2010 4.0l Explorer: 2 Weeks with multiple codes. P0302 Remains What Next?

[sbbloom69]

Son’s 2010 4.0l Explorer. Had a nagging check engine light. I believe P0106 (Baro or MAP Sensor). I found broken vacuum line to HVAC. Patched. Code came back a month later. I found more bad vacuum lines in the bundle that hooks to intake manifold. Replaced the vacuum hose bundle. P0106 and 0302 remained. Common sense says it’s ignition, fuel, or mechanical. I checked spark on #2. It was OK. I replaced plug (which looked good), and changed wire. No change. I pulled #2 and #3 plugs. Compression on both was about 123 lbs. In spec. I used stethoscope. I got same even clicking on #2, #3, and #6 injectors. I had 12V on the injector signal plug. I haven’t looked at pulses on plug yet on my O-scope. I measured resistance on #2 and #2 injectors. Both were about 15 ohms (about right). Wasted spark coils, but I swapped #2 and it’s twin lead. I decided to attack P0106 code. Cleaned MAF (which has Baro sensor). No change. Replaced MAF. No change. I looked for more vacuum leaks. None found. But, I replaced the other bigger vacuum lines. No change. Didn’t want to buy new EGR (which has the MAP embedded in it). So, I pulled the intake up to the manifold (didn’t want to pull the manifold). I had just enough room to loosen the fuel rail and pull #2 and #3 injectors. I used battery and carb cleaner to test the spray. They didn’t look bad, and the spray was consistent between #2 and #3. I had a mechanic buddy say they looked good and the same. I swapped the #2 and #3 injectors and put it all back together. No change P0106 and P0302. Finallly, so replaced the EGR valve (with embedded MAP). The P0106 code cleared. P0302 remains. I pulled the PCV. It shook and was not clogged. It was dirty so I cleaned it. I bought a new one, but it had the same blow and suck response (clear in the vacuum direction, almost, but not sealed in the pressure direction. No change. Still have the P0302 code and the #2 cylinder is definitely misfiring (pull #2 plug wire and it runs the same).

What next?
I intend to check the PCM pulses to the injector.
Should I replace the fuel filter (no other cylinder problems).
I”m going to trace out the fuel injector signals to see if I missed a rat chew (a problem here).

There is a chance, that I did NOT swap the injectors. I may have put the old one back in. I guess I’ll just have to check that again.
I may buy one fuel injector for #2 just for troubleshooting.
What else is there that can affect only #2 misfire? I”m an engineer, and have worked on my own cars, trucks, motorcycles, and small engines my entire life. I understand the old and new technology.

I just bought a new ANCEL scanner. My old tester was just a ODBII reader. Can I drill down any further with any of the real-time data from the scanner before I tear into it again and buy more parts? I may buy the 1 month ALLDATA service manual for this.

 

[Turdle]

Recheck compression, against a cylinder on driver side. 123 is low

 

[sbbloom69]

Recheck compression, against a cylinder on driver side. 123 is low

OK Thanks.

 

[sbbloom69]

Bad news. I rechecked compression:
6 was 169 spit
5 was 165
4 was 165
3 was 163
2 was 0, zero

I put a few table spoons of oil in and rechecked It read 23 psig. I checked it again about 15 minutes later and it read 0 again. I don’t know how much the “wet” compression test is supposed to improve the reading. Does going from 0 to 23 mean it’s definitely the rings? A holed piston? When I put my finger over it, dry, I could easily keep my finger over the plug hole. I have a borescope. I think I’ll take a look for debris, or a holed piston.

I think I know what I did last week. I think I forgot to release the pressure from the gauge. So, when I read pressure on #1 (not 3), and then 2, I was still reading #1’s pressure. I know I said 24 or 28 # before. I was reading the gauge upside down and read the wrong side of 150. Anyway, not good news.

Damn. The truck only has 103k miles. The PO was the grandma of my son’s friend. She always garaged it and had the dealer do the maintenance. He’s only been driving it since March.

How far do I go with a 14 year old exploder? (I”mm allowed to call it that. I put over 240,000 miles on two different 1993 explorers).

Decision time for my son. Thanks for the help.

 

[sbbloom69]

Latest. Again, all of the P0106 codes cleared. #2 cylinder still bad. I bore scoped it. Valves seem to be closed at TDC. I pressurized the chamber with about 25#. First, it drove the piston down. Then I had my son reset the cylinder to TDC and then he held the crank still. I again added pressure. We didn’t hear any hissing from the intake or from the exhaust. I should have pulled the oil dip stick or cap, but forgot. On a whim, I pulled the radiator cap. When I had pressure on the cylinder, the coolant level in the fill neck raised about 1/8”. Maybe a head gasket? But, with pressure off, the level went back down. I haven’t run a hydrocarbon test on the coolant yet. I lost my leak down tester. I ordered a new one. That will be next. I took the truck to a local mechanic (has good rep). He is charging me a time fee to verify my diagnostics and drill down further. We’ll see. I’m hoping it’s just a valve spring, or maybe a head gasket. But it could be a slightly bent valve preventing the seal. Could also be a crack. WE’ll see. I can’t do any more work on my own for a while. I’m recovering from eye surgery. I have to stay down. Thanks for the input.

 

[sbbloom69]

Latest. Again, all of the P0106 codes cleared. #2 cylinder still bad. I bore scoped it. Valves seem to be closed at TDC. I pressurized the chamber with about 25#. First, it drove the piston down. Then I had my son reset the cylinder to TDC and then he held the crank still. I again added pressure. We didn’t hear any hissing from the intake or from the exhaust. I should have pulled the oil dip stick or cap, but forgot. On a whim, I pulled the radiator cap. When I had pressure on the cylinder, the coolant level in the fill neck raised about 1/8”. Maybe a head gasket? But, with pressure off, the level went back down. I haven’t run a hydrocarbon test on the coolant yet. I lost my leak down tester. I ordered a new one. That will be next. I took the truck to a local mechanic (has good rep). He is charging me a time fee to verify my diagnostics and drill down further. We’ll see. I’m hoping it’s just a valve spring, or maybe a head gasket. But it could be a slightly bent valve preventing the seal. Could also be a crack. WE’ll see. I can’t do any more work on my own for a while. I’m recovering from eye surgery. I have to stay down. Thanks for the input.

Update. The explorer sat while I recovered from my surgery. No compression in #2 still there.
I took the explorer to a local shop. I gave the head mechanic my list of troubleshooting.

He re-performed much of my work (compression check specifically). They did some “additional checks” which I’m not sure of from Thursday. His opinion is a head crack, stuck valve, head gasket, or broken valve spring. This in no order of probability. My wife wants me to stop and let my son “take care of his own stuff”. I don’t disagree. We’ve worked on it together about 70% (he works full time, I’m retired). With repeating lots of the stuff I already did, and the intake pulled, we are in $400. If they pull the valves cover, for valve spring inspection, it’s another $300.

After that, if the head needs pulled, just for inspection, another $500. If it’s the gasket, that plus head surfacing, another $400. If the head’s cracked, another $2000. You see where this is going. I have told the shop to stop after the valve train inspection. If it s the spring, we will finish the repair. If it points to the head (crack, gasket, etc), we will take stock on the final costs, now approaching $3500, and still not be certain of the outcome.

I’m now considering a remanufactured, warranted engine, or at least a long-block. Anywhere from $2800 to $4000 with a better hope of a long term solution. My son got a good deal on the truck ($4500, with 102,000 miles, now 104,000). If it points to just the head, how much is a reman head or heads? I have the tools, the capability, and my son to work with on weekends. I even have an engine hoist.

Opinions? Which option? $3500-$4000 for a head repair (worst case) from the shop v.s. $3500-$4000 for long block / reman engine? Or taking it on with my son with pulling heads / head repair / reman heads?

Stu
Los Alamos, NM

 

[sbbloom69]

Bad news. I rechecked compression:
6 was 169 spit
5 was 165
4 was 165
3 was 163
2 was 0, zero

I put a few table spoons of oil in and rechecked It read 23 psig. I checked it again about 15 minutes later and it read 0 again. I don’t know how much the “wet” compression test is supposed to improve the reading. Does going from 0 to 23 mean it’s definitely the rings? A holed piston? When I put my finger over it, dry, I could easily keep my finger over the plug hole. I have a borescope. I think I’ll take a look for debris, or a holed piston.

I think I know what I did last week. I think I forgot to release the pressure from the gauge. So, when I read pressure on #1 (not 3), and then 2, I was still reading #1’s pressure. I know I said 24 or 28 # before. I was reading the gauge upside down and read the wrong side of 150. Anyway, not good news.

Damn. The truck only has 103k miles. The PO was the grandma of my son’s friend. She always garaged it and had the dealer do the maintenance. He’s only been driving it since March.

How far do I go with a 14 year old exploder? (I”mm allowed to call it that. I put over 240,000 miles on two different 1993 explorers).

Decision time for my son. Thanks for the help.

Update. The explorer sat while I recovered from my surgery. No compression in #2 still there.
I took the explorer to a local shop. I gave the head mechanic my list of troubleshooting.

He re-performed much of my work (compression check specifically). They did some “additional checks” which I’m not sure of from Thursday. His opinion is a head crack, stuck valve, head gasket, or broken valve spring. This in no order of probability. My wife wants me to stop and let my son “take care of his own stuff”. I don’t disagree. We’ve worked on it together about 70% (he works full time, I’m retired). With repeating lots of the stuff I already did, and the intake pulled, we are in $400. If they pull the valves cover, for valve spring inspection, it’s another $300.

After that, if the head needs pulled, just for inspection, another $500. If it’s the gasket, that plus head surfacing, another $400. If the head’s cracked, another $2000. You see where this is going. I have told the shop to stop after the valve train inspection. If it s the spring, we will finish the repair. If it points to the head (crack, gasket, etc), we will take stock on the final costs, now approaching $3500, and still not be certain of the outcome.

I’m now considering a remanufactured, warranted engine, or at least a long-block. Anywhere from $2800 to $4000 with a better hope of a long term solution. My son got a good deal on the truck ($4500, with 102,000 miles, now 104,000). If it points to just the head, how much is a reman head or heads? I have the tools, the capability, and my son to work with on weekends. I even have an engine hoist.

Opinions? Which option? $3500-$4000 for a head repair (worst case) from the shop v.s. $3500-$4000 for long block / reman engine? Or taking it on with my son with pulling heads / head repair / reman heads?

Stu
Los Alamos, NM
[/QUOTE

 

[sbbloom69]

Well, the end has come. The mechanic who took over looking at the Explorer called me in (I’m still recovering for eye surgery). He had pulled the intake manifold to pull the passenger side valve cover. He had done a leak down test that showed some compression was building, but dropped almost immediately. Well, he showed me the problem. The #2 intake valve spring broke, just at the right time (he had fished the spring, disk, and the stem locks out of the rocker area). Apparently, the valve dropped into the cylinder with the piston at the bottom. The position then pushed the valve back up, and punched a hole into the head about 3/4” from the valve seal. The valve was now stuck through the new hole. From my bore scope, it looked like the valve was up and sealed. It was up alright, but stuck into the punched hole. That also means the stem was bent since the valve seemed to be seated. What we don’t know is whether the hammer damaged the piston (doesn’t look like it from the top) or if it bent the rod. Too much repair (labor was going to be huge without finding out if any block damage was done. My son is going to look at a low mileage engine from a local wrecker (he knows the owner). If unsuccessful, the explorer will be sold for salvage. The interior is immaculate (leather). Body is in great shape, even with the faulty factor roof paint (no rust through). My son doesn’t want to spend another $6000 on a truck he spent $4400, for a truck only worth $5500. Oh well. Thanks for the help. you can see the valve stem punched up into the rocker area under the cam.

 

[Turdle]

Oh. Crap. Never would have assumed that.

 

[sbbloom69]

Hi. My son and I are going to consider a used engine and just swap it out. I have a question:

This 2010 Explorer Limited has an oil cooler. Engines from the breakers are listed as “with oil cooler” or “without oil cooler”.

Can I pickup a “without oil cooler” and use the cooler from the old engine? Are there any ports or fittings on the limited engine that are not available on the “without cooler” engine? I can save about $300. From my Quick Look, it looks like the oil filter has the cooler fittings, but I couldn’t look below the filter with the car in the weeds.

As I mentioned before, we’re not up to spend $3500 on a warranted “reman” engine. If we can get by with a $1500 engine with about 125k on it, it’s worth a chance, and would keep the car on the road another few years. The car only has 103k on it. I have the tools, and a hoist, and I’ve swapped an engine before. My son wants to try it. I’ll probably do a thorough maintenance on the engine.

If I go this route, what all should I consider replacing with the engine out?. I was at least going to check / replace the plugs, wires, perhaps the water pump. I have a brand new EGR/MAP from the old engine. What about the oil pump? Fuel Injectors? I’ll check compression / leak down as well.

Stuart