My 2001 Ford Excursion Limited 6.8L V10 4x4 has recently started a new behavior—after we took it into pep-boys for a brake diagnosis (why is it our cars always come out worse at these places than they go in?)

PROBLEM: At first the car would shudder as we drove up hills around 40MPH.

Fix attempt #1) I tried getting some Heet (Something like this on Amazon: HEET 28202 Iso-HEET Premium Fuel-line Antifreeze Water Remover and Injector Cleaner - 12 Fl oz.)

Outcome #1) This SEEMED to make it a little better, then it seemed to make it slightly better so I figured I should double down on that:

Fix attempt #2) I tried seafoam (Looked like this but I got it at O'reilly I just dumped it in our fuel tank

Outcome #2) Now the new symptom is that my car smells like burning matches when I stop the car. The smell seems to have diminished over time. The old symptom, the shudder seems to be worse now, I get it whenever I go about 35 - 45 on a straightaway. when I go faster, or floor it at that speed the shudder goes away.

Note:
Later on youtube, I saw people putting 1/3 in vaccum line on master cylinder 1/3 in gas line and 1/3 in motor oil—so I got another can of seafoam at the ready.

Here is what I have tested so far:
Vacuum Line test with Vacuum Gage: (my altitude is 4775 ft, so I am adding 4.7 in Hg to my measurement) I measured 13.3 In Hg at Idle + 4.7 = 18 in Hg. My book says at sea level good is 17-22 in HG so I think I might have a few minor leaks, but overall my vacuum should not impair my engine performance.

Any suggestions on what to look at next?
Thanks,
Jim

 

Don't put seafoam in with your oil!!!!

 

Sounds like a miss from a coil pack to me off the top of my head. It will probably not give you a check engine light, but good chance it will have thrown a code or a pending code. Try getting it scanned at the parts store.

 

It seemed a little bit weird to me too, given that oil is supposed to lubricate, and chemicals like this seem designed to clean and remove build up of carbons in the engine. The guy at O'Reilly thought seafoam was awesome, but he didn't know how to use it. So I looked online and found this.. Since it was posted by Seafoamsales, and it had an official sounding narrator, I assumed it was real instructions. Of course just because the maker of Seafoam thinks putting it in oil is a good idea doesn't make it so.
But I thought maybe it helped remove varnish in the cylinders or something like that, so I was willing to give it a try.

Anyway, I can say, using seafoam in my gas only DIDN'T fix my problem--but after using it my problem changed from happening only uphill to happening on flat roads too, and it made my car smell like matches.

So I am not a seafoam proponent...yet, but it seemed to be likely touching my problem, since the hesitation/vibration now happens on the straightaway--but that could be a coincidence.

Did you have, or know someone who put it in their oil, and had problems? What happened?
(I am not trying to feed the trolls here I am curious, but I am mostly trying to resolve my car problem...)
Thanks!

 

Sounds interesting, I hadn't gotten it scanned, because there is no check engine light. Now I will, thanks! (After I finish changing my oil).

On a side note, I am planning on replacing my spark plugs, and read somewhere Autolite plugs aren't a good choice for this type of car, are the platinum plugs worth it? I have also looked at platinum + Iridium I saw last time I was at Wal-Mart...

 

The sulfur smell could mean you have a catalytic converter giving you the problem. You can easily check with a backpressure gauge which screws into the O2 sensor location. If you don't have one available then just remove the O2 sensor and take it for a quick drive. It will be a little loud but the exhaust will have a place to exit. If the problem is reduced or eliminated then you have a clogged catalytic converter. I just went through this and replaced it with a Magnaflow stainless one. The correct PN for our trucks is 49959 if you decide on a universal one - it's a 3" in/out and is rated for the 6.8 V10 and GVW of up to 15000 lbs.

 

The problem I see with seafoam is once all the sludge build up starts to brake up.... Well you can imagine....

So, the way I see it, seafoam is great for a newer car with little miles that gets an oil change every 3k miles or less, and gets driven everyday.

I use a penzoil oil that cleans the engine in a milder fashion every 6 months, I run it for 1000 miles and change it back to motorcraft. The penzoil is very clear( looks like cooking oil).

I'm very picky in what goes into my engine, and often refer to most things like this as crap in a can.

IMO....

 

I had a similar problem with my 1999 F350 with a V10 and what I noticed was some of the plugs on the wiring harness for the coil packs and the fuel injectors were not getting a good connection because the clips were broke off. So I zipped tyed the connections down and the truck runs like a top now. Maybe look into that?

 

I can't add much to the discussion on probable causes, but I've got a different opinion of SeaFoam.

Let me start by saying that it's a FUEL ADDITIVE. I've never dumped any into the oil and have no intentions of it. If your vehicle is properly maintained with regular oil changes you shouldn't have a deposit buildup in the crankcase, head assemblies, valve trains, etc. If in doubt about the crankcase deposits, use an oil additive that's engineered as a high detergent oil additive, like the Rislone oil treatment.

I've used Seafoam in several vehicles as a fuel additive. Some fuels (like Chevron and Shell) have an effective cleaning agent in them that keeps the injectors clean. They will even slowly clean dirty injectors. But many of the discount fuels have minimal detergents in them. They may not foul your injectors, but they can result in a slow deposit buildup that slowly deteriorates the injector performance. If deposits are preventing your injectors from working at their best, Seafoam (or similar additives) can help clean the injectors and restore performance to you vehicle.

Seafoam isn't a panacea. But it can help make an engine run better by cleaning up some of the things that dirty or low-detergent fuels leave behind. This includes moisture which has an opportunity to get into the system every time you remove the gas cap.

 

My '02 has had an issue like this ever since I bought it at 84k, and I've yet to figure out what it could be. I've done the following:

-10 new Motorcraft plugs
-new eBay coil packs (thinking that might be the problem)
-new fuel filter
-cleaned cold air intake assy (did not completely remove though)
-cleaned mass air flow sensor
-tightened/sealed the front transmission dust cover that I read can vibrate sometimes
-found some of the intake manifold bolts loose just recently, so I tightened those.
-ran injector cleaner through a couple tanks

After all of that, the noise is still there. I have another Ex to compare it to also, and the '02 has always sounded significantly different.

I've also noticed the engine is significantly louder in the 1700 RPM range, whether cruising in that range or in acceleration. Give it a little more gas to get above 2k, and it isn't as loud. The '05 does not do this. Tightening the trans dust cover helped the noise a little, but it is very tight now (tapped it with a hammer) but the 1700 range noise is still there for the most part.

My next step was going to be to try seafoam in the tank only just to see if it would make a difference, but now I'm not so sure I'll bother since it may not do anything like my other attempts.

I did find/remember my front left coil pack connection (is that #6 ?) had the little plastic plug part broken and I taped it really good with electrical tape. Well, the tape let loose... I decided to pull that plug out just because to see how rich/lean it was running, and when I put it all back together, I put new tape plus a cable tie to hold it down better as it had backed off a little before. Yet again though, didn't make a difference, unless another is loose like that.

I'm very interested to hear what comes of this thread. Since it hasn't affected performance at all (just is annoying to my incredibly particular self), I'm about ready to let it be before I actually cause a problem.

 

I pulled the codes over at Oreillys, and I had a P0301 and a P0306
Misfire on cylinder 1 and 6.

So I assumed it would be bad plugs (Im not sure when it was changed last, but I know it has been more that 100k miles) and bought some, last night I opened up the hood and pulled the cylinder 6 COP and boot. Inside was an plug immersed in coolant!!!

So I suctioned the coolant out and blew out the spark plug hole the rest of the way with compressed air, changed the plug and dried out the Coil/boot and replaced it. I also replaced the #1 plug (although there wasn't anything visibly wrong with that other than a really old plug) AND the smell is gone

The coolant seemed to be coming in because my #6 is right next to a radiator line that comes into the intake manifold housing and any leak seems like it will pour right into the spark plug hole

I'm figuring I need to get a gasket for the radiator line but for now I put temp gasket goo under the boot to keep the coolant out.

So I went back to oreillys and cleared the codes. Then engine was idling much lower and was faster at lower rpm, so I was hoping I was mostly done, but my wife drove it on the highway, and said at around 50-55 mph is is making a similar racket and sometimes the vibration comes back, so I gotta pull the codes again and see if #1 is still misfiring and/or if #6 is reverted.

I'm guessing I need to figure out if the problem is fuel injector/COP/or connections as suggested above (thanks mckservices) on Cylinder 1, I'll post an update. Anyone know of a thread on here with really good troubleshooting tests to figure out which of the components is the failed one?

to Sunline Fan, did you pull the codes? I have to tell you that was a most valuable suggestion, since it took the problem from a bunch of symptoms with a lot of possibilities, to a more narrowed list and a specific place to look.

Thanks to all and TIA,
Jim

 

Hi Jim,

No, I have not had any codes pulled from Autozone or O'Reilly's. My Scanguage shows no codes stored, but I haven't taken it to have a fancier code reader put on it.

 

The Scan Tool said P0301 and P0306 again.

I came back home and checked and there was no coolant in cylinder 6, so I had to check my logic. So I swapped the 1 and 6 coil packs with the 3 and 8 coil packs.

I figured if the coil packs were bad I would stop getting misfires on 1 and 6 (P0301 and P0306), and get misfires on 3 and 8 instead (P0303 and P0308).

If the fuel injectors (or something else with the cylinder were bad, then the errors would stay at cylinder 1 and 6.

This morning I got over to the shop, and now my codes were P0306 AND P0308. To be clear, I had moved the coil pack from 6 to 8 vice versa.

The fact that swapping the coil packs on 1 and 3 stopped the problem made me think maybe the coil pack on 1 wasn't seating properly before, and when I switched it, I got it to seat properly.

I had to think on the other one as I was really not expecting that outcome.

When I was reconnecting the coil pack from 6 to 8, the connectors snapping tab broke off. So I had to zip tie it on. I think it might have been loose, and I didn't use any dielectric grease after cleaning out the rubber boot when it was originally flooded with coolant. So I bought some dielectric grease and repacked both coil packs still getting codes, drove out and came back.

Now my code is only P0308!!!

So now I am down to coil pack, rubber boot, connecter missing tab.

I will remove the rubber boot and put that in another cylinder, put the coil top somewhere else, and tighten the bejeebees out of the zip ties on the known good coil I put on cylinder 8.

I'll check in later.

 

Me too.

Here's a post of mine from back in 2008 from here in the Excursion forum.

From this thread by G8Scott72: https://www.ford-trucks.com/forums/7...ml#post6762841

Stewart

 

SO the last test was that I put the suspect coil on cylinder 9, zip tied the connector on 8 to a known good coil pack, put the suspect rubber boot on cylinder 2.
I got a new misfire on 9 and the other cylinders (2 and 8) weren't giving me any codes.

So I bought a new coil and replaced the bad one on cylinder 9, and was surprised to get a code P0359 but quickly realized I forgot to attach the connector to Coil 9 in my excitement.

Now it runs great! Thanks to everyone for their help!

I think I will try that other bottle of seafoam now!
Jim