Gearbox Valve Control Unit

[Guest Saint Billy]

Firstly, this is my first post and many thanks for the tips on here. Managed to sort out the dreaded faulty fan and save loads due to taking up advice on this forum. Also managed to get the Heater resistor pack from these people who saved me £10 from the normal price of £56 with really quick service, here is the link if anyone is interested, they seem to specialise in French and Italian cars. http://www.eurocarcare.net/

 

I have recently purchased a 2003 C5 2 Litre petrol auto. It has a fault with the auto that has been well documented on here, and the popular fix seems to be replacing the Gearbox valve control unit. I have tried to find out more info about this part on the web but cannot seem to find anything. I would be grateful if anyone could give me a heads up, such as: Is the part expensive? Is it a specialised job to fit it? does anyone know the part number? Where is it as I cannot see the part in the Haynes manual.

 

The problem is, from a cold start and after travelling a few hundred yards the auto changes gear but not smoothly and then a clunk followed by the service light coming on and then goes into limp mode. Turn engine off, service light goes out and once the engine/gearbox has warmed up it runs normally for the rest of the day.

 

I know this fault has been covered on here alot but there is not much info on the actual part if indeed it is the valve control unit.

 

Any info would be appreciated.

[Guest Saint Billy]

 

The problem is, from a cold start and after travelling a few hundred yards the auto changes gear but not smoothly and then a clunk followed by the service light coming on and then goes into limp mode. Turn engine off, service light goes out and once the engine/gearbox has warmed up it runs normally for the rest of the day.

 

I know this fault has been covered on here alot but there is not much info on the actual part if indeed it is the valve control unit.

 

Any info would be appreciated.

 

Anyone, anywhere!

[coastline taxis]

before you start changing bits on the box you should really get a diagnostic done on the box as it might be a very simple fix. Also it might pay you to pm cfryve on hear as he rebuilt a auto box last year and could give you some helpfull info

[Guest Saint Billy]

before you start changing bits on the box you should really get a diagnostic done on the box as it might be a very simple fix. Also it might pay you to pm cfryve on hear as he rebuilt a auto box last year and could give you some helpfull info

 

Thanks for the advise, yes I think a diagnostic is in order and fingers crossed it may show up a minor fault.

 

Just wondered if anyone else had a similar fault.

[Guest C5buff]

Hi, I had a similar problem, but my car is a diesel and its fitted with the AL4 box. Not sure what you have but if it is an AL4 then you can remove the valve block without taking the gearbox out of the car. It is mounted on the front of the box under a black cover held by four screws. You need to take the Battery off and its tray together with the engine air filter. Also take off the under tray. You will then have access to the said unit. Of course you will have to drain the oil out first. There are 8 valves on the block, two of which are the most likely to be the trouble, they are the two conveniently mounted at the top end of the assembly. They are to do with pressure regulation and lock up. The lock up one prevents torque slip I think on the two top gears, no doubt an economy measure. Because these two are busier than the rest they are more likely to fail, the others are more momentary in their use, only as the gears change. The cost of the solenoid valves is £40 odd each plus vat and delivery they cost me £100.96. The oil cost me £80 as I bought enough to do two drainouts because you cannot drain the torque converter which retains approx third of the box oil. So a second drainout after driving for a week does a better job of putting new oil in. I have had no further trouble with my gearbox.

This is a doable job but is NOT for the faint hearted. Be careful how you remove the detent spring nothing must move when you remove it. Similarly when you put it back make sure its jocky roller is properly seated exactly as it came off, again nothing must move. The solenoid valves can be obtained from JPAT their web address is www.jpat.co.uk. their part number is N221 35 03

Doing it the Citroen way they quoted me £96 diagnostic, £450 for the complete valve block assembly. Then of course the oil say £60, Labour guess £150, Then calibration as its a new unit and has to be integrated, together with software updates

Plus the governments cut at 20%. you will be lucky to get away with £800.

Look on the web for details of the box inards as I have lost my info so cannot point you. But you should be able to find an exploded drawing of the box and the said valve block showing the position of the valves in question.

Good luck

[Guest Saint Billy]

Hi, I had a similar problem, but my car is a diesel and its fitted with the AL4 box. Not sure what you have but if it is an AL4 then you can remove the valve block without taking the gearbox out of the car. It is mounted on the front of the box under a black cover held by four screws. You need to take the Battery off and its tray together with the engine air filter. Also take off the under tray. You will then have access to the said unit. Of course you will have to drain the oil out first. There are 8 valves on the block, two of which are the most likely to be the trouble, they are the two conveniently mounted at the top end of the assembly. They are to do with pressure regulation and lock up. The lock up one prevents torque slip I think on the two top gears, no doubt an economy measure. Because these two are busier than the rest they are more likely to fail, the others are more momentary in their use, only as the gears change. The cost of the solenoid valves is £40 odd each plus vat and delivery they cost me £100.96. The oil cost me £80 as I bought enough to do two drainouts because you cannot drain the torque converter which retains approx third of the box oil. So a second drainout after driving for a week does a better job of putting new oil in. I have had no further trouble with my gearbox.

This is a doable job but is NOT for the faint hearted. Be careful how you remove the detent spring nothing must move when you remove it. Similarly when you put it back make sure its jocky roller is properly seated exactly as it came off, again nothing must move. The solenoid valves can be obtained from JPAT their web address is www.jpat.co.uk. their part number is N221 35 03

Doing it the Citroen way they quoted me £96 diagnostic, £450 for the complete valve block assembly. Then of course the oil say £60, Labour guess £150, Then calibration as its a new unit and has to be integrated, together with software updates

Plus the governments cut at 20%. you will be lucky to get away with £800.

Look on the web for details of the box inards as I have lost my info so cannot point you. But you should be able to find an exploded drawing of the box and the said valve block showing the position of the valves in question.

Good luck

 

Wow, thanks for that.

 

Yes I have the AL4 box as well.

 

I will have a diagnostic done to confirm that this is the problem although I suspect it is, but I think the repair is beyond me so I will probably get the parts from Jpat and pay a mechanic to do it.

 

Thanks once, really really helpful.

[Guest C5buff]

Here are some links to show the valve block with the cover off. Also a close up of the jocky roller. That quadrant which the roller is engaged in is what must not move when removing and replaceing the spring. The picture of the valve positions shows the top two which are the pressure and lockup regulation. They can be removed without removing the umbilical electrical connection to the block as it is just long enough to angle the block out to get access to them.

 

http://farm6.static.flickr.com/5057/5390157739_5b068e2007_b.jpg

 

http://farm6.static.flickr.com/5057/5390160147_a7057a94c9_b.jpg

 

http://farm6.static.flickr.com/5138/5390256177_8cfe68a77a_o.jpg

[Guest Saint Billy]

Here are some links to show the valve block with the cover off. Also a close up of the jocky roller. That quadrant which the roller is engaged in is what must not move when removing and replaceing the spring. The picture of the valve positions shows the top two which are the pressure and lockup regulation. They can be removed without removing the umbilical electrical connection to the block as it is just long enough to angle the block out to get access to them.

 

http://farm6.static.flickr.com/5057/5390157739_5b068e2007_b.jpg

 

http://farm6.static.flickr.com/5057/5390160147_a7057a94c9_b.jpg

 

http://farm6.static.flickr.com/5138/5390256177_8cfe68a77a_o.jpg

 

Thanks very much for the pics. Shows me what I am dealing with, gulp!

[Guest Saint Billy]

Update on this.

 

The car has been in the garage to have the problem diagnosed but various diagnostics have not shown the fault up. Also a specific test was done via software to check the solenoids and if they are working properly and no fault was found again.

 

The garage then referred the problem to an autobox specialist who has said that the autobox needs rebuilding as there is a certain amount of clutch slip which indicates that various clutches need replacing the cost of which being £1040 for autobox rebuild plus a days labour for taking the gearbox out and putting it back in again plus VAT on all of this. That all comes to more than I paid for the car a month ago.

 

Back to the problem, when the car is playing up when cold as described in my first post, there is a little bit of slippage initially but this clears with the other gearbox faults once the gearbox has warmed up and then drives normally.

 

My dilema now is,

 

1. Do I ignore the autobox specialist and take the chance and have the two solenoids replaced as per C5buff's post above in the hope that this will fix the problem as this seems to be the common fix for the typical problem I am having?

 

2. Do I have the autobox rebuilt as recommended by the autobox specialist? (probably out of the question due to cost).

 

3. Do I look for a recon autobox?

 

4. Do I dump the car and say goodbye to the best part of £1000?

 

Help guys!!!

[Guest C5buff]

Hi,

Well you could just drain the oil out and examine it. If the clutches are worn then the debris of them will be in the oil. If it is black in colour and smelling burnt this would also indicate that the box is in a bad way. If either or both is true then the box may well be in need of overhaul.

If the oil has no debris in it and does not look black and smell but has normal discolouration due to use, that is a good sign. You say that when it is warmed up it then works ok. I take that to mean there is no excessive noise and that the gear changes are smooth. That brisk acceleration gives normal performance for the car, with the gears changing normally. If this is the case then the box would seem to be ok with correct oil level (something that its fussy about so needs to be spot on, has this been checked?). I would at least change the oil, run for a week reassess, and if still the same, then drain out again and change the two valves.

N/B If you have older type valves then a software update may be necessary to make the newer type valve work the box better.

In any case I don't think you can still get the older type. It may work ok without the update but be mindful of it.

Best of luck.

[Guest Saint Billy]

Hi,

Well you could just drain the oil out and examine it. If the clutches are worn then the debris of them will be in the oil. If it is black in colour and smelling burnt this would also indicate that the box is in a bad way. If either or both is true then the box may well be in need of overhaul.

If the oil has no debris in it and does not look black and smell but has normal discolouration due to use, that is a good sign. You say that when it is warmed up it then works ok. I take that to mean there is no excessive noise and that the gear changes are smooth. That brisk acceleration gives normal performance for the car, with the gears changing normally. If this is the case then the box would seem to be ok with correct oil level (something that its fussy about so needs to be spot on has this been checked?). I would at least change the oil, run for a week reassess, and if still the same, then drain out again and change the two valves.

Best of luck.

 

Hi, thanks so much for that, your advise makes total sense. Yes when warmed up the gear changes are smooth and the fault goes away. My take on it being a novice is that if it was clutches slipping the problem would be there all the time.

 

In any case I am going to go the route of your suggestion and see what happens. I really like the car so I dont want to give up on it yet.

 

I will keep you posted.

 

Thanks again.

[Guest Saint Billy]

Just an update.

 

Had the gearbox oil changed, and if anything the symptoms are worse and the car is taking longer to clear the fault before running normal for the rest of the day.

 

The mechanic said that the oil was black and smelly but he did not check for fibres in the oil.

 

My problem is, why is the fault worse after an oil change? is it because not enough oil has been returned to the gearbox?

 

I am tempted to just get the two solenoids and go for it, as my gut feeling is that if the gearbox performs normally after warming up how can it be clutches etc.

 

If anyone here lives in the Ashford/Romney Kent area capable of replacing the solenoids and doing another oil change drop me a message. I will obviously get the parts and pay for the labour and supply numerous cups of tea/coffee and sarnies.

 

Cheers

[coastline taxis]

Who did your oil change for you. To do the oil change properley you need the oil at 80c and you have to use proper esso oil and not the bog standard automatic fluid from the discount store. Ive got a feeling your mechanic has drained it and fill it with atf fluid if so you need to get it out. Take it to the dealers and only the dealers for that. We get town center citroen to do ours about a hundred quid

[Guest Saint Billy]

Who did your oil change for you. To do the oil change properley you need the oil at 80c and you have to use proper esso oil and not the bog standard automatic fluid from the discount store. Ive got a feeling your mechanic has drained it and fill it with atf fluid if so you need to get it out. Take it to the dealers and only the dealers for that. We get town center citroen to do ours about a hundred quid

 

Hi Coastline, the garage that did the oil change are an established Citroen only garage and he did mention that he used the Citreon recommended oil and that there is a right way and a wrong way of doing it. Although I recon he used the correct oil I am wondering if the correct amount was used. He did tell me to go back after a week or so and have it changed again but at over a £100 a go this is starting to get expensive and I have not even had the solenoid valves replaced yet.

 

I dont want to take it back to the same garage as they seem convinced that it is not a solenoid valve problem and are reluctant to do the job and they keep leaning towards a gearbox rebuild at over £1500 which they cannot do themselves. They ofcourse might be right but I just have this gut feeling that it is not as bad as they portray due to the fact that when the gearbox is warmed up and after a few resets the gearbox functions as new. I do not have money to throw away and I broke the bank to buy this car a little over a month ago (£900) and despite the fact that at the moment it is causing grief, I really do like the car and dont want to give up on it yet.

[Guest C5buff]

Hi

The oil change should have had either a good effect or no effect. It is the only thing that has been done so I agree with coastline. Is the oil of correct type and is it set at the correct level. This box requires an accurate level.

( go for a drive first to ensure oil temp is correct ). Then it is properly obtained by putting in a slight overfill and with the vehicle on level ground hand brake on and in Park and with the engine running and oil at correct temperature the box oil drain plug should be removed and the oil allowed to drain out. At first because of the overfill it will gush out. Then it should reduce to a drip drip, at this point the level is correct so put the drain plug back in. The reason all of the oil does not drain out is because there is a tube up inside which when the level falls to the top of the tube, then drips. Thus setting the level accurately.

The correct oil is ESSO ATF 4HP20AL4. This should be listed on your bill from the garage. If they have put in something else they had better be sure it is an equivalent. So I would go back and question them about the oil and the method of setting the level. If they say it pretty well as above then they did it right. Ask them to re check the level again.

NB to drain the old oil that is trapped by the tube a (I think 8mil) allen key is required to reach up inside the tube so it can also be removed. Check they did that bit as well. Some older boxes may have a different tube arrangement but the procedure is similar.

[Guest Saint Billy]

Hi

The oil change should have had either a good effect or no effect. It is the only thing that has been done so I agree with coastline. Is the oil of correct type and is it set at the correct level. This box requires an accurate level.

( go for a drive first to ensure oil temp is correct ). Then it is properly obtained by putting in a slight overfill and with the vehicle on level ground hand brake on and in Park and with the engine running and oil at correct temperature the box oil drain plug should be removed and the oil allowed to drain out. At first because of the overfill it will gush out. Then it should reduce to a drip drip, at this point the level is correct so put the drain plug back in. The reason all of the oil does not drain out is because there is a tube up inside which when the level falls to the top of the tube, then drips. Thus setting the level accurately.

The correct oil is ESSO ATF 4HP20AL4. This should be listed on your bill from the garage. If they have put in something else they had better be sure it is an equivalent. So I would go back and question them about the oil and the method of setting the level. If they say it pretty well as above then they did it right. Ask them to re check the level again.

NB to drain the old oil that is trapped by the tube a (I think 8mil) allen key is required to reach up inside the tube so it can also be removed. Check they did that bit as well. Some older boxes may have a different tube arrangement but the procedure is similar.

 

Thanks again CBbuff.

 

Well thats two of you in agreement. I must admit that I did not expect the fault to be worse after the oil change, so it looks that you and coastline have a point. Ah well, back to the garage.

[Guest C5buff]

Hi Billy

I have had further thoughts about it all. Decided to invent a story to fit the symptoms to see if it makes sense, and it does. Lets assume the garage did the correct oil and that the level is correct.

The two regulating valves are weak lets say only 70% effective due to internal breakdown of their electrical windings. When the oil is cold it is thicker and this causes a high oil pressure which the weak valves cannot cope with giving rise to the problems. After a short while and due to friction the oil warms up and becomes thinner with consequent less pressure which the valves can now control, which is why the box suddenly behaves itself. You have fitted new oil so the valves will have the same trouble with the cold and cannot regulate the pressure. The difference now is that the box takes longer to warm up. This is because the friction is now less due to much better lubrication so it takes longer to warm up. I said in my previous post that an oil change should have either a good effect or no effect. Well what it happening is a good effect and fits the story. It also confirms in my mind that the valves are the problem and your gut feeling about it. The diagnostics did not show the fault because they did not conduct the test under fault conditions ie the box was already warmed up.

Further more the tests and the testers are not intuitive as we are, who can see the wood from the trees. In the end to test this theory you have to change the valves and oil again. As you are not willing to fit a recon box going this way gives a good chance of success. I hope I am right for your sake as I am mindful of what its costing you.

How does that grab you Billy.?

[coastline taxis]

Tha sounds very plausable that

[Guest Saint Billy]

Hi Billy

I have had further thoughts about it all. Decided to invent a story to fit the symptoms to see if it makes sense, and it does. Lets assume the garage did the correct oil and that the level is correct.

The two regulating valves are weak lets say only 70% effective due to internal breakdown of their electrical windings. When the oil is cold it is thicker and this causes a high oil pressure which the weak valves cannot cope with giving rise to the problems. After a short while and due to friction the oil warms up and becomes thinner with consequent less pressure which the valves can now control, which is why the box suddenly behaves itself. You have fitted new oil so the valves will have the same trouble with the cold and cannot regulate the pressure. The difference now is that the box takes longer to warm up. This is because the friction is now less due to much better lubrication so it takes longer to warm up. I said in my previous post that an oil change should have either a good effect or no effect. Well what it happening is a good effect and fits the story. It also confirms in my mind that the valves are the problem and your gut feeling about it. The diagnostics did not show the fault because they did not conduct the test under fault conditions ie the box was already warmed up.

Further more the tests and the testers are not intuitive as we are, who can see the wood from the trees. In the end to test this theory you have to change the valves and oil again. As you are not willing to fit a recon box going this way gives a good chance of success. I hope I am right for your sake as I am mindful of what its costing you.

How does that grab you Billy.?

 

Hi C5Buff, Yep I am with you on that 100% and it is the route I would prefer to go down. Once again I am extremely grateful for your helpful comments and that of Streamline and others that have posted. I have no option as I cannot afford a recon or rebuilt box so I will be ordering the valves in the next few days and will let you know how it goes. Thanks again guys

[Guest cfryve]

Hi Billy, sorry for not answering your pm but I'm having trouble with the site.

How's the job going? I would endorse everything that the buff and coastline are saying, I was lucky and picked up a whole valve block assembly on ebay brand new and that solved my problems. Well sort of solved, still get a bit of clutch slip on heavy acceleration and no kick down but I can live with that. Changing the oil and checking the level is always fun but then I do have a lift in my garage.

Regards

[mlkey]

The oil is easy to change, but as stated, great care should be taken to get the correct level at the correct temperature. The AL4 box is supposed to have its level checked when the oil is between 58 and 68c. For this, I purchased a little temperature probe from Maplins. Make sure the car is level, the drain plug has two pieces, undo the larger outer one to drain. It will come out with the level tube. When ready to fill, refit the drain plug and tighten. Then, after removing any dirt from around the square drive filler on the top, remove it. You will need to add about 3 litres of the AL4, available in 2L bottles from Citroen for around £20. Refit the top, run the engine. Put your foot on the brakes and rev the engine to about 1500 RPM in each gear for about 15 seconds to ensure the converter is nice and full. You are now ready to check the level. Put the transmission back in park and leave the engine idling. Now remove the smaller centre nut from the drain plug.

 

You should get an initial flow or gush of oil, which will reduce to a drip after a minute or so. At this point, the level is correct, and you can refit the drain plug. If when you remove the inner drain plug to check the level, the oil only drips or nothing comes out, you should refit the level plug, stop the engine and add another 0.5 litre. You then need to repeat the above process before rechecking the level.

 

All the above said and done.. I had a similar issue to you on a C5 with only 31k miles on the clock. It was hanging onto the gears too much when cold, and shifting harshly. I decided to change the oil, and after one change, it has significantly improved the gearshifts. The old oil was pretty black, but did not seem to smell much different to the new oil. As previously mentioned, you need to flush auto boxes twice, or even three times as each time you empty it, you are only getting about half of the oil out. I shall change mine again next week.

 

Hope this helps, and would be interested in the outcome of your issues Billy.

[Guest cfryve]

Just a bit more to add,

When i was considering changing the solenoids i was warned by an auto specialist about this. It's not just the solenoids you've got to replace, you should also put in over size spool valves. This is because the solenoid is constantly moving the spool and it gradually wears the bore and oil can then leak past. I think that this is why some of the kits advertisied actually sell reaming tools to increase the bore before you fit the new spool. That's why I went for the whole new block. Incidentally the AL4 is fitted to several vehicles so you might pick up a good one at a breakers/ebay.

Regards

[Guest C5buff]

With regard to the spool wear, I would think this is a less likely fault because Billy says that the box behaves normally when warmed up. If the spools were showing excessive wear then he would have trouble all the time. Of course a 100% job is better than doing just a fix, but as there are cost limits in this case, doing the minimum necessary seems to be what’s required. If he gets a complete block from a scrappy and assuming it’s a better one than he has already, it may (or may not) still require a visit to Citroens to set it up to work properly with a different box. More cost!

[Guest Saint Billy]

Thanks guys above for the really useful advice and comments above, I really do appreciate it.

 

The update is that I have had problems getting someone to look at this, most seem to shake their head when I mention auto box problems.

 

Pete Simpson at Maidstone who has been recommended on here several times is going to look at it in the first week of April. I could not book it in any sooner as his garage is really busy.

 

The car is now running worse and the fault is appearing now every 10 minutes or so, I suspect this is because it has only had one gearbox oil change and the level is on the low side, so I am hardly using it which is a real pain. I may have a go at changing it myself in the meantime as per the great instructions above.

 

If the worse comes to the worse, I have noticed an AL4 auto box for sell from an accident damaged Peugeot 207 with only 3,577 miles on it with a 90 days guarantee for £500. As this is an AL4 is this likely to fit or are there varying types of AL4 box? A tuffy I know but someone may well know.

 

Cheers once again guys