Technical 1.6 multijet 88kw engine compression

[tomicdd]

Hi mate,
After few min at idle egr closes and full air is entering the engine and that's why measured air is higher than target in. Same happens when you block egr at idle measured is always higher.
Could you send video I'd like to see it please?
+381603389588 is my number
Info about dpf change, it's done but I'm not satisfied. Measured dpf pressure with new sensor is higher - 5-8mbar at idle. It's still clogging very fast and today it might do first regeneration after dpf reset. I was able to do reset only with alfaobd, mes and bosch diagnostics couldn't do it! Also I can't calibrate new dpf sensor it shows 2mbar at mar. No calibration from any diagnostic equipment is possible. I'm in touch with dpf service who did it but I'm not optimist. Cleaning egr and injectors test are only what's left. Boost and vacuum test also. Ecu might be faulty, I was measuring reference voltage like 3,5V. It might mess sensor data. We'll see, the year is young

Ps. Your boost pressure measured at idle it's much lower than mine. I'm about 920+mbar
That - 3mbar presuure, was it at mar od engine idle?
At the end, I'm just thinking that all this is happening because we have low compression and not full combustion in cylinders and that's why a lot of soot and smoke is made. What ever we do, we'll have the same. The only way is to reduse those 2 is new engine or properly rebuilt one. I'm praying that I'm wrong...

 

[tomicdd]

Hi guys! Yesterday I did a smoke test. Result: no air leaks anywhere. I thought that the smoke device was faulty, but when I unscrewed the oil filler cap, this smoke came out under good pressure. So there are no leaks...
On Mike's advice, I compared the values of boost, air supply, and rail pressure. When idling, the same value of incoming air quantity is maintained for about 2 minutes, but then the Intake air quantity value starts to grow! In addition, at idle, the values of the pressor boost are also different. Although the turbine after repair on the stand, where it showed that it did not blow enough even before the repair. The geometry position is normal, it seems. What could be the matter?
There are also some differences in the EGR valve. Actual position is -0.02, desired position is -0.40. Attached a photo of the program. I also have a video, I can attach it or send it to the website (if possible) or WhatsApp if necessary.
In addition, I performed an endoscopic inspection of the cylinders and valves. The cylinder hone is good, there is a small carbon deposit, but the valves do not shine at the point of contact, and are also covered in carbon deposits. I also have a video, I will send it to the person who understands and can help.Please share your opinion on this matter. Thank's!

How did you do smoke test? Usually, line is disconnected at turbo and butterfly valve which you block. At turbo side you put 2-3bar pressure and wait for needle at manometer to drop, or hissing or soap-water mix. Without boost in the system, crack might not open. Only at higher pressure. Let's say, all is tight up to 1,5 bar and then opens which we can see as lower maf and map readings.

 

[Aviator144]

How did you do smoke test? Usually, line is disconnected at turbo and butterfly valve which you block. At turbo side you put 2-3bar pressure and wait for needle at manometer to drop, or hissing or soap-water mix. Without boost in the system, crack might not open. Only at higher pressure. Let's say, all is tight up to 1,5 bar and then opens which we can see as lower maf and map readings.

According to the specialist, the pressure is 3 bar, which is similar to the engine vacuum pressure. The smoke supply hose was installed immediately after the MAF before the turbo.Yes, I thought that there was not enough pressure, but from under the oil filler cap, when it was opened, a very thick stream of smoke came out, and I think it also went to other pipes.

 

[Aviator144]

Hi mate,
After few min at idle egr closes and full air is entering the engine and that's why measured air is higher than target in. Same happens when you block egr at idle measured is always higher.
Could you send video I'd like to see it please?
+381603389588 is my number
Info about dpf change, it's done but I'm not satisfied. Measured dpf pressure with new sensor is higher - 5-8mbar at idle. It's still clogging very fast and today it might do first regeneration after dpf reset. I was able to do reset only with alfaobd, mes and bosch diagnostics couldn't do it! Also I can't calibrate new dpf sensor it shows 2mbar at mar. No calibration from any diagnostic equipment is possible. I'm in touch with dpf service who did it but I'm not optimist. Cleaning egr and injectors test are only what's left. Boost and vacuum test also. Ecu might be faulty, I was measuring reference voltage like 3,5V. It might mess sensor data. We'll see, the year is young

Ps. Your boost pressure measured at idle it's much lower than mine. I'm about 920+mbar
That - 3mbar presuure, was it at mar od engine idle?
At the end, I'm just thinking that all this is happening because we have low compression and not full combustion in cylinders and that's why a lot of soot and smoke is made. What ever we do, we'll have the same. The only way is to reduse those 2 is new engine or properly rebuilt one. I'm praying that I'm wrong...

Is this EGR behavior normal?Yes, all these parameters were read at idle. But later I made a video at 4000 and 2000 rpm. I'll send it to you now.Regarding our problem, as the Russian proverb says: we'll live and see!

 

[bugsymike]

Hi guys! Yesterday I did a smoke test. Result: no air leaks anywhere. I thought that the smoke device was faulty, but when I unscrewed the oil filler cap, this smoke came out under good pressure. So there are no leaks...
On Mike's advice, I compared the values of boost, air supply, and rail pressure. When idling, the same value of incoming air quantity is maintained for about 2 minutes, but then the Intake air quantity value starts to grow! In addition, at idle, the values of the pressor boost are also different. Although the turbine after repair on the stand, where it showed that it did not blow enough even before the repair. The geometry position is normal, it seems. What could be the matter?
There are also some differences in the EGR valve. Actual position is -0.02, desired position is -0.40. Attached a photo of the program. I also have a video, I can attach it or send it to the website (if possible) or WhatsApp if necessary.
In addition, I performed an endoscopic inspection of the cylinders and valves. The cylinder hone is good, there is a small carbon deposit, but the valves do not shine at the point of contact, and are also covered in carbon deposits. I also have a video, I will send it to the person who understands and can help.Please share your opinion on this matter. Thank's!

Were all these graph figures starting from a cold engine and at idle?
The reason I ask is I may be able to run a similar test on my 2010 Doblo 1.6 MJ though using a different diagnostic tool , but I need to know what the benchmarks are i.e. hot/cold engine , revs , stationary etc.
Another thought is if you have a suspect EGR valve, has this been checked?

 

[tomicdd]

Mike,
Look this cylinder and engine head border surface at photos. What do you think? Can it be coolant leak/bad gasket and reason for excess smoke? Or even oil from Channel?
Can it be damaged engine head?
That means that gasses can escape into the cooling system and can be detected in expansion box with cap removed and that co2 liquid changing colour test?

 

[bugsymike]

Mike,
Look this cylinder and engine head border surface at photos. What do you think? Can it be coolant leak/bad gasket and reason for excess smoke? Or even oil from Channel?

Sorry not quite sure the direction I am looking at, I can see the boring/honing marks on the cylinder which don't look very smooth to me.
Am I looking up at the cylinder head via a valve or injector hole, in which case something is leaking from the head gasket area, which doesn't look like a clean defined edge of a gasket?
So are you losing coolant or oil?
Obviously hard to be sure but if poor job on liners/cylinder sleeves it could be head gasket not sealing around cylinders.
When you had the leak test done, with pressure in the combustion chamber, if the head gasket wasn't sealing correctly I would have expected the coolant to start to rise in the expansion tank if you had the cap off, as the air pressure escaping from the combustion chamber in to the cooling system would displace the water causing the level to rise or overflow. I have seen that many times when checking for a suspect head gasket.
There is certainly some strange colouring around the edge of the cylinder.

 

[tomicdd]

Yest, that is up the cylinder - head, valves etc. It's aviators photo from the inside of engine. So, coolant blow out check is the fastest way to see if something is wrong? Something like this kit https://www.cosda.com.tw/combustion-gas-leak-tester-kit-sd-1025.html

 

[bugsymike]

Yest, that is up the cylinder - head, valves etc. It's aviators photo from the inside of engine. So, coolant blow out check is the fastest way to see if something is wrong? Something like this kit https://www.cosda.com.tw/combustion-gas-leak-tester-kit-sd-1025.html

That is one test, what we used to call a "sniffer test" where the crystals change colour if combustion gas is detected in the coolant reservoir.
Sometimes it is possible to simply rev the engine with the lid off for 30 seconds or so, then let it idle and you may see bubbles rise, if safe to do so you may smell exhaust gas in the bubbles. My way costs nothing
However the test I meant involves checking each individual cylinder by locking the engine when on the firing stroke so inlet and exhaust valves are shut and piston at TDC on the cylinder to be tested and then air pressure from a garage compressor ( I use 150psi /10 Bar) is connected to that cylinder via heater plug or injector adaptor, if a petrol engine then via spark plug adaptor.
While this is connected it is then possible if head gasket is leaking to see the water level rise in the expansion tank if lid/cap off and filled to brim start to overflow.
You can also see if pistons are worn/not sealing as pressure will be escaping via oil filler cap or engine breather.
You can also see if inlet valves are not sealing by air escaping from induction side/air filter etc.
You can also see if exhaust valves are leaking by listeing at the exhaust tail pipe for pressure escaping.
It is an excellent test but takes a long time to check every cylinder, but is conclusive.
It is an expensive bit of kit to buy and has the gauge to measure % of loss , however if you have access to a good compressor and can make suitable adaptors and a bit of hose, then that works quite well
In your case what I suspect is a poor job was made of the cylinder liners and maybe the cylinder block wasn't skimmed flat afterwards so a poor seal was allowed at the head gasket area. I would have also had the cylinder head machined flat also.