 0.0%, Basic Settings 00110110
Group 003: Engine speed 1150, Intake Manifold Pressure 91.8 mBar, Throttle Drive Angle Sensor 7.2, Ignition Timing 1
Group 032: Lamada Self Adaptation 0.0%
Group 036: Bank 1 Sensor 2 Voltage 0.019V
Group 001: Engine speed 946, Coolant Temp 52C, Lambda Controller 0.0%, Basic Settings 00110110
Group 011: Resistance Bank 1 Sensor 1 80 Ohms, Htg. S1 ON, Resistance Bank 1 Sensor 2 16 Ohms, Htg S2 ON

I'm running without the airbox so I can see the engine and listen for any leaks or other issues. One thing I noticed is there is quite a lot of hissing. At first I thought this was a leak (although the data pointed otherwise) and after checking out the hoses I noticed the hissing is due to the air passing over the throttle body/butterfly. Since I normally run with the airbox on I had not really noticed this before. Does that sound normal? It's like the butterfly is only barely open and causes a rush/hiss of air passing over it. Not sure how the idle control works so I guess this could be normal?

It seems unlikely that one new third-party MAP sensor, the original (used) off eBay, and the sensor installed before the rebuild are all faulty. Since the engine runs sort of OK with the MAP sensor unplugged (stationary - I've not road tested) and it being a factor in the calculated engine load I cannot rule it out.

Does anyone have any pointers where to go from here?

All the best for the new year!

[bvs]

Just one thought - is it the correct throttle body for the engine/ecu ?

[alexperkins]

That’s a valid point. How much has been swapped from the old to new engine. ECUs down to the last letter have to be matched to the correct components

[littlepolo]

The ECU is original. Only the head, cams, and oil pump has been swapped - all from a BBY engine. The throttle body is original. New parts are O2 sensor (pre-cat), thermostat, coolant temp sensor, and gaskets. MAP swapped for used then back to original. That is all that changed. Still no codes except when I unplug the MAP.

Is there any other data I can look at via VCDS that might give a clue?

[alexperkins]

I’ll have a sift through Elsa for you. It’s for some useful diagnostic pages