Should I Pull the Trigger on an IACV on my my 2001 Grand Marquis

Did that resolve the issue?

I drove it around a bit last night but honestly not sure if it's enough. It wasn't idling rough but I didn't hit the highway either and get it good and warm.

Have you replace the IACV gasket?

I did that yesterday when I smoked it the first time thinking it was the source of the leak around the IACV. But it is still there and either the plastic thing or the crimp where the motor (guessing?) is.
 
Sealing the PCV in the valve cover helped idle speed but still misfires once in a while. Next step will be a compression test in the spring.

I might swap injectors between 5 and 6.

But it idles at 820 in neutral warm and 575 in gear warm. That's better.
 
If you hear a flat spot in the starter while cranking and you definitely have a compression issue
 
If you know what you’re listening for, it’s not needed.
I was kind of hoping to get enough other stuff taken care of that it wouldn't set the misfire code. It doesn't bother me much but it won't pass inspection when the time comes. I may swap injectors around (only $6 for a set of o-rings) and see if that buys enough that it stops.

Ultimately it's going to be a compression issue. I can get a video in clear flood mode. The starter speeds up on one of the cylinders. That usually means it's quite a bit of compression loss.

I'm going to hold off on any major repairs until spring. Just don't have the time. If anything I'll bring it to a friend's shop to get a leakdown test done.

My 5.4 idles at 500 and I never thought twice about it. Maybe I should?

Wonder if it's because it is infront of a manual but my 01 5.4 idles at 750 warm.
 
2001 is in the middle of the date range that was know to have bad timing chain tnesioner arms where the plastic failes. That will affect cam timing and result in issues similar to what you describe.

See if any of the injector or coil pack release fingers are missing from the connectors, if they are, it is kinda likely that one of those little pieces went into the cylinder. When that happens it will get stuck in the exhaust valve and hang it open just long enought to whack the piston. I have seen this a small number of times.
 
I would not take heads off when junkyard motors are a dime a dozen...... 2001 thru 2011 are all interchangable. Its the 2000 and older that are hard to find.
 
Well bit of an update here. I'm sure I'll jinx myself.

Was towing about 2000 pounds to the dump with it. I pulled out in front of someone going a bit above the speed limit (at least 75 in a 55, I stopped accelerating at 75) and had to get on it. With 2000 pounds on a trailer. When I had to stop to scale in I thought the car stalled. Nope, idled smooth as glass. Went through the dump, drove into town and stopped at a few stoplights and I've never felt the idle so smooth. For the first time the light went out on its own, but did come back on.

Brought it up with a friend and he was thinking maybe the injector is bad and washing out the cylinder?

I decided to fix it the right way and dumped 3 cans of seafoam into 1/2 tank of gas (6x dosage recommendation) and drove it a ways on the highway with overdrive off. With how comically tall geared this car is that's only like 2000 RPM 🤣 but still ...

Anyway, it went out again on its own after that and hasn't come back on. Idles at 575 RPM like it's supposed to and really smooth. Once in a while it will get rough -- rough now being more smooth than "good" was before -- but a tap of the gas brings it right back to smooth as glass.


I would not take heads off when junkyard motors are a dime a dozen...... 2001 thru 2011 are all interchangable. Its the 2000 and older that are hard to find.
Certainly easier to pull apart a whole engine at home rather than standing in a junkyard pulling a head on an OHC engine. If it keeps the light out like this, I'm okay with it!

I've found a few people parking out crown vics with the 4.6/4r70. The trans is year specific but the only change I know of on the PI heads was getting full threads for the spark plugs mid year 02. Same as my truck with the 5.4, I'd like to find a newer engine with the full threaded heads.

My truck is just about do for an engine. The 240K mile 5.4 is showing it's age. Econolines ran that engine up until 2015. Just need to find a low mileage wrecked econoline!
 
Well bit of an update here. I'm sure I'll jinx myself.

Was towing about 2000 pounds to the dump with it. I pulled out in front of someone going a bit above the speed limit (at least 75 in a 55, I stopped accelerating at 75) and had to get on it. With 2000 pounds on a trailer. When I had to stop to scale in I thought the car stalled. Nope, idled smooth as glass. Went through the dump, drove into town and stopped at a few stoplights and I've never felt the idle so smooth. For the first time the light went out on its own, but did come back on.

Brought it up with a friend and he was thinking maybe the injector is bad and washing out the cylinder?

I decided to fix it the right way and dumped 3 cans of seafoam into 1/2 tank of gas (6x dosage recommendation) and drove it a ways on the highway with overdrive off. With how comically tall geared this car is that's only like 2000 RPM 🤣 but still ...

Anyway, it went out again on its own after that and hasn't come back on. Idles at 575 RPM like it's supposed to and really smooth. Once in a while it will get rough -- rough now being more smooth than "good" was before -- but a tap of the gas brings it right back to smooth as glass.



Certainly easier to pull apart a whole engine at home rather than standing in a junkyard pulling a head on an OHC engine. If it keeps the light out like this, I'm okay with it!

I've found a few people parking out crown vics with the 4.6/4r70. The trans is year specific but the only change I know of on the PI heads was getting full threads for the spark plugs mid year 02. Same as my truck with the 5.4, I'd like to find a newer engine with the full threaded heads.

My truck is just about do for an engine. The 240K mile 5.4 is showing it's age. Econolines ran that engine up until 2015. Just need to find a low mileage wrecked econoline!
Send the injectors to @Trav and he will clean them and get them perfect.
 
Oh yeah? Wonder how much he charges. OE Injectors are $50 a pop. I could get a set of 8 from the local junkyard and send them out. Just gotta get the time to go to the junkyard.
Here’s his info. I bought 6 used ones on eBay for my Jeep for him to do. 2 turned out to be bad, so if you do junkyard get some extras.

 
Oh yeah? Wonder how much he charges. OE Injectors are $50 a pop. I could get a set of 8 from the local junkyard and send them out. Just gotta get the time to go to the junkyard.
Unless you're buying it from a dealership, there's a lot of counterfeits out there to watch out for, even on RockAuto. Trav was able to source me a set of 8 from Bosch and flow match them.
 
Getting it there slowly. If I had known how hard it would be to change the driver's side injectors, I would have bought 4! Ridiculous!

Anyway it's been running poorly again. The last few days I decided to check to see if there was a lot of fuel pressure after shutting off. Pretty much immediately after turning the car off the pressure would bleed off. Pulled the #5 spark plug and it was pretty fouled out.

Swapped out the injector today and it seems to be running great again. At this point I'm thinking the injector was stuck open causing it to wash the cylinder out. Hopefully it didn't score the wall bad enough so it can come back around on compression. I let it sit for a few hours and it still squirted pressure out of the fuel rail so that's good !

I also found the belt squeal. Alternator bearings are tired and the tensioner pulley is shot. It's almost to the point it's eating into the timing cover! Guessing that pulley not being completely straight with the bad bearing is why I keep smelling burning rubber.
 
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