940 w/ low Oil pressure and a knocking ?

alpineturbodriver · Post by **alpineturbodriver** » 28 Aug 2010, 23:51

I have been restoring my 940 for a long time and It was running great for a while. Then it sat for a year with a bad ignition control unit, oops! Replaced it, oil was low so I added 2 quarts and after a 50 mile test drive, I got a low oil pressure light, burnt turbo and loud tapping or knocking ? With too many new parts to list, what's next ? I did replace the turbo w/drip line gasket (which it didn't have) and now at least it idles quiet, but at 1500+ rpms it produces a loud knocking !! So, do I have to drop the oil pan and check/clean the oil pump ? Did I throw a rod ?

I love this car and we very much appreciate the help....

Post by **billofdurham** » 29 Aug 2010, 12:04

Welcome to Matthew's Volvo Site.

If the engine is still running you didn't throw a rod. Usually a thrown rod appears through a new hole it creates in the block.

How old is the oil, apart from the 2 quarts you have just added? You can't revitalize worn out oil by adding some new.

Bill.

alpineturbodriver · Post by **alpineturbodriver** » 29 Aug 2010, 18:03

thanks for that clarification on if I threw a rod it would have created a new hole, thank goodness !
the oil was not that old and I have since then given it a fresh oil change.
I did replace the oil pressure sender too.
still, what should I do about the oil pressure lite ?
and what could be causing that knocking ?
Any thoughts ?

Volvofix1 · Post by **Volvofix1** » 11 Sep 2010, 09:15

Drop the oil pan and look at the color of the connecting rod end caps,the con rod furthest away fron the oil pump will probably look darker than the others wiggle .it and you will see that it has excessive play. I hope you did not have an orange oil filter on the engine, remove the end cap and look at the bearing. Maybe you caught it in time and can clean the crank journal with fine emery cloth and measure it with crankshaft micrometer. On the inside of the con rod cap if the bearing was not too bad and you can still see cross hatch hone marks the con rod did not streach and a new bearing insert can be installed. You might want to replace them all. Then use an OE type filter and semi-synthetic 10/40 Valvoline oil,but this all depends on the condition of the crank journal. Worst case senario pull the engine and remove the crank to be turned and fit all new bearings, if you are good you won't have to remove cyl. head or pistons. This is easy for me to say because of my background,but give it a try.

Dick K. from Fla.