Wankenstein

2007 Mazda 3 (2.3L) with a 2012 Ford 2.5L swapped engine. Manual Transmission. 200k miles on car, 50K miles on engine. Please skip to the question portion if you don't care to read the history.

History:
One month after swap engine overheated and obvious signs of a head gasket leak. White smoke from exhaust, loss of coolant. A day after overheating I performed an (ezone approved..lol)) dry compression and the result was cylinder 3 was at 75 psi. and the other three cylinders were at 160 psi (normal). I then performed a wet test with (ezone recommended) two tablespoons of oil in the cylinder and the compression did not change which points to the cylinder compression rings are not the cause of compression loss and the valves or valve guides are the cause.

I brought to the mechanic that did the engine swap and told him the symptoms and compression test results. I asked him if a leak-down test would further isolate a compression ring and/or valve(s) leak before replacing the head gasket. I told him that my concern is if there is a cylinder compression ring I'll just sell the car as a shell and not bother any further with the engine. He told me there's no need for a leak-down test and it won't help since the head gasket is most likely leaking compression.
From my understanding if there is compression loss from a breached head gasket then it's usually located a the portion (of the head gasket) located between two cylinders and both cylinders would have low compression.
He said there's no way to get accurate compression test with a blown head gasket. I was skeptical but, went on his word that the head gasket the issue along with the possibility of a warped cylinder and leaking valves.
He stated he warranties his labor and the machinist's labor for 12 months.

After the head was pulled he brought it to the machinist and was told it needs resurfacing and two exhaust and one intake valves are leaking. The machinist resurfaced it and did a valve lapp job on it. Now, one month later there's been no overheating but, the compression in the same cylinder is down to 100 psi during dry and wet test. and CEL has cylinder #3 misfire code for that cylinder. I did power balance test, coil lift for spark and spark is very good. Swapped coils, removed fuel injectors and watch the spray into a bucket..all four look good. Replaced spark plugs but, no change.
I isolated the issue down as much as possible before calling the mechanic
I called him and said bring it in.

Today:
Mechanic performed OBD2 scan and showed same cylinder #3 misfire code. He then did the same test other than fuel injectors and wet compression test that I did the day prior. He also used a camera to look into the cylinders. I told him I did my wet compression test yesterday with two tablespoons of oil. So, at this point he said that indeed cylinder #3 is low on compression and that he (under warranty and at no charge) will remove the head and bring it back to machinist. He said if the machinist doesn't find a valve leak then any other source of compression loss fix (cylinder rings) would be at my cost. He walked away, came back 10 minutes later and then did a wet compression test. However, when he performed the wet test he poured in way more than two or three tablespoons of oil. He poured in several ounces of oil and that made me suspicious. I recall reading in a few various post of ezone's that only 2 tablespoons is sufficient.

Question (finally, LOL):
When performing a wet compression test can adding to much oil cause over inflated numbers or temporarily seal a faulty valve?
Related info: http://www.dsmtalk.com/forums/showthread.php?t=140859
Should I ask him to perform a leak-down test in front of me to confirm either rings or valves?

Another issue I have is that if he gives that particular machinist a lot of business it would be easy to for that machinist to lie for him and say that it's not due to leaking valves under warranty work. I told the mechanic, when we were discussing warranty work (before his wet compression test), that if he pulls the cylinder head I want to bring it a different machinist, one I used in the past. He didn't react to that very well but, said I could but, he wouldn't pay for it. I then told him I find the machinist's work that he used very suspect if the valve-lapp that he supposedly did failed so early.

ezone

tl;dr
lunch is over and bizzy as hell today
maybe a tablespoon of oil?

Wankenstein

When he added what seemed to be about a 1/4 of a quart, compression went from 100 to 160 psi. I plan to have him to re-test it again with one ounce of oil. I will also ask him to do a more definitive leak-down test since it involves possible warranty work.

Is this correct?: (copied and pasted) "Compression is artificially raised whether you add a little or a lot of oil, it doesn't matter. The wet test is inaccurate and really doesn't tell you anything useful. If you had a low cylinder and did a west test, the compression would be bumped up and you'd say "the rings are shot" and go to the trouble of rebuilding the bottom end when really the problem was a burnt valve or seat in the head."

or this?: (copied and pasted) "The problem is that if you put in too much oil you reduce the volume of the cylinder and create an artificially high reading."

And there is more: http://www.waybuilder.net/sweethaven...Num=7&modNum=6
(copy and pasted) "Do not put too much oil into the cylinder during a wet compression test or a false reading may result. With excessive oil in the cylinder, compression readings go up even if the compression rings and cylinders are in good condition."

I honestly don't know if he purposefully does things in this type manner or he doesn't know what he's doing. He accuses me of watching to many youtube auto repair videos and reading to many internet auto repair information for diagnosing. I am wondering if he doesn't read enough information or is too overconfident in his abilities.

Wankenstein

Here's more: http://www.dsmtuners.com/threads/com...esting.338152/

(copy and pasted) "The problem is that for one thing, the wet test is dependent on the profile of your pistons. If all the oil remains at the center of a dished piston instead of out at the rings, then the results won't change much. Another problem is that adding too much oil can effectively lower the displacement of the cylinder and naturally increase compression, leading to false assumptions."

ezone

Ask to see his ASE certifications.

If compression test came up low......Why no leakdown test as the follow up check? That test would have proven valve leakage long before pulling the head and sending it out.

IF the machinist did a valve job (or whatever) and it's already got more valve problems on the same cylinder.......



Just reading, I've little confidence in either of the parties.

Seek out better? Borrow tools from the Zone and DIY all the way?
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A wet test needs JUST enough oil to get the cylinder walls wet with oil and fill excessive gaps in the compression rings, if there were excessive gaps in the rings that were leaking during the dry comp test. If rings were normal and not an issue you would gain maybe 10 PSI or so between dry and wet.
If rings are leaking badly, you may expect the bad cylinders reading to come up to nearly equal to the other good cylinders with the wet test.



Dished pistons present issues as described above. You have a turbo engine, are its pistons dished?

If one dumps in so much oil that it takes up all the space in the combustion chamber, that gives falsely high compression readings and could cause hydrolock and bend rods.
As you posted in #4 above.

I bet a big enough slug of oil could make leaking valves look good too.

Wankenstein

That would really **** him off.He doesn't like my doubting attitude as it is now. I feel my reason for concern is valid though.

Yep. Same thought here. I will ask him this Friday to do one to further isolate the compression leak. I asked him to do one before he pulled the head over a month ago and just blew it off stating it won't help to isolate leak when gasket is breached. I probably should have walked away at that point.

I stated to him that if the machinist that he chose to do the valve job failed this early that I don't want him doing another one. I guess that will be another point of contention if it's not a compression ring causing the leak. I've read that these valve assemblies have to be shimmed properly or they can easily leak.

I should have but, got lazy. If this turns out to be a compression ring I will most likely keep the car and replace the engine at my leizure. My son is shopping for an auto loan currently.
=========================

Being that I used a near recommended amount of oil and the compression stayed around 100 psi (same as dry test) and he used much more (near 1/4 quart) which brought it up to 160 psi (same as other three cyinders) Is it possible over-filling it that much would result in a gain of 60 more psi or more likely just a failed compression ring?

It came out of 2012 Ford Fusion and I'm not sure if that engine was turboed or if it has dished pistons.

I read that too and was concerned today when he poured in as much as he did.
Side note* He told me today that when he first got the car after the overheat and knew from our description that coolant was getting into cylinder(s) that he ran it only a short time because he was concerned about hydro-lock. He said he limited it to a dry compression test only at that time due to coolant in cylinder.

Seems like with the amount of oil he used it could temporarily fill leaking valves. It ran real well for about a minute until the oil burned off and smoke was coming out of exhaust.

If my son continues to run it as is, is it possible to disconnect the 3rd fuel injector to avoid a rich running condition and a possible clogged cat converter?

ezone

Post #1Really? But then:
Post #6Why not on the first one?
Why bother on the second one?
Was I not supposed to point out the contradiction?
So he has no certifications of any sort, current or lapsed?
How about the "machinist"? Any certs there?

In almost everywhere in the US (except maybe Michigan), any clown with a shoebox full of tools can call himself a mekanik, and hang a shingle and start his own shop. Don't even have to know a dang thing about what he is doing.

My certifications issued by Honda are proudly displayed for customers to see.
I have certs from other manufacturers, but they won't let me display them in the Honda dealers customer waiting area LOL
Long ago?
Need help finding someone else? LOL



If it has flat pistons then I'd probably say you're right, he's wrong. Not a ring problem IMO. Leakdown test should verify valve leakage problems.

Also, you mentioned this but I don't know anything about your engine so....if this engine uses hockey puck shims for valve adjustment, who is adjusting the clearances and where are they getting shims?
Tight valves burn.

Wankenstein

Because, apparently that's how he operates as I now know. When the opportunity for him to get paid arises he provides less information. After he gets paid, then things go wrong, the info that should have been provided prior to the start of job becomes available after the work is done, issues arise and then I interrogate him. I even asked him today wether or not he checked the block for warping after the head was removed and he said he didn't. He does repair work at a lower fee than most and now I know why.

Yes, he is ASE certified, in current standing and has been a mechanic for 27 years.

The secret machinist? I have no idea if he is certified. The mechanic would not provide an address or phone number for him even though I asked a few times. He said the machinist only does work for mechanics and does not deal with the public. The mechanic wrote on his reciept (company lettehead) that he (the mechanic) is fully responsible for the machinist's labor which includes resurfacing and valve job and is warrantied for twelve months or 12k miles.

Unfortunate.

Okay. I'll post results of leakdown test.

Maybe it's the 2007 Mazda 2.3L head that has the shims and not the 2012 Ford 2.5..here's a parts diagram: https://www.bluespringsfordparts.com...ion-parts.html

Wankenstein

In addition to the low compression issue one or both transmission/cv output shaft seal(s) is leaking. Though my son brought it back to him two weeks after the head gasket replacement to find an oil or gear fluid leak, he couldn't find one. Three weeks from that point my son couldn't get the MT into 5th gear so, I did a MT drain and fill and there was only 1/2 a quart of gear oil that drained out. It's calls for GL-4 gear oil and the only easily available GL-4 rated is Royal Purple Max full synthetic. It's rated for GL-5 too and GL-4 compatible. I spoke to an RP tech support and he said it won't harm yellow metal synchros. The mechanic is purchasing and replacing both seals and not charging labor. He removed the engine to do the head gasket and should have replaced those seals anyway at the time of installation.

When I pick up the car tomorrow I am going to ask him to do a leak down test and re-test wet compression correctly. Should I ask him to leakdown test each cylinder at TDC and BDC ?

Wankenstein

He replaced outer shaft seals. Afterwards I asked him about doing a leakdown test and retest of wet compression. Surprisingly, he took it calmly and said to bring it back Monday. He also said the only way to to proper leakdown test for the valves is with the valve cover off and then something related to the cam gear. I wasn't paying that much attention because my only concern is wether or not the 3rd cylinder compression ring is leaking and if the bubbles appear in the coolant reservoire. If, the compression ring isn't leaking or if there's bubbles in the coolant system then it's under warranty work.

I've never performed a leak-down test however, I've read about it and watched videos. Here's related info: http://www.dsmtuners.com/threads/com...esting.338152/ My son and I plan to be there when he does the leak down and wet compression test. Any other suggestions on what I should be watching for or concerned about?

ezone

Jeez. Valve cover off why? I want that damn thing ON to contain and funnel any air movement into a small controlled area...if there is a leak, it's much easier to feel the air movement coming out of something the size of a straw (breather vent tube) instead of a wide open window.

Spark plugs are the only thing removed to do the check.

Remove the radiator cap before pressurizing a cylinder.

Find my video in the overheating sticky thread. I'm doing the same thing in that video, only I'm looking for leakage into the cooling system and using full shop air pressure instead of a leakage tester with dials and gauges..

So you do the same thing, and then you'd stick your sensory receptors up to the tailpipe and intake or throttle to feel/listen for air movement. Any air movement indicates valve leakage. I've even stuck one of my blue gloves over a pipe to tell if it fills, that means a leak.

If you feel air coming out another spark plug hole, screw the plug in that hole so you can tell if/which valves were leaking on the pressurized hole.

Wankenstein

Probably, because he knows it will be harder to pinpoint a valve leak with the valve cover off. I told him after he said that, that I've never read or seen videos of a leakdown test done the way he described. I said I'm fine with not taking the valve cover off and just listening for air through the TB (intake hose removed), oil cap and dipstick removed, coolant tank cap removed and from the tail pipe.

Okay. Great suggestions. I'll watch your video. Thanks.
How many PSI of air should be used?

Wankenstein

I'e decided to break down and purchase a compressor. It's been long over-due and I can use it for other non related home projects. I don't plan on running an impact gun with this but, should work for leakdown testing: http://www.homedepot.com/p/RIDGID-6-...-206859412-_-N

Cheap minimal tester: https://www.powernationtv.com/two-mi...down-test-tool

Better DIY tester:

ezone

Valves don't leak into the crankcase, rings do.
Depends on your needs. A real leakdown tester is regulated and could run anywhere from (guessing) 30-100 PSI.

The video I made is using as much pressure as I can get because I am trying to prove a head gasket breach from the cylinder into the cooling system, and real combustion pressures are extremely high.

Wankenstein

Okay. I guess what I am trying to say is that he hopes it's a compression ring leak and I hope it's an intake valve leak (heard through open TB flap) or exhaust valve (heard through tailpipe) leak. In his mind a compression ring leak would absolve him from warranty work although, he should have done more to detect a potential ring leak before he initially pulled the head off over a month ago.

If, it comes down to a small claims suit I will have to find a professional mechanic/witness to state that in court. Hopefully, a civil suit will be avoided.

ezone

Keep in mind:

If you think one cylinder has a problem, you need to check the other 3 good ones for comparison before you say for sure.

During a leakdown test, you WILL find leakage into the crankcase from every cylinder. That is normal and correct because rings are never perfectly sealed.

IF your questionable cylinder has zero leakage from valves, then before you condemn rings you are going to have to quantify the amount of leakage somehow to determine leakage from that one cylinder is far more than the others.

Wankenstein

Thanks Ezone.

From what I've been reading after I read your response is 20% and under compression leak is acceptable depending on age/wear of engine. If t's 30% or more then it's considered severe damage.

Is it possible to have zero leakage from the valves? IIRC I read at some point in time that during a leakdown test there will always be a small amount of leakage through the valves at TDC as well (unless I confused it with rings). Some reads say to slightly rock the crankshaft (when piston is at/near top of stroke) to find true TDC.. is that okay to do on an intereference engine?

Something I forgot to mention is that he told us (my son and I) that he performed a dry compression test after the head gasket replacement/ valve job and psi numbers were 158 (stock) psi on all cylinders. It did seem to run well for a couple a weeks afterwards. If, his compression numbers were truly correct then, in my estimation, would further point to his or machinist's work failing than a compression ring on this 50k mile engine.

ezone

Depends. Testers may vary.
Always compare to your known good cylinders, use that info as your guide on the questionable one.
Damn well better NOT be any leakage at all.
There is always leakage past the rings.

A 4 cylinder engine will always have either pair of pistons in the same physical part (location) of a stroke, but opposite points in the 4-stroke cycle.

If you picked the wrong cylinder to test, it's valves may be on overlap instead of firing. That might be what you are thinking of.
In most cases but not always.
Some engines you are not supposed to rotate backwards at all, but a few degrees of rocking may be ok. The concern as always is to not jump time.

The Ford engine may jump time if you back it up too far, because the chain tensioner doesn't have oil pressure behind it if it is not running. (I know some of theirs can jump time if you let it run out of oil)
IMO just lapping in new valves isn't a proper valve job, even though in the real world it probably happens a lot and is usually successful. Once in a while a shortcut can bite you in the azz.




The '07 2.3 and '12 2.5 engines you mentioned, in Alldata both are described as using hockey puck shims for valve adjustment..
Specs look about the same for both,
in .009"-.011"
ex .011"-.013"
(in .25mm and ex .30mm, .....+/-.03mm)
You know the compression is low, has anyone checked valve clearances? Valves too tight can sure lower compression, and tight valves burn.

Wankenstein

Okay. Will do.

Thanks for clarification.

Then I will avoid rocking it.

It should have been a three angle valve job? Another concern I have is if the valve springs were ever tested. At 50k miles I wouldn't expect any of them to be weak but, a good machinist would have checked them.


Thanks for posting that data. He never mentioned wether or not he checked valve clearances so, it's very possible they weren't done unless the machinist did it. Given the mileage should he have installed new shims?
The mechanic said only the valve stem seals were replaced.

A few days ago he said if a valve guide(s) failed than the warranty wouldn't cover that. Seems like these: http://edgeautosport.com/supertech-v...d-3-2007-2013/ can be inspected for failure, or at least he could have given me the option to purchase new ones when the head was off.

ezone

Every valve job is supposed to be that.
However, it's also easy to screw it up and do shoddy work that won't last.

I'm suspecting the mechanic did the work (lapping in valves), not any professional machinist.


The shims don't wear out. Shims are only changed or moved to adjust clearances.
Whomever assembled the head and cams should have checked and set clearances, and if not during the head assembly then when the head and chains were installed enough to spin the cams.

Wankenstein

Seems to be about 50/50 at this point. I know for sure he pulled the head off though because I asked to to see it at that time (over a month ago). He could have sanded it down (resurfacing) on a glass top surface with sand paper and then did a valve lapp himself. Last time I went over there he offered to bring me to the "machinist" shop and talk to him in person. I told him I would like to but, not until after the compression leak is isolated. I figure in the meantime I can research, as well as pick your brain concerning the shims, valve guides and other useful intake/exhaust valves operation info that I can arm myself with before I meet him.


If a proper adjustment wasn't done or at least not performed correctly I doubt he will own up to it.

ezone

Regarding valve adjustment shims.....back when I worked with at least a couple different car lines that did use shims, for each type of shim there was a big box with a selection of every shim size...we just grab the box and swap out whatever shims we needed to use. No clue if any were actually billed to the customer, because this work was like an exchange instead of outright.

Of course, each manufacturer uses different diameter shims, so they aren't exactly interchangeable. Even some of the different engines within the same manufacturers car lines didn't share the same shims.
I'm just a mechanic. I'm not a machinist.

Wankenstein

I'm neither and trust that your knowledge concerning both far exceeds mine.

I purchased the compressor I linked last night. HF has all the pieces needed to build a leakdown tester except the pressure gauge. Fortunately, HD sells a 300 psi gauge. I'm skeptical that the HF regulator will last long but, I'll try it first. Hope to do a leakdown test tomorrow but, my wife and I are hosting Thanksgiving and all the home and food prep that comes with it may take precedent.

I told my son that from this point on (exception of warranty work) that we will DIY repairs. In that way what ever goes right we can feel good about and save money. Whatever goes wrong we can only blame ourselves and then try to correct it.