hello. I have a 2002 Blackwood that I took to the shop to get checked out and fix a slight shake or flutter that you feel in the seat at idle or stopped at light. The RPMs do not fluctuate at all, it stays at 700.
The shop replaced the spark plugs, changed the valve cover gaskets due to oil in plug holes, replaced vacuum line due to hole and still have the slight shake in seat.
It isn't rough or bad but it is noticeable to me.

I checked the coils and they were fine. I ran Lucas cleaner through the gas twice.

I checked the motor mounts. they seem fine. The engine seems to run fine and sometimes you don't feel it in the steering wheel. It is mostly noticeable in the seats and body. Once I step on the fuel it runs great. No shake nor loss of power from what I can tell.

The transmission was replaced last year from what I was told. Thought maybe it was torque converter or harmonic balancer but I am stumped.
Seems to accelerate good but sometimes I think it has a vibration accelerating like a slightly out of balanced drive shaft but nothing that makes you think twice about it.
When I take foot off brake the truck doesn't edge forward like most vehicles.

Any help would be great. My mechanic says its a fine truck and doesn't acknowledge an idle problem but to me it is kinda annoying. ( of course he also said there wasn't anything wrong with the air bag suspension until I ordered them and had him install them and he saw the old ones never worked)
If it were any more pronounced it would be a rough idle and act like it wants to stall but like I said the idle stays the same. I even tested the MAF, IAC, TPS and they all are good.

I took off one of the vacuum lines and it sucked in air like crazy and tried to stall out until I put it back on. That was on top the Intake next to the IAC.

Thanks

 

Did you clean the MAF? I would clean the throttle body as well.

 

I didn't clean it, I just checked it for build up.

I just got back from store and some idiot pulled in front of me so I stopped real quick and for about 2 red lights the truck ran perfectly. Then it started back into the flutter.

I'm thinking of taking it to a shop and have them check out the tranny and engine mounts better. When I stand on the brake and gas it, the truck rolls to the right slightly.
Thinking the drivers engine mount is worn but I never had one break so I don't know exactly how they feel. I am just guessing from the Dodge I had before that when I stood on the brake and gassed it it just revved and had no body movement.

Makes me wonder.

() Ok I got Maf Cleaner and gonna clean it tomorrow. will update with progress. Hopefully I can avoid trip to garage.

 

Could be a number of things. Trans mount where the exhaust hangs from could cause a vibration. Worn body mounts could be a problem as well.

You say you "checked the coils and they were fine) visual inspection only benefits the condition of the boots. There is no way to tell by looking at them whether they could be weak or causing low grade misfires. How many miles on the cop's? What plugs did the mechanic install?



Where is the idle in gear with foot on the brake?

 

Also check the engine oil level. These engines can generate quite a vibration when over filled with engine oil and feeling it in the seat was one of the characteristics.

 

I checked the engine oil and its perfect. Although I think my smell is off cause the oil kinda smells gassy but that could be in my mind. The exhaust doesn't smell like gas. There is 129k miles on the truck but not sure how much on trans or what exactly they did to the trans last year, the previous owner said he had the transmission replaced last summer. He was the only owner of the 2002 Blackwood and pampered it. But little things are bad with it thats why he traded it. The fold in mirrors don't fold in, the cruise control doesn't work and its not a fuse, the air suspension was out so i replaced it and the dealer replaced the air pump, the radio volume button was going out so I put in a Kenwood dvd player stereo, the valve cover gaskets were leaking so Replaced along with the plugs and the plug boots, vacuum hose was worn and holed so replaced that.

Now theres two vacuum hoses that I can't here leaks but they are not rubbery, more like dried and when you touch them you get grease on your fingers. I wondered bout finding and replacing each of them. One goes from intake to brake booster area, another goes from brake booster are across firewall into a tiny plastic hose running down the passenger fender, and a small 90% one on intake but that all don't seem to have any leaks, just figured the engine cleaner they used caused them to be like that cause the engine area looks armor alled. lol I pulled one off and checked the inside and the inside looks like a new hose would on outside.

I didn't visually inspect the coils. I took each one off while the truck was running to see if the shake was still there among the misfire and it was. It was tedious but I couldn't find my ohmmeter. And since it doesn't throw any misfire codes or any other codes its kinda frustrating.

I will say when I come to a stop on off ramp on Interstate it doesn't have the flutter until the next red light.

I was going about 125 on the Interstate to test the engine at speeds and was great. It does seem like it has a slight strain on full take off but I've been driving a Lincoln LS for the last 10 years so I'm used to quick solid smooth take offs. What I am talking about is it seemed like it was air/fuel that was dragging but it wasn't dragging really cause it was quick, it only felt like it was if that makes any sense. hah lol

I think I'm going to find an Engine shop because my mechanic is a general mechanic and I believe a specialists can probably help this problem better seeing its not a big problem just annoying. I get 11-12 in city and 13-13.5 hwy mpg and that is normal for a Blackwood considering the specs are 11/14.
Thats why it being a fuel/air doesn't make sense to me but I'm not an expert just a mediocre mechanic. I always had problems diagnosing but I can fix so I guess I'm just a grease monkey. hahaha

I'm gonna keep truing to figure it out but will post when I go to the garage next week.
Thanks guys

 

Thought I would update this. I went to my mechanic and he put the truck on the computer and found out it had misfires mostly in 1, 2, 3 cylinders and since it doesn't throw codes it showed in the cylinder test part of the computer so I will be replacing all 4 coils on the one side and see how that reacts. If its not them it will be the injectors and after that would be compression but think its just the coils.

He wanted 325 to replace all 4 and I said no but thanks. lol Considering that is the easy side. haha. If I don't post again that means it is the coils.

I hate when I search the internet and find a forum with the same issue I am having and no one posts updates to let people know what actually was wrong with their vehicle. Cheers and thanks everyone for your help.

 

Well I replaced the 1234 cylinders coil and it seems to run better but I can't really tell cause it still has a slight shake. I even cleaned the IAC valve.

I am thinking now it is the fuel injector. Tried the lucas treatment but going to run Seafoam and use Chevron techron gas to see if that helps.

It just baffles me that the RPMs stay the same and the mounts are all ok.

 

Don't bother with Lucas or Seafoam - just use the Chevron gas and/or put a bottle of Techron in the gas.

 

I replaced the IAC because when I unhooked it, the truck isn't stall. It did nothing so.

I put a bottle of techron in and time will tell right now but I am back to thinking 1-2 of the injectors or harmonic balancer cause when I rev the engine it seems like a vibration between 1500-2000 Rpm.

I was thinking EGR because the top intake hose by the IAC had a whining suction but when IAC was replaced I did not hear it. I even unplugged the battery so the PCM can adjust to a new part if needed.
The vibration I am figuring is just the stutter/shake at higher rpm. Over 2000 Rpm it is smooth or at least it seems smooth. lol
The shake doesn't seem as pronounced as it was or that is just my mind playing tricks on me. lol

 

Just a real rough stab - make sure you don't have a bent or damaged fan blade or a wobbling pulley.

 

I recall a few issues with phantom vibrations that drove us crazy. A defective damper/harmonic balancer or broken key way is one, bent flex plate, low level miss fire of course and one that eluded us for a while was the exhaust system. An exhaust system that was installed under tension can cause what you have. The fix is to loosen all the system fasteners and retighten. Found this on some F150's, Mustangs, and Lincoln Town cars and it was felt in the seat. Just a phenomenon that can take place. You could try removing the serpentine belt and see if it goes away. One thing you said above is that you thought the oil smelled like gas...This can also change your oil fill level and that will make a vibration, you already checked I know. That is also a indication that you are still getting a miss fire. Not knowing the complete history on a vehicle is difficult as well because an accident even a minor one can change everything.

 

First of all Thank you for the Replies.

The previous one owner said he had a couple small accidents but nothing too major. One is all that showed up on the car fax report but didn't say to what extent. He didn't elaborate and the truck doesn't look like it was in any, everything lines up perfectly so either they were really minor or the body shop did a wonderful job.
He did have the transmission replaced last year but I think he said they didn't change the torque converter cause it was fine.
He seemed genuine and said he pampered it, which the truck interior is showroom quality but I dunno cause he told me he didn't change the spark plugs and needs a tune up. Which when the garage went to change the plugs and found oil, I got skeptical.

When you first start the truck she runs great and idles at 1000 Rpm. Then slowly she slows to 700 and it feels like a misfire. Now I started noticing it seem like a vibration until past 2000 Rpm. I always thought it was just the tires but focusing on it, it may be just the shake accelerated.
I was just out there testing all the vacuum lines. Can't do extensive tests because I live in apartment building but unhooking them and seeing how she runs it did not mimic or make the shake get worse. Ofcourse a few hoses unplugged it wanted to stall and thats normal.

When she is revved up to 1000 you really can't notice the shake, may be just cause its revolving higher.
I was actually thinking of biting the bullet and having the injectors replaced but I am going to wait to see if this Techron works. I have a suspicion that it won't.
I did have an injector go bad on my Lincoln LS and that was actually caused by the valve cover gaskets leaking and fouling the coils. Which this one had the valve cover gaskets replaced cause oil in the plug holes but it had no symptoms or issues.

I have heard that using aftermarket oil filters can cause issues and I don't know what the "truck dealer"; not ford, used (It is white but didn't notice any brand), since some dealers are cheap.
I guess I will do that next. get an oils change.
When i was testing the truck this morn, I did notice white exhaust but it was cool, not cold and has been humid lately. I smelled it and it smelled normal. Not gassy nor sweet.
I have to take it to a mechanic this week to get my PCM number since I can't get to it to read it and was gonna get a tuner from 5 stars. I thought maybe being a 2002 that the timing was off a tiny bit and a new tune would fix the problems giving it a different firing retard. Of course it also runs the risk of making the issue worse. lol

I will also take the serpentine belt off when it stops raining and see if that does anything. The fan is smooth and not wobbly.

Sorry for long post.

 

I am also having a vibration in the seat when in gear. You feel it when its in drive at 700 rpm it shakes when your foot is on the brake. It never did this until i had the head gaskets replaced. The heads wheir rebuilt. new timing guides and tensioners,new plugs. I cleaned the maf no good. I even tried new coils no good. It only does it when in gear and foot on brake at idle. She drives great. The shop did take the body off the truck. I was thinking body mounts. And they also put all new manifold bolts. Not sure what it is or what to do but its driving me crazy.

 

Is it only when the foot is on brake or is it in park and foot off brake? Sounds like its the brake booster vacuum, I came across that in my searches.