Changing Valve Stem Oil Seals on TU1 engine.

alanshep · Post by **alanshep** » 27 Jul 2006, 19:43

Hello.

Further to a recent post about compression test results on a TU1 engine I'm looking at changing the valve stem oil seals on this engine.

I wondered if anybody has done this job successfully without removing the cylinder head?

I was thinking of using a tool similar to that in this link:-

http://www.machinemart.co.uk/product.asp?p=040211452

I know I'll need to stop the valves from moving and one way of doing this is to pressurise the cylinder with compressed air via the spark plug hole. Another suggestion I've heard is to feed nylon string /rope into the cylinder to take up the volume.

Just interested to know what people think really.

Thanks.

Alan

slim123 · Post by **slim123** » 27 Jul 2006, 20:38

My opinion, for what it's worth.

To use this tool, you will need to remove the camshaft, so much to take off, you'd be just as well removing the head and doing the job once and right.

If the valve stem seals need doing then I guess that the car has done a few miles, so remove the head, clean, decoke and lap the valves into the seats, this way you know that this job will not be needed again for a long while.

Well thats my opinion!! others may differ.

Regards
Slim.

AndersDK · Post by **AndersDK** » 27 Jul 2006, 22:25

Slim -

The TU1 engine has the good old fashion rocker arms

You "only" need to remove the rocker assembly - i.e. rockershaft with all the bits attached. Then you can reach down and compress the valve springs.

http://www.citroen-pr.net/catalogues/il ... 120050.gif
http://www.citroen-pr.net/catalogues/il ... 230050.gif
http://www.citroen-pr.net/catalogues/il ... 243050.gif

Still the job will provide many hours of entertainment for the patient DIY mechanic.

citronut · Post by **citronut** » 27 Jul 2006, 22:53

once you have removed the rocker gear the head is all but completly off as the rocker gear fixing bolts are the head bolts,also that tool needs the cam shaft in place as it hooks under it,why are you replacing the valve stem seals as this will not improve you compresion as the compresion takes place below the valves and the stem seals are above the valves
regards malcolm

alanshep · Post by **alanshep** » 27 Jul 2006, 23:46

Thanks for the response.

The compression test I did gave good results but the engine is smoking a bit. I wanted to change the valve stem oil seals to see if it cured it.

I have removed cylinder heads before but the thing that puts me off with this engine is the 'wet liner' concept. The Haynes manual suggests that you have to be very careful not to disturb the bottom cylinder seals.

I was thinking I would try first to do it without removing the head. As Anders says, I think it might provide some hours of "entertainment". If I struggle badly then it will have to be head off.

For the record, the engine has done about 85000 miles.

Thanks again.

Alan

slim123 · Post by **slim123** » 28 Jul 2006, 08:18

Sorry didn't read the post right, you could get away with leaving the cam in, but on this engine I would still go for the head off, cos they are sooo easy to do and, It's gonna need doing one day, cos sure as eggs is eggs, it's going to spring an oil leak, right above the alternator.

They all do eventually!!!

Regards
Slim

alan s · Post by **alan s** » 28 Jul 2006, 08:54

The case against doing the beheading job of course is the extra cost of a gasket set, if the stretch type headbolts, a new set of headbolts as well as a new exhaust flange kit, then the risk of neding the liner seals if things don't quite go as planned.
If it was an expensive car that you intended keeping for many a long day, then I'd probably go with the head off bit too but if it's mainly a case of just seeing if it still smokes after the seals are replaced, then it's almost self defeating going the whole hog first up.
Little risk moneywise by taking the head left on option and if it works, all well and good; if it doesn't then decide if you want to go the extra would be my way of looking at it.

Alan S

citronut · Post by **citronut** » 28 Jul 2006, 09:13

these engines dont usualy suffer with stem seal probs unlike the F***ds and the Va****lls,and just because the copresions where good it could still be the oil control rings,and if you do remove the head all you must do is pivot it diagonaly to break the joint then DO NOT rotate the crank whilst the head is off,also bolt a matal bar diagonaly across the top of the block to stop the liners lifting
regards malcolm

AndersDK · Post by **AndersDK** » 28 Jul 2006, 10:55

Haynes earlier manual (grey/brown issue) on BX has a very good description on dismantling/ overhauling a K1G engine - which is a TU3 engine (1.36L).
This is in essence the same engine as the later TU1 (1.124L).
I do believe that the first Haynes manuals on the Citroen AX and Peugeot 205 with this engine type will be as good on this description as well.

There are indeed large riscs that overhauling this TU1 engine would end up in success. Its a nice little engine - not complicated - and very basic in construction. Parts are readily availabe in huge counts from Breakers, Aftermarket dealers, Peugeot stealers & Citroen stealers.

alan s · Post by **alan s** » 28 Jul 2006, 12:04

So basically, the logic is that you spend a reasonable amount taking the head off to see if it still burns oil, do valves, seals gaskets etc and if it does then still burn oil, you then take it off again to do rings and possibly liners instead of doing just a few quid on a valve stem job to test the theory?

Lost me.

Alan S

AndersDK · Post by **AndersDK** » 28 Jul 2006, 13:05

What you dont know AlanS - is that alanshep in another post submitted the mileage of this little motor.
Its not that high that I would go for the piston rings. I would certainly try the valve stem seals.

One last test would be to check the blow-by from the sump. This will be greatly increased if the piston rings were worn. And the oil scraper rings alone will not wear as single items.

alan s · Post by **alan s** » 28 Jul 2006, 21:28

AndersDK wrote:

What you dont know AlanS - is that alanshep in another post submitted the mileage of this little motor.
Its not that high that I would go for the piston rings. I would certainly try the valve stem seals.

One last test would be to check the blow-by from the sump. This will be greatly increased if the piston rings were worn. And the oil scraper rings alone will not wear as single items.

Which in my opinion, is why it would be more prudent to take the option that requires the least amount of dismantling of the engine as the first step.
If the seals didn't fix it, then move on to removing the head etc and look for things like glazed bores etc.
Depending on the type of oil that has been used, I recently found an Mi16 that was dismantled at 85K klms due to badly leaking valve stem oil seals and unfortunately, the engine now only has 118K klms and they are still trying to sort the problems created when they pulled the head to rectify the problem. The job incidentally was done by a professional engine rebuilder not a DIYer but a DIYer has managed to be volunteered to try to sort it all.
I won't mention any names, but his first name starts with "A"

Alan S

howzat · Post by **howzat** » 31 Jul 2006, 22:12

I have found that Citroen valve stem seals do become hardened when a vehicle becomes older, leading to excess smoke and MOT failure. This can occur at quite moderate mileages. Replacing the seals effected a complete cure.

Howzat

Post by **Peter.N.** » 02 Aug 2006, 12:22

If its the seals that are causing the problem, it will usually smoke when started after its been standing and then clear, if its smoking all the time, especially after a long descent, its more likely piston/bore wear.

alanshep · Post by **alanshep** » 28 Aug 2006, 10:01

Hello again.

I decided I would have a go at trying to do this without removing the head - nothing to loose but the time involved.

I made a simple tool at work similar to the one in my original post. I fastened a piece of chain between the rocker cover studs and 'hooked' under this to lever against. Plenty of rope fed into the cylinder and compressed seems to stop the valve moving.

Had a go with it yesterday and quite easily managed to remove the collets on one valve. So far so good...but the fairly obvious problem is that with collets removed the spring just expands up to meet the rocker arm and is effectively still 'wedged' in. The valve stem (in the fully closed position) ensures that there is no room for manoeuvre.

So this idea just won't work unless it's possible to remove the rocker shaft and rocker arms with the head on. On this engine the rocker shaft is supprted in brackets held down by the cylinder head bolts so just lifting it off is not an option. However after reading the Haynes manual I am wondering if it is possible to 'pull' this shaft out from one side of the engine.

Does anybody know if this is possible?

Sorry if this is getting a bit obscure - I'd just throw in the towel and take the head off apart from the fact that tools like this:-

http://cgi.ebay.co.uk/3789-CITROEN-VALV ... dZViewItem

exist. I've never see one 'in the flesh' but it looks like it fastens between the rocker cover studs and allows the valve springs to be compressed. This implies to me that this job should be possible with the head on (otherwise why would this tool exist?).

Any thoughts / comments appreciated.

Thanks

Alan

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Changing Valve Stem Oil Seals on TU1 engine.

Changing Valve Stem Oil Seals on TU1 engine.

Valve stem seals.