***Let me start by saying this is purely a vent session. ALL the issues described in this post have been resolved but it’s just been a rough week and I need to let off steam to people who know and understand the true headache that engine repair can sometimes be.

That said, I’m not, by any means, discouraging anyone who wants to respond.***

First a little background:

I’ve been an auto hobbyist/shade tree mechanic/DIY’er for about 25 years now - about 10 years ago, I was in a position to make a career change and decided to become a professional tech. I took time to attend classes and get an AAS in Automotive Technology from the local community college and have been working for the same independent shop for about 6.5 years.

In that time, I’ve performed approximately a dozen head gasket repairs, primarily on GM engines but also a few jeeps - a 3.7, 4.0 and 4.7 IIRC. During those repairs I’ve learned from some rookie (as well as pure bone head) mistakes and at this point, I approach advanced engine repair with caution as much as confidence.

2 weeks ago I tackled my first head repair on a 5.7 hemi in a 2012 Ram 1500 due to a misfire on #5. Not surprisingly, the lifter roller seized and ground down the camshaft lobe. I’ve diagnosed a few 5.7’s as needing a cam or lifters but the customers elected not to repair them, so I was actually a bit excited to finally get the chance to take one of these engines apart as I enjoy being able to compare differences between manufacturers.

I should point out that I tend to use a different strategy than many techs. I’m blessed to be straight hourly as opposed to flat rate, but I do the best I can to keep within standard flat rate times; however I also don’t tolerate anything that makes a job more difficult than it should be. In the case of this truck, I removed all the wheels so I could lower it nearly to the ground, front fender liners, AC compressor and lines, radiator and condenser so I could climb into the engine bay in order to reach the bolts at the back of the engine without over-extending my arms and trying to balance on the front end.

I’m also meticulous with prep work. I thoroughly clean any parts that will be re-used (valve covers, intake & exhaust manifolds, air filter box, vac hoses, bolts, etc) and make a checklist of anything that needs to be done as I go (specific order of assembly, for example).

Fast forward to this past Monday - the heads are back from the machine shop, all the necessary parts/gaskets are on the bench, and I got the truck pulled back into the shop just in time to prep the block for installing the cam, lifters and heads the next day.

I took time to clean/inspect the cam bearings and didn’t see any concerns, so I pre-lubed the cam and installed it, followed by the cam sprocket and timing chain.

To avoid pulling the oil pan and pump, I made reference marks on the chain, cam and crank sprockets to make sure it was assembled in its original position/relationship, including using a zip tie to prevent the chain from falling off the crank sprocket when the cam was removed; and even going so far as to rotate the crank until my marks lined up again.

I was satisfied the timing relationship was accurate, so I installed the new lifters, making sure the front and rear lifters were in the correct positions, and proceeded to install the heads.

Now, I KNOW when I pulled the heads that I marked them left and right (learned from a past bone head mistake) but when the heads came back, my marks were gone. Not sure why as the machine shop never erased them before, but I carefully scoured them to decipher which was which and couldn’t make a determination.

So I made my first mistake of this job… I took a chance.

It wasn’t until the next day, when I was about to bolt on the exhaust manifolds (and after installing the push rods, rockers and valve covers) that I realized I had bolted the heads on the wrong sides.

For those who don’t know - the difference is in the position of the 2 rear most bolts on the bottom row - they are closer together than the upper row. The way I had the heads bolted on, the manifold outlets would face the front of the engine, not the rear.

In hindsight, I could’ve easily identified them had I just paid attention to the part numbers that were stamped on the ends.

So yes, it was a bone head mistake, but not a big deal. I had to order new head gaskets and bolts, but in the course of the overall job, I considered it the “hiccup” of the repair (and EVERY repair has one ).

With the heads now in the correct positions, the valve train, timing and valve covers, intake and exhaust manifolds installed, it was time to verify my work.

Here’s where experience can be a real teacher, if you’re willing to learn….

The first time I swapped an engine professionally (about 6 months into my job), I tried to fire it up as soon as it was ready. And it did start, but the CEL came on almost immediately with a crank to cam correlation code (P0016 IIRC). Long story short, I spent a week trying to figure it out, only to find that the timing chain had jumped a tooth on the crank sprocket. Twice I had removed the timing cover for inspection and it looked correct, but I was actually looking at a different mark on the crank sprocket. I realized what happened is that the chain jumped a tooth on initial start because the tensioner was dependent on oil pressure, and the cylinders started firing before oil pressure could completely build.

Ever since that engine swap, whether it’s advanced repair or engine replacement, I not only verify timing visually by rotating the engine with a ratchet and watching the valve movements, but also prime the oil system by jumping the starter relay and cranking the engine up to 30 seconds to make sure the tensioner “has a grip” on the chain before starting.

A secondary benefit of doing this is you can actually tell whether or not the base timing is correct, because the cranking speed will be consistent if it is and inconsistent if it’s not. The way the engine sounds is the indicator.

Now, the cranking speed was consistent except for one spot - I could literally count the seconds and determine the offset noise happened in the same place - but I wasn’t too concerned because, by the sound, it could’ve been a worn spot in the ring gear or starter brushes, so I pressed forward with adding fluids and finishing assembly.

It’s worth mentioning that there was heavy corrosion on the timing cover and some pitting on the block where the timing cover gasket seals. I cleaned it up as best as I could, but I was still concerned the gasket wouldn’t properly seal, so I applied liquid gasket to the groove in the cover as well as the block to ensure I wouldn’t have to reseal it. I get extremely annoyed when I have to disassemble an engine because a gasket didn’t seal.

I filled it with oil and coolant, then attempted to start. It fired up and stalled right away. OK, no surprise there - that happens all the time because the fuel rail and injectors usually have air in them after repairs like this. I cycled the key a few times to prime the rail and tried again. It fired up, sputtered, then stalled. Tried it again with the same result.

Hmmm…. never had a fuel rail that was this difficult to bleed, but it’s the first time I’ve done this repair on a 5.7 so maybe I just need to keep trying.

Start it again and try working the accelerator - I get it to stay running but it’s shaking quite a bit, doesn’t smooth out unless it’s above 2000 RPM and sounds like it has an exhaust leak.

Maybe I forgot to hook up a primary sensor or ground?? I put the scan tool on it and all I find is P0301 which is confirmed by live data - #1 appears to be missing on every single revolution, with random misses happening on a few other cylinders.

So what happened?

I’m going to end this post for now, mainly because it’s getting to be a lot longer than I expected and more than once I’ve accidentally deleted posts in the middle of writing them. If that happens, I won’t be attempting to finish it.

I’ll post the conclusion tomorrow. Thanks for reading.

 

Ok, this is new. A forum post that ends on a cliffhanger....

 

Well, I’m sorry to make you wait on the edge of your seat for another day, but I had some unexpected transmission issues with my truck and I don’t have time to conclude the saga tonight….

I’ll pull you off the cliff ASAP.

 

We would appreciate that.

 

***Sorry for the extended delay in posting the conclusion - life has been quite busy and I’ve had nearly zero time (or energy) for my "social media" lately. (This is as close as I get to facebook or any other social platform). I didn’t have time to add all the fun smilies and accentuations, except this one. ***


THE SAGA CONCLUDES....

I started with the basics - verified power to the coil & injector, and verified the PCM was pulsing each one. I listened to the injector with my "stethoscope" (long screwdriver) and it sounded the same as the other injectors. I removed the coil and rigged it up for a spark test using a couple of the old spark plugs (which I had saved, because I've had to learn the hard way that, during any repair, you never throw anything away until you're absolutely sure you don't need it). With the injector unplugged to prevent washing down the cylinder, I started the truck and could see both plugs firing away with strong spark. However, I noticed the engine operation had smoothed out. It was obvious it still had a miss, but the vibration was almost non-existent. That’s interesting…

Despite having just seen the coil functioning properly, I decided to try swapping it with #2 anyway, just to see - not surprisingly, no change.

I pulled one of the spark plugs out - yes, they were new, but I'd had the engine running long enough that even new plugs could indicate what might be happening. However the electrode was clean. None the less, I swapped the spark plugs as well - again, just to see, because sometimes the simple things can be overlooked or ignored for no other reason than ASSuming they can't be bad. "Because they're new they must be good." But as any seasoned mechanic (pro or not) can tell you, a new part does not mean it's a good part.

Still no change - the misfire remains on #1. *sigh* OK, I'd better check compression.

As with priming the oil system, I crank the engine using the starter relay during compression testing, for 2 reasons:

1) By not relying on the ignition key, there's no attempt by the PCM to initiate combustion which can affect results.

2) It's much easier to keep eyes on the compression gauge, because you not only want to know what the final pressure is, but you also want to see what the initial pressure is, which should be at least 1/2 the final pressure.

Additionally, many vehicles automate the cranking process once the key is turned, so the engine can crank upwards of 30 seconds even after letting off the key, so jumping the starter relay allows me to control the amount of time the engine cranks.

...moments later...

ZERO COMPRESSION!?! HOW CAN THAT BE!?!?!

Then I perform a leak down test....

WHY IS IT LEAKING OUT OF THE INTAKE MANIFOLD!?! (If you don't know, that indicates the intake valve is open, whether it's due to the valve being bent, burned or just not closed at the correct time.)

At this point, I needed a break. I'd been working on this truck (i.e. crawling into and out of the engine bay) for nearly 2 straight days and just needed to move on to something else for a bit to give my brain a chance to reset. It's amazing how much difference it can make when you stop thinking about a problem, even for a short while. I service a couple of other vehicles for the next hour or so and then come back to it.


Internally, I'm replaying the assembly in my head - yes, I messed up and bolted the heads on backwards, but once that was corrected, I verified the timing before reassembling the rest of the engine. Didn’t I? Yes, I’m sure I did, because I turned the engine over by hand and watched the rocker/valve movements and there was no indication of problems.

So I realize, at a minimum, that I have to pull the bank 1 valve cover for inspection. And since the brake booster is so conveniently mounted within 2 inches of the valve cover, and the AC lines are so conveniently routed right in front of it, and the PS pump/lines is so conveniently mounted in front of the AC lines, that means removing the S-belt, PS pump and AC compressor to gain the clearance needed to get the VC off. *sigh*

15 minutes, 2 bleeding knuckles, and several curses later, the valve cover is off.

Visually everything looks fine, so I rotate the crank to bring #1 to TDC. Unfortunately the intake valve is just barely open at TDC. Ok, I’d better make sure there’s no issues with the push rods or rockers, so i remove the intake valve rocker bridge and inspect everything. No problems, so I reinstall it.

Great, now I have to pull the timing cover back off to verify valve timing. The timing cover that was heavily corroded, a complete bitch to clean, and then I’ll have to clean all the liquid gasket off in order to reseal it again.

And I’ll have to drain fresh coolant out of it too. GRRR! I hate wasting good fluids. (technically, yes, I could’ve saved it, filtered it, and put it back in, but my boss is of the mindset that a little bit of coolant isn’t worth risking damage to a newly repaired engine, especially when it’s as invasive as head gaskets. And I agree. But I still don’t like wasting it.)

An hour or so later I get the timing cover off and, sure enough, the timing is off on the crank gear by a tooth.

My only conclusion is it had to be off when I first assembled it - despite my attempt to keep it in place with a zip tie - but whether it was the viewing angle/lighting or something else, I believed it to be correct at the time.

So now I’m pulling the oil pan and pump anyway (GRRRR! - more wasted fluids!) Out of both frustration and attempting to save time, I opted to lower the front diff, leaving the axles installed and suspended it with wire (service procedure states to raise the engine) which actually worked (FINALLY something that went to plan on this thing!).

I pulled the pump and got the timing marks lined up. Again I verified it by rotating the crank at least 4 times and everything felt good and the timing marks were in the correct positions. Hooray!

After getting all the gasket surfaces cleaned up and reapplying liquid gasket to the timing cover, I reassembled it, filled it with fresh oil and jumped the starter relay to crank it and have a listen.

It sounds perfect.

With no further concerns, I filled it with coolant and fired it up.

…wait a minute…..

WHY IS THERE A RATTLING NOISE COMING FROM THE DRIVER SIDE VALVE COVER!?!?!

My stethoscope confirms that’s the source. UUUUUUGGGGGGHHHHH!!! Now I have to pull the valve cover AGAIN!!

This time I leave everything in place and just slip the cover off to the side - it doesn’t come all the way off but it’s a good enough view to see that the foremost bolt of the intake rocker bridge isn’t fully tight.

Now I’m mentally kicking myself for making such a bone head mistake. How did I miss just one bolt???

As I was soon to find out, it wasn’t just one bolt - it was all the bolts for the intake bridge! I must’ve tightened them down initially and then forgotten to torque them (I’m often interrupted by customers if my boss isn’t available, so it’s conceivable I was interrupted and just overlooked torquing them.)

Ok I’m not taking any chances this time - once again I repositioned the PS pump and AC compressor to pull the cover. After verifying all the push rods are in the correct positions, I run through the tightening and torquing sequence for both the intake and exhaust rocker bridges, then rotate the engine with the starter a few times, then check them again to make sure they’re tight. Ok, good to go.

Now to install the valve cov…oh, wait, the gasket fell off. So I Reseat the gasket. Now to install the valve cov…the gasket fell off again. So I reseat it. Again. Now to install the valve cov… GRRRR!!!! ARE YOU FREAKING KIDDING ME RIGHT NOW!?!?

The gasket had softened up from the oil and heat of running the engine, as it should, but just wouldn’t stay seated in the VC no matter what - even after cleaning it. We happened to have another gasket on hand from a previous repair, so I just swapped it with the new one and gave the VC a quick shot of brake cleaner and compressed air to remove residual oil.

Now to install the valve cover….done!

I reassembled everything, praying this would be the last time I need to take it apart, and fire it up again. It sounds smooth and there’s no indication of other issues.

I let it idle up to temperature, change the oil to remove contamination from the repair, and then take it for a test drive. Everything is fine - no concerns, no codes. Once it cools down I verify there’s no leaks, top off the coolant, test drive again and then tell my boss to get it outta here.

​​​​​​…..then I move on to head gaskets on a jeep with a 3.6…..

 

This is a good example for people who have no idea about working on things to study. Vehicles present every domain known to man. The amount of tools you need, the things you need to know and to do 100% correctly every time, is absurd. And if one thing goes wrong, or a new part is bad, you lose your shirt on the job. Glad you eventually tackled it.

 

This is also one of the reasons I posted about the experience - so that others may benefit/learn from it.

I’m very meticulous with engine repair, regardless of how in depth it is. In addition to cleaning all parts and chasing threads, I keep parts in as orderly a manner as possible as I remove them. That way I’m not wasting time trying to sort through a pile of parts that blends together during reassembly.

The “bone head mistake” I referenced in the first post about marking the cylinder heads was because I made a similar error the first time I replaced the cam and lifters on a GM 5.3L. I can’t recall the year but it has the same setup as the 5.7 - single cam with roller lifters under the heads. At that time, GM used a coolant bleeder pipe that connected to the front of the heads and the ports on the rear were not drilled out. I couldn’t discern the difference between them and I failed to notice the bleeder ports until the heads had been torqued down and I was trying to install the pipe. Ever since then I’ve been intentional with marking them.

And sometimes, as with the VC gasket that kept falling out of place, things just don’t go as planned, regardless of how well organized you may or may not be.

There’s a few different names for these “rules” - my father called them “Murphy’s Laws” - but they apply to projects of all types.

1) Nothing is as easy as it looks.
2) Everything takes longer than you think.
3) If anything can go wrong, it will.

And, one more specific to automotive repair:

4) If you drop a bolt or socket, it will land and/or roll to the darkest, least visible space nearby.