Engine failure / timing chain slipped

[roundel318]

3rd owner, 267,000 miles. on its 2nd timing chain tensioner, original everything else

[G-Man]

The chain tensioner on my 91 318i broke at 129K in DEC 07 and needless to say, the engine was trashed.  I was lucky enought to score another M42 from a fellow BayE30.net member for $350 whose girlfriend had recently wrecked his 91 318is.  Before the motor went in, a new clutch was installed, all hoses under the intake manifold were replaced, new timing chain and oil pump along with a new chain tensioner.  I hope to go for another 200K with this engine.

G-Man
91 318i sedan
89 325i 5 speed sedan (totaled last week, RIP)
86 325 eta 5 speed coupe (youngest daughters DD)
81 E12 528iA (Euro spec)
74 2002tii 5 speed, lsd, (many other mods)
79 E3 2800 4 speed (Euro spec)
96 4Runner 4cyl, 5 speed, (parts hauler)

[Kingsly]

189,000, no major work done, still running smooth and pulling strong. Just replaced the original chain tensioner (which was seized at about half extension) five days ago. Plan on flushing the oil and dropping the pan to check for bolts/gasket problems sometime after the holidays.

[Deftones]

my e36 has over 315000 km and still runs well; the e30 has "only" 180000 so i think his life is so long!

[DesktopDave]

Thread back from the dead!  I'm researching M44 upgrade parts for the M42.

Anyway, I'm running 269K miles on the original chain.  The PO's mechanic updated the guides & tensioner, so I'm likely running newer M44 parts.  Cam teeth are pointy though, so I'll be replacing them sooner or later.  No bits in the pan either, just the typical bolt impact mark on the oil pickup & mirror image on the lower pan.

[B318M42W]

still running at 315K km, went FI@6psi 2k ago and still breathing. replaced chain,sprockets, rails @ 288K.  hadrollers in the oil pan trigger the replacements

[Home made iS]

m42 still kickin at 220k kms, previous m40 lasted 400,000. then dropped 5l oil at 100kmh, smashed bearings and rods . made way for e36 m42 conversion, best upgrade ever.

[DesktopDave]

You upgraded an e30 M42?  I thought about the serpentine belt & electric fan bits, but did you do something else fun like enable knock sensors with the e36 DME?

[hnilsen]

I'm at wit's end with my 1991 BMW 318i M42B18 which probably has about 200,000 miles on it. For about a year there has been a distinct rattling emanating from the upper engine, leading me to guess the problem was maybe valves, hydraulic lifters, maybe a loose timing chain...? The engine, however, seemed to run fine and since the car is so old I didn't do anything about it.

Then 2 weeks ago, I'm driving along at about 40 mph and without any big noise or fanfare, the engine just dies. Upon trying to crank it over, the very first attempt, the engine sputtered just a bit, then every single time thereafter, absolutely nothing. It cranks incessantly but doesnt catch even a little.

Having had a past fuel pump failure give me similar symptoms, I checked this out and the fuel pump is fine. Pulled the plugs and made sure I'm getting good spark...all OK. I site down each of the cylinders and can at least confirm that all pistons are moving up and down.

Thinking maybe I broke the timing chain, I pulled the valve cover. Timing chains look fine. Thinking maybe the timing chain jumped, I checked the timing itself and it looks good too, at least from everything I can tell by studying my Chilton manual. I'm not 100% sure about this, but here's how it looked: I turn over the engine clockwise until the #1 piston is at TDC, at which point the intake and exhaust valves are more or less facing towards each other, and the arrows on the cam shaft sprockets are facing up, and the rear end of the cam shafts where the square end flats are parallel with the valve cover, and the 2 dimples are up. Does this sound right?

So I'm now thinking that I have not slipped the timing, so I do a compression test on the cylinders and find that I've got ZERO compression in all cylinders!!! How can this be? Did I bend all the Valve rods? Is something the matter with the lifters?

Surely I can't have a cylinder or piston ring issue that manifested itself instantly! If that was the case, the engine would have been running like crap, burning oil, etc. for weeks leading up to the failure, and this was not the case. It was running fine right up until it dying.

So that's my dilema. Any ideas about what's wrong and what to do about it? I'd love to hear from anyone with any suggestions>
Hnilsen@canalbarge.com

[a930rocket]

A compression test only does so much.

Although the valves are moving, they may be bent. Do a leakdown and see where the air is coming from. Intake = bent intake valves. Exhaust = bent exhaust valves. Crankcase = broken/etc. rings

I'm at wit's end with my 1991 BMW 318i M42B18 which probably has about 200,000 miles on it. For about a year there has been a distinct rattling emanating from the upper engine, leading me to guess the problem was maybe valves, hydraulic lifters, maybe a loose timing chain...? The engine, however, seemed to run fine and since the car is so old I didn't do anything about it.

Then 2 weeks ago, I'm driving along at about 40 mph and without any big noise or fanfare, the engine just dies. Upon trying to crank it over, the very first attempt, the engine sputtered just a bit, then every single time thereafter, absolutely nothing. It cranks incessantly but doesnt catch even a little.

Having had a past fuel pump failure give me similar symptoms, I checked this out and the fuel pump is fine. Pulled the plugs and made sure I'm getting good spark...all OK. I site down each of the cylinders and can at least confirm that all pistons are moving up and down.

Thinking maybe I broke the timing chain, I pulled the valve cover. Timing chains look fine. Thinking maybe the timing chain jumped, I checked the timing itself and it looks good too, at least from everything I can tell by studying my Chilton manual. I'm not 100% sure about this, but here's how it looked: I turn over the engine clockwise until the #1 piston is at TDC, at which point the intake and exhaust valves are more or less facing towards each other, and the arrows on the cam shaft sprockets are facing up, and the rear end of the cam shafts where the square end flats are parallel with the valve cover, and the 2 dimples are up. Does this sound right?

So I'm now thinking that I have not slipped the timing, so I do a compression test on the cylinders and find that I've got ZERO compression in all cylinders!!! How can this be? Did I bend all the Valve rods? Is something the matter with the lifters?

Surely I can't have a cylinder or piston ring issue that manifested itself instantly! If that was the case, the engine would have been running like crap, burning oil, etc. for weeks leading up to the failure, and this was not the case. It was running fine right up until it dying.

So that's my dilema. Any ideas about what's wrong and what to do about it? I'd love to hear from anyone with any suggestions>
Hnilsen@canalbarge.com

[a930rocket]

Now my car...

142k miles. 2nd owner, so I don't know what was done prior to me owning it. Engine sounds good though.

I'll probably do a a timing chain, gears, etc. sooner than later.

[hnilsen]

How do I perform a leakdown test? I'm guessing for the intake side, when cranking over the engine I need to make sure that the engine is sucking in air? But how much air? Do I need a vacuum gauge and if so, what should the readings be?

I'm also guessing for the exhaust side, I need to be sure that the engine is pushing out air. How do you recommend this be done? My half-assed guess would be to put a plastic bag over the exhaust and crank over the engine to see if it fills. Is this too amatuerish?

Appreciate anyone's help on this.
Hnilsen@canalbarge.com

[DesktopDave]

Leak down tests use an air compressor.   It's connected to a bung that you screw into the spark plug hole, with a two gauges to measure PSI.

Compression tests use a pressure gauge on each plug in turn.  You thread them into the spark plug hole & turn the engine over, then guess what the little bouncing needle is trying to tell you.

You're talking about a vacuum gauge, different beast there.  A vac gauge is a great way to determine fuel economy & general engine health.  But you should test each cylinder individually to get a really good idea of what's right & wrong with the motor.

I'm not usually going to give advice like this, but I'd strongly recommend getting a good mechanic to do the tests.  It's a bit more expensive, but having an experienced mech do it right will save a ton of frustration.  For instance, if you decide to use cheap HF gauges and spend hours of frustration trying to guess what the compression gauge reading actually means (not that I know about that firsthand).

So for a leakdown test, you'd have to pull the plugs then test each cylinder in turn (four tests for the mighty M42):
1. Turn motor over to TDC on the power stroke for the cylinder you're testing (both valves closed)
2. Lock the motor (you don't want to turn the motor over with 100psi pressure)
3. Pressurize the tester, say to 100psi on the compressor regulator
4. Measure how much pressure you have at the plug.
5. Divide the cylinder psi with the compressor psi and you'll have a percentage that each cylinder will hold.  It's not a perfect test but a good diagnostic.

Here's a better description with some pics: http://www.meyerracingonline.com/leak.html

[pdxmotorhead]

+1 Leakdown test is next. .... Should tell the tale. Measure the installed valve spring height, if you have bent ones the height should vary a bit.. Be out of spec at least.

Dave

[Home made iS]

You upgraded an e30 M42?  I thought about the serpentine belt & electric fan bits, but did you do something else fun like enable knock sensors with the e36 DME?

Nah Dave Ive put the whole engine loom etc onto the standard gearbox, with original m40 mounts, and moved stuff round a bit lol, exhaust had to be modified to fit as RHD e36 are much wider that e30s and the steering shaft didnt fit :confused: (I'm in Australia) other thatn that its an e36 in an e30 body