Technical EGR valve, throttle body or inlet manifold problem?

[s130]

And your intercooler is also post turbo
And the sump is under pressure hence why you have a crankcase breather in the first place to vent the pressure and fuel out of there z

Of course the sump is under pressure. Turbo or no turbo. In non turbo cars there is always a bleed for crankcase fume recovery. This is normally in a healthy engine just what I would called natural/normal recovery and associated recovery contamination.

My concern/observation is in the turbo systems I have seen is because oil is fed/injected into the turbo for cooling and lubrication purposes that over time the oil leakage increases but does not affect turbo performance so goes un-noticed.

In a petrol engine this is not a big issue because any EGR system is not having to cope with the soot of a diesel engine exhaust being refed back into the intake and mixed with oil.

Let us be clear in that I'm not trying to pick a fight with diesel engines. I'm stating that diesel burn, especially when off optimum conditions like when encountered in varied dynamic loads, produces more combustion soot than a petrol, alcohol, gas based engine.

Add to that with EGR which includes both sump oil fumes, turbo seal oil leakage (if a turbo system), and just poor diesel engine performance and clean burn when conditions are out of range/scope then we will and do get excessive carbo/soot build up and contamination.

The dirtiness of diesel engines has been well understood for many years. However diesel engines have showed their value in what I would call long hard and steady operation. e.g. Trains, road trains, haulage, tractors, ships, etc. and in these operational circumstances they are basically controllable and in the long term not a bad choice etc.

My concern/criticism is putting a diesel engine into everyday dynamic load operation and associated average household/family usage is not what a diesel engine is good at and certainly not clean at. You can add all the DPFs, filters etc, you like but dynamic diesel load and burn is by any means NOT clean.

Many governments backed diesel on the basis of CO per mile. So a petrol engine of a given cc would create x CO. Same diesel would create less CO. They did not take into account other pollutants (as far as I can tell).

Anyway I hope the OP gets their problem resolved and we will all be happy.

 

[davidthelodge]

thx Portland Bill & others, interesting comments. The exhaust gas cooler was replaced last year as the corrugated end section had a split in it.

 

[portland_bill]

Diesel engines create soot. Even modern ones with DPF when run/booted "out of optimum range" create soot. That is why I've always maintained the diesel engines are NOT suitable for *dynamic* operation. Diesel engines are best suited, tuneable and clean when under designed constant load.

There is nothing wrong as such with a diesel engine when run in accordance/sympathy which what it is good at. Sadly IMHO motor vehicle as in cars is not IMHO a good use. Long haul trains, road trains, etc. then yes but not urban, semi urban stop/go etc.

I've never been a fan of diesel engines in cars for this reason also. I liken the diesel engine to a carthorse, heavy haul, hard work, is what it does best. Gearing is what makes it work in a car. A petrol engine is more like a racehorse, ready to sprint and run, much better suited to cars.

Diesel engines are right for heavy work, vans, trucks, etc.

Diesel efficiency is better now than when I did my motor vehicle science at college, but then, (1976) diesel engines in cars were less efficient than petrol.
Efficiency is not the same as economy, which is why people will argue with this. Diesel fuel contains more energy per millilitre than petrol, but of the avialble energy in the fuel, we use a smaller percentage of it to push us along with diesel, than with petrol. So whilst diesel will give better economy, of the energy available, less is used for benefit. As S130 said, a diesel working hard is cleaner and more efficient, converting more of its energy into power.

 

[davidthelodge]

multiscan shows throttle valve opening does'nt move from 4.99% when the engine is revved, is this normal as it seems odd to me? Turbo is obviously not boosting. thx

 

[g8rpi]

That's not normal. It should fully open. It may well have stuck or the control valve / line failed or blocked

What happens when you operate the "flow modification throttle solenoid valve" under the actuators tab in MES?

Robert G8RPI.

 

[s130]

I would also check that throttle valve opening when driving.

Throttle valve opening does not follow throttle pedal position other than following an increase / decrease in demand. There is a relationship but it is not a 1:1. You can run MES to monitor and graph the values, along fuel/injection/airflow values and hopefully get a better overall picture of what is going on.

 

[davidthelodge]

I have connected MES again and can hear the "flow modification throttle solenoid valve" making a noise when I use the actuator tab in MES.

The problem is linked to a lack of air & turbo boost. Throttle valve opening in MES is still not moving when driving, still at 4.99%.

I recorded the data for air/boost and I have downloaded it on my laptop, but its a ".csv" file and it says its invalid to be uploaded or even opened !

 

[davidthelodge]

multiscan shows throttle valve opening does'nt move from 4.99% when the engine is revved, is this normal as it seems odd to me? Turbo is obviously not boosting. sorry this is the only way I can down load it. thx

Time Intake air quantity Desired intake air quantity Boost pressure Desired boost pressure
sec mg/i mg/i mbar mbar
0 378.5 376.5 995 1044
0.93 376.5 379 998 1054
1.85 379 459.5 994 1183
2.77 398.5 474 988 1208
3.69 452.5 375.5 994 1000
4.61 432.5 301 999 1000
5.54 326 326 999 1000
6.46 317 349 999 1002
7.38 335 873 986 1263
8.3 515 442.5 991 1235
9.21 513.5 503 1004 1659
10.13 545.5 957 1056 1615
11.05 582 314.5 1028 1000
11.97 487.5 256.5 1005 1000
12.9 300 275 992 1015
13.81 316 325.5 989 1013
14.73 531 301.5 991 1000
15.65 368 299 998 1000
16.57 329.5 325.5 998 1000
17.49 319 359 998 1000
18.41 360.5 369 989 1232
19.33 511 490 994 1271
20.25 517 1014.5 1030 1628 - problem
21.17 550 997.5 1073 1670 - ditto
22.09 550 1166 1097 1070
23.01 484.5 447 981 1057
23.93 487.5 383 972 1039
24.85 496 350 976 1031
25.77 498 339 981 1009
26.7 537.5 287 1001 1000
27.62 352.5 321 999 1000
28.54 322 459.5 989 1246
29.45 505.5 643 1002 1512
30.38 532.5 1063 1049 1610
31.29 548.5 1037.5 1085 1659
32.21 550.5 1053 1094 1716
33.13 558 1199.5 1120 1842
34.05 551.5 540 1008 1117
34.97 477.5 497.5 972 1063
35.89 477.5 457 970 1051
36.81 482 423 972 1037
37.73 490 406.5 978 1022
38.65 509.5 391.5 988 1000
39.57 506 363.5 1001 1000
40.49 384 390 999 1000
41.41 369 397 999 1000
42.33 399.5 396.5 999 1000
43.25 398.5 467.5 995 1007
44.17 493.5 434.5 995 1041
45.09 500 396.5 998 1046
46.01 432.5 385.5 998 1017
46.93 379.5 396 998 1006
47.85 398.5 396 998 1005

 

[portland_bill]

Wastegate stuck open?

 

[chris3234]

I wouldn't worry about the throttle valve not moving diesel's don't usually use this to control engine speed like petrol's do
Many engines don't even use one

 

[davidthelodge]

thx, is there anyway of checking the turbo wastegate ?

 

[davidthelodge]

When I found the problem I solved in 1 minute. Its unbelievable as the car has been unusable since around the 10th August.

There was a small split on the joint where there is a plastic connector in the rubber pipe that goes to the turbo boost control valve. I put the Fiat P0238 fault code in Google and up popped a link to post on FF by Do I or Dont I, he had the same problem and had to have his 2.4 Croma recovered home. Its amazing that a small split in a pipe can disable a car. Thx everyone

https://www.fiatforum.com/croma-ii/241283-guess-problem.html