Honda Pilot - Honda Pilot Forums banner

Help! No compression cylinder #5

12K views 260 replies 11 participants last post by  undivide 
#1 ·
Ok so any help here would be great. I'm a single mom, with a 2011 pilot. Always kept up with maintenance, oil changes ect. Yesterday I went to merge onto the highway and instantly my CEL started flashing and I could tell it was misfiring. Drove it to my mechanic, they read code amd said misfire on 5...they replace cpil and plug and the misfire would move around. (Not sure what that meant). I left the truck there. Today they said they did a compression test and all cylinders are good, except 5 has no compression at all. And bc there a small local shop there trying to figure it out and the next step is to check if my rocker is broken. Does this sound right? I'm so confused bc I all hear is $$ and being I just paid off my daughter's college bill I'm broke!!! Also to note it smelled slightly of antifreeze when he opened my hood. Although it never over heated and never has in the past. No rough starts ect..no riding different or funny sounds. The only sound I heard over this past month was a squeeling noise from what I assumed was my serpentine belt. Not super loud or crazy just mildly. Any suggestions??
 
#157 · (Edited)
Your engine needs compression, air, atomized fuel, and healthy spark to combust. You can pretty much rule out air since that would make all cylinders misfire, and would have an associated code when the O2 sensors trigger. You can have fuel, but you need atomized fuel to be exact, since liquid fuel doesn't combust, that would have to come from an injector that is working the way it is supposed to be working. It can leak and that would be liquid fuel, it could clog and that would be low fuel, and can come out uneven and not enough to make a full combustion.
You could have a spark issue where either the spark plug or the coil is faulty, which is easy to check by the method I describe above. It is free and easy. Actually only need a few tools. Spark plug socket, ratchet, and extension two 2" extensions, and a 10 mm socket. Preferably a torque wrench but most don't use them. Just swap them around and see if the problem migrates. A compression test is also simple, if you can remove the spark plugs you can do a compression test. Just need to disable the fuel injectors by removing the relay, and remove the spark plugs and screw in the compression tester, which is cheap at harbor freight. Crank the engine over 5-6 times and the compression tool will hold the compression for you to check. This will tell you if it is a problem with the piston rings or valves. Put a little oil in the spark plug tube hole, and check the compression again and you can see if it is the piston rings since it will temporarily plug the rings and raise the compression if even a little bit. If no bump in compression it is the valves.
He could have even got the timing off. You have to line up the front and rear cam to the crank, and this can be challenging for some. You can run it off 1 tooth, but it isn't good for the long term health of the engine. You can have the crank and the front cam on and the rear off, or the front off, or the front and rear cam can be timed together, but the crank off. The marks can look off if you are not looking at them dead on. If you look at them from any angle, it will look on, but be off.
I hope he didn't use a cheap ebay brand timing belt that says it is Honda, but is not. The material is too weak and can stretch easy. This will give you off timing, and in a day to a few months they just fail. Some can go longer, but it depends on the driving habits. They are made from inferior material and have cost many engines their lives. Couple that with a bad timing belt tensioner and either one can fail in less than a year.
It is unfortunate that he was able to get this far. The first red flag was that he had to take the heads off to do what a simple compression test would have told him. From there it just goes downhill. I actually wonder if he even knows how to do a valve lash. It used to be a common thing way back in the day, but Honda is one of the few that still require it, and they are the few sticking to the rubber belts. Not to mention the interference engines. All 3 are engine killers.
Why don't you buy the tools to check these things yourself?
You can use the universal joint in the kit, or get an extension kit like the one below. The issue is you can't get the long extension down the tube with the spark plug socket, so you have to put the socket with 3" extension down the tube, and attach the second 3" extension after, or you can try to get the swivel extension to maneuver down the tube.
A few things to note. Remove the #R2 Relay under the hood relay box (Check video). Crank the engine until it doesn't start and run. Remove all of the spark plugs. This would be a good time to send us some pics of how they look. With the spark plugs removed install the compression tester on #6 and #5 cylinder. Send us the readings.

 
#158 ·
You could ask him what machine shop did the work, and call them and probe them if they remember your head coming in, what the issue was, and if they did the valve lash, and if the mechanic should have verified anything before installing the heads. That way you can verify he even sent it to a machine shop.
 
#159 ·
On soap box. I didn’t like the “Mechanic” vs. “Technician” reference. Off soap box.
Anyway, yes, a compression test is used to evaluate the mechanical condition of a cylinder, but what is the next, or sometimes, preferred test instead of a compression test, to evaluate a cylinder’s condition mechanically?
I’ll be back this afternoon to give the answer I’m looking for if nobody hits it by then. I’ve been following along pretty well, and I’m surprised that nobody has mentioned this test yet.
 
#160 ·
You're not talking about a leak down test? I only ask since you said "next". A leak down test would follow a compression test since a compression test requires very little money, knowledge, tooling, and time. Leak down test is involved, requires more tooling, and is more difficult to track down. I have seen leak down test abandoned for a smoke test since listening for the air coming out of lets say the exhaust valve is very hard to hear or feel if you have a sealed system. Once it gets to the muffler tip it is muffled. A smoke test in the cylinder would actually be a better way to track down a leak compared to air.
If not, I'll keep thinking of what you meant.
 
#162 ·
Leakdown test. Yes, that’s correct.
I disagree with substituting a smoke test in lieu of a pressurized leakdown test. A smoke machine does not put out enough pressure or volume to be valid. A leakdown tester quantifies the integrity of the cylinder by using pressure and measuring volume better than the flow meter of a smoke machine. Costwise, the leakdown tester is somewhat affordable at $79.99 at HF.
bottom line is that if cylinder integrity is questioned (as in this case) the correct diagnostic procedure would be a compression test followed by a leakdown test. These two tests will validate cylinder seal and valve timing at once.
 
#163 ·
I just went back to the top of this thread, and it had a good start with some solid advice. When your tech said the miss was moving around, and then said #5 had no compression, that was a bad indicator and a hook should have been called immediately.
I really feel bad for you, Kari.
You need a good tech or mechanic to start from square one.
 
#165 · (Edited)
If you already know you have a leak at a cylinder with a compression test, and you did a dry/wet compression test to role out the piston rings. You are left with a crack, head gasket, tight valve lash, timing off, bent/burnt/dropped/broken valves, or valve stem. Smoke will find all except for maybe head gasket, depending on if it is going into coolant or not.
How does it show you if your timing is off? Wouldn't it be the same symptoms of a failed valve for reasons mentioned above? I would think checking timing through the timing covers would be an easier venture. As far as valve lash being off, same would apply. You wouldn't know until you check lash, as any number of reasons can keep a valve open.
If you figure in the price of air that $79.99 which is twice the cost of a compression tester it gets real expensive real quick. Which makes it unobtainable for most DIYers. We already know this mechanic doesn't leak down test. He would have done it from the start. She even told him to, and he said he did, but this was after he already took the valve cover off to look at it, and after he took the head off.
Going off of the advice I was giving Kari specifically for her to do herself, a leak down test is involved, and requires you to know a lot of things to figure out where the air is going. I have seen many that know what they are doing have the hardest time tracking down the air, because the sound is too faint to tell where it is coming from. Some giving up because they just can't pinpoint where it is going, or not knowing how to do it correctly, like allowing the valves to be open and giving a false leak.
 
#166 ·
These guys did point out red flags, but at that point my pilot was in pieces, so I gave him the benefit of the doubt, and told him a few things that I wanted (leak down test, compression test, oem timing, valve lash ect) and he just doesn't seem to think that's it and doesn't bother with what I say, or doesn't seem to bother with what I say, bc what do I know???
 
#167 ·
I didn't read every post but I caught you saying your mechanic was going to quote valve adjustment. You shouldn't be paying 1 penny for his incompetence, he should have done it upon reassemble. It's quite easy to graph and log the map sensor and see if a valve clearance issue is causing your miss issue. HOWEVER he needs to check and adjust your valves ( for free, as it was part of the job to begin with), because they need to be set correctly for various reasons. I would take the veh to a good shop for the valve adjustment and deduct it from the final bill at his shop.
 
#168 ·
He didn't say he was charging me, he said he'd check the valve lash, after i told him too. But he said the machine shop did it (which made no sense) but said he might check the #6 bc its misfiring alot..but the next day when i called him he turned around and said he's not going to do it because after speaking to some of his "colleagues," that if it was in fact my valves, it would throw the engine light immediately upon starting, and it would be on constant, unlike how my pilot is with the engine light on after 10 min of driving. It made no sense. He leaves tmrw AGAIN ON VACATION....I spoke to another shop who said that's insane that he could've rebuilt 20 Motors in the same time frame that this mechanic has had my vehicle. And also it could be a mistake from the machine shop and the mechanic isnt checking that. If my truck is not taken apart I will be taking it tmrw (if it's not repaired) when he leaves for vacation. He didn't call me at all today. My friend drove by his shop (after hours) and my vehicle wasn't outside , and the lights were on. So hoping he's in there figuring out what's wrong.
 
#171 ·
The other shop also said that they can try to find out what he did but it could be a big disaster, and for round about the same price, they can put a refurbished motor from a reputable place in with all new timing and fluids (my timing was just done also, so he said he can alvage that then)
 
#174 ·
Just spoke to him, he was there all night and hasn't figured it out . He said it's currently apart again, he's going to check the cam and rear cams to makesire timing is accurate
And he said it could be the machine shop messed up, and he'd have to re-send it out , and start over but it wouldn't be on me to pay again. But to call him at 5pm. as of right now he did fuel injector, coil, spark ,and.its not any of those (told him i already knew it wasn't that)
 
#175 ·
If anything, your mechanic's argument against valves could be used for timing too. Usually if the timing is off even by a tooth it will run poorly all the time, not just sometimes.
 
  • Helpful
Reactions: royalbiggster
#176 ·
I would put money on your mechanic doesn't know how to do the valve lash. If timing was off, all 3 cylinders would misfire, there would likely be associated codes, and as wiimaster mentioned it would be all the time like he argued for valve lash. I'm really not sure what the machine shop would have gotten wrong except for the the valve lash. Too bad we can't see what is actually wrong with it, and do the proper diagnostics to see what is really wrong with it.
 
#179 ·
Strange he didn't role out valve lash. The tools to check it are under $10. Takes less time and less parts removed compared to checking the fuel injectors. Checking timing is also very easy and doesn't cost anything. The proper diagnostics wouldn't require pulling the head and sending to the machine shop to have them verify all is good with the head. So what is going on here?
 
#180 ·
He said this morning he has been there all night trying to figure it out. He said to call.him at 5pm today. Bc he has the valve cover back off and is trying to figure it out. That it's not injectors ,plugs, or coil. He was going to check the timing also today
And I asked if the machine shop could've not done the correct work and he said that's possible but he doesn't know yet. I asked him in that situation what happens bc I'm not paying for it to go back, and he said if it did I wouldn't have to pay for it. But as of right now I have to call him at 5pm (he leave on vacation tonight again to myrtle beach) I was hoping and am still hoping it's drivable by 5pm bc I want it out of there.
 
#182 ·
As a professional technician, I'm fine with a customer being educated and asking some questions. However a customer that is constantly calling a asking for things to be done and trying to lead the diagnosis is very annoying. I've pulled cars out and told them to take it elsewhere if they think they're so much smarter then me.
Not that I believe you think you are smarter then him, but I'm not good a sugar coating things. My opinion is to let him be and allow him to figure it out. That fact that he is still working on it and hasn't just said sorry but I'm done with, says a lot about him personally to me. Believe me, he is as much or more frustrated with this situation too. Unfortunately your part of his learning experience right now and it sounds like so far he is trying to treat you fair.
 
#183 ·
As a professional technician, I'm fine with a customer being educated and asking some questions. However a customer that is constantly calling a asking for things to be done and trying to lead the diagnosis is very annoying. I've pulled cars out and told them to take it elsewhere if they think they're so much smarter then me.
Not that I believe you think you are smarter then him, but I'm not good a sugar coating things. My opinion is to let him be and allow him to figure it out. That fact that he is still working on it and hasn't just said sorry but I'm done with, says a lot about him personally to me. Believe me, he is as much or more frustrated with this situation too. Unfortunately your part of his learning experience right now and it sounds like so far he is trying to treat you fair.
Got it! Thank you! The only thing I was really Adamet about was weeks ago, the compression test. And then the valve adjustment
But thank you, I get what you mean.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top