Well, that was exciting.
My wife was driving our Escape near Davis, CA, when it ejected the #6 spark plug. Took it to a garage, where they heli-coiled the hole. Total for the repair was about $600. This leads to a couple things.
First, the car has a tick now that it didn’t have before. Is it possible that the spark plug ejection stressed the rod bearing or wrist pin to the point where one of these is now about to disintegrate?
Second, how likely is it that this repair will hold for more than, say, one year?
Third, I have heard this is a common problem with the Ford modular engines, but not so much with the Escape/Taurus Duratech engine. Is this true.
"Is it possible that the spark plug ejection stressed the rod bearing or wrist pin to the point where one of these is now about to disintegrate? "
No.
"how likely is it that this repair will hold for more than, say, one year? "
Very likely. If done right, and most are, it is as good as new, sometimes better.
#3 I don’t know.
$600 to install a Heli-coil??? There must have been something else to the repair.
The Heli-coil should last the life of the engine if was installed properly.
No, the ejection of the plug wouldn’t stress the rod bearing or wrist pin.
Well, I think the reputation of the garage where I took it is very good. Hopefully, that’s true.
Thanks for your quick reply.
One more thing: The frequency of the tick, to me, sounds like it could not be a rod bearing or wrist pin. At 800 rpms, I’d expect 1,600 ticks per minute; one for TDC, one for BDC. Instead, it sounds like every other revolution – a lifter.
It just so happens that Ford has a TSB to fix a noisy intake lifter, specifically for the #6 cylinder (the TSB applies ONLY to cylinder #6). It’s not a hard job; basically, you retorque the caps on the intake cam, which should take about an hour. Very few parts involved.
It seems reasonable to me that ejecting a spark plug could trigger this problem. Opinions?
$200 in parts, 3 hours of labor… I wasn’t that surprised.
The repair should hold forever. These problems are generally caused by overtightening of the spark plugs.
Considering the parts total is 200 dollars I assume this means not only a Heli-Coil but a new spark plug and coil also?
Just wondering if they reused the original spark plug or coil and the ticking is a spark jumping inside the tube.
I don’t see an ejected spark plug causing a problem with engine bearings or the valve train.
What are the chances the ticking was there before and was just not noticed? The plug problem occurs and now more attention is being paid to engine sounds?
A LOT of the time, a loose spark plug or exhaust leak is incorrectly diagnosed as valve train noise. Unfortunately, I think either your spark plug is not sealed, or you have an exhaust manifold leak.
Yes, it needed a new coil too, at over $140. I also asked the garage to check the tightness of the other plugs, so there was extra labor there, too.
One thought occurred to me, and this seems like a highly unlikely scenario: Maybe the mechanic nipped one of the valves with the helicoil tap. Like I say, I doubt that.
The car wasn’t making the noise before this; it’s a very loud and obvious ticking. I was thinking of asking the garage to perform a compression test on that one cylinder, because I also heard that leaking plugs can sound like a loose tappet.
This sound is definitely new since the incident, because it is very loud. It doesn’t seem like the correct frequency for a loose rod bearing or wrist pin – I’d expect two ticks per revolution, and it seems more like 1 tick every other revolution.
One other thing: The car is running really well. If I didn’t hear that noise, I’d think it’s in perfect shape. That also seems consistent with “lifter”; it doesn’t take much additional clearance to make a lot of noise with a lifter, and the car can still run great with a loose lifter (within reason, of course).
I put a long screwdriver at various points on the engine (poor man’s stethoscope), and it sure sounds like cylinder #6 to me.
See my response above.
It could be a gummed up or faulty lifter. They use a valve lash adjuster that looks like this.
http://www.partsamerica.com/ProductDetail.aspx?MfrCode=CLE&MfrPartNumber=2131766&PartType=169&PTSet=A
These kind of adjusters are used on many different makes of cars and can be more problematic IMHO than the “old style” lifters, if you want to call them that.
You’re correct in that the engine may run perfectly fine with a faulty one up to a point and you should not worry about a valve problem caused by a thread tap.
One way to verify if the plug is leaking is to remove it and note if any part of the plug above the plug tapered seat has any residue on it. This could mean a leaking plug seat. I’m inclined to think this is not your problem if the thread insert was done correctly.
Another potential cause of a tick, or even a loud knock, can be a piece of debris floating around in the cylinder. This is unlikely because a small piece should blow out past the exhaust valve and if a large piece was in there it will cause detonation and noise like you won’t believe.
Kind of leaning toward a lash adjuster coincidence here. If it were my vehicle, I would add can of SeaFoam to the engine oil, drive it around for a day, and see what happens. If an adjuster is acting up due to grunge or whatever the SeaFoam should clean it up. SeaFoam is a cheap (about 6 bucks) alternative to digging.
JMHO and hope that helps.
I’ll give the SeaFoam a crack, er, try.
I want to ask this again (this is my way of bumping my own post):
Is it possible that ejecting the spark plug and then driving for 6-8 miles at freeway speeds could have wrecked a wrist-pin or a rod bearing?
The mechanic insists that’s the problem, and I am very skeptical. I think it’s leaking around the plug hole. How would one test for that?
While I suppose anything is possible, I don’t see this causing a wrist pin or rod bearing problem.
A rod bearing is going to come across as a noticeable deeper rap sound and a wrist pin normally appears as an erratic rattle that is not steady.
Remove the coil on the questionable cylinder and start it up for a few seconds. It will run rough but if the noise remains you know it’s not likely a bearing or wrist pin.
If you suspect the plug is leaking remove it and note if there is any blackening around the plug hex and eyeball the plug taper seat very closely. The seat and hex should be clean. Hope that helps.
You should be able to squirt some sort of non flamable liquid around the sparkplug and see if it is ejected.Plug blowby is a real possibility if the helicoil wasn’t installed right.
Thanks for the heads up. My 05 Sable has the Duratec 30. Owner of VW bug 60’s I knew but didn’t connect.
did you remove the plug and look inside and use a feeler to ensure the helicoil was NOT inserted too deep?
the helicoil web site has complete instructions which must be followed and the only way to check that this was followed would be to remove the plug and feel around.
did you look to see if the small nib of the helicoil was snapped off inside the helicoil (inside the head in the cavity?)
if the helicoil was not installed properly; that is what may be hitting/impinging on the valve.
have you (or someone independent of the original mechanic) ascertained this?
Well, I’m back, because I had to think about this some more.
The mechanic who did the work insists that the noise is in the bottom-end. I reject this partially. First, the sound isn’t random enough to be a wrist pin. I think I can eliminate that.
I cannot, however, definitively eliminate the rod bearing… To which you’re all saying, I must be nuts. I don’t blame you.
But hear me out.
Think about the normal intake-compression-ignition-exhaust cycle. With the plug out, during a “normal” compression stroke, at 2,000 rpm, the velocity of the air coming out of the cylinder has to be extreme. At that point, you have a spark plug dancing around in the tube, being pretty unpredictable. Now, on the normal power stroke, the valves will be closed, meaning that there will be a huge vacuum through the plug hole. It seems possible to me that, because this spark plug is dancing around pretty good at this point, it could land back in the hole. If the timing was just right, the vacuum inside the cylinder would be unbelievable. This car has quite a high compression ratio.
To make this work, things would have to be just right. Suppose in the 18,000 or so revolutions the car was run before it was shut off (6-8 miles at freeway speeds on the Yolo Causway, in case anyone’s interested), the above scenario happened 10 times. Wouldn’t that ruin a rod bearing cap? Is it possible I now have, say .020 play instead of the, say, .005 it’s supposed to have? Would I hear that?
To this point, I’ve rejected the idea of “rod bearing” because it just didn’t seem possible. But it could be, IF the situation I described can happen.
If this is the case, could the mechanic drop the pan and check the bearing clearance? Any Duratec experts out there know if this can be done?
The original mechanic insists the problem is in the bottom-end. The Ford dealer partially concurs, but insists the sound is from inside the cylinder. But when this engine is stone-cold, the first start is pretty clacky (and regular). It sounds sorta like a rod bearing. But once warmed up, at 3,000 rpm, you can’t hear a thing. It sounds great. I would not really expect a rod bearing to do that, unless, of course, the clearance “only” increased from .005 to .020. Would I hear .020?
This mechanic, for some reason I don’t really want to know, doesn’t want to pull the plug. This makes me really suspicious. I’m leaning towards the “head must be pulled” theory, not the rod bearing. But I wanted to put it out there: Is what I described possible?
If you have a rod bearing clearance at .020 you’re not going to hear knocking for very long. When one gets this loose it’s probably going to spin and when that happens the engine is either going to blow up or quit. (And .005 is WAY too loose.)
If you suspect a rod bearing then do what I suggested previously. Disable the coil and plug on that cylinder and start it up. It will run rough, it will trigger the CEL, but so what.
If the noise subsides a lot then the odds of a rod bearing problem are at least fairly likely. At that point, drop the pan and pull the rod cap on that cylinder.
If the noise disappears completely then that may point to something in the cylinder NOT getting hot and causing detonation.
I still don’t see this plug problem causing a rod bearing fault and I don’t understand for one minute the hesitation to remove a single spark plug.
Has something been added to the symptoms or have I forgotten something? Now the noise disappears when the engine is warm and it sounds great at 3 grand? That could point to a lifter or piston skirt fault.
In retrospect, there may be a very valid reason why the mechanic does not want to pull the plug. You stated previouly that you overtorqued the plug to 15 ft. lbs. instead of the stated 11 ft. lbs. (which is also too high IMHO).
If the tech knows this then he does not want any part of this deal for fear of being blamed for anything that goes wrong.
See, that’s just the thing. He is extremely reluctant to remove that spark plug. This leads me to think he’s afraid to.
With that in mind, I don’t want to pull it either.
I feel like he wants me to step in front of the bus so he doesn’t have to see what happens if he does.