'90 745TI (141,000 miles)$1,100 - documented timing belt change2,500 miles ago.

Just purchased this brick & it's been a fine ride so far. (1 month)
I've replaced all vacum lines,changed oil to Mobil1 syn 5w30,changed oil filter,(did this without raising the car if you can believe it!)adjusted downshift cable,(this really made shifting alot better/it was high revving)switched to cone type air filter w/ home-made heat shield,(removed air intake box)cleaned all intake hoses & components,added strut tower brace(home-made version/made a huge difference in turns)

After all this I'm still trying to quiet the knocking sound; Its mainly during idle and while cold. & sometimes idon't notice it at all.I keep 92oct. in the tank.
It seems every pre '95volvo motor i here running has this "knock".mine is just a little louder sometimes.
Is this someting I could cure with......
a new knock sensor?
a valve clearance adjustment?
different oil?
or did i get ripped?
I know a more extensive tune-up couldn't hurt. I'm just worried about starting down the wrong path on this particular problem.
The car runs great & has plenty of power.I can't believe it's a four banger!
where should i start?
any input is appreciated.

 

Well, are you talking about top end valve adjust type clicking or engine pinging, aka pre-detonation? The former is cured by a simple valve adjustment, the latter by timing adjusts or higher octane fuel (which you already use). If you hear it at idle then it is fairly certain to need a valve adjustment which is easy but may need shims.

 

"deep" ping/knock.(sounds like a gremlin hitting the block w/ a wooden mallet)[:@]sometimes faint, sometimes not there at all.(when warm)but it's not clicking/rattling.
I hope it's not a rod. after i switched to synthetic it became quiet (sometimes)when it warmed up.
I'm pretty sure adjustment has never been done(is this bad?)
I've never done a valve clearance adjusment.what's a good flat rate from a pro?
I think I'll go over the timing first.any special considerations while checking timing?

This car has a good maint. record(although Valvoline is the common oil change)as well as repair receipts.
shims?

 

The valve clearances should be checked every 30K mi. Not necessarily adjusted but at least checked.

Pros in my area are getting around $100/hr.

 

thanks for the info.
a friend told me today it was "piston slap"(non-threatening)the knock occurs about 3 time per second.
another said it was "umbrella cushions" on top of the valve stems that crumble over time,with a "cushion" life of around 5 years.
anybody ever heard of these things?