Cold start - engine vibrations, changing RPM - what to check

Share your FORScan experience with other users

Cold start - engine vibrations, changing RPM - what to check

Postby rmkk » Fri Jan 08, 2016 10:04 am

Dear friends,

I decided to write to this forum and ask kindly for help. I own Mondeo/MK4/TDCi/103kW/2007 the second winter. While engine is cold then, after starting it, the vehicle vibrates, lights blinking slightly, engine runs irregularly. However after warming to 30/40 dg vibrations going to be unnoticeable.

This winter I decide to solve it. So I give the car to Diesel service with Siemens/VDO certification. They did following changes: Starter(new), 3 injectors (rebuilded), CR pump (rebuilded), EGR (new), Alternator (new), Fuel filter (new), cleaning of all fuel pipelines and basin.

It did not help :-(. They started to examine again (free of charge) and found that on one cylinder there are still high corrections even if they exchanged the injectors. So they offered following
- reprogramming PCM
- exchanging all injectors with brand new ones

PCM was reprogrammed yesterday, firmware was upgraded from 7G91-12A650-UK to 7G91-12A650-UM. Still not helped.

Today in the morning I made a record of cold start in ForScan.
- I noticed that in idle state Cyllinder1 shows value over 1, but others show below 1
- after RPM increase to approx 1000 all values of CylBal shows the same 1.00007939 value
- engine was started and left as is, then offline I noticed on oscilloscope, that something changed in 98th second where Cylinder balances started to change even if RPM was still around 800

I'd like to ask You kindly for help with analysis my problem.

Thanks in advance !!!
Attachments
run20160108-cold.zip
(185.4 KiB) Downloaded 127 times
cold_start_20160108_99second-values.png
cold_start_20160108_99second-values.png (15.82 KiB) Viewed 5768 times
cold_start_20160108_99second-graph.png
cold_start_20160108_99second-graph.png (52.77 KiB) Viewed 5768 times
Last edited by rmkk on Sat Jan 09, 2016 12:05 pm, edited 1 time in total.
rmkk
 
Posts: 17
Joined: Thu Jan 07, 2016 6:20 pm
Vehicle: Mondeo 2007/2.0TDCi/103kW, Focus 2006/1.6TDCi/66kW

Re: Cold start - engine vibrations - what else to check

Postby FORScan » Fri Jan 08, 2016 11:53 am

Vibration and noise is about to be normal for diesel engine when it is cold, why do you think there is a malfunction? Anyway:

CylBal PIDs show contribution of each cylinder, they give 4 in summary. Ideally, every cylinder should be 1 (100%), in your case we see that cylinders 2 and 3 are close to 100%, cylinder 1 is up to 120% of normal, and cylinder 4 is 80% of normal. The contribution is calculated only at idle (this is why balances become equal when you increase RPM or stop the engine). In simple words, the picture is: cylinder #1 has the best health (as it provides more power than any other), cylinders ##2 and 3 have worser health, and cylinder #4 has the worsest one. Did the service perform injectors leak back and cylinder compression tests?
FORScan
Site Admin
 
Posts: 2521
Joined: Fri Jun 13, 2014 2:21 am

Re: Cold start - engine vibrations - what else to check

Postby rmkk » Fri Jan 08, 2016 12:32 pm

Thanks for reply.

I suggested to service to do the compression test. They refused it saying that different compression measured does not prove anything, so that it is no reason to do that test.

Injector leak test I didn't suggested, I don't know what for is it. The service didn't do it, I'm sure. I'll try to find something on youtube.

Do you have some indication what happens in 98s second when CylBal started to change even if I do nothing and engine was in idle state and RPM was still the same (around 800) ?

Just note that I have second car - Ford Focus/1.6TDCI/66kW/2006 (260.000 km) without any vibrations with smooth engine start even in cold. Here I see a big difference and feeling that something is bad on my Mondeo and this is a reason why I'm trying to resolve it.
rmkk
 
Posts: 17
Joined: Thu Jan 07, 2016 6:20 pm
Vehicle: Mondeo 2007/2.0TDCi/103kW, Focus 2006/1.6TDCi/66kW

Re: Cold start - engine vibrations - what else to check

Postby FORScan » Fri Jan 08, 2016 12:51 pm

rmkk wrote:Injector leak test I didn't suggested, I don't know what for is it. The service didn't do it, I'm sure. I'll try to find something on youtube.


For example:

http://www.fordwiki.co.uk/index.php?tit ... k-Off_Test

rmkk wrote:Do you have some indication what happens in 98s second when CylBal started to change even if I do nothing and engine was in idle state and RPM was still the same (around 800) ?


May be, CHT reached some minimum threshold (like 10 degrees)?
FORScan
Site Admin
 
Posts: 2521
Joined: Fri Jun 13, 2014 2:21 am

Re: Cold start - engine vibrations - what else to check

Postby william » Fri Jan 08, 2016 3:15 pm

when the car is started from cold the balance pids show a default value until the car has run for a few seconds, that change is the pids going from default value to live data.

Check your engine and gearbox mounts, a bad mount can cause vibration when engine is cold.
08 mk4 mondeo 2.0 140 bhp
william
 
Posts: 109
Joined: Fri Jun 20, 2014 7:41 am

Re: Cold start - engine vibrations - what else to check

Postby rmkk » Fri Jan 08, 2016 10:25 pm

FORScan wrote:The contribution is calculated only at idle

I undertand this when engine is in idle state and consuming some portion of fuel and gives some power to move its own mechanial parts. But the same values regarding contribution of cylinders are calculated and shown when vehicle is moving with no gear selected and fuel consumption is zero - so what is measured when there is no power from fuel - so there can be any contribution of cylinders to give a power ... ?

Sorry for maybe stupid question.
rmkk
 
Posts: 17
Joined: Thu Jan 07, 2016 6:20 pm
Vehicle: Mondeo 2007/2.0TDCi/103kW, Focus 2006/1.6TDCi/66kW

Re: Cold start - engine vibrations - what else to check

Postby rmkk » Fri Jan 08, 2016 10:48 pm

I'm still not satisfied mainly with changing RPM when engine is cold, it changes in idle from for example 870 to 910, or 770 to 820 depending on temperature outside, and this results in vibrations I think. Then there are only few parameter that are changing along with RPM. Those are: MAF, FRP, EGRVP_V, PCVPWM, VCVPWN. Online data in attachment.

However I can not recognize if the changing values are result or can be a cause of changing RPM. This is what I'm trying to check.

And one more thing - there were lot of things changed in my car, so I thinking if all the learned values was cleared after reprogramming of PCM, it seems to be logical ... but I don't know.

Thanks for help.
Attachments
run20160109-morning-cold.zip
(401.63 KiB) Downloaded 123 times
rmkk
 
Posts: 17
Joined: Thu Jan 07, 2016 6:20 pm
Vehicle: Mondeo 2007/2.0TDCi/103kW, Focus 2006/1.6TDCi/66kW

Re: Cold start - engine vibrations - what else to check

Postby FORScan » Sat Jan 09, 2016 12:30 pm

rmkk wrote:
FORScan wrote:The contribution is calculated only at idle

I undertand this when engine is in idle state and consuming some portion of fuel and gives some power to move its own mechanial parts. But the same values regarding contribution of cylinders are calculated and shown when vehicle is moving with no gear selected and fuel consumption is zero - so what is measured when there is no power from fuel - so there can be any contribution of cylinders to give a power ... ?

Sorry for maybe stupid question.


Analysing FSL you sent, we see that CylBal PIDs do not change (freeze at their current values) when engine has no load (LOAD PID is 0%). They may be not equal at that moments, but do not change.
FORScan
Site Admin
 
Posts: 2521
Joined: Fri Jun 13, 2014 2:21 am

Re: Cold start - engine vibrations, changing RPM - what to c

Postby william » Sat Jan 09, 2016 5:56 pm

Had a look at your saved file and it shows two of your cylinders in the balance pids at 0.6 and one at 1.3, any more than 25% difference between cylinder pid values would indicate a problem, could be why your idle rpm is erratic.
I think as Forscan suggested you should ask the diesel specialist to do a leak off test and have another look at the injectors.
08 mk4 mondeo 2.0 140 bhp
william
 
Posts: 109
Joined: Fri Jun 20, 2014 7:41 am

Re: Cold start - engine vibrations, changing RPM - what to c

Postby rmkk » Sat Jan 09, 2016 6:39 pm

william wrote:you should ask the diesel specialist to do a leak off test


William, the service is offering to me to replace all injectors for the new ones to test if the problem is in injectors. This is an adequate substitution of leak off test, isn't it ?

Thanks for the answer.
rmkk
 
Posts: 17
Joined: Thu Jan 07, 2016 6:20 pm
Vehicle: Mondeo 2007/2.0TDCi/103kW, Focus 2006/1.6TDCi/66kW

Next

Return to Diagnostics and Maintenance using FORScan

Who is online

Users browsing this forum: No registered users and 4 guests