Dissecting a failed Coolant Bypass Valve that caused P26B7 fault code

I dissect the failed Coolant Bypass Valve from my 2014 Ford Escape to see why it failed.

[@Bobkachal]

Thanks for making this easy to understand.

[@glasser2819]

2 thumbs up, great video

[@TiktokBrandoniMacaroni]

This code is what’s popping up for my 2019 Nissan Titan that has 14,900 miles on it how could it be broken already,could it just be coolant levels low ????

[@patrentfrow]

I'm a very dyi person (won't even tease calling myself a mechanic) and have done a lot of replacements/repairs on my 2014 Ford escape and I have a very important question. Where can I find the exact tool to pressure test the coolant system? I have a coolant leak somewhere and I've looked everywhere I think I possibly could and can't find it. I've found many kits on Amazon or elsewhere, but as you know, the escape doesn't have the traditional radiator cap. I want to purchase a pressure testing kit, but don't want to purchase the wrong one

[@hackfreehvac]

I'm a HVAC tech not a daily car mechanic. But you may be able to see if the auto parts store has a loaner tool. Something that screws in place of the coolant cap that goes to a hose with a gauge and a pump. Pump it to like 15 PSI.

[@fynetuneyrgf]

Yeah, years ago I wondered why all of these new coolants and their new colors were coming out, like the orange stuff that is used in these new Fords. Well with all of these new bypasses and such using plastic bodied electric components and rubber seals everywhere, all probably for emissions and such by the way it goes. They likely need these specific coolants, along with the correct and timely flushing of the system at recommended intervals, all so these parts have the supposed life. So when you see a new Ford or whatever manufacturer car running with the old school bright neon green coolant and not the correct factory orange, blue, yellow or whatever new color it should have. You should probably drain that old green stuff and spend the “double the cost” for the correct manufacturer supplied “new” stuff. Plus probably half of these Escapes, Focus, Fiesta, Milan, fusion, and the others, Ford autos out there still running the original none updated 1.6 long block or updated 1.5 head. Have had or most probably will have a bad coolant leak into cylinder 2 or 3 by 80k miles or as early as 35k by most accounts. It’s a Turbo motor designed by Volvo based on the old naturally aspirated ford Duratech block pushing 14 psi of boost, with a open deck, the thinnest cylinder liners ever (which are cast into the block as to make the surrounding aluminum cast also thinner. all for weight savings, super thin when all together), leaving little surface around the cylinder for the gasket to lock and seal to. Which then on top of that, Ford then proceeded to mill a small groove in between each cylinder on the top deck/gasket mating surface to allow coolant to circulate through, while making the whole deal even thinner for the gasket to seal to. It all =s to a warped head on the 1.5 Ecoboost, and almost certainly a warped block and head on the larger 1.6 Ecoboost. If you were lucky and your engine blew and was replaced under warranty, due to there being a TSB for this on the 1.5 and 1.6. No recall, should have been, but there was At least a TSB ordering to change the long block (1.6) or head (1.5). The 1.5 got the same old head, and will probably do it again, but the 1.6 got a whole new updated design block. It had the milled grooves deleted to add surface and strength, and the cast around the cylinders was supposedly very very slightly thicker. But all in all, there is no excuses, the Japanese manufacturers have already been through this in the 80s. Look at their turbo cars now, they are all semi closed deck, closed deck, or iron block. US manufacturers just lack the experience of the Japanese in this area. But using a stronger deck when needed isn’t rocket science.

[@hackfreehvac]

The turbo Japanese cars in the 80's were absolute JUNK! LOL. I was driving in the 80's. The Nissan 300Z and Mitsubishi 3000GT had major issues all the time. Blue smoke soon and then occasional BOOM. They did have the most power per liter in those days. But not known for reliability by any standard. Same for the Mitsubishi 4 cyl Eclipse As from what I understand, the EcoBoost is more similar to the Mazda Speed Direct Injection as both were being designed and tested when Ford owned controlling stock of Mazda until the recession in late 2000's. Ford happened to own Volvo as well. And Astin Martin, Jaguar, Land Rover etc Anyway. Not to jinx us. But the car has been driven every day by a teen for the last year and it is still going. Just cracked a hose so it lost boost. I just need to order that hose and that will be fixed. I haven't had to fix that much in this vehicle's now 9 years of hard life. I used to drive this car HARD and now a teen has driven it for a year. I think most of the issues you mentioned are from Focus ST and Fiesta owners. Of course a bunch of them had done some mods and tunes to jack the output up. So...

[@BorgWarnerKP39]

​@@hackfreehvac Interesting that you mention Focus SY and Fiesta ST owners when both uses different engines (2.0 and 1.6 ecoboost), as far as i know the problematic one is the 2.0

[@shadowbanned69]

They make that shit to fail....they know it’s gonna fail within so long and that’s how they make there money now.....not thru new car sales...nooooo it’s tru fixing the shit they put into it

[@jmparrish]

Think you could just replace the top part to fix the issue? I’m not looking forward to replacing this one tomorrow in my wife’s car. Trying to take the easy road if there is one.

[@hackfreehvac]

I don't think they sell pieces to repair it. It's a simple replacement, however. I also imagine it likely would have worked again if cleaned out. But it isn't too expensive so I just replaced it.

[@mer2016]

@@hackfreehvac I was thinking of just buying the complete part and only replacing the top part. Especially after seeing this video and that that much of the sludge and problems with movement are at the top. Thoughts on that?

[@cml2953]

my check engine light is on and the code was this code. can I still drive the car until I get it fixed?

[@hackfreehvac]

As long as you don't leak fluid. Should be fine. Btw. A popular Ford tech youtuber just did a how to on this failure last month. FordTechMakuloco kzbin.info/www/bejne/kF6QXoewa5xjqs0

[@MrLuwitin]

Mine reads 7.9 ohms. Anybody knows what a good one should read?

[@vlqllvol]

7 to 16 ohms go see at 0:55 in that video kzbin.info/www/bejne/anzRcomYhZeZgtE

[@swatxr6]

give it a clean and see if it moves when back together.

[@hackfreehvac]

I wasn't even able to make the plunger budge!

[@swatxr6]

@@hackfreehvac Shit

[@coldfinger459sub0]

Looks like you don’t change your coolant or you add tapwater to top off with with all that muck corrosion buildup When you’re with it coolant passages have your heater core microchannel looks like Even after 300,000 miles in 10 years a cooling system should look pristine and clean.

[@hackfreehvac]

The car only has Luke 50k but looks like I probably will flush it. It actually lost some coolant a year ago when the overflow tank cracked. I replaced it and topped it off.

[@glasser2819]

I guess not all "long-life coolant" are created equal. OEM is always the best match... for what's required. Seems the new cash-cow is controlled failure or degraded mode to force premature service.

[@coldfinger459sub0]

G Lasser It’s not a new cash cow it’s been that way for decades. And coolant cannot handle topping off with tapwater because of the magnesium the calcium and iron in the water the salts act as a electrolyte creating a battery deteriorating metal from one metal surface to another and breaking down the coolant anti-corrosive additives. There’s also many coolant chemistries they all say coolant and sometimes they may say compatible with a certain model vehicle but the aftermarket coolants of different chemistry that are compatible require a complete system flush with distilled water before adding the new chemistry type coolant otherwise you end up with half the life that was designed by the coolant when intermixing. Over 40 years ago before I even got into junior high school my dad taught me if you don’t like somebody and you want to cause a failed heater cores or expansion plugs or radiators top off their coolant with tapwater ticking time bomb. It’s the difference between a coolant system that fails at 50 Kto 80,000 miles or a cooling system that goes 200 Kor 300,000 miles you make your choice

[@titogaray5224]

why would there be sludge if coolant got in? Coolant should keep the car coolant system clean.

[@hackfreehvac]

Coolant breaking down, etc.

[@missa160]

4.7 ohms its a normal value of resistance?

[@hackfreehvac]

It can be on magnetic coils for solenoids or larger relays. But that's a little low for smaller ones.

[@MrLuwitin]

Mine reads 7.9 ohms. Whats normal resistance?

[@vlqllvol]

7 to 16 ohms go see at 0:55 in that video kzbin.info/www/bejne/anzRcomYhZeZgtE

[@denrayr]

It's a chicken and the egg scenario. Did the sludge come from the coolant system and gunk up the valve? Or did the valve fail and gunk itself up. My money is on the valve being the source of the sludge. It wouldn't hurt to do a flush because some of that rust likely made it into the system. I'm even more curious now to find out how the computer knows the valve failed. I have 2 theories: 1. The stuck solenoid would have drawn excess amps. If the computer measures current, then that could explain the code setting criteria. 2. Another explanation would be a ptc or some type of self resetting thermal fuse built into the coil. It would overheat while being energized and the protective device would make it go open circuit. Then, when the computer de-energized the coil, it would see an open circuit and set the code. Take my theories with a grain of salt. I'm just thinking out loud here. Anyway, I'm glad you got it fixed. P.S. I just want to add that I've been following your channel for years, and I appreciate the content. My favorite video is when you showed how useless PTC start devices are. Thanks for all you do to fight the infamous run cap bandit lol.

[@hackfreehvac]

Thanks man. That PTC video is a decade old now. Lol I had talked about some theory of the circuit setting the fault but edited it out. I know that at least on ac powered coils the current is higher if the steel core isn't pulled into the windings. As we have probably all experienced, if you pull a coil off of a pump down solenoid or hot gas bypass valve and leave it energized long it will pull crazy current and melt. Maybe it measures current in a similar way?

[@denrayr]

@@hackfreehvac I was going to let this go, but I couldn't get it out of my head. I did a little more research and found that DC solenoids don't have the same short circuit characteristics as AC solenoids do when the plunger is stuck open. DC solenoids have a fixed resistance and don't react to the changing inductance as the plunger moves through the coil. I also found a sheet from Ford that explains the setting criteria for your code. The code sets when the computer measures either an open or short in the coil circuit. See this link for a snapshot that I took: ibb.co/sJDmcw1. Now I'm back to square one. I think there may be 2 separate failures here. The computer doesn't have any way of measuring the state of the valve. It may have jammed some time ago with no noticeable consequence. The second failure would be caused by an intermittent open or short circuit coil. This is the failure that would have set the check engine light. I wanted to see what your thoughts are here. I feel like I'm stretching to fit a diagnosis to the available data. It's an interesting case nonetheless.

[@hackfreehvac]

@@denrayr Well I did replace the part a few weeks ago now and the code never came back. So the car seems to be good now. Although I want to remove some coolant and examine it to see if I should flush it.

[@patmurphy2472]

Back Flush the cooling system. The extreme heat in your area, and turbo are hard on coolant. Use the Motorcraft premix stuff.

[@denrayr]

It's only 50,000 miles and the coolant looks perfect. I don't think the coolant broke down at all. The materials in the valve weren't made to hold up to the harsh environment of the cooling system. People all over the country are having failures, not just those in hot desert climates. I bet the new valve is made to last longer. I haven't seen the tsb for this issue, but I bet it calls for replacing the valve. The presence of a tsb indicates that Ford is aware of the problem and likely means that they have addressed it in the new part. The reason for the coolant flush would be a precaution in case some of that rust from the valve contaminated the system.

[@olderolderman4603]

Chris Fix or Our 👧 fry