2011 CROWN VIC POLICE PKG. OIL NOT CHANGED IN MONTHS, REPORTED "ENGINE KNOCKING" ??

Joined
Aug 14, 2021
Messages
13
Hi folks,

Hope I can get some fair advice on this car

2011 crown vic
4.6 romeo engine
130K miles

So I buy and flip police interceptors and picked one up at a local police auction this week. The fleet guy said last officer never changed oil in almost a year and engine started knocking and was parked since.

So before I placed a bid on the auction I drove to the PD car lot and jump started the car and it knocked for a few seconds but then went away ?? Oil was BLACK AS BLACK but it was level not low ??

Have been told engine is trashed, I need new timing chain/tensioner guides, I need new lifters ??? Any ideas or suggestions ??


Was planning to run some b12 berryman's oil flush and some Delo 400xle 10W30 to "flush out" and then go with some rotella gas truck 5w20 and marvel mystery oil ??


Really hope I can save this car its VERY clean and has low miles !!!
 
Joined
Jul 23, 2021
Messages
974
Location
PA
Timing chains don't cause knocking to my knowledge but I am not sure. Spend $50 on a quick possible solution.

Main culprit is probably the oil and the incorrect non-Motorcraft filter. Many report a knock on startup with the wrong filter. Use the Motorcraft 820S since these engines need that bypass valve the way MC design.

I'd put a $5 MC filter on it, $5 motor medic flush in it, $10 of conventional oil, idle it for 5 minutes per the instructions, drain it, put the MC filter on it, fill it with again with inexpensive conventional, idle it for 5 minutes and see if there's any audible improvement. Then drain that, let it drain for as long as you can, and maybe put another new MC filter on (optional $5 step), and premium high mileage full synthetic or blend. Hopefully the knock is gone.
 

P71CROWNVICMAN

Thread starter
Joined
Aug 14, 2021
Messages
13
Timing chains don't cause knocking to my knowledge but I am not sure. Spend $50 on a quick possible solution.

Main culprit is probably the oil and the incorrect non-Motorcraft filter. Many report a knock on startup with the wrong filter. Use the Motorcraft 820S since these engines need that bypass valve the way MC design.

I'd put a $5 MC filter on it, $5 motor medic flush in it, $10 of conventional oil, idle it for 5 minutes per the instructions, drain it, put the MC filter on it, fill it with again with inexpensive conventional, idle it for 5 minutes and see if there's any audible improvement. Then drain that, let it drain for as long as you can, and maybe put another new MC filter on (optional $5 step), and premium high mileage full synthetic or blend. Hopefully the knock is gone.

Ya i didnt check what filter was on it when I went to look at the car but I ONLY use MC filters for these cars. Just common sense when they're only $4 @ walmart but I get my local AZ to price match so I can rack up my rewards points lol

BTW the end of year 2009-2011 police vics use the smaller 910S filters. I think 2008 was last time they used 820's on the police vics ??
 
Joined
Jan 24, 2008
Messages
12,670
Location
OH
Try doing a few short interval oil changes then send it. Rural King, Menards, WM for cheap but decent oil.
 
Last edited:
Joined
Jul 23, 2021
Messages
974
Location
PA
Oh, you might be correct. That might have occurred. I'm also aware the MC820S was redesigned to be smaller but I'm not sure if they are interchangeable. Good luck and let us know how the $50 solution turns out.

I'd bet that knock is a incorrect filter and old oil.
 
Joined
Jul 15, 2018
Messages
195
Location
Valley Forge PA
Try doing a few short interval oil changes then send it.
Do this like 500 miles first time then increase to 1000 etc, I have lost count of how many beat ass P71 I have used in my career and never ever seen one actually blow an engine, trans always goes first even rear axles... So many times they were run on like 3 qrts of oil for a month and nothing ever actually broke they just end up using oil or knocking... runs forever its so under stressed its rediculous.
Put some new plugs in there after the first oil change also and run some gas cleaner in tank and maybe even through intake and of course service anything else you can think of like PVC etc... Dont pay to put a motor in that unless you can do the swap yourself just sell it like that to someone who can....
 
Joined
Jul 23, 2021
Messages
974
Location
PA
Agree with the above poster, it's probably due for other items if the oil was neglected. Make a list, that includes PCV, plugs, rear diff, and several iterations of transmission spill and fills and a pan drop with new filter, cleaning various sensors, new belt etc. All things that can be done in an afternoon. But I would not get too invested until after a few quick oil changes and filter to see if that knock can be eliminated, and then reassess the investment.
 
Joined
Jun 3, 2005
Messages
16,312
Location
Santa Barbara, CA
Ya i didnt check what filter was on it when I went to look at the car but I ONLY use MC filters for these cars. Just common sense when they're only $4 @ walmart but I get my local AZ to price match so I can rack up my rewards points lol

BTW the end of year 2009-2011 police vics use the smaller 910S filters. I think 2008 was last time they used 820's on the police vics ??
It is hit and miss on the FL-910S. I have seen a bunch of 2010 and 2011 take the FL-820S for fleets here.
 
Joined
Nov 14, 2008
Messages
12,217
Location
Phoenix
Sounds like they topped off the oil, the blacker than black appearance confirms poor maintenance. I'd plan on a motor, they can't be too expensive for these. If the body and interior are clean, it would be worth it.
 
Joined
Feb 15, 2003
Messages
11,276
Location
Jupiter, Florida
Timing chains don't cause knocking to my knowledge but I am not sure. Spend $50 on a quick possible solution.
In the 4.6L, they do. The tensioners are oil pressure operated, and in some cases they cause a distinct knock upon startup. This is actually quite normal on the 4.6's. Motorcraft oil filters generally do a better job sealing and preventing the oil from draining out of the oil passageways. I've even had Motorcraft oil filters that knocked when new, but after a while sealed better and the start up knock went away.

Obviously I can't know the condition of the engine based on what you said. However, as I'm sure you know, the 4.6 is a very, very tough engine, with a low level of stress, and it would take some serious neglect to cause it to fail. I'm guessing it's OK, and the knock is the typical timing chain tensioner pump up time.
 
Joined
Jul 23, 2021
Messages
974
Location
PA
In the 4.6L, they do. The tensioners are oil pressure operated, and in some cases they cause a distinct knock upon startup. This is actually quite normal on the 4.6's. Motorcraft oil filters generally do a better job sealing and preventing the oil from draining out of the oil passageways. I've even had Motorcraft oil filters that knocked when new, but after a while sealed better and the start up knock went away.

Obviously I can't know the condition of the engine based on what you said. However, as I'm sure you know, the 4.6 is a very, very tough engine, with a low level of stress, and it would take some serious neglect to cause it to fail. I'm guessing it's OK, and the knock is the typical timing chain tensioner pump up time.

I did not know that! Learn something new every day. I figured a timing chain would be a rattle, not a knock. Thanks for the wisdom pill.
 
Joined
Dec 30, 2006
Messages
25,857
Location
Dallas,Tx USA
The startup knock could also be from sitting a long time unstarted. Just grab a Motorcraft oil filter and a jug of 5/10W-30 and give it a normal oil change. Maybe some Maggie 5W-30.
 
Joined
Aug 23, 2020
Messages
271
Location
Wpg. Canada
This is what I'd do.

Pennzoil Yellow bottle 10W30 and a new filter and give it a Italian Tuneup for about a few hundred miles then change the oil again and see how it runs.
 
Joined
Mar 12, 2007
Messages
1,425
Location
canada
This is what I'd do.

Pennzoil Yellow bottle 10W30 and a new filter and give it a Italian Tuneup for about a few hundred miles then change the oil again and see how it runs.
Don't imagine a police interceptor would benefit from a Italian tune up ? Rest of the advice is sound !

I'm guessing after a year of service it was low on oil , starts knocking officer knuckle head brings it in with knock complaint they top off with oil and decide to move it out ?
 
Top