I've had the ole girl parked going on two years. I stopped driving her after I got this knock. I thought is the oil pump. Took in to a shop , had the mechanic look at the truck. Said it was not oil pump. The dash Guage was dropping to 0 and the "check gauge" pop on when I would come to a stop. He put a mechanical guage and confirmed there was pressure. He said it was on the lower end but still with in spec. He replaced my harmonic pulley. He said that where the knock was coming from. I drove her home about a 30 min drive and she still sounded loud. I spent about 600 and the problem was still there. So I just parked her and put her on hold. My second child was born so I had no free time.
I stared to read up on the knock. And there was too many variables. I tool it to another mechanic and he said the turbo was bad or it could be a internal engine issue. So now I have two completely different opinions. It stumped me.
I did find a 3 guy that haven't had time to personally look at it yet. Bit I told him the symptoms,
1 loud knock
2 would rev up on her own , all the way. Had to pop it in neutral amd turn engine off. It has done this 3
3 stalls
4 black smoke comes out when it revs up on it own.
5 lift pump fuse keeps popping
6 battery slowly drains if not ran every day or other.
The guy said the first thing I should try is the change the pmd.
Said the knock could be a "fuel knock"
I ordered a new one and will be swapping it out soon.
Do any of you guys have any ideas on what wrong with my girl?
If you replace the harmonic pulley you should also be replacing the harmonic balancer. Both contain rubber and if the pulley was bad that means the balancer isn't far behind, needing replacment. Always replace both as a matched set..
When those are neglected they can create negative harmonics that will travel through the crankshaft, eventually, breaking the crankshaft and/or crack the engine block.
A loud knock can be a fuel knock or something within the engine.
Remove the Serp belt and briefly run the engine. if the knock remains then it's something internal like Injectors, valve train, harmonic balancer, etc.
If the knock is gone, then concentrate on things like vacuum pump, pulleys, etc..
Uncontrolled revs can be a couple of things:
1. bad PMD. If you replace the PMD always make sure the new PMD has a resistor installed. The resistor is important for proper PMD function.
2. worn armature within the Injection pump= replace the Injection pump.
Stalling can be a lack of fuel ( issue with the fuel delivery system, ie.. lift pump, air in fuel, fuel contamination, PMD, etc)
When you mention lift pump fuse keep popping do you mean the fuse is blown or do you mean literally popping out of the holder?
If the fuse blows then it shows you have a short to ground issue within the lift pump circuit and you need to hunt for the rubbed through wire causing the issue.
Battery drain can be due to old/defective batteries or you have a parasitic draw in your electrical system.
Start by removing your batteries and take them to your local auto parts store and ask the staff to perform a load test on each battery.
If one or both fail replace them both as a matched set..
The oil pressure gauge issue should be a faulty OPS ( Oil Pressure Switch). Replace the OPS ( AC/Delco brand only).
As a reminder, ANY part you replace that is electrical in nature ( ie sendor, sensors, etc) need to be AC/Delco brand.
Aftermarket parts will bring electrical gremlins into any issues you may be having and will create other issues on top of what you are trying to diagnose and fix..
