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Re: 'upper timing chain guide rail' same as pad mentioned? Posted by Cmyles [Email]  (#1126) [Profile/Gallery]
(more from Cmyles) on Wed, 27 May 2015 20:59:37
In Reply to: 'upper timing chain guide rail' same as pad mentioned?, Sri, Wed, 27 May 2015 20:07:48 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Yes, two names for the same item.
When a B202 engine makes noise at 120,000 something unusual is going on. These engines will run much longer than that with no internal problems if the oil and filter are changed regularly. Either your engine had way more than 120,000 miles on it when it started making noise or it was driven by someone who didn't bother to change the oil, drove it low on oil or otherwise abused it.
Be sure that the noise in question isn't just a sticky lifter or lifters too. That's pretty common, can make a lot of noise (from the same general location) and is fairly easy to correct. Does the oil light come on for a second or three when the car is started and then go out (like it should)? If it doesn't come on at all or stays on you may have an oil pressure problem and top end noise is inevitable (and may be the least of your problems).
The '87 head had external oiling and has little tubes with plastic connectors to route oil to the lifters and cams and the connectors will get old and crack and the lack of oil can cause hellatious lifter noise. When you have the valve cover off examine all those and maybe just replace them anyway (Saab # 09 98 460).
You could install a later style tensioner (Saab part number 75 85 086) and seal (75 08 690) and see if that helps and have a look at the chain pad in the valve cover (see previous post for part number) and see if it's rock hard. If you can get a used late style chain tensioner it should be fine, they don't generally go bad and you'll save a few bucks but put a new seal on it or you'll have a leak. Screw it in and load it, turn the engine a few times, then remove it and measure it to see of the chain is actually stretched. Then put it back and drive it or install a new chain if needed. Be sure you know the right way to measure it too. The maximum allowable according to Saab is 11 mm but you have to know at what points to measure (it's shown in the Saab manuals, not sure about Bentley).
Rolling in a new chain is a little trickier than it sounds and you'll be well advised to hire a real C900 Saab mechanic who has done them before. If you do it yourself just budget some time, go slow and check everything twice (or four times). It's good to have a helper and take some close up pictures and make diagrams so you get the cam timing just right. NEVER turn the engine by turning a camshaft, use the crankshaft to turn the engine or you can shear the key that indexes the sprocket to the camshaft. You can use a modified bicycle chain breaker to push the pin from the old chain and buy a new chain with a master link to make installation easy.
Anyway, rule out the lifters as the noise source before you go in too deep.
, Wed, 27 May 2015 13:08:02
, Wed, 27 May 2015 11:43:21, Wed, 27 May 2015 14:14:17, Wed, 27 May 2015 17:29:03
, Wed, 27 May 2015 20:46:01, Thu, 28 May 2015 06:31:53, Thu, 28 May 2015 07:04:07, Wed, 27 May 2015 19:56:20, Wed, 27 May 2015 20:59:37 <-- Viewing This Message, Thu, 28 May 2015 07:18:56
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