95 318i Sudden Loss of Compression

[1995black318i]

Hey all. New to the forum. Didn't know where else to go for help or ideas.
I have a 1995 318i with only 72K miles. The car has had a whining sound from the the engine. Mechanic took a quick look and said it sounded like maybe the belt tensioner bearing might be going. I drove it for about a month this way. I finally got a chance to take it in and was literally taking my stuff out of the car to drive it over to leave it with him, when the car just quit. No warning, no smoke, not strange sounds, no stutter. Didn't even have a chance to warm up. It just stopped and then wouldn't start. When cranking it sounded strange, kind of "hollow".
I had it towed to the shop and they found no compression on ALL cylinders and they are baffled. Mechanic says the engine is turning, all parts are moving that can be seen without tearing the engine apart.
Any ideas what could have happened? Don't know what to do. It is worth fixing or just selling it, junking it?
Any ideas would be appreciated.

[RsKeyz]

Sounds like cylinder washdown. Get a second opinion as well from another shop. Or test the compression yourself if you're able.

[walker7182006]

ya you should be able to get some form or fashion of pressure from in the combustion chamber. id say get a second op from some one else

[1995black318i]

These guys have done work for me for some time. They are like friends even lending me tools. They invited me to come over and see the compression results while theynhad it hooked up. So I trust them. The main guy said he went through each cylinder and got no pressure at all.

[patrick houston]

Is this Denmark? *sniff * sniff

[flyfishvt]

There are only a few things that could cause zero compression on all cylinders at the same time. Most of these would make some pretty horrible symptoms.

I vote for cylinder wash down. Its the only thing that makes sense given the symptoms or lack of symptoms you had. Does your oil smell like your gas tank?

I guess I would start by taking the valve cover off and inspecting the cams then do a compression check with the cover off so you can see the cams operate as they go through their stroke. Then do a wet test. Taking the cover off will also allow you to inspect the lifters to see if one or more are collapsed.

At least that's a starting point. If your mechanic is any good he should know what to look for.

[strad]

One thing that needs to be done is to make sure the cam timing is correct.

[sunbrn]

What is cylinder washdown?

If the timing chain broke then you might have bent valves. That be cause for no compression in all of the cylinders. Strange for such a low mileage car.

[flyfishvt]

he said that he was standing next to the car or was in it and it just stopped. No noise, smoke...nothing. If the timing chain broke it would have made a terrible amount of noise, sputtered, coughed etc. Its just odd that it is Zero compression and in all cylinders at the same time.

[1995black318i]

Just got back from the shop. Checked for fuel in oil. Oil is normal. No strange smell and not thinned down. Mechanic is going to start a tear down Monday. Just can't figure out what could cause total failure with no obvious warning. There was no noise like a timing chain busting. Just shut off as if you had stalled.

[sunbrn]

Just got back from the shop. Checked for fuel in oil. Oil is normal. No strange smell and not thinned down. Mechanic is going to start a tear down Monday. Just can't figure out what could cause total failure with no obvious warning. There was no noise like a timing chain busting. Just shut off as if you had stalled.

Be sure to keep us posted.

[Toby B]

It's your timing chain, sorry. nothing much else will cause those symptoms.
Pop the cam cover for a quick diagnosis.
'Cylinder washdown'- that's going to be a very gradual process of deterioration...
...if you're talking about gross overfuelling washing oil off the piston skirts...

I'm ASSuming LA means somewhere in the US- if it's a Euro car with a belt, well,
that's even more likely...

But seriously, 10 minutes to pull the cam cover will tell the story.

t

[walker7182006]

even if you had a blown piston you would still get some form of compression even if it was very little + it would sound like you had a leprechaun trying to get out the engine

no matter what you should get compression unless your starter was not turning the engine. so you might want to look at the starter and the fly wheel...

+ doing what Toby B is good to but instead off taking it off you could try and look down the oil cap whole while some one is cranking and see if the cams are spinning but i say starter/flywheel

[sunbrn]

no matter what you should get compression unless your starter was not turning the engine. so you might want to look at the starter and the fly wheel...
...but i say starter/flywheel

I'm pretty sure his mechanic could figure out if his engine isn't turning over while he was doing the compression test.

[1995black318i]

Engine is turning. I was hoping it wasn't and I'm still hoping something is broken that's allowing compression to escape. I hope the cylinders are not damaged. We will see.

[walker7182006]

[QUOTE=sunbrn;21295931]I'm pretty sure his mechanic could figure out if his engine isn't turning over while he was doing the compression test.



If hes saying that hes not getting any compression what so ever. that means somethings not turning the crank shaft. cause like i said before even if each and every piston had a buck shot in it or even if the piston rings or even if the valves were damaged he would have heard something knocking or had some sort of compression even if it was very little there would still be some compression in there

[sunbrn]

[quote=walker7182006;21301311]

I'm pretty sure his mechanic could figure out if his engine isn't turning over while he was doing the compression test.



If hes saying that hes not getting any compression what so ever. that means somethings not turning the crank shaft. cause like i said before even if each and every piston had a buck shot in it or even if the piston rings or even if the valves were damaged he would have heard something knocking or had some sort of compression even if it was very little there would still be some compression in there

You would have to be a complete idiot to tell a customer that he has no compression in any of the cylinders and not realize the engine isn't turning over. That is how you do a compression test: 1- turn engine over, 2- read gauge from spark plug hole. Pretty simple concept.
If a timing chain or belt breaks in an interference engine, you will bend valves in all cylinders or crack pistons. Sometimes both. If a valve is bent and can't seal the cylinder will not build any pressure.

[walker7182006]

ya but you'll still get jump when doing the pressure test you shouldnt get an absolute zero psi reading all the way across even if there were bent valves. I mean I'm not expert at all but that's just imop. if there's a bent valve he should still be able to get some form of detonation + hear a slight ticking or slight knocking noise no? dam to bend every valve. have you smelled any raw fuel coming out of the exhaust of the car or from the intake?

[sunbrn]

I had a Nissan years ago that broke the timing belt While I driving about 20 mph. No noise, just died. There was no starting it again. All four exhaust valves were bent. Another way to tell is turn the engine over by hand/ratchet on crank bolt. You should be able to feel the compression, if not then something is wrong.

[walker7182006]

Ya high compression engine driven buy belt = bent valves if timing mess's up but owner's are chain driven not to say that its not possible cause i thought i bent a valve or messed up something on the bottom end of my block a while ago. but if his timing chain would have popped he would have heard some form of knocking when it happened or even when ever he cranked it. he says that the mechanic said that all the parts are moving that can be seen without tearing the engine apart so that means the cams to me which eliminates what i said and anything about the timing chain. that's why i say there's something iffy there.

[RsKeyz]

So, OP, have you been experiencing any hard starting recently, excessive cranking to get it started, rich smelling exhaust fumes?

[1995black318i]

Nope, nothing like that. As mentioned there was a whining sound that sounded like a bearing going out. Also had a vibration but it was in the shaft and very likely a center support bearing or the flex disk. Nothing in the engine that sounded serious.

[1995black318i]

Well, the poop has hit the fan and several of you guessed it. The whining sound was from a belt tensioner/guide that broke, causing the timing chain to jump and the valves to bend. How bad is this on a scale of 1-10? Is it a matter of just replacing the valves and tensioner, or are we talking about rebuilding the engine? I'm not doing it, my mechanic is, I don't have that kind of experience. Throw me a radiator job, starter, shocks, alternator etc. I can handle that. I even replaced the intake manifold gasket! But valve stuff?
Sigh, how much are we talking? How dependable will the car be after that kind of damage? Is it worth sinking money into it, or should I get rid of it?
Thanks everyone.

[flyfishvt]

You might want to look for a used head. It might be quicker and easier. Its a toss up. You have to take the head off anyway and if you swap in a used head you will probably want to get it tested and possibly planed. Changing the valves on your head is no big deal for the machine shop. they have to take them out to replace the valve seals anyway.

The vlaves are very soft compared to the pistons so I doubt you did any other damage. once you get them replaced the engine should be good as new. If you have the funds to get it repaired then do it.

ONe thing you will want to seriously consider is swapping in an M50 or an S50. The labor and machine shop costs are going to be very close to what it would cost you to buy and install a new/used engine. S50 engines are going to cost a lot more. $1500-2500 just for the engine. Once again its a tossup but I would seriously consider an M50.

[RsKeyz]

Flyfish is right. The labor involved will be close to an engine swap. If you can find a good deal on an M50 you will be right in the ballpark of having all the headwork done and have 50 more horses to boot.
ie; I had the headgasket replaced on my '91 318is. About $1300, and that was a pretty fair deal. About a year later, the bottom end went (220k miles). I replaced the engine, tranny, and clutch. All with items out of a 150k donor car for $1450. Including labor.
Now there's a little more involved since this wouldn't be a straight swap. But start looking for an engine, talk to your mechanic, and start crunching the numbers.
Good luck.

P.S. The reason my bottom end went? You guessed it, no compression. Cylinder washdown.