Noisy chain / knocking

[phoenix]

Two main differences spring to mind:

-the brake vacuum servo which is mechanically driven on an auto via a pump on the end of the front camshaft. You'll need to remove that from the donor and swap over the blanking plug.

- the sumps are different. Pretty sure you'll need to retain the one from the manual car


Beware- the auto gearbox is heavy- twice the weight of the manual (90kg vs 45kg)

[carrera]

Thanks both.

No worries on the gearbox weight, I won't be lifting it manually, that's what the engine hoist is for. 

I didn't think about the servo, knew the reversing light switch would be different and assumed there may be changes on vacuum hoses. I did an engine swap on a non Saab last year, manual engine into a Tiptronic shell. There were pretty significant differences, so the whole of the ancillaries, intakes etc were swapped over, not least because the tiptronic box was water cooled. Hopefully the 9-5 will be less involved.

The car is at home on the drive now. 110,000 miles, loads of service history, completely rust free on the rear arches and in pretty clean condition, she's been looked after. I only put her on the trailer using Low, apparently the gear change from low to 3 is lumpy / notchy and there is a transmission warning light on the dash. When in D the engine goes into a limp mode as well. I will have to see if my reader can get the code  (no Tech 2 as yet) and have a little drive to see what the symptoms are.

I doubt it's an easy / cheap fix,  but it would be silly to embark on major works without diagnosing the problem better.

[Audax]

I expect you'll find it's a sticky solenoid in the valve body.

[sgould]

The manual car and autos have different radiators. The auto gearbox cooler is part of the radiator. The engine oil cooler is separate on both.

[carrera]

Thanks both again.

I've been reading around since my last post and one thread suggested sticky solenoids were likely and then said "not repairable". Another one said a Saab specialist won't touch the auto boxes any longer as they are always having problems, while another said, strange we haven't seen any issues with them. My local tech said they hadn't seen any auto issues when I said I have seen a few auto cars for sale with box problems (before this one came up for sale). Maybe it's a "in original dealer network" / out of network experience difference.

I have also gone through the thick wad of invoices, including the first service at 6,000 miles and there's no sign of the ATF having being changed or checked at any point. Maybe that's my first port of call after the scanner.

If I do transfer the engine the rad will be staying in the recipient car and the oil cooler will come over with the engine.

The oil cooler was part of my thought process when I bought this car. Having reckoned it would be a minimum £200 in parts for bearings and chains, I then realised that with all the bearing material in the sump I should also change the oil cooler, it's the only way to be sure no metal remained within it.

[carrera]

Curiosity got the better of me and i just went outside in the dark with my codereader. Best surprise was that it pulled the code 

P0748 Control pressure Solenoid A electrical

Oooh electrical, could be a much easier fix than messing with hydraulics.

I haven't cleared the code yet, that's for tomorrow, time for some more specific background reading

[Audax]

Oooh electrical, could be a much easier fix than messing with hydraulics.

It's possibly wiring from the loom to the solenoid, but I am expecting it more likely to be a failed solenoid and needing to open the gearbox up to replace if you're keen on fixing it.

[carrera]

I didn't get as much time on it as I hoped today, anyway

Code cleared, engine tickover became smoother as well as EML and transmission light going out.

No performance at first when using D, after a few forward / backwards using low and R it seemed to get better, maybe setting off in second or first. Sport mode improved things.

The error code returned when I was holding the engine on a fast idle. It takes about 3 seconds for D or R to engage, and then with foot on the brake there's a fairly sharp kick as the drive engages.

I checked the ATF level, got the engine / box warm, did the drive / reverse engagement bit then left it idling. The level was just a couple of marks above minimum. The fluid was not a bright red, more of a brown/red, a bit like dried blood ?? It didn't smell burnt.

I didn't buy the car to fix it, but you never know. It's only done 110,000 miles too. I don't generally do automatics, most of the posts I read suggest that as the car is post 2003 it will have a 5 speed box, but it only goes up to 4 on the shifter and dash.  Speaking of which, why no turbo gauge 

My plan is to test the 4 resistances for the solenoids through the loom tomorrow, if they check out OK then I have read that the transistors in the  Transmission Control Module ECU's fail too.

I am getting the message that you suspect the pressure control solenoid regardless, sounds like the voice of experience, I just need to follow the right diagnostic process 

[Audax]

I am getting the message that you suspect the pressure control solenoid regardless, sounds like the voice of experience, I just need to follow the right diagnostic process 

I do suspect that but you should always do the diagnostics, It's nice to be proven wrong and for it to be something simple.

[carrera]

OK, so I have whipped out the transmission control unit this morning, mainly so I could see the prices of replacements on ebay etc.

It's part number 51 64 256, two plug connections, made by Aisin, and also has the code 93-50 with a GM (not Saab) underline.

2002 model were 5540599, and the replacement is 55352924
2003 model  is simply listed as 55352924
2004-2010 is listed as 55 560 029

From what I have now read these seem to be very regular failure items. I found a thread at https://www.saabscene.com/forum/threads/162410-Gearbox-ECU-issue/page2 which suggests that the TCU out of a 9-3 can be used. I'm not sure whether that means simply replaced, or replaced and reprogrammed with the 9-5 software. There are 9-3 TCU's on ebay at the moment at a very affordable price. Interestingly, while mine looks like new, the 9-3 ones (55 353 074, 2004 for B207E) all look weathered, are they in the engine compartment rather than the cabin ?

I have tested the resistance of the SLT solenoid winding - came in at 5.3 ohms with a spec of 5.1 to 5.5 ohms at 20 degrees, so subject to me doing a bit of loom wiggling and checking the connector in the engine compartment to make sure there isn't a broken wire it would appear to be another potential TCU failure.

Anyway, any further insight into the diagnosis or use of a 9-3 TCU / reprogramming would be appreciated.

My assumption would be that all the TCU's will be of the same component design, just with different software loaded ??

[carrera]

Some progress, of sorts.

I removed the battery and with a meter on the connector watched for changes in resistance for the SLT solenoid. All seemed fine, so I put some contact cleader in the 16 pin connector and reassembled.

Restarted and after about 10 seconds it threw the P0748. I cleared the code and left it ticking over. The error did not recur so with a warm engine / car moved backwards and forwards. the delay on the selector seemed to have gone, but while there was a fair thump while engaging R and  L, there wasn't when engaging D. D only seemed to give a high gear, 4th / 5th I suppose.

Switched off,  restarted, did some messing with throttle position looking at live data and retested. Still no CEL, but now D gives the low gears too. That's an improvement, but having checked the gearbox code FA57A01 I know it's a 5 speed, even though the dash doesn't have an indicator for it.

But, the thump when engaging R and L remains and the three second delay is back...... but no error codes. Wish I knew what a good 9-5 auto was like 

So, progress of sorts, could still be:  solenoid / TCU / old ATF

If I do the pressure test will that help in diagnosis ?

[Audax]

This sounds like a failed solenoid, however any of the other problems will need to be sorted before you take it apart to replace the solenoid (assuming it is dead). I would suggest cutting losses here and get a replacement box unless you really enjoy the fixing part.

[carrera]

I had a chat with my local Saab specialist today.

TCU's from the 9-3 cannot be reprogrammed to the 9-5, different bus apparently. The guy there remembered one car with the same symptoms and a TCU swap cleared it.

I'm progressing on the diagnostic front, before potentially spending cash. I have tested the thermistor for the transmission fluid temperature sensor as it appears that there is an interaction between the SLT line pressure reading, the temperature sensor and the behaviour of the TCU. It makes sense to me as the pressure of the ATF will reduce as temperatures rise, other things being equal.

I have a reading from the TCU connection and 14 pin block that says 6140 ohms. WIS says that at 20 degrees that should be 900 ohms and at freezing it should be 2000 ohms. A bit of graphing and interpolation and at 10 degrees I reckon that should be 1400 ohms. So the temp sender looks dodgy, which could throw the pressure readings out.

Biggest problem now is I cannot find the temp sender  WIS says it's underneath the box in one part, but I have followed the loom and the only connections are on the top, with what looks like two speed sensors. EPC only has the part listed for 1998-2001, part number 51 160 106. Is this a 4 speed / 5 speed difference I wonder if the sensor is integrated in somewhere else. There's a big multiplug that looks a candidate, but why integrate with another 10 or so connectors for the solenoids and how to replace it ?

Once this bit is finalised I'll do some ATF pressure readings as the final diagnostic




 

[Audax]

Biggest problem now is I cannot find the temp sender  WIS says it's underneath the box in one part, but I have followed the loom and the only connections are on the top, with what looks like two speed sensors. 

You certain on that? My copy of WIS says it's "mounted on the valve housing" although now clue as to where or which component it is.

[carrera]

I'm certain I'm confused 

Transmission / Automatic Transmission / Technical description / Transmission Fluid Temperature Sensor does say valve housing, 2002 model year

Transmission / Automatic Transmission / Wiring Diagram / TCM part 2 / Component 535 says on underside of gearbox , but the graphic does look like the valve housing.

It isn't a translation issue either. I just created a Swedish language user and the description in the wiring diagram section is the same in Swedish