1986 FORD 300 SIX CYLINDER ENGINE KNOCKS
Hi Bill 609!
Definitely sound like a rod insert to me. With my practiced ear, I cna tell the difference between a main bearing knock (deeper sound, more of a thudding noise), rod bearing knock (not so deep, gets louder as the engine revs, kind of a rat-tat-tat-tapping noise), and a wrist-pin knock (not quite as loud or deep and gets louder with decelerating RPM).
You can tell which cylinder the knock is on by removing the spark wires to each cylinder one at a time while the engine is still cold enough to knock. (Don't get shocked!)... when you hit the right one, the knock will noticeably quieten or possibly quit altogether!
The 300 Six is a tough old motor and I have seen them survive for years with rod knocks... Just allow the engine ample warm-up time before driving, drive on the conservative side, and keep an eye on oil level and pressure.
An oil and filter change to a higher viscosity oil with a can of STP Oil Treatment (Or something similar) is a good band-aid fix for now, I would recommend Castrol GTX 20/50w... in my opinion, Castrol is the best brand out there, I use it religiously - - - I have a customer with a Chevy Suburban who has followed my advice and adhered to good maintenance discipline that has racked up over 300,000 miles on the original small block and no consumption or engine issues, and is still running strong!
Bill, the temporary fix will work for a while, hopefully a long while --- BUT when it reaches the point that the knock doesn't go away, it is time to park it until the real repair can be done --- otherwise you risk throwing a rod and destroying your engine beyond repair!!!
Please don't hesitate to post a comment or ask if you have further questions. I hope this information answers your question and concerns and wish you well with the Ford. *** And remember to rate my assistance... Your rating is my only compensation for helping you in the free blog!!!***
Jun 27, 2008 |
2007 Ford F-150 Harley Davidson