Author Topic: Noisy chain / knocking  (Read 19070 times)

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #30 on: 04 December 2018, 12:45:31 AM »
Another evenings reading (including some things called a Volvo) and I'm better informed

The thermistor is located within the valve body, not externally accessible, and according to page 11 of the pdf linked below, at 10 degrees C the expected value is 6445 ohms, pretty close to the 6416 ohms my meter said.

So, that's that theory out of the window, also meaning of course that the test values in WIS are incorrect, but the component referred to is only present in the earlier 4 speed boxes, so perhaps a different thermistor / response profile.

https://www.myvolvolibrary.info/Tech_files2_ficheiros/AW55-50%20SN.pdf

That means tomorrow should be a chance to do the line pressures. Could be fun  :o
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #31 on: 04 December 2018, 08:26:19 AM »
Some more references for other forum users

Link for the earlier 4 speed box - thermistor resistor readings agree with WIS, so the values in WIS only apply to the early box

http://www.vectra-club.ru/images4faq/ova/AKPP/50-42LE.pdf

A pretty detailed set of test procedures for the 5 speed

https://www.sonnax.com/tech_resources/196-aw-55-50-af23-33-diagnosis-and-valve-body-information
« Last Edit: 04 December 2018, 10:39:30 AM by carrera »
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #32 on: 04 December 2018, 04:23:16 PM »
The system presures have been tested according to WIS at port B5.

When the car is started it shows about 5 bar in P, and within about 10 seconds it suddenly goes up to a solid 15 bar. When cold it throws P0748

Increasing the revs results in a slight increase in pressure, next the designated tests

Idling speed - 850rpm
In drive, 0 bar actual, 4 bar spec
In reverse, 15 bar actual, 5 bar spec

Stalling speed - 2400rpm
In drive, 0 bar actual, 13 bar spec
In reverse, 20 bar actual, 20 bar spec

The guidance in WIS doesn't fit this pattern, so more thinking to do, though the low pressure in D in both situations does point to "too low system pressure, fault in clutch C1"

I have found a TCU, but am not yet satisfied that is the fault. What is certain is that I am methodically getting way out of my depth  ;D


****

a bit more data, I decided to measure the pressure on the SLT, another reference document gave some typical values, though I have to convert from psi every time

Idle speed, actual value 5 bar, 0.3 bar spec
Stalling speed, actual value, 5 bar, 5.4 bar spec

Now my gauge isn't that precise and it's a long way from the drivers seat to where it is located, so for me at stalling speed the value is correct. I did notice as I engaged a gear the pressure dropped down to almost zero before returning to 5 bar.

Something seems to be forcing the SLT pressure to be high at idle
« Last Edit: 04 December 2018, 06:35:31 PM by carrera »
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #33 on: 08 December 2018, 01:32:42 PM »
Problem solved  ;D ;D ;D

I picked up another transmission control unit and fitted it today.

Cleared the stored codes, switched off, on again and immediately felt the difference. I don;t have the ability to clear the stored adaptation values so just did a bit of the workshop test and a short test run. All seems fine.

This has been a bit of a diversion from my noisy chain / knocking thread. The engine was going to be a donor, but now this car is rescued and will be going back on the road. A bit of minor work to do and then she'll be ready for a new owner.

As there's a fair bit of auto transmission diagnosis / information here, and it could probably deserve being in its own thread, is it possible to pull them out into another thread where the info may be easier to find ?

Thanks for all the help and advice along the way


 
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #34 on: 08 December 2018, 01:34:03 PM »
Now, I'm back on removing the engine from the glacier blue car. Everything is off, it's on the hoist, I just need to get the angles right and hopefully she will be out later today.

I have located another engine to inspect (from another auto) and hopefully drop in
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

Audax

  • SaabTechTalk Team
  • Wide open throttle
  • **
  • Posts: 3332
  • Number of thanks: 207
    • View Profile
Re: Noisy chain / knocking
« Reply #35 on: 11 December 2018, 09:56:48 AM »
I picked up another transmission control unit and fitted it today.

Cleared the stored codes, switched off, on again and immediately felt the difference. I don;t have the ability to clear the stored adaptation values so just did a bit of the workshop test and a short test run. All seems fine.

Good progress, one thing I have heard but do not have experience of is that if the solenoids get sticky then the resistance increases and causes some component in the TCM to fail, so if it starts doing it again soon it would point to a possible solenoid problem.

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #36 on: 11 December 2018, 11:20:30 PM »
The engine is finally out of the glacier blue car. Note for others, no you don't need to remove the electrical connectors from the fan housing, but if you do there's just 2 bolts and the whole fan housing can be removed giving necessary additional room to get the engine out.

I have been reading around about setting / adjusting the solenoid valves. When the box and engine are out of the breaker car I am going to have a little look inside the valve housing cover to see what's involved in refurbing / swapping them over
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #37 on: 01 April 2020, 08:20:31 AM »
Bringing this topic back to life as the good news did not last on the transmission.

The car sailed through its MOT with no advisories.

In use however the car has started to misbehave and throw a P0748 after around 40 miles driving. The code will clear when cold, but comes back when hot. Further investigations:

The error occurs with the correct TCM and also a 2003 TCM that is "known good"
Transmission fluid temperature sensor - Has the correct resistance / translation to degrees C
Wiring, continuity and light bulb tests done on the wiring to all 3 linear solenoids
Resistance tests on the linear solenoids show all three reading 5.8 ohms. This is just a little higher that the 5-5.7 ohms I have seen quoted, but all three are the same

Now the important new information:
PWM confirmed at 300hz
Current draw - virtually zero , maybe 60 ma
Duty cycle on the SLT 55% at idle in P, dropping to 38% at 2000 rpm

Now reading around I have seen a theory that problems with the linear solenoids cause the TCM to go into "high current" mode. I am pretty convinced that this is a myth. Why ?, well these two graphs give the answer (courtesy of Sonnax)

Before I go any further I am trying to be certain that this is a mechanical problem rather than electrical. I have read and been told that with the development of the valve body the design of the SLT was changed with the electrical connector moving from the top of the SLT to the bottom which was done apparently to reduce contamination.

You can see that low amperage gives high line pressure (the opposite of the prior hypothesis), and also that the duty cycle is above the expected range. It makes sense to me that higher duty cycle would give higher line pressure.

I'll admit I haven't got my head around how the different control pressures work inside the box to provide a smooth shift, but do get how those pressures are tweaked by adaption to take account of wear over time. I also understand that the linear solenoids can be rebuilt and are mechanically adjustable.

Any further thought or suggestions for me. Key to my understanding is answering the chicken and egg question. Does the TCM adjust the amperage to achieve a target SLT pressure, or is it the duty cycle that is adjusted. What is really throwing me is the high duty cycle combined with low current.

 

https://www.sonnax.com/tech_resources/196-aw-55-50-af23-33-diagnosis-and-valve-body-information



9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #38 on: 04 April 2020, 04:46:02 PM »
Can you guess what I'm doing ?

I suppose the colour is typical for 110,000 miles.

I'll be seeing linear solenoids before long :)

9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

sgould

  • Aerobic
  • SST paid up supporter
  • Overboost
  • *
  • Posts: 5388
  • Number of thanks: 345
  • 2006 9-5 Aero estate - Hirsched.
    • View Profile
    • Christine Bennett - soprano
Re: Noisy chain / knocking
« Reply #39 on: 04 April 2020, 05:08:48 PM »
Does it smell a bit burnt?  Mine did, but it was a lot blacker than that.
Help support SaabTechTalk by making a Lump Sum donation or by opening a subscription. 
Options available are in your Profile/Actions.

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #40 on: 04 April 2020, 05:55:29 PM »
It smells, in a similar way that hypoid gearbox oil smells, it's not that pleasant at all, but I wouldn't say it smells burnt. I just had a whiff of GM manual gearbox oil and that was sweet in comparison.

After another check of WIS (to check that there wasn't something else to do to get the valve cover off) I spotted something new to assist my understanding.

Quote
The solenoids are controlled by a 300hz PWM voltage via pin 26 B (SLS) and pin 35 B (SLT) and grounded via pin 36 B (SLS) and pin 15 B (SLT). They are controlled by a current that changes primarily in relation to accelerator position. A high pulse ratio producing a high current (approx 1A) results in a low system pressure. A low pulse ratio producing a low current results in a high system pressure. An open circuit produces maximum system pressure. The valves are then fully open.

The control unit uses bus information on the current "Engine Torque" and the gear currently engaged to control system pressure 

Now that's quite interesting. Though I do not know what the correct parameters are for an engine on idle and in Park, what I am seeing is a high duty cycle (55%), but a low current (60 ma)

Those two measures appear to be totally inconsistent, which is what I was guessing before.

Further head scratching required, but for now here's a picture of the internals of the valve body. The cover itself is beautifully clean, and I note that on the range of - A B C valve body designs mine is an A version, so the second iteration, which has the SLT connectors at the top, and the shorter wiring harness



« Last Edit: 04 April 2020, 11:11:46 PM by carrera »
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #41 on: 04 April 2020, 10:18:42 PM »
I decided to be really careful in trying to remove the electrical connectors. Good job, as apparently if the plastic bridge on the linear solenoid breaks the solenoid is u/s........ unless you buy some aftermarket clips available on ebay in the US (Sonnax parts).

Having tried a couple of techniques I left it before I did any damage to allow me to do some more research, in the process of which I found this. Looks like I was doing it wrong and right at the same time. Of course, at the moment the solenoid is still up in the valve housing area, but it is possible to unhook the wiring harness to release the SLT from the housing

http://faeriesintheattic.com/wordpress2/wp-content/uploads/2016/08/aisin-solenoid-harness-removal.pdf
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #42 on: 08 April 2020, 06:45:50 PM »
Finally managed to get the electrical connection off  by using a small jewellers screwdriver under the plastic tab, while at the same time pushing down on the plastic tab that retains the connector.:) 

Now, having said that my brain cell has been whirring away on the failure mode. This is a fixed frequency PWM application - 300Hz, which means the solenoid switches on and off 300 times per second. More "off" time (it is a normally open solenoid) through variation of the width of the pulse is seen as an increased duty cycle, which should mean lower SLT pressure. So maybe running at too high a duty cycle on the PWM causes the electronic problem ???

A second consideration is that when there is an electrical failure (think of it as zero duty cycle) the SLT pressure defaults to high which is what is felt as a hard shift. In my case I think the TCM is trying to get the SLT pressure down (but how does it know??) by giving a high duty cycle, and then, because of the contamination the actual movement of the solenoid is reduced which makes the TCM try to go ever higher on the duty cycle. Duty cycle not current.

That's my current theory anyway, happy for others to thoughtfully develop it. Augmented slightly by having disassembled my SLT.  This was quite helpful, even though it is for something called a Volvo  :D https://www.youtube.com/watch?v=0nh0rp7HSrw

Next step is cleaning this solenoid. The holes look clear, but there was some gungy resistance to withdrawing the spindle

Time for a picture
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD

sgould

  • Aerobic
  • SST paid up supporter
  • Overboost
  • *
  • Posts: 5388
  • Number of thanks: 345
  • 2006 9-5 Aero estate - Hirsched.
    • View Profile
    • Christine Bennett - soprano
Re: Noisy chain / knocking
« Reply #43 on: 08 April 2020, 09:12:54 PM »
I've never been that far into a gearbox, and I don't do anything oily anymore due to dermatitis, so I won't be going there in future :)

But, did you have to "uncrimp" the end of the cylinder to get the piston out?  It looks very rough.
Help support SaabTechTalk by making a Lump Sum donation or by opening a subscription. 
Options available are in your Profile/Actions.

carrera

  • SaabTechTalk-Team
  • Test pilot
  • *
  • Posts: 1107
  • Number of thanks: 17
    • View Profile
Re: Noisy chain / knocking
« Reply #44 on: 08 April 2020, 09:34:53 PM »
I've never been that far into a gearbox,

I've never been this far into an auto gearbox.

Spot on with your guess on the disassembly method. In the US you can buy repair kits where a replacement over cap is provided.

Any thoughts on the control methodology ?  I have just had another look at the wiring diagram and can only see the solenoids, input shaft output shaft and temperature sensors. Nothing that would provide direct feedback to the TCM on what pressure is being achieved.

So how does the adaption (aka variation from the default program map) work ??? 
9-5 Aero Estates, 2002 Cosmic Blue, 2003 Steel Grey, 2003 Graphite Green, 2004 9-5 Glacier Blue 2.0 saloon, 2004 Nocturne Blue 2.2 diesel estate, 2006 & 2008 Black Aero saloons, 1998 9000 CSE with Aero engine, 9-5 NG Aero XWD Turbo4, 9-5 NG Aero XWD TTiD