Guess that rattle

[blalor]

Not even 10 full days into E30 ownership and I had to get a tow home. I got an alignment done today after replacing the driver's side tie rod and when I picked the car up it didn't want to start, and when it did, it sounded like someone was under the hood with a jackhammer. It ran very rough, stalled a bunch of times, and the sound when revving above 1,500 RPM was unbearable. :curse:

I don't have a good feeling about this. The engine's got about 182,000 miles on it. The previous owner replaced the tensioner, but not the chain. I've been hearing what I believed to be a noisy timing chain and was planning to replace that soonish. I really don't know much about engines, specifically this one, but that noise is awful and I'm wondering if the chain slipped, which probably means munged valves, which would explain the rough running, right?

Here's a quick video I took in my garage, just to capture the noise: http://www.flickr.com/photos/blalor/4444562224/

Someone please tell me that it's just a broken tensioner or something and that it'll all be better soon?

Wishful thinking aside, does this noise and the description help narrow down the problem? How much can I run the engine to pinpoint the noise and diagnose the problem without causing further damage?

Thanks,
B

[rafiki]

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

[jrobie79]

did u check out m42club.com, great resource

[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

[blalor]

did u check out m42club.com, great resource

No. Heading over, now. Thanks!

[rafiki]

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

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

[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.

[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.

[blalor]

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

[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]

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?

[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]

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]

told you it was the timing.

[blalor]

told you it was the timing.

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