Guess that rattle

[blalor]

My future father-in-law came over this morning to help me assess the motor. He's currently rebuilding a '47 Ford Coupe and has about 50 years more experience with engines than I do. We started out with a leakdown test of cylinder 1 … and found 100% leakage. The air coming from the intake tract was pretty audible, and you could feel it blowing up the spark plug holes for the other cylinders. Since he had another couple hours to burn with me, we decided to press on and pull the head, just to see how bad it was. It's pretty bad.







That last one is of the intake valves for the #1 cylinder. And yes, the valves are "closed" there.

So.

Now I have to figure out what to do next. A friend recommended Clearwater Cylinder Head in Florida to get a replacement head, but they charge about $1,000 including shipping both ways for a refurbished head (complete w/ cams, I believe). Before I commit to buying another engine (most of the available ones right now seem to have similar miles to mine, or about 182k, so I'd still want to do the timing chain stuff), I'm going to try to get a local machine shop to look at the head and give me a quote for repairing the seats, guides if necessary, and installing new valves.

The other "interesting" thing is that it's apparent that the exhaust valves suffered a similar fate at some point in the past: there are similar divots in the pistons on the other edge, but they're coated in carbon. There's that red Permatex stuff on the head, too. I'm gonna have to go back and look a little more closely at those receipts the previous owner gave me…

[blalor]

When in doubt, read the manual. If you're still confused, re-read the manual.

I bit the bullet and went with the starter motor trick for breaking the harmonic damper bolt free. Worked a treat. I'm glad I went this route, because I realize now that I was misreading the Bentley manual. It says to "hold the vibration damper hub stationary while the bolt is loosened" using a "heavy duty holding device" such as BMW special tool 11 2 150. The very next step says to lock the crankshaft at TDC with a different tool, 11 2 300. I thought that the point of locking the crankshaft was to make it possible to get that bolt off, and I couldn't have been more wrong.

Moving on, with the timing case open, I saw this:

Well, there's yer problem.

Still haven't done a leak-down test; chain's a little too wonky right now to actually turn the crankshaft and not have the chain slip on the sprockets. Hopefully tomorrow, but otherwise Saturday.

[xwill112x]

oh and to get the tstat out, use a small screw dirver and small hammer taps to wiggle it loose. atleast thats what worked for me.

[blalor]

told you it was the timing.

I don't even have it all apart, yet! :mrgreen:

[xwill112x]

told you it was the timing.

[blalor]

Well, my progress has been incredibly slow, but I think I'll call it "methodical" instead. :D In 8 hours on Saturday I managed to get the radiator out, but I also helped a friend do the brake lines on his Jetta, so it wasn't concentrated time, at least.

I'd hoped to do a compression and/or leak-down test by now, but haven't had much luck. I chickened out on the compression test because the threaded adapter on the end of the hose looked like it could get stuck in the spark plug hole. I've since borrowed a leak-down tester and started to play with that tonight but was having difficulty (a) finding TDC, (b) keeping the crank at TDC, and (c) finding the hole in the bellhousing to lock the crank. I've since solved (c), but even with the plugs out, I'm having a hard time getting the crank to do a complete revolution and get the allen wrench to lock the crank. This is despite spinning the engine with the starter on Saturday, with the plugs out, and hearing no noise, which I took to be a good omen.

After being somewhat stymied by my inability to find a means to lock the crank in place and wondering how I'm going to tighten the 19mm bolt for the vibration dampener, I decided to just dig in and remove the valve cover and upper timing case. Here's what I've found so far.

There's this rubbery red stuff all over the place:

Is that Permatex of some kind? Is it necessary when reassembling, or should new gaskets be sufficient?

The sprockets have gotten very pointy, and possibly chewed up:


A couple of the bolt holes for the timing cover appear to have some threads that have broken loose:


The arrows on the sprockets aren't pointing in the same direction, assuming they were assembled correctly:

Just how far off is that, anyway? Enough to bend a valve or 8?

I cannot for the life of me get the thermostat to come out. Should I just plan to replace it and use excessive force to coax it out?


I managed to get the viscous fan and clutch off, but the pulley on the water pump isn't coming off. It spun slightly when removing the fan (I removed the pulley bolts, trying to take a shortcut), but doesn't want to pop off. Pulley puller?

I still need to tackle the vibration damper before I can get the lower timing case off. A BFH and breaker bar will probably do the job once the flywheel's locked, but how the heck do I torque that bolt to 244 ft•lb? I think my torque wrench only goes up to like 150! To say nothing of my back… And the pulley puller here again for the v-belt pulleys?

Thanks for your patience with the new guy. I'm starting to feel a little in over my head, but it's the only way to learn, right?

[xwill112x]

Thanks, Will. I'm going to do a compression test first, and then see what grenaded in the timing case.

when your m42 sounds like a diesel, which it's known to do, it's time to do the timing. :cockbloc:

[blalor]

The thought's crossed my mind, Fred. I'm watching some here and on a couple other boards. The trick would be finding one that has substantially fewer miles, otherwise I'm afraid I'd just be setting myself up for deja vu. But I'm seeing that I can probably pick up a complete engine (and maybe transmission) for what the timing chain components cost new!

Can you put me in touch with the local guy?

[FredK]

Argh. Good luck dude. It might be easier to just drop in a lower mile engine. I think a local guy might still have one (or two).

[blalor]

Thanks, Will. I'm going to do a compression test first, and then see what grenaded in the timing case.

[xwill112x]

... i coulda swore mine made a similar sound but i thought that was normal. usually stops clicking after its warmed up. but im not sure if its the same sound. ill have to check this weekend.

you need to change out your sprockets, guides and chain.





op: dont run it anymore before its fixed. whats your hearing is metal on metal because the chain ate the guide. replace your sprockets/guides/gears aswell, ASAP.

[tonywonder]

... i coulda swore mine made a similar sound but i thought that was normal. usually stops clicking after its warmed up. but im not sure if its the same sound. ill have to check this weekend.

[rafiki]

Then where's the massive torque and super fuel economy? :D

its not broken in yet. dont worry, itll come. :D

[blalor]

did u check out m42club.com, great resource

No. Heading over, now. Thanks!

[blalor]

i think the previous owner converted it to a diesel without telling you.

Then where's the massive torque and super fuel economy? :D