2001 LS V8 runs rough cold, fine when warm

Didn't you learn anything from Don?

Ahhh, no not much other then how to pester others with useless wrong information on a daily basis.



Damn Drizzle your having a bad go at it with that issue ... hope it smartens up for you soon. Wierd symptoms for sure, almost like something is shorting out causing these misfires. PCM rework possibly.
 
Quote Twisted:

"Joegr.......I hate you and your 60 degree weather right now.....it's 24 here..... "

Tell me about it. Looking at an overnight low of,,, 0 drgrees F in a few days. Winter came late this year,,, but it seems to be coming hard and fast.
 
Drizz,

To see if the issue is a PCM problem,,, get one of those small 120v ceramic heaters,,, put it by the PCM and see how it starts the next day. If fine,,, you then know where to look. Could be a loose solder joint in the PCM,,, or a problem in the connector. You could also get a wiring diagram,,, and locate all grounding points on the LS... and check for proper grounding... or corrosion at those points.

Otherwise,,, all of those misfires could be cause by something else... triggering multiple misfire readings on the coils. The diagnostics on the LS is not the "be all-end all". Lean misfires could be a possibility,,, due to a faulty IAC or MAF.
 
Gus also had a good idea with the smoke test on the intake. A leaky intake could cause lean misfires,,, which could possibly be why you are seeing faulty coil codes.
 
As far as a coil killing a plug,,, that is more likely true in reverse. Coils die due to heat... so it's more likely that a bad plug would kill a coil. I think you have other issues.
 
Quote BR:

"Oil vaporizes? Pardon me? Come again?

Quote Joe:

"Didn't you learn anything from Don?"



Are you sure both of you are in the right thread? Didn't see anythingthing mentioned about that here.
 
...Are you sure both of you are in the right thread? Didn't see anythingthing mentioned about that here...

Yes

...First,,, since this is an '01 LS... it has know issues with the valve cover gaskets. Make sure there is no seepage of oil into the plug wells. Even minor soaking of the plug boots can cause a misfire eventually... until the oil vaporizes...
 
Yea it could still be the PCM, but I got cheap amazon coils. It could be they are just DOA/marginal on arrival.

I ordered 8 more motorcraft coils and NGK plugs. Only around $350 for it all, so not too terrible. I pulled the plug on cylinder 7 to inspect it since that is the one misfiring the most, and it looks pretty normal. Just kinda chalky looking.
 
Ok... fair enough Joe. Forgot I said that. Would "cooks off",,, "boils off"... or "evaporates from the heat",,, have been better terminology???
 
Oil needs a lot higher temperature then the 220 the car will produce on a normal or running hot basis. Some molecules within the oil can vaporize at lower temp rendering the oil useless and past it's purpose. BUT ... any oil that has seeped past the plug well o ring seals and collected within the plug wells touching the plug and or coil would never see enough heat to even begin an oil vaporize process. Simple not high enough of a temp within those wells to affect the oil.

.... I suppose, might be wrong.
 
Okay got the 8 new motorcraft coils in. Still misfire when cold. STILL cylinder #7, and also says #3 this time.

P0300
P0303
P0307 (this is the only cylinder that has been consistent with my issue)
P0316

Is it possible to have a cylinder [#7] that is toast but would be fine when the engine is warm? I am going to turn back toward the PCM/wiring again now, since knock-off coils are now ruled out.
 
Interesting (maybe) that those are next to each other in firing order (1-5-4-2-6-3-7-8).
 
Again... (hate to beat a dead horse),,, #7 is where the oil fill tube is. Look for a white milky substance on the coil boot. If so... the oil is somehow getting on the plug boot,,, and shorting the the coil out. Same but possible different issue with coil 3#.

BR,,, tonight I drove my LS, (V8) long enough to get the engine up to temp. I took an infared temp meter,,, and checked the plug well area on several cylinders. Best I could get was 105 F. Keep in mind that ambient temp in garage after warmup... was 35 degrees F.... and I have no engine cover or coil covers. The hottest point was about 105 F. Also keep in mind that i was checking abve the "sealed" coil boot.

I have a Wavetek 235 DMM that will do temp probe. I can push the temp probe past the boot seal on the head and get a reading at the base of the plug. You may be right about 220!!! I thought temps would be higher at this point. I'm curious as to temps at plug base.

If anyone isn't satisfied at this point... I am willing to do a "water test"... to see how well the plug boots seal out water. Keep in mind that the test will be with coil covers off. So if interested... I will simulate, (to the best of my ability), water saturating the coil boots and plug wells,,, without shorting the coils. At 100k miles on the aftermarket plugs, boots, and coils,,, I have nothing to lose. I have a spare set of plug boots standing by... along with a few used but acceptible coils on reserve.

If I can get my son involved... he can video me pourinng water on the plug boots, (with my best attempt at keeping it off the coil connections. Again... I don't replace just one,,, I replace all 8. So I know I have some good factory coils... and i bought a spare boot kit quite a while ago.

I still think Drizz's issue may be PCM related,,, and he needs to heat the PCM up and see if his vehicle runs normally. Thatn is step one,,, as far as I am concerned. Coils and plugs haven't seemed to cure the issue at this point.

Yesss... Ford, (along with others), was know for bad solder joints on their PCM's,,, which would either cause a fail to start,,, or rough running upon startup. Outsourced foreign crap will do that!!!
 
Update for my issues. I did a lot of troubleshooting today and digging around.

For one, I attempted to replug in everything to the PCM. That did not change anything, by the way - removing the air filter box is a real pain. I left it all unbolted in case I need to replace PCM.

I pulled plugs and took a look. They seemed pretty black for being 2 weeks old. Photo below.

I did some carb cleaner spraying all around the intake to check for leaks and apparently I had leaks in the front of the intake near the TB. I loosened and re-tightened the plastic manifold as much as I was comfortable doing (was afraid of breaking it or the bolts). I was able to seal the leak on the driver's side, but the passenger side is still very much leaking. Now I am not sure how this would cause ignition coil misfires, but I am sure this can't be good for my A/F ratios that the PCM is using.

I switched out all the plugs with new ones, I was still getting very rough cold idle and a CEL (the car even died). However, this time there was no coils codes - only Lean Bank 1 and 2.

I replaced the fuel filter and am running injector cleaner (snake oil) through the tank now.


So I suppose my next step is to replace the intake manifold gasket. Having a hard time clarifying the part # online.

15592365_10104053779505342_853415810_n.jpg
 
...So I suppose my next step is to replace the intake manifold gasket. Having a hard time clarifying the part # online...

If you are talking about the gaskets between the intake manifold assembly and the cylinder heads, then you need two of 2W9Z-9439-AC.
 
Yes the area im pointing to with the screwdriver here:

15592312_10104054150561742_400281201_n.jpg


If I spray near that little U-shaped indention, the engine idle does putputputputput. Same thing all the way around the front of that part of the intake towards the TB.
 
There is a gasket on each side between the metal part of the intake and the cylinder head. That is the part number I posted. There are also gaskets or o-rings between the plastic part of the intake and the metal part of the intake. Ford never intended for those to be changed (instead they sold the whole manifold). Someone on here found a source for them anyway, and posted it awhile back.
 
I ordered the gasket you posted above. It comes in a pair.

I wonder if I could lay a bead of RTV down along the plastic to metal joint when I have it off?
 
Vacuum leak, replace all the hoses and connectors with better material like I did. I replaced the "T" connector with brass, replaced the vacuum lines with gas lines or heater hose lines. replaced boots with coupled hose lines. mine V6 always did the same thing, rough on startup in the cold, it turned out to be the cheap vac lines.
 
So I tore into the intake over the holiday weekend. The weather has warmed considerably, so it is difficult to say if anything is changed.

The gasket I got had a raised center bolt portion that the OEM gasket did not... I am not sure why, as it doesn't fit into either the intake bolt hole or the block. I ended up having to cut the raised portion off and file it down. It should not affect function, as it is just the bolt hole and the port openings were fine. I posted pics of the gasket below.

Things I found:

First, my injectors were completely filthy, all gummed up around the tips, some had debris on the actual spray area - but most were just gummed up all around the tip. I cleaned with gasoline, the seals seemed in great shape. I did notice, that the excess fuel that came out of the rail while I was cleaning the injectors, was black colored. I have a new fuel filter, so not sure what that is about, maybe just residue inside the rail.

Second, the gaskets between the plastic and metal part of the manifold were separate units that had little squares (photo below). These all seemed to be in good condition, and appeared to be designed to almost allow some air passage?? Thought that was weird. These little square areas along the intake's seam is where the carb cleaner was making the engine change idle pattern.

Third, my actual ports down into the block are caked full of carbon build up, I am not sure what type of buildup to expect @ 150K miles, but it seemed excessive. I did my best to clear some of the gunk, but was afraid to get loosened pieces down into the engine - so I did not do any extensive cleaning.

Also I forgot to put back in one of the little brown insulation/sound dampening pieces that was somewhere sitting on top of the block... But it was all beat up and seemed useless.


Old gasket next to new gasket.

Po3auJD.jpg


Little gaskets between plastic and metal part of intake.

Tgd4r4b.jpg


DpDkOVQ.jpg


Build up in the engine:

cpCwdcf.jpg


f8iDU6k.jpg
 
...Second, the gaskets between the plastic and metal part of the manifold were separate units that had little squares (photo below). These all seemed to be in good condition, and appeared to be designed to almost allow some air passage?? Thought that was weird. These little square areas along the intake's seam is where the carb cleaner was making the engine change idle pattern...

No, the blocks are there to hold the gaskets in during assembly. There is not supposed to be any air leak. If you can't find new gaskets (they are hard to get), then put some RTV on the existing ones to get them to seal.
 
Damn. I'll check again for leaks at those points. I really don't want to open it all up again, it was a major PITA.
 
Hey joe, when I take the intake off again (this coming weekend). Can i re use the gasket I just put in? The makeup of the gasket doesn't seem like a one-time-use thing. In fact, I was actually pretty underwhelmed with the gasket. The brand new one I put it seemed to be not much different than the OEM one I removed in regards to degradation.
 

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