Well, I took the Escape to get a second opinion, and they want to pull BOTH heads. I am certain the problem is in the left head, so if they need to pull a head, I only want them to pull the left one.
The problem is, now I’m sure that the problem is caused by debris left in the cylinder from the helicoil job, and for some reason, the garage that did that job won’t admit to it.
What should I do? I think the garage that put in the helicoil should at least reimburse the labor they put into it. The bill was $559.
This second mechanic, to pull both heads (and not put them back on, mind you) wants nearly $1,000; it’s $1,700 to pull them both and then put them both back on.
And after all this, there’s a chance that it’ll need a new piston, if whatever’s in there has done too much damage.
Gar, this is bad.
I have a line on a wrecking yard engine for $650, plus $250 to deliver, but if that fails, I’m still out $1,000 to remove and replace the engine.
Can I just sell it as-is?
Or donate it?
A lot of questions, I know. But I think I’ve answered a question definitively: Can helicoil jobs go wrong?
Yessiree, they can.
There are things to use other than helicoils. They are solid nuts with threads on both sides and they won’t just blow out like some helicoils. The only bad thing is that they often come out when you remove the plug and it’s a little bit of work to get it off the plug.
now I’m sure that the problem is caused by debris left in the cylinder from the helicoil job
Why specifically makes you sure the problems was caused by debris left in the cylinder from the helicoil job?
Why did the second mechanic say he or she wanted to pull both heads?
Indeed, that is something of a gray area here. Lil more info?
Why are they charging you so much, their twice as much as most shops.
Helicoils are a patch, they were doing you a favor doing that, and it is risky to do, the chance a crap falling in is great but can save money and buy time if your lucky. You were not so lucky.
How did the threads get stripped out to begin with is my question of the day?
Exactly how is it known there is debris left in the cylinder from a Heli-Coil job?
A piece of debris, be it metal, piece of carbon, etc. CAN cause a knocking or rattling sound if left inside a cylinder. The particle becomes red hot and instantly causes severe detonation.
However, any particle from a job like this should be small enough to be blown out past the exhaust valve or out of the spark plug hole if the plug is removed. The only particles I can think of would be drill residue and most of the smaller stuff would vaporize in the first few combustion cycles. A piston with a severe nick or gouge could also heat up in that area and cause detonation but I don’t see how a plug being blown out or installing a Heli-Coil would damage the piston.
The only other thing would be if the piston suffered damage due to lean running the engine for miles with the plug out. A fluke IMHO but since it’s automotive related any weirdness is possible.
Any chance of finding a mechanic with a bore scope or possibly renting one to take a look inside that cylinder?
All of your options are pretty pricy and if it were me I would want to know for sure before tearing into the engine or replacing it.
The second mechanic was the dealer. They concluded from using a stethoscope that the knock is from inside the cylinder. Without going into the head, they have concluded that there is some “foreign object” (they cannot tell what) in there. It’s now either lodged in the piston or in the head.
The engine itself runs great. That’s the awful part. These plug holes are so small and at the end of a tube so long, I’m not sure they could even get a borescope to work. I did ask about using one.
I do think the shop that did this work botched it, but they made it clear they could not guarantee it, either. Looking at it now, I think they did something wrong, probably to do with removing debris.
My wife and I have discussed this, and I could have them remove and reinstall the heads… AllData says it’s a 13 hour job on this car, and after reviewing the steps, I can see why. It’s six passes through the tightening sequence; I think it might take 2 hours just to torque each head. It’s really complex.
We’ve decided to get rid of it. I really can’t stand this process any more. I can’t say the shop that installed the helicoil is liable, but I do think if they figured this was a hard job, they should not have attempted it. Turns out the dealer was willing to helicoil…
So now I’m stuck with a car that has a book value of about $9,000, and for which I think we’ll be lucky to get $5,000. Expensive mistake, for sure.
I’m also thinking of just driving it. If it’s a tang that has lodged itself in the piston, and now whacks against the top of the head on each revolution, won’t that eventually stop? And who would buy a car making such a noise?
This is a real predicament.
Here’s the punchline: I made the final payment on it TODAY.
Not kidding.
By the way, I no longer think this is a wrist pin (the sound is just much too regular) or a rod bearing (I’ve had it up to 6,000 rpm several times now, that rod would be wrapped around my forehead by now if the rod bearing was damaged). Nah, it’s in that cylinder. And to get that head off and on is 13 hours of shop labor. I’ve had the valve cover off; I can see why it’s 13 hours.
I think we are very heavily inclined at this point to sell this car, which is in otherwise excellent shape, at a steep discount. I think we’ve made up our minds.
The plug ejected. The book said 11 ft lbs, and I used about 15 (and followed Tom and Ray’s advice on using antiseize, which was a mistake).
Now, I know you’re not supposed to overtorque things, going 15 instead of 11 should be well within the abilities of those threads. If it’s not, Ford needs to use harder alloys. I’d think there’d be a pretty huge margin for error on something like spark plugs.
To get a better look.
I think whatever got left behind lodged itself in there. Yeah, I admit, it seems like fine aluminum shavings would just blow out of there. But it’s a very, very regular knock, so regular I thought it was a collapsed lifter. Not a random rattle, like a wrist pin would make.
Hmmm. I wonder if I could attach a .wav file to one of these postings.
Attached is the sound of my car.
hey mike:
don’t give up yet!!!
have YOU removed the plug from this cylinder and inspected it yourself? look at the end of the plug spark gap arm. is it scratched,. dented, or showing abrasion?
is the end of the helicoil insert BELOW the bottom of the spark plug?
i ask, because if the “extra” helicoil isnt snapped off correctly (inside the cylinder) it can hang down into the head cavity.
with the plug out measure the distance from the top of the head to the bottom of the thread insert. compare this to another cylinder to see if there is a difference between the length. i would be willing to bet the helicoil was not snapped off flush with the inside of the head. (although that may get "banged out of the way eventually, it should be removed)
ALSO, have you checked to make sure the shop installed the correct length spark plug? pull a couple to check their work.
in the process of drilling and threading the helicoil it is possible (although unlikely) that they drilled/tapped a little too deep, thus letting the plug go too deep into the cylinder. A shorter plug may help if the plug is too long. (also if they oversized the hole they would have to change sparkplugs. which may account for a different length.)
Yes, it’s the same plug on all cylinders.
One odd thing I noticed about this car is that the plugs hang down into the cylinder. That is, it looks like several threads are exposed inside the combustion chamber. I personally think this is what lead to the failure; when I removed the original plug, carbon deposits took out just enough of the threads to make the eventual ejection of the plug inevitable.
Anyway, with this design in mind, it would take a very long coil to go past the spark plug.
Did you listen to my recording? I still say it sounds like a lifter. I really do understand the velocities involved here. Is it possible that debris is inside the exhaust valve port, and that’s what I’m hearing? I understand pieces of aluminum would be vaporized there, but how about a piece of stainless wire (the coil)?
It doesn’t sound like a lifter. It is too fast for the speed of the engine. It sounds like something solid hitting something just as solid. I suspect that some debris from the retapping got down into the cylinder. Usually this debris will be expelled out the exhaust passage. Once the debris is past the exhaust valve there is no concern. If it gets between the valve and seat, you will have low compression in that cylinder and possibly the valve will burn. I don’t know if the Escape engine has hydraulic lifters. If it has solid lifters you would get a valve tap until the debris was displaced.
I think what has happened is that the debris has become imbeded in either the piston or head and the two are making contact on each revolution of the engine. Since the piston speed is not that high at the apex of its travel, the piston is not hitting that hard but it probably is cocking against the cylinder wall making a sort of slapping sound as well as the contact with the head.
Usually when a Helicoil is treaded, the tap flutes are filled with heavy grease. The tap has to be backed out and the chips cleared at regular intervals. It is still possible that all the chips may not stay embedded in the grease. So the question is moot whether the mechanic was hurrying and cut corners or it was just bad luck.
What it looks like is that you are going to have to go in an assess the damage so you will know the full cost of repair. Once the damage is visualized and the cause is determined, an automotive specialist can opine as to whether it is the fault of the original mechanic or just bad luck.
Let us know the progress of this case.
A long time ago, I used to own a VW. I stopped by that shop the other day, told the mechanic what happened and about the noise. He told me that when he’s done this job on VWs, they can make this noise for a while, and that stuff can get embedded in the head or piston with no real long-term consequences. It’s not like the top of a piston is 1/16" thick or something like that; a piston is, by design, a stout hunk of metal.
His advice was to “drive the Hell out of it for a couple weeks”, and that the sound would probably go away. Now, he’s more familiar with VWs than with the Ford Duratec, but it does seem possible that he’s right.
When the mechanic yesterday explained my options, that he could tear out the heads and possibly find enough piston/cylinder damage to require a new piston, I chose Door Number Three, “Do Nothing.”
The guy who did the original work thinks it’s a rod, which makes zero sense to me. Running with nothing in the spark plug hole, and with the valves opening and closing as normal, would put LESS stress on the rod bearing/rod/wrist pin/piston, don’t you think? And then there’s the chance that something got between the piston and the cylinder wall, and is now scoring the heck out of the cylinder wall, which means the block is ruined, but this seems extremely unlikely to me.
I almost wonder if a 3 hour drive on a freeway isn’t in order. Just drive down to Gustine, and turn around and drive back.
If there was debris keeping the valve from closing completely, or damage to the valve seat, it’d be running very badly, don’t you think? But other than this knock, which makes me think your diagnosis is the closest, it’s running great. Plenty of power. Revs freely to the redline.
I’ve listened to the clip several times, and while it’s hard to be defintive due to PC speaker quality, it does not sound like a lifter to me. The tone is a bit deep and resembles a rod bearing or something in that cylinder, but I don’t see a rod bearing being affected by the original problem.
There is a valid point made by Cappy about the possibility of the thread insert extending into the combustion chamber. If this were the case the edges of the insert will glow red almost instantly and cause severe detonation. This can result in a rod bearing like knock.
A guy I used to work with had a '56 Ford Crown Victoria, went out to start it one day, and it was knocking like crazy. It was not knocking that morning when he drove it to work. We determined the problem was in a certain cylinder, removed the plug, and when the engine was cranked over a huge chunk of carbon went zinging out of the spark plug hole. Reinstalled plug and the knock was gone. In your case, if the insert is protruding too far the knock will remain until the insert problem is cured.
I know the plug is down in a hole but this should not be a problem with a borescope.
In regards to spark plug torque, I still say that 11 ft. lbs., is too much for a tapered seat spark plug on aluminum.
The reason why is that with a tapered seat you’re applying solid metal against solid metal. The only thing that has any give in there when 11 ft. lbs. is obtained are the threads and it’s far more likely the aluminum cylinder head threads are going to pull rather than the steel threads of the spark plug.
Gasketed plugs are different because that gasket is essentially a crush ring and has some “give” built into it. The gasket will crush before the threads pull; up to a point of course.
As I mentioned, I’ve always tightend plugs by palming a stubby ratchet and the torque estimate is probably around 3-5 ft. lbs. at the most. There’s never been a problem with plugs coming loose or stripped/pulled threads.
Don’t know what to advise at this point other than a borescope, etc. and take a look inside the cylinder. If the shop installed an insert that is too long then this is their fault. They have an obligation to make sure things like this do not happen. JMHO anyway and hope it helps.
That does make sense because the spark plug hole is really, really close to the valves on these engines. I was pretty surprised when I saw a picture of it.
Time-Sert makes a “Big Sert”; it’s what to install when a HeliCoil or TimeSert installation has gone awry (haywire?). The problem with that kit is that it’s $350 for the tool and $15 for each insert. At this point, I do not want to spend money for a tool I’d use exactly once; I’d rather find a local shop that is already using these. It just seems like that would turn out to be a quick repair – if I could find someone to do it. Frankly, I don’t think I have the skills to do this job.
I like the detonation answer in theory. I have sent an email to TimeSert, who makes the Big Sert, asking if they know a shop in Sacramento who can do this installation.
15 ft-lbs is not too much at all. I never herd of using antiseize, that is not recommended by a real pro ever. Could you have cross-threaded the plug? This is the only way I have seen this kind of problem, and is easy to do if not careful.
I’ve never seen this design before, but to me, it looks like the tips of the plugs extend into the combustion chamber. That is to say, the end of the plug isn’t flush with the top of the inside of the head, but protrudes in maybe 3-4 threads. I don’t like it, but I think that’s how these work.
My thinking is that unscrewing the plugs probably did it. Get a little carbon on those threads – not hard to imagine after 100k miles – and simply pulling it out will damage the threads.
If I cross-threaded, it means I was able to get it all the way in cross-threaded. I just don’t think that happened. I remember the plugs going in very easily.
The more I think about it, the more I think I didn’t do anything wrong, per se.
here’s something to think about,
any debris is most likely NOT stuck between the cylinder and the side walls, your noise sounds like a dead end slap, at the end of the cylinder throw. if it was embedded in the side wall, you would hear a long scream, changing tempo with the speed. i think the valve problem would be indicated by bad exhaust(exhaust valve, or rough running (intake valve) so it doesn’t sound valve related.
what i hear there, is a repetitive slap. the aluminum head will eventually embed this into the head, or the cylinder head itself. BUT, this is assuming that it is from a loose piece of helicoil debris.
since im am not sure what your spark plugs look like, im assuming they have a bevel about half way down the shaft. the plug depended on ‘seating’ in the head on that bevel. the process of helicoil slightly reams out, then rethreads in the hole. the bevel would be changed, maybe even removed (which could let the
plug too far into the head. as i suggested before, have you really looked at two sparkplugs side by side, to compare them? (not one after another, but together, out of the block, side by side) i would be willing to bet the helicoiled plug would look different from the regular one.
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after you ascertain that the helicoil is NOT going down too far into the cylinder head area,
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find a washer which fits over the plug, and fits into the recess around the aluminum housing cast into the head. (but NOT into the hole.) i am thinking a stainless, fenderwasher, ground down to fit into the recess. (as an alternative, take a plug to the auto parts store, and have them find a plug with a shorter thread , with the bevel closer to the end of the plug.) This is WAY cheaper than doing a sert, of another helicoil!)
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reinstall BUT don’t over torque (even under torque is better (in the test run)) the plug and see if the increase in clearance changes the noise.
this would ‘lift’ the plug up out of the detonation area, to remove that as a possibility of the noise.
if this still leaves the noise, then (personally) i would live with it.
possibly you could do an oil change and have a matalurgical test of the oil to see what particles are in there. (that would let you know how bad the damage is, and what is damaged.) if the damage is below the rings, or even if the rings are involved the oil sample would tell you what metal is involved. this could let you know how much could be involved in damage. (but again i would just run it myself.) if there is NO metal in the oil, run it to death, and get used to the slap!
I was going to suggest the same thing, just drive it.
You mentioned that the plugs extended be on the threads and then had a build up of carbon. Are these plugs the original plugs or are they replacements that may be the wrong ones? The reason I ask is that I found that aftermarket listings are all to often wrong. I had this problem with getting plugs for Fords before, they were to long.