Update 02 LS V6 Shaking at idle/low RPM

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Adam_Dawg78

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I posted about this problem previously and am still going through to try and find the problem. Here is a brief history.

December had misfire code, replaced all spark plugs. Month later problem happened again, went back in replaced all plugs, broke a couple of connectors so I just secured them back with tape.

Shaking became more noticable. But power steering was acting up too. Fixed power steering by installing new Pressure Switch. Shaking still there.

Went back in and replaced the electrical connectors that connect to plugs. since I had the intake off, I replaced gaskets, pcv valve, pcv elbow. DPFE Sensor, EVR Vacuum Soleniod. After putting back together had to go back in and replace the o-rings on the fuel injectors that I messed up.

So now everything is back together and shaking is still present.

It shakes when stopped. At low idle, evens out and shaking isnt present past 2k rpms. Then around 50mph shaking occurs again. not as bad as idle/low rpm. I cant get a code to register. It seems to be worse at low rpm, when shifting into reverse and reversing slowly and shifting from reverse to drive. I ended up doing this multiple times, not applying gas just letting the car go a little forward and then same in reverse and the car died. did this twice. Still no code.

I ended up going to the auto parts store and bought a new IAC Valve and EGR Valve. I havent replaced the EGR vavle yet, but I did do a test on the existing one. I hooked up a line to the vacuum line that connects to the soleniod, cranked car and applied the line to the valve, few seconds later it started sputtering and almost died, took line off engine back on, applied again, this time it seemed to want to stall but never got there. So Im still confused about this part.

I decided i would replace the IAC Valve on the car first Cranked it still noticed some shaking, but the odd thing is it stayed at a very high rpm, never settled back down. then it all of sudden did and died. Cranked again and revved it up, it idle at about 1500 then slowly started to accelerate. Turned it off. Cranked again, and finally after staying around 1500 dropped back down to about 900.

I thought maybe they gave me the wrong valve, but I checked it out online and its the right one. I have just cleaned up the old IAC Valve about to go put it back on and see what I get.

I will be checking back here, so if anyone has any theories or has had this problem please let me know. Is there anything else you think it could be, would a vacuum leak or lmass air flow sensor do this?
 
Have you replaced the coils yet? You'll need new plugs as well..
 
when U say shaking?????

Is it just a rough idle?

Is the engine shaking in park or just in drive under load?

be specific, can U start the car and let it sit running without problems?

I have the 01V6, any roughness in idle is usually a vacuum leak. A complete loss of idle is usually the IAC valve.

If U replaced the PCV valve and elbow, but not the vacuum line from the elbow to the throttle body, then that may be the problem. On the throttle body there is a booted line that runs to the back of the engine and down to the PCV elbow. There is a rubber boot on both ends of this vacuum line. The boot at the rear of the engine splits from the heat back there but it's hard to find. Put a light back there so U can see, lean in from the driver side and pull up on the vacuum line, or just remove the entire line and check it closely for splits.

check all clamps and hoses after the air filter for tightness. remove engine plastic cover, check small vacuum hoses leading into main air flow chamber for leaks, cracks, etc.

U may have gotten a bad IAC valve also.

Took me awhile to find all the vacuum leaks in mine but once I did, it runs smooth as silk.

You should get a code tho for a leak,,,,,something like too lean bank 1, can't remember exactly.
 
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Starts fine and drives fine, no shaking when driving except for the small studder/shaking feeling when you hit 50mph. When you crank the car and it drops back down to idle it begins to shake. Also when you come up to a stop sign it shakes.

I put that I replaced the boots, I should have put I replaced the coils, boots included with new coils.

The vacuum line that connects to the manifold to the pcv elbow looks like it has been replaced before. The connectors are rubber, the line is a solid plastic which is covered by a soft rubber tubing. The connectors were split at the opening, i ended up putting some 3m weatherstrip adhesive around the tube and inserted it back into the connector.

Could I do some sort of smoke test on the lines or into the manifold to find out if I have a vacuum leak?
 
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How well does it idle if you unplug the MAF sensor?
If it gets better, you probably have an air leak somewhere, probably those couplers that you already know are bad.
 
i unplugged the maf the car died, recranked it and shaking was same. unplugged both connectors, the maf and smaller one connecting just to side of maf and shaking still present.

Cleaned the original IAC and put it back on. It starts up 1300-1500 rpm's then drops down to about 900 to 1000rpms. still shakes. put in drive rpm's drop to 600-700 still shakes
 
can't figure out why I am not getting a code, i unplugged batter, fired back up and nothing shown. Connected the reader and erased codes waited nothing shows up.

The shaking I am describing can be felt through out the car. Shaking felt through seat, so there is something wrong. I am starting to lean toward a leak, but cannot find anything. I've sprayed carb cleaner all around and didnt notice any changes. Im so frustrated
 
I didnt think this information was necessary, but know that I am completely confused I will add it.

When I replaced the coils, I only replaced the 3 that were under the intake. All spark plugs are new, but since I got the misfire again and it was the one under the intake, I replaced all 3 so I wouldnt have to go back in.

The 3 that are easily accessed on the driver side are still the older ones. is this a big no no, would it cause the problem? I dont want to waist $150.00 on 3 coils if there isnt anything wrong with them.
 
You should replace all coils and plugs at the same time. Any broken connectors should be replaced if questionable. Otherwise secure with zip-ties, and not tape. Start there. This will improve your drive. It $uck$ but your lincoln LS eats coils.
 
i did replace the broken connectors and the code for the misfire was for the one under the manifold so i replaced those three while in there.
 
no pic in photo bucket. I am thinking it may be a leak. I took a hose, held one end to my ear and ran it across some of the lines. I can hear a leak in one of the lines. Sprayed with carb cleaner, didnt notice any change in motor. The hose in question is bundled. One connects just past maf and when I pulled it off had a good vacuum pressure. The other two run up, combine into one hose and connect to the manifold.

anyone know how to check for a vacuum leak using a cigar and hose? Ive heard to plug it into the manifold, but is there a certain area best to use?
 
before december????

you original post does not say if the engine was good before december. did it ever run good?????

was it running good then a cel code, the started running rough?

i assume it was good until you replaced the plugs and cop's right?
 
Adam_Dawg78 said:
anyone know how to check for a vacuum leak using a cigar and hose? Ive heard to plug it into the manifold, but is there a certain area best to use?
Click to expand...

You'll have to ask Bill Clinton..... Or Monica.... Hillary probably has no clue....
 
lol, love some scotty kilmer.

Car has ran great for as long as we have had it. This is the first issues we have had. we are at 140k miles. 1st prob code on misfire, then all the repairs made above.\

when you drive it, it runs great. it just shakes like crazy when you stop and after you crank it and it is idling. Also if you put in in gear and do not apply gas, it shakes as it moves. once you accelerate no shake rattle or roll.
 
It shakes when in park too? Possible busted engine/transmission mount? Pop the hood and watch the engine while someone else pops the gas. The engine should shift a bit, but if it moves a lot there's your problem.
 
hey buddy, that sounds like you have a bad motor mount, shaking occurs especially at lower rpm's then fades away as you accelerate, your engine has very little support...
 
Have you replaced the PVC elbow, under the intake manifold? If not it definitely needs replacement.
 
IDK if that gen has intake manifold tuning valves, but if they do the o ring fails causes a vac leak. When mine failed rough idle.
 
youre on a goose chase if you only replaced coils on one bank. you need to replace the coils on the other bank. unless they have less than, i dont know, 20k miles, 2yrs, and from a reputable brand... then maybe its not the old coils on the other bank...
 
tuning valve

forgot the o-ring on the valve on the back of the intake manifold. it will also leak oil onto the exhaust manifold causing mystery smoke.

check all your connections behind the manifold, are all the connectors and hoses in the correct spot.

I agree with the other commentor, replace all the coils and plugs, then we'll talk some more.
 
forgot to come back and update this. I finally got fed up and told my wife to take it in and find out. Bad head gasket.

So i replaced the passenger side head gaskets and no more shaking.

Still heard an air leak, would turn out to be at the rubber pcv elbow that i tried to rig but wasn't affecting car so I just left it. Couple weeks ago it finally blew and made a god awful high pitch noise when you stopped. Took it off and decided to cut out that metal tube that connects the elbow to the intake air hose, then connected a hose to the pcv and ran it straight up to the intake, hose is 1/2 inch if i remember right, i plugged a 5/8 hose up to intake and used a reducer to connect to the 1/2 inch hose, no more elbow, no more air leak.
 
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