No compression, photos & questions from newbie (Long)

[DanOKC]

Hi, I'm new here, so quick intro 1st, been on 2002Faq for awhile, owned 2002's since late 1979, have an E28 w/M20 also,  familiar with engine repairs etc,  doing my own maintenance last 20 years, so have adequate tools & experience, but I'm new to the M42. I just bought a "does not start" 91 318is,  have been reading up as much as possible & have the electrical ETM & the E30 factory manual.  Am looking forward to getting this M42 to run, & may have to pull the head & do a valve job is the way it's looking, but want to ask for some help here before I get to that point.  Short list of what I have done so far:

1. fuel pump, gets power when cranking,
2. checked for spark on plug # 1, Great w/new plug laying on intake
3. checked compression,  was 0 on all 4 cylinders
4. Stomp test, only engine code was 1444, no problem there.
5. Pulled valve cover to check cam timing,  put long screwdriver into cyl 1, cranked by hand to set TDC, noticed the arrows on cams don't point straight up, they are to the left of pointing straight up. If I turn crank to where arrows are straight up, the #1 piston moves down about 5/8" (put mark on screwdriver for reference).  I have 3 pics to attach for reference.

My guess is someone screwed with the tensioner, or the cam timing, or something to make it this far off.  Supposedly the car simply stopped running one day, no overheat etc... Oil & coolant look fine. There is a receipt for service done in past few months from reputable BMW shop & the tensioner was replaced.  I circled in red the pointers I see on sprockets, this is what I am supposed to use as reference, right ?

 Also you can see the intake sprocket has been adjusted far to one side to retard the cam I am guessing. Is this acceptable ?

Should those bolts be dead center from the factory or is this a common tweak for power or  ?

Also since reading about the loose bolts in the uper pan thread & loosing oil pressure, is it possible the tensioner could loose enough tension when that happens for the chain to jump ?  

1st photo is Gears at TDC


2nd photo is #1 piston 1/2inch down from TDC to get pointers on gears close to straight up.

[nicknikolovski]

Any binding up or locking up off the pistons with the valves?

The cam sprocket arrows should point up and make a 90 degree L shape with the surface for the valve cover like you have pointed out. And the 4x bolts on each cam sprocket should be in the middle. There was an adjustment you could do to the intake cam but no worth it. Also when properly timed the square ends of the cams should be parallel with the valve cover surface and on both camshafts, the lobes for cyl 1 should point up and in towards each other.

How are you setting up your crank TDC for cylinder one?

[romkasponka]

You should align flywheel hole with hole in cylinder block to be shure that you are TDC.

[Boosted E30]

+1 for nick

you should be fine just lineing up the mark on the crank pully with the arrow on the chain housing should be just under the oil filter housing if i remember correct. then the back of ur cams the square part should be flat with the valve cover surface, the lobes for #1 should be pointing up and towards each other. the arrows on the cam sprockets should be pointing up but its not critical to have it that way, its better to use the back square parts of the cams as your referance.

if you did a compression check and have none on any cylinders. do you have a cyl leak down tester? or just use the hose from ur compression tester and hook up and air line to it so you can have pressureised air in the cyl. so put each cyl on tdc compression stroke and hook up the tester see if you can hear air coming out of the intake or exhaust if you do the valves are most likly bent and you will have to pull the head common problem when ppl think they are race car drivers and miss a shift say redline 3rd to 2nd instead of 4th i call it money shifting.

[quinn11m20]

Wait a minute, If I read this right. The engine has been running with it way out of time. You said there was an inch of travel needed to reach top dead center. You only have +-15 deg of timing. Usually. Of course, I know someone is going to follow up with this thread and completely undermine me and say they know exactly what is what. IE. DeskTopDave.
How did the engine run so far out of time? That doesn't make any sense.
Please elaborate. Thanks.

[DanOKC]

Thanks for the help, after reading the messages above & reading the pdf of the factory manual I found with bittorent, I found the flywheel hole for alignment inside the drivers side motor mount, found a 12 mm dia bolt fits, probably could find a drill bit a little bigger for a tight fit, not sure if that's needed, but I have that now for TDC reference. & intake cam is off by a few teeth & ex cam by maybe one tooth  Looking at the square ends at back of cams, they confirm that both cams are counterclockwise a little more than they should be. Intake sprocket bolts being fully clockwise would acount for some of that cam timing being off.  I do have a leakdown tester, just a cheap harbor freight one, and I suspect bent valves is what I've got here, but I want to set the timing right as last step to see if any of these 4 cylinders can make compression. I don't see how a cam being off just a little would kill compression, bent valves is only thing that makes sense, but hate to give up hope so early on, just got the car yesterday, so if I have a $600 machine shop bill in my future, I'm trying to prolong the pain of that reality :eek:  Also when turning crank by hand, I do get a little resistance near TDC, not sure if it's normal, as I'm used to 2 valve motors w/rocker arms.

If I want to correct this timing, I need to pull tensioner, pull top guide, loosen intake sprocket bolts, turn that cam so square on back is flat, may have to lift chain & move a tooth or two, not sure, do same for ex cam, then reinstall tensioner. Now I've read factory manual about tensioner, still not sure what to do there, it talks about compressing it in a vice ? because it gets locked in out position when it's removed ?  and then they say rev motor to 3500 first 20 seconds to get hydrualic pressure to tensioner. I read a thread on here about better way to do it, not to rev to 3500. Assuming I even get a motor to make compression  & start, what do I need to know about that tensioner to remove & replace it ? It is only a few months old, so I should have a good tensioner. So does this tensioner have 2 circlips that lock it in a full out or full in position ?  

The engine has not run since I have owned the car, bought it this way, so I suspect boyfriend or idiot was involved, not sure, she claims it just stopped running while she was driving, and I asked was it hot or overheated & was told no.

[quinn11m20]

Ok. First, work on your grammar and punctuation. I had a real hard time reading that whole run on sentence. Second, Yes you do need a vice to compress the tensioner piston. And by the sound of it, you are probably going to have to do a rebuild to be sure there is no other damage.

To just readjust the cam sprockets and "jump a couple of teeth" is not going to guarantee you any kind of performance and life out of that engine. If that is what you are looking for. I seriously suggest you do a rebuild and or find another car.

[Boosted E30]

Ok take out the tensioner so the chain goes slack. Loosen ur cam sprocket bolts and center them and tighten. The. Adjust ur cams so the square end is runs flat with the back of the head use the slots In the cam sprocket to fine tune. The tensioner you should be able to just put back in with out compressing it in a vise if I rember corectly.

[quinn11m20]

+1 on Boosted.

[AcSchnitzer318is]

^Yep no need to compress the tensioner.  When removing my regrinds and putting stockers back in... just had to push it back in really hard and tighten with ratchet.  No pre-compressing or other stuff needed.

[DesktopDave]

Of course, I know someone is going to follow up with this thread and completely undermine me and say they know exactly what is what. IE. DeskTopDave.

Hey now...I'm not being a jerk!  Just a nice guy, trying to help.  If I've stepped on your toes I apologize.  

I think you're right about the bent valves though.  These engines can't run that far off, their timing is even tighter than the M20.  Zero compression is a bad, bad sign.  I don't think the cam gear can be installed incorrectly, so I'd bet the last overhaul was done poorly & the chain slack put it out a few degrees or the lower guides are gone.

I'd pull the lower timing case apart & check the lower chain guides first.  Then I'd pull the head based on the zero compression reading.  Did you do a 'wet' comp test with a spoonful of oil in each cylinder?

Your cam sprockets look great though, maybe they're new?

You've eliminated my favorites one by one...the crank position sensor is OK because you have power to the fuel pump.  You get codes, so the DME & main relay is likely OK.