Rookie mistakes all around on reinstalling the timing belt on the Miata
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This picture sums up how well putting the Miata back together is going. As soon as the parts arrived and I had the head back on Wednesday I started working on it. Unfortunately, during head reassembly in my bedroom I discovered I was missing a couple of gaskets so I had to pause for the day. Then I resumed the next day after acquiring the missing parts and a borrowed fancy Snap-on torque wrench from @His_Stigness. This still took a couple hours to finish assembly so I didnt put anything in the car yet. Then on Friday evening I got started for real just with removing the water pump and cleaning gasket material and prepping a few things. I didnt feel like starting the real work in the dark so I took it up Saturday morning at 1000 and worked until 1900. The last couple hours were in the dark but my headlamp and worklights made it no worse than daylight really. So I finally got to the end where I ran out of bolts to put back in, every connector was connected, and the vacuum lines looked right. Well turn the key and no start. Also, water leaking profusely from front and center on the block. Gave up that night and passed out from the exhaustion of it only to return to it this afternoon for some troubleshooting.So on day 2 (Sunday), I first did a compression check. This showed 180, 180, 60, 150. This meant that something was certainly amiss. The good thing though is that before all of this work, Cylinder 2 was about 150 so my exhaust valve replacement has probably fixed that problem! I then tore down to access the timing belt and lo and behold it was very clearly off. I had checked it twice before reassembly. But what I neglected to do was check after setting the tension!!! So doing so must have un-aligned it. As you can see from the picture above, those two marks are supposed to align. In the picture below, the camshafts are at what would be TDC if timing was correct. So its very not right!
This should be a simple "put it back together correctly this time" but unfortunately that water leak is due to the water pump being installed incorrectly. The gasket must have fallen off while I was bolting it on because the gasket was torn and crumpled into a ball when I removed the thing. And since its a Sunday and its a part for an old car, its not in stock for pick up anywhere until tomorrow. So another day will pass before I can finish this!Hopefully this will be done tomorrow as I am so so close. Assuming of course I didnt mount the head wrong and the compression issue is completely separate from the timing issue... But I cant worry about "what-ifs" until I resolve the "definitely wrong". I think its time for a break and I will go on a bike ride!
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But I cant worry about "what-ifs" until I resolve the "definitely wrong".
For some of us, this is a lesson it takes decades to fully internalize.
Good luck!
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Oof. Yeah, I always install the belt, tension it, re-check the marks, turn the motor through a complete cycle by hand, and check the marks again.
But at least it's a BP, so you don't need to worry about the B6 crank bolt issues...
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At least you didn't do the clever "leave a shop rag in the water pump while installing it" trick. Which I did.
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I'll be doing this next spring if I have enough patience to wait that long. Wish me luck lol
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@just-jeepin I wish realizing it would make me worry less but it's more of a do as I say not as I do thing lol
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@mark-tucker yeah it being this motor and being non interference means that you can play it loose with the timing belt. I casually joke about getting the timing wrong and multiple people have turned ghostlike and immediately feared death on my behalf.
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@vincentmalamute yeah I'm not missing any bolts nor have any extra so at least I'm pretty sure I've kept track of things well! Still very annoying to have messed up both of these things. At least I needed to wait on parts before driving it anyways since I also have a ruined exhaust gasket. But that one would have only made it noisy to drive really.
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@poor_sh I didn't know enough about miatas to ask about the water pump when I bought mine. I know they did timing, and I hope they did the water pump along with it, but ingot no way to know.
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@cash-rewards that's not something you want to chance. Broken timing belt just means you need a tow. Broken water pump means you need a new engine. These engines don't handle overheating at all! But yeah only an idiot would go through the hassle of changing the belt and not bother doing the water pump too. Unfortunately I assume all previous owners are idiots.
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@wrong-wheel-drive I'm planning on timing belt, tensioner/pulley, seals, water pump, accessory belts. I'm wondering about accessory belt pulleys as well...
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Hopefully it goes better than my 4Runner. Got the belt on and now it's whining every now and then. Tensioner was replaced but I think it's slightly off because it only happens at a certain point in the revolution cycle. Really disheartening, but I'll replace the tensioner when I replace the A/C bracket...
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@wrong-wheel-drive Ooofff! That's rough. Hopefully the third day is the charm!
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@wrong-wheel-drive That water pump gasket isn't fun to keep in place. A bit of gasket tack makes it a lot easier to get back together without it falling out of place.
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@shop-teacher said in Rookie mistakes all around on reinstalling the timing belt on the Miata:
@wrong-wheel-drive Ooofff! That's rough. Hopefully the third day is the charm!
I'm going to go bail him out tomorrow, so it will be fine.
And if it's not, he has someone else to blame.
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@ita97 said in Rookie mistakes all around on reinstalling the timing belt on the Miata:
@wrong-wheel-drive That water pump gasket isn't fun to keep in place. A bit of gasket tack makes it a lot easier to get back together without it falling out of place.
Technically that's my fault because I forgot to give him some. It's been so long since I've done a water pump or needed gasket tack that I didn't have it laying around.
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@wrong-wheel-drive it's tough to tell. I had a mechanic look it over and he was very concerned about the amount of oil everywhere. Thought it must be leaking. So I kept an eye on it, and it's not leaking. So whoever did the belt did a good job, but also didn't bother to clean up the engine bay any. I got no feeling on the previous owner and their thoroughness
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@cash-rewards yeah there's all those seals to replace when doing the timing belt as well. That was the reason I did the last timing belt job I did on the other car. It had probably been only like 50k from the previous time it was done but I was tired of the cam seals leaking. So I did the timing belt and water pump while I was in there anyways. Unfortunately that car still was leaking like a quart of oil every 1000 miles. Some of it probably burning and the rest out of the oil pan and rear main seals. I went through like 5 quarts of oil driving across the country in it. At least it meant I did an oil change in a week basically lol. 
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@his_stigness Outstanding!
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@his_stigness yeah electric cars don't tend to need water pumps lol
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This is why I like timing chains
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@wrong-wheel-drive said in Rookie mistakes all around on reinstalling the timing belt on the Miata:
@his_stigness yeah electric cars don't tend to need water pumps lol
That's like the one mechanical thing they do have.
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@his_stigness hey, my leaf is air cooled, like vintage porsche!
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@cash-rewards said in Rookie mistakes all around on reinstalling the timing belt on the Miata:
@his_stigness hey, my leaf is air cooled, like vintage porsche!
My VW is air cooled too, but there's still coolant for the HVAC.
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Meanwhile in 2JZ world, I have an oil leak that requires taking the timing belt off to fix. You know what? Iām ok with having to add a quart once a year.
