codes P0171, P0174 Lincoln LS V6"

[00V6LS]

I wanted to come back to the forum to provide the answer to my question; just in case this will ever be valuable to anyone else.

I traded email with Rod and he gave me some things to consider; then I went to work.

I found that although there are rubber boots on the coil packs, they do ot seat real well onto the surface of the valve cover. So, it is very possible for this bad seal to be comprimised and for water to find a way past and into the spark plug well. When this happens to many of the cylinders, the engine experiences severe misfire and does not start. A very hard lesson learned for me is to NEVER use water on this engine.

The good news is; once I took the time to access each spark plug well and vaccumm out any moisture and completely and thoroghly dry out every coil pack and reassemble the engine; this car runs like brand new. Smooth. Fast. Wonderful.

So in short, here is what corrected my P0171, P0174; engine light on issues:

1. Replaced a bad rubber connector 'elbow' at the EGR.
2. Replaced all spark plugs.
3. Replaced the coil paks on the left side of the engine.
4. Replaced the valve cover gaskets on the left side of the engine.
5. Replaced the front O2 senors in the exhaust system.

Yes, this was a lot of work. I did this all on my own and I'm good with following instructions but I'm not a mechanic. None of this work was too hard for me to perform. I did buy a OEM Shop Manual and would recommend this to anyone who is going to perform their own repairs.

My car now runs beautifully; I really like my LS.

Two things to be aware of.... and really watch out for...

1. All plastic parts. Use extreme caution as not to break any.
2. Prelube the bolts to be removed on the crossbar; 2 on each side and 3 in the center. 4 of the 7 of these broke when I attempted to remove them.

FINNALLY:

Listen to Rod, he provides valuable insight

[shorod]

Thank you for the feedback and letting us know what it took to fix the issue.

There are a lot of folks on this forum that know their stuff, which is where I learned much of what I know about these cars. I probably just spend too much time on here and address questions where I can before the others have a chance to.

-Rod

[Casper_LS]

Hey Guys,

OK Guys, I'm far from mechanically gifted -- but my local mechanic isn't familiar with this car, so I'm hoping I can at least figure out what's going on so I can tell him exactly what I need done.

After replacing the fuel pump and filter (at the mechanic's suggestion) I'm still having all the issues this thread mention as PCV elbow issues. (Stalls at idle, RPM's drop randomly when I'm stopped at a light, stutters and RPM drop when I'm pulling a hill at freeway speeds)

I know when I first took it to the shop it had a misfire code (he didn't give me the code number, unfortunately, but said it was a lean code). This code was cleared when they replaced the fuel pump and filter and now the car is showing nothing on the code reader -- but it's still running terribly.

It also has a smell of gasoline when I start it on cold mornings -- which doesn't seem to fit the PCV elbow symptoms... at least from what I've read on this thead

I'm up for any ideas you may have. Also, specific instructions on how to diagnose the PCV Elbow - or anything else you think it might be- would be great (I'm sure they're posted here somewhere... but I can't seem to find them).

Thanks!

[joegr]

If you have a gen I LS, then a bad IAC would explain most (but not quite all) of your symptoms.

[shorod]

Per your PM I sent you an e-mail. For future others that find this thread during searches I'll give a short synnopsis of other areas to consider.

The electrical systems are very sensitive. If the battery is old, even if it doesn't have symptoms of being weak, change it out and see if that changes the symptoms.

Since you had prior misfire codes, pull at least the three coils that you can easily access and check them for signs of oil, white powder, or rusty colored powder. Leaking spark plug well seals are fairly common up to through the 2002 model year, and there are reports of leaking windshield cowl seals allowing water to puddle on the coils and in plug wells, both of which could cause misfires and coils to fail.

From the LS forum main page, in the upper right, there is a "Search this forum" tool which allows searches for keywords.

-Rod

[Casper_LS]

So after the fuel pump and filter were replaced, and we ran a fuel additive through one tank, I'm happy to report that it no longer stutters when going uphill.

However, it still stalled on my yesterday when I first started it up. (Put the car in reverse and was holding the brake waiting to back out ... all of a sudden it was dead).

I went down to the auto parts store and used their OBDII scanner. No codes initially -- then I did the "advanced test" or whatever that option is and it showed a p0316 in memory (misfire in first 1000 rpms on startup... or something along those lines).

It also (seemingly randomly) drops RPMs when stopped at a light. (from 800 down to about 400).

Does this still sound like PCV to you guys? or IAC, as joegr said.

I searched the forum for IAC diagnostics and I'm going to go figure that out right now... more later!

THANKS AGAIN!

[Casper_LS]

So I just checked the IAC valve using these directions that Shorod put up elsewhere in the forum:

As for a test for the IAC, try turning on the A/C with the engine at idle, assuming your compressor engages. If, when the compressor clutch engages, the engine speed does not drop noticeably, the IAC is probably doing its job. You could also turn the steering all the way to one of the locks for a second or two. If when you reach lock, the engine speed doesn't drop noticeably, that's test 2 indicating the IAC is doing its job.

Both of these made a significant change to my RPMs.

So now my question is -- how hard is this IAC to swap out? Could I do it myself with normal tools and limited know-how, or should I take it back to the shop?

[joegr]

Originally Posted by Casper_LS

...So now my question is -- how hard is this IAC to swap out? Could I do it myself with normal tools and limited know-how, or should I take it back to the shop?

It's very easy to change. Two bolts, one hose, and one electrical connector.

[shorod]

One hose? There's no hose to the IAC. The trickiest part is probably making sure the metal gasket doesn't fall when you remove the two 10mm bolts. Also getting the gasket to stay in place when reinstalling.

The IAC is mounted to the throttle body. It's probably the easiest part to replace under the hood.

-Rod

[joegr]

Originally Posted by shorod

One hose? There's no hose to the IAC. The trickiest part is probably making sure the metal gasket doesn't fall when you remove the two 10mm bolts. Also getting the gasket to stay in place when reinstalling.

The IAC is mounted to the throttle body. It's probably the easiest part to replace under the hood.

-Rod

http://www.autopartswarehouse.com/sk...%26+Drivetrain
Isn't this the valve? The hose is the air supply into the valve. I don't have a gen I LS, but I had several cars with the 4.6L and it used a very similar IAC assembly. One side bolts to the manifold, and a hose hooks to the other side to supply air to the valve. Looking at the picture of the valve, it sure looks like a hose connection on one side to me.

[shorod]

Geesh, I've never seen one like that. Everyone I've seen has the inlet and outlet cast as part of the mounting base. The Gen 1 V6 LS has the cast housing, no hoses.

http://www.autopartswarehouse.com/sku/Lincoln/LS/Motorcraft/Idle_Control_Valve/2002/Base/6_Cyl_3-dot-0L/MICX1766.html?tlc=Engine+%26+Drivetrain

-Rod

[joegr]

Originally Posted by shorod

Geesh, I've never seen one like that. Everyone I've seen has the inlet and outlet cast as part of the mounting base. The Gen 1 V6 LS has the cast housing, no hoses.

http://www.autopartswarehouse.com/sku/Lincoln/LS/Motorcraft/Idle_Control_Valve/2002/Base/6_Cyl_3-dot-0L/MICX1766.html?tlc=Engine+%26+Drivetrain

-Rod

Sorry, I've only dealt with V8s.

[shorod]

We both learned something, I've never seen an IAC with hose connections.

-Rod

[Casper_LS]

so i pulled off the IAC and MAF and cleaned them (didn't replace them). RPMs are dropping much less when I run my AC Compressor at idle. However, it still stutters (feels like a misfire) when I'm stopped at a light.

No check engine and it's not throwing any new codes ... PO316 (misfire in first 1000 RPMs) was stored in memory when I checked it a few days ago, but nothing new.

Any other ideas?

[shorod]

The factory service manual suggests the following possible causes for the code P0316:

• Damaged CKP sensor
• Ignition system
• Fuel Injectors
• Running out of fuel
• Fuel Quality
• Base Engine
• Damaged PCM

-Rod