[Mort]

After a recent short drive in cold weather (about 3C/37F) at night, I returned to the garage - with a noise that I thought was associated with the chain. Having read numerous posts about the chain getting extended etc. A little concerned, I thought I would ask what the general best practice is regarding this.
Here is the basic info:
OG9-3 Aero Auto, 2000. (B205R engine). Current Mileage approx 175k km/109k miles.
I don't drive it every day - it really only gets a run - once or twice a week plus the long annual holiday trip.

I had the valve cover gasket replaced about 12 months ago, and it does get regular oil changes, normally on average now - every 10 months, which I would have covered about 4 or 5000 km.

If it is the chain getting extended (ie slapping) - what should I be actioning, - Is there anything I should replace at the same time?
Is this major surgery to do this - eg engine out? If a Saab shop was to action it - could they do it without removing the engine?
What are the pros and cons?
I haven't looked at the WIS at this stage.
Thanks in advance.

 

[AUSSIE900]

The first step is get a measurement at the chain tensioner . from memory the service limit is 15mm.
a new chain can be rolled in In-isutu , however my prefernce is an endless chain with the guides replaced as well ...
I have read that some maintain this can be achieved in place , But I have always done with engine out as typically I have wanted to do more than just timing gear .
If the engine is Out , then you would consider front and rear crank seals depending on what you know re history
You may even consider bearings etc , In the aero B205 I did up recently I did Rings , bearings , Crank seals and Chain and guides it only had 130,000 K's , Also had work done on the head.
Measure the chanin tensioner , perhaps get a compression reading and let that info guide you .

 

[Mort]

Thanks, Aussie.
I did the front crank seal when I did the oil pump o-ring. That was about 8 months ago.
I do have an extremely minor weep from the rear main seal near the trans.
Some things I can do with family help, others I leave to the experts with all the tools and knowledge.

There was a frank Drebin post that described the in-situ replacement I recall reading.

 

[AUSSIE900]

Checking the tensioner is pretty easy , Just be sure to remove the small bolt on the face of the tensioner so as to remove the spring tension . If you dont do that the tensioner will continue to ratchet out under spring tensioner as you undo the Body of the tensioner , thus giving an inaccurate reading , Take care to collect the spring and the small push rod held in by that small bolt, A reading will tell you where your at and tell you whether it can be on the back burner ot more urgent ,

 

[Jeremy R.]

It’s a lot of work to replace the chain with the engine in the car. I’ve done it, though, on my 1997 900 turbo. You have to undo all of the engine mounts and slide the engine over an inch or so to get enough clearance to get the timing cover off. Next time I’ll take the engine out.

 

[multisaabguy]

Mort, it can certainly be done instu, but yes check the tensioner first and the condition of the guides(after you pull the valve cover) with only 109K on the clock I can't imagine it's gone, although short drives aren't good for it either. the WIS explains it pretty good and the chain holder can be crafted from pieces of wood.(it's just to keep the chain down on the sprockets while turning. The WIS shows removing the link and then peening, crushing a solid one but the removable one holds up just fine. your choice.

 

[Mort]

Reading up a little more - I didn't realise the tensioner indicator was accessible without having the valve cover etc off. Looks like it's just moving the idle pulley to gain access to the bolt that holds the tensioner spring etc after you move the air box.
So when you do this - do people replace the 2 gaskets/o-rings associated with the tensioner bolt?
This seems to be good preventive maintenance regarding oil leaks as well.
Do people replace the tensioner itself at a particular service point?
Given at 109k miles I don't think I'm at that point yet.

 

[Jeremy R.]

The tensioner itself rarely or never gets replaced. It’s very sturdy and simple. The only times I’ve heard of anyone replacing one is if they accidentally damage it or lose parts.

 

[Mort]

Thanks, Jeremy. What about the O-rings on the Tensioner? Is that a particular service point item?

 

[Jeremy R.]

The seals need to be replaced whenever they leak, but there’s no real service interval. The larger one on the tensioner body can create a real mess when it leaks. It’s one of those rubber-lined steel dowty seals. The one on the spring cap is a regular o-ring. Neither one is particularly cheap.

 

[Saaberachi]

Agree with above. Check chain tensioner extension 1st. You will need a 26mm deep/or long shallow socket. Be sure to keep the socket square. I broke a tensioner once from letting the socket get cockeyed while breaking it loose. If you do it in car, the water pump must be pulled away from the timing cover as well & i'd recommend at least loosing the oil pan when putting the timing cover back on so you don't lose your anaerobic sealer

 

[Mort]

Esaab shows these in stock. $11 for a seal - I can understand your comments.
For future reference we are talking about these part numbers:
Large O-ring : 7508690
Small O-Ring: 8048670
Timing Chain Tensioner: 7585086.

 

[BobSaabit]

I would replace the seals since you have time to order them beforehand.