1990 745TI engine knocking(cold @ idle)

riverdoug · Post by **riverdoug** » 01 Jan 2008, 23:03

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-maid 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 i don't notice it at all.I keep 92oct. in the tank.
It seems every pre '95 volvo 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.

Post by **sseir39** » 02 Jan 2008, 11:20

A very common problem which is worse then cold. Piston slap. In '93 Volvo started using piston oilers which reduced and practically eliminated the problem. I have owned two 90's and have a 91' which all knock. Best advice: drive it and don't worry about it. We have put at least another 100K miles on one and it runs perfectly. I did put in a HD oil pump and changed rod bearings which made a little difference, but not enough to worry.

Sounds like you have basically a good car.

Dick

riverdoug · Post by **riverdoug** » 02 Jan 2008, 12:20

Thanks Dick.
Now i can sleep.
I'll change the oil & filter again in a couple weeks.
the "Black Brick Wagon" has 141,000 miles.
Maybe it can triple that

Roll On.