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Timing Chain - Roll In

19K views 111 replies 19 participants last post by  fastcorner 
#1 ·
Hi All

Just thought I'd share our latest repair experience with you. A bit long I'm afraid.

With 160,000 miles on my 2000 2.0 LPT Auto estate it was time to investigate all the rattling from the engine. With the rocker cover off it was clear that the timing chain was seriously slack and in danger of jumping a tooth on one of the cam sprockets. With the cost of a proper timing and balance chain job more than the car's worth I decided to try a roll in chain to give me some more time in my favourite ever car.

Step 1. Jack up front right hand side, remove wheel, put in axle stand and remove jack.

Step 2. Remove engine lower cover and support engine weight with a piece of wood on the vehicle jack. Remove the righthand engine top mount and yoke.

Step 3. Remove DIC, Camcover and the air pipe at the banjo connector on the intercooler pipe. this just gives you more room to work.

Step 4. Relieve the tension on the serpentine belt by inserting a breaker bar into the square hole on the belt tensioner, pulling it forward and putting an allen key into the hole on the side of the tensioner to lock it in place. Take out the breaker bar.

Step 5. Remove the sparkplugs and cover the holes with a clean rag. Using a 27mm socket on the crank pulley turn the engine to TDC. There are marks on the timing cover, the crank pulley and both camshafts. Make sure all are lined up as shown in the Haynes manual.

Step 6. Stuff all openings into the timing case with clean rags cos if anything drops in its engine out time!

Step 7. Remove the 12mm bolt from the timing chain tensioner and carefully remove and the spring and pushrod. Remove the timing chain tensioner by using a 27mm thin walled socket. On my car I had to partially undo the top idler pully for the serpentine belt as the bolt fouled the socket. Check the tensioner and measure how far it has extended. On mine this was 20mm, way beyond the max allowed showing how far the chain had stretched, or the guides/pulleys had worn. In fact the tensioner was at the end of its travel. Clean up the tensioner and fit a new seal but leave the tensioner out of the engine.

Step 8. Using a dremel or similar tool grind down the heads on one of the chain links on the inlet cam. Using a chain breaker its then easy to push the link out. I cable tied the chain to the pully so it couldn't slip off.

Step 9. I used a master link chain which is similar to a split link except the master link is rivetted in place. You do need a chain rivetter for this type. Connect the new chain to the old using the old link and side plate. This is really important because if you use just the link it can slide out and split the chain in the engine or jam.

Step 10. In theory after cutting the cable ties you hold the chain on the inlet cam and very careflly turn the crank pulley clockwise to wind the new chain in as you pull the old one out. We found the cams jump due to pressure from the valve springs and ended up losing the engine timing. Solution was to take out the cams!. This is dead easy only about 20minutes but you must remove the sprockets or the cams won't come out. By doing this the valves cannot hit the pistons and it is then dead easy to roll the chain in as its only going around the crank sprocket. It is critical to set the crank pulley TDC once the chain is in. Make sure you keep the chain tight.

step 11. Refit the cams making sure they are at TDC. Some of the cam bolts have an oilway in them, make sure they go back in the correct holes. Note that if you have a vacuum pump on the exhaust cam the drive tongue is offset so you need to get it right or the cam will jam. Just ask how we found this out!

Step 12. Refit Sprockets and refit the chain. Using the rivetter fit a new link and rivet the ends over. DO NOT TURN THE ENGINE.

Step 13. Reset the timing chain tensioner to minimum and refit it. Refit the pushrod, spring and hollow bolt to the tensioner.

Step 14. Carefully turn the engine 2 revolutions clockwise using the 27mm socket on the crank pulley. Go slow, if you feel resistance make sure the timing hasn't slipped. On mine, once I'd refitted the tensioner everything was plain sailing. First off we turned the engine without the tensioner in. Big mistake had to reset the timing and could have damaged valves.

Step 15. Put everyting back and then time for a brew.

Last thoughts.

Was it worth it?

For me yes, the engine is quieter and the chain was shot. On an engine this age and at this mileage it was worth having a go.

Have the noises gone ?

No, they are not as bad and the harsh rattle has gone but the balance chain is also rattling but without removing the engine no chance to replace.

Costs ?

£40 chain, £35 rivetter, £10 bits and pieces.

Would I do it again?

Definitly not on a low mileage or more valuable car, too many things to go wrong and easy to mess up.
On a car where the repair is more than its worth, yes but I know how to do it now, yesterday was a real rollercoaster mainly focussed around why did I touch it !

How long to do ?

Took about 7 hours but we were learning as we went. I reckon I could do it in 3 hours now.

Hope you weren't too bored with this very long thread.

Cheers

Tony
 

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#2 ·
Well done Tony :cool:
 
#4 ·
was thinking about doing mine but its only done 90,000 miles ,and although it rattles "due to a very long time without a oil change"before i had it :roll:. when i took it to an independent saab repairer, he said he had heard them a lot worse than that ,and when i said about rolling one in ,he sniffed, and said not to bother ,as he had never had one snap ;)!!!!
 
#5 ·
Glad to hear yours isn't too bad. If that's the case I'd say leave it. Mine had been rattling for about 30,000 miles but had recently got much worse.
An easy check is to remove the tensioner, take out the small bolt in the end first, and measure how far it extends. This indicates the amount of wear/stretch of the chain. Mine was way beyond the design limits so the tensioner basically wasn't doing anything.
One of the problems with rolling in a chain is the old guides are still in there, as is the balance chain. On mine the sprockets weren't badly worn and I didn't think the chain would snap but the chain was so slack I was concerned it could jump a tooth and as the tensioner was at the end of its travel it could only get worse. See the first thumbnail for how bad it was!
The new chain is tight and the tensioner is actually working now. There is a very small hole in the tensioner body so when the engine is running the tensioner is actually pressurised by engine oil. If you do the job make sure this hole is clear.
I've done 200 miles since changing the chain and I have to say it seems to have bedded in. The engine is much quieter now, just whirs a bit with no bad rattles. Still early days yet.

One other thing is the fuel consumption has got better. A mixture of town and open road driving today has returned 34mpg, the best I ever had before was 31mpg. Maybe the cams are now closer to their design positions.

All the best.
 
#8 ·
This is what the whole lot brand spanky new looks like for those who've got lots of rattles and want to get rid of the whole gallery of noises.
 

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#10 ·
All it's cost so far was my dads sanity and my mechanic buddies patience, I've got a few more bits to do on it the whole kit was good value from genuine saab was great value and has all the bits needed, including a healthy amount of o-rings and seals. I would not have a clue how much it would cost from a dealer to get that work done but it would not be cheap. I'm finding lots of little bits to do that make sense to do whilst the engine is out which is adding up the cost to do the overall job, its better to do now than later.

My chain was stretched, the main tensioner was extended a lot and the hydraulic tensioner seemed a bit weak, the guides etc had a bit of wear on them from the chain being stretched/slack. Mine was in need of the whole lot but I had other work to do in it so it made the job worthwhile to pull the engine and gearbox out.
 
#11 ·
Taking camshafts out when rolling-in timing chain

Tony-
I know it's been a while since you posted this, but I wanted to say thank you for the excellent write-up! I'm getting ready to do this job myself, so this is very helpful prep. I'm intrigued by one thing you said:

"Step 10. In theory after cutting the cable ties you hold the chain on the inlet cam and very careflly turn the crank pulley clockwise to wind the new chain in as you pull the old one out. We found the cams jump due to pressure from the valve springs and ended up losing the engine timing. Solution was to take out the cams!. This is dead easy only about 20minutes but you must remove the sprockets or the cams won't come out. By doing this the valves cannot hit the pistons and it is then dead easy to roll the chain in as its only going around the crank sprocket. It is critical to set the crank pulley TDC once the chain is in. Make sure you keep the chain tight.

I like the idea of taking-out the camshafts, which is not big deal. But I'm confused how this would avoid having valves and cylinders hit when you turn the crank. How does one know when all valves are in their closed positions? Is that when the engine is at TDC or?

Any wisdom on this by you or anyone else on the forum would be helpful and appreciated! I've googled this topic but without any luck. I just don't want to remove the camshafts and start cranking and hear valves getting crushed!:lol:
 
#12 ·
that's a very good question...I would imagine once the camshafts are out... the valves would be pushed out by the springs since you have no more cams holding them down.
 
#16 · (Edited)
at tdc with the chain cut/removed, just rotate the exhaust cam forward 60 degrees and the intake back 60 degrees (you'll feel them come to a natural resting point) and all the valves will be closed. Then just roll the chain in by rotating the crankshaft ONLY. You can also skip steps 1 and 2, no need to remove that mount
 
#17 ·
I will need to do my chain too as well and don't really want to do what must be done according to the forums, WIS and such. All I want to do is just to roll in the new chain for now, ( not my daily car ) I will overhaul the engine when time and place is right.

N.E. Swede, to my understanding the only thing moving will be the crankshaft, not the camshafts? If yes then i know it will be easy.
 
#18 ·
^^ Yes, just the crank. When you get the chain rolled in, set the crank to TDC with the marks on the pulley and timing cover and turn the cams back (opposite direction) to TDC. Easiest to do the roll in with an extra set of hands, but 2 bungee cords to keep tension on both ends of the chain works too. I like to remove the cam gears and bring the chain as far towards the front of the car as possible to remove and install the link. Less chance for debris/pieces of the new link/etc. to fall into the timing cover
 
#19 ·
N.E. Swede-
Thank you very much for that insight. So, roll the cams back/forward as prescribed and then remove the camshafts? I'd also like to get cam sprockets out of the way to have no interference.

Regards
Bjorn
(Also a Swede but living in the US of A since 1989...)
 
#21 ·
seems like a lot of trouble. When I did it... I just had one person holding the new chain end and pulling the old chain out as I turned the crank... It's not so bad as long as you keep the tension on both ends... a tip is to keep the chain down on the exhaust spocket... you can make yourself a jig to hold it down fixed to the head with a bolt like the real saab tool....

It's not that hard to turn the crank with the cams....

good luck!
 
#23 ·
thats even better.... I don't have a son.. only a 3 yo girl and another one in two months!

Those sprockets are can be so tight sometimes... at least mine was on the B207R. Get a really long breaker bar/tube extension so you don't hurt yourself.
 
#24 ·
felchi80-
She'll come in handy soon! I have a 5-year old daughter, 6 and 19 years old sons and one more in the oven (due 1 January)...maybe someone on the board can explain to me how these baby things happen. I don't have a clue, obviously! Actually, I'm already training the 5 and 6 years old...giving me wrenches, sockets, etc. They like it!
 
#26 ·
Wow... 19 to 6 and now 0!! Very courageus ... my daughter used to play with my sockets when she was two while I was fixing the car... she managed to lost some.... :banghead:
 
#28 ·
I have been reading the discussions on how to properly roll in a chain. It appears that there are many different ways to accomplish the task. The question in my mind is which one is the easiest, and most accurate.
My wife's SAAB 9-5 has 186,000 miles, sounded perfectly with no engine rattle until recently. It is drivable with smooth idle but I decided to garage it until the Timing Chain is replaced. I am 100% certain that the chain is stretched. With the Crankshaft pulley aligned on the Timing Mark, the Camshaft marks are off the marks. See attached picture. A stretched chain will throw off timing but engine compensates for that. On the attached picture, the Timing mark on the Exhaust Cam is a bit off but the Timing mark on the Intake Cam is even more, possibly close to 1/2 an inch.. The picture exaggerates how far off is the Intake Timing Mark.
I will continue searching for the best answer but I am leaning on the idea of rolling the chain in by turning the Crankshaft clockwise, and align crankshaft and camshafts pulleys to the timing marks before inserting the Master Link to the new chain.
A couple questions:
1. Should I roll in the chain with the Tensioner in place? If tensioner is removed, the chain is loose on the Intake Side of the housing and it could skip a tooth or two which appears to be the case with many write ups.
2. Can someone describe in detail the process of rolling in the New Chain? I cant get a visual on how to do it with another helper. Pictures will be appreciated.
270663
 
#30 ·
On the attached picture, the Timing mark on the Exhaust Cam is a bit off but the Timing mark on the Intake Cam is even more, possibly close to 1/2 an inch.. The picture exaggerates how far off is the Intake Timing Mark.
I am blind, ignorant, or both...I can't figure out where I should be looking in the photo to find the timing marks.

Also, in the photo, is the intake side the right side? I presume so, since that's the firewall/throttle body side of the engine, but in the spirit of "there are no dumb questions" I'll ask anyway.

When you roll in a new chain, do you temporarily attach the new chain to the old one and use the old one to feed it through?
 
#29 ·
The proper way to check the chain for stretch is to take the tensioner out and measure the extension. IIRC it's 15mm maximum between the shoulder and the back half of the tensioner plug.


Run the chain all the way around at least once, are there any links that are painted yellow? If so that's an indicator that the chain has already been changed. The factory chain did not come with those yellow links, the replacement chain does to make it easier to time the engine.

I do know that someone did a tutorial on how to roll in the chain on this site. it was a long time ago but you should be able to find it.
 
#31 ·
Exhaust on the left in the photo, intake on the right

On the bearing cap just before the timing gears you will see a triangle shape notch at about 1-oclock. You should also see a triangle shaped mark in the casting of the cam that lines up with it when the car is timed correctly.

You can see this on the exhaust cam, it's pretty much dead on. The intake cam looks like it is about 3-oclock from what I can see although that could be just the lighting since it's hard to tell from that angle
 
#32 · (Edited)
Viewed on my laptop it looks like the intake cam notch (right sprocket) is a little to the right of the bearing cap mark but agree it's hard to see. Be sure to rotate the crank pulley clockwise (looking from the right side of the car) a few turns and then recheck / rephotograph the marks. As you approach the crank mark turn it very slowly and don't overshoot it. If you overshoot, don't go counterclockwise as it'll change the tension - instead go around again clockwise. It may be easier for us to see the marks in separate photos.

As Uncle says, remove the tensioner to check stretch - but don't disturb the setting - and measure the extension.

Yes, you attach the new chain with the new link which has a slide-on clip to the end of the old chain. Once finished the clip is replaced with a permanent clip and then the two master link pins are peened or flattened with a special Saab tool.

Edit: Engine internals look very clean. If the "rattle" only occurs during a cold start at fast idle and then quiets a bit within a minute, take a look at the upper chain guide in the valve cover. It gets brittle with heat and age and the chain is probably rubbing it when started from cold. Sometimes, simply replacing it will quiet the chain during warm-up.
 
#33 ·
Looking closer on a better display I can see the notch on the intake. This is within the margin of error that I've found over the years. These marks are not always "dead on" as there is a bit of stretch in the chains when installed. I don't think this thing is that far out of time.

measure the tensioner and it'll tell you how far out the chain is

and Steve's comment about the upper guide on the valve cover is 100% correct, those things get hard as a rock after a while and the chain rattles against them. Easy replacement
 
#34 ·
UncleMiltie has a good point - rattle against that valve cover guide is not the same thing as a bad chain. So measuring the tensioner extension is a good idea.

A long time ago, when I rolled in a chain on a 1999 SE with AT, I zip-tied the ends of the chain to the cam sprockets (but used 2 or 3 zip ties per cam gear). I 'broke' the chain with a proper size chain tool, and I fixed one end of the new chain to the front end of the old one (make sure this connection is good, you don't want it coming apart inside the timing cover !). I did it in an unheated, open-rafter garage, so I attached the new chain to a rafter with a long bungee cord.

The chain tension was from above and behind the exhaust cam sprocket - hood struts were released so the hood was restrained in vertical positon. I kept the chain under tension via the bungee, I kept removing and renewing zip ties on both cam gears as I rotated the engine, and I had to periodically re-position the bungee cord on the new chain.

I rolled in the new chain because the tensioner was at maximum measurement, there was cold idle chain rattle, AND because the engine had 237K miles at that point in time. The chain noise from the valve cover chain guide might have partly been because it was hardened with age. I knew this did nothing for the balance shaft chains. The engine was not original to the car. It came from a MT donor car with high miles after the original engine died from oil sludge. I bought the car with the transplanted engine, but I had the records. Several years and 53K miles after the new chain the car was still running well when I gave it away (about 290K on the motor then).

Just my story. These days I might choose to do either a more thorough refurbishment or move to a different vehicle - these cars have a certain appeal that many cars don't.
 
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