Noisy tappets - how bad can it be ?

[carrera]

I have just taken sympathy on another 9-5, this time a 2006 Dame Edna Aero saloon.

I bought it with "noisy tappets". A quick inspection showed the oil was low, 1 3/4 litres later it was above the minimum mark 

I have left it ticking over to get up to temperature, in the hope that the tappets would pressurise up and silence themselves. 15 minutes on tickover and numbers 3 and 4 inlet are still noisy, like an old diesel, 3 and 4 exhaust are almost quiet.

If I take the engine to 2000 rpm they become much quieter, clattering resuming as revs drop below ~ 1200 back to idle. I am assuming if they were going to pump up they would have by now.

Number 1 plug looks good, 3 and 4 look oily, and the exhaust is a bit smoky, oil rather than steam I think

My plan of attack is to remove the valve cover to have a look, check the chain tensioner extension and drop the sump to have a look at the bottom end even though I understand the sludge issue was solved on the DE's ?

Any other suggestions ?

[sgould]

The sludge issue was solved on the Dame Ednas by design and maintenance.  Sludge can still occur if the wrong oil is used.

Sludge on the early cars was caused by a combination of rubber particles from decaying rubber pipes in the breather system and semi-synthetic engine oil breaking down in the sump from the extreme heat from the adjacent exhaust catalytic converters.  From 2004 the breather pipes were mostly changed to hard plastic and all cars had fully synthetic oil specified. So the later cars still had a sludge risk if an owner used cheaper semi synthetic oil.

[carrera]

Thanks for that.

I have been doing more reading around as well, so it would seem that a sump drop to look at the pick up would be the best idea. I started her again this morning, seemed a little quieter, especially at 1500 rpm, but the tap returns when going back to idle and I noticed quite clear blue smoke from the exhaust, much more than yesterday, which may be reflective is that there is more oil to go at. I would seem a compression check is in order.

Once the pick up has been looked at, I may look at putting a bit of ATF in the oil to clean out any bits stuck in the hydraulic tappets. Any views / experience of this approach ?

[phoenix]

If it doesn't need to drive anywhere soon, chuck a can of engine flush in there. Run it up to temp a few times idling over the next week or so.

[carrera]

It isn't going anywhere soon, so I can certainly do that.

With the lack of oil and blue smoke I thought a compression test would be useful, in case the rings / bores had been destroyed , the results from the jury are in, left to right is cylinders 1-4, the engine had been running for 5 minutes to get a bit of heat in, these results were after 6 crank rotations, but after 4 the readings didn't really increase

14.0 - 15.2 - 14.4 - 15.0

I cannot find a specification in WIS for this which is a bit surprising, but these numbers look plenty good enough to me.

As before the plugs were oily, so suspecting failed seals on the turbo I separated the intercooler to intake pipe expecting to find that oily. It wasn't, so that's that theory out of the window. 

I noticed that the cam cover has been removed, the tell sale sign being grease that has been used to seal the gasket.  I was about to whip that off to inspect the cam / tappets, but I discovered I didn't have the right torx bits with me, so that's for another day.

Before I do the sump drop I am going to check the oil pressure. To save removing the starter / oil pressure switch I have decided to make up an adapter from a flange bolt on the oil filter housing as special too 83 95 576 doesn't seem to be available. The plan is to get an m14 x 1.5 flange bolt and drill a hole in the top and then tap a thread for one of my oil pressure gauge adapters. 

There's something wrong with the PCV system too. I thought this would have the latest design, and it has a connection on the oil filler tube, but nothing is connected there, and the vent pipe from the throttle body goes to the right and then down to the oil separator I think. The one way valve in that run is also broken off from the feed pipe so it's actually an open vent to atmosphere. I haven't noticed any smoke from either of these open ports so it doesn't look like there is a crankcase pressure problem.

[fka]

Recent compression test on mine came back with 210psi on all 4, which the Saab specialist/ master tech told me was very good so you're pretty much on the money..

Latest PCV doesn't have a connection to the oil filler, the tit is still there but its a blank.

[sgould]

If you poke a wire up the spigot on the oil filler you should find it's blanked off at the end.  The branch was only used on the 1998-2003 cars for the final upgrade to the PCV system.

[carrera]

Thanks guys, good to know the compressions are fine and I don't have a Frankenstein PCV system

I poked a screwdriver up the spigot and it is blanked off. Curious that the final evolution of the PCV system on the early cars used a modified oil filler tube, but Saab decided not to use that on the later cars. I can only assume it was of nil or marginal effect.

Thanks for filling in a bit of my knowledge gap on the development of the PCV system, I realise I am doing a 15 year catch up, not having lived through the changes with my blue car 

[fka]

I can't find the webpage now but I read somewhere that the PCV got to revision #10 or something. #6 being the one that was/is sold as the "updated PCV"

[carrera]

I managed to get time to take the cam cover off this morning.

Apart from grunge between the spark plug holes the cams etc look in very good condition, with no signs of sludge, full size photos below.

Then I turned the engine over getting each lobe in line with the valve stem and tested each of the tappets

Cylinders 1,2 and 3 were all hard

On cylinder 4 the left hand intake was very soft, the right hand intake soft

The left hand exhaust was also soft while the right hand exhaust was hard.

So, three soft tappets on number 4, which I believes means there is no /little oil in them.

I could go down the ATF route to try and clean them, but am wondering if they are blocked will the detergent actually remove the debris ? Perhaps it is just better to remove the faulty ones, clean them soak them overnight in oil and them refit ?

I haven't looked at WIS yet, but I am thinking about taking the following route:

Tiewrap the chain to the camshafts in a number of positions
Remove the chain tensioner
Remove the camshaft caps
Lift the camshaft out of the way to allow removal of the offending tappets

So in other words, I think this can be done without even removing the camshaft gear from the cam. Then again if that is a trivial job (simple bolt and keyway perhaps so no chance of losing cam timing) then I can just whip the gear off

Does that make sense

Here's the photos, again, let me know if you see anything that doesn't look right

[sgould]

If you tie the chain to the sprockets, it will keep the timing at that end, but once you remove the camshaft supports the chain could drop an you could lose the timing of the chain comes off the crankshaft. Some sort of wedge on the guides may hold it.

[phoenix]

I think the safest thing is to lock the flywheel at TDC. There are corresponding marks on the camshafts.

[carrera]

I have put the pulley to TDC and seen the alignment marks on the camshaft.

All the inlet caps are off and my hope was that there would be sufficient clearance to allow the cam to be moved with the gear still on the camshaft. It seems that this is not possible, so have come indoors to see how to remove the cam gear nut, which is when I saw these posts.

I didn't see anything in WIS before I started the job, so I'll need to have a bit more of a search, unless you already know

Found it:

Under cylinder head, removal in situ.

There is a hex on the other end of the camshaft, used to hold the cam in place. They are to be tightened to 63NM..... which seems a bit tight with spanners as my first attempt to remove didn't work, so I came in again to see just how tight it should be.

There are also instructions to use a rubber band to hold the chain guides together 

[carrera]

Success 

I had another look and realised removal of the half circle bung would mean a socket could go on, necessary for torqueing it up again of course.

With a long breaker bar (for reach, not force) I was then able to release the bolt. The cam is located by a cutout, so cannot be be assembled incorrectly.

I suspended the gear using a bar across the head along the cut out. The gear is not so far out of position so that will be fine as I am only doing one cam at a time to minimise disruption

Now for tappet removal and inspection

[carrera]

Inlet tappets on numbers 3 and 4 have been removed, bled of oil and primed 3 times each until no more air can be expelled. They still seem to be soft, whereas the tappets on 1 and 2 are still solid. I hope that they will pump up when the engine runs.

Making sure that the caps and bolts go back as before I checked that the cutout in the cap and the corresponding groove in the bolt are in the row nearest the spark plug position. They all seemed to be correct, but I was worried because the markings on the caps were not consistent and the cap nearest the gear does not have the grooved bolt. I checked this was correct with EPC.

Onto the exhaust side. I wish I knew what the letters on the bearing caps meant.