Author Topic: Timming Chain replacement..PLEASE HELP!!! (Read 7263 times)

elementskater_xx · « **on:** April 25, 2008, 06:35:12 PM »

Ok so about a week ago on my way to work my car crapped out on me. I pulled over and checked it out. Sure enough i broke my timming chain not only that but i also tore up my crankshaft sprocket and two guide rails. So me and my buddy pull the whole thing apart. We get a new gear on and new chain with rails. Get all the way to the final steps and wi wanted to start it and see if it ran (to make sure i did not crack a valve). What exactlly is top dead center? My car will not turn over. Does anyone have a pic of exactly it should look like? Or maybe how many links it should be, or where exactly the arrows are? I figured out how to get 1 piston locked in just cant get my cams to line up. I am confused i tried everything from ripping it back down to fix it. Do those little things that stick out on my cam pully's have anything to do with sensor? PLEASE HELP.

elementskater_xx · « **Reply #1 on:** April 25, 2008, 06:37:15 PM »

BY the way it' a M-42 engine. 1992 318is

nomad · « **Reply #2 on:** April 25, 2008, 07:03:29 PM »

http://www.esatclear.ie/~bpurcell/318istimingchain.html

Follow that info step by step.

TDC (Top Dead Center) is the first piston (front of car) is at its highest point in the stroke.
From what I hear you can lock the flywheel in 180* off from TDC if you are not paying attention.
At TDC the cams have their two front lobes basically facing each other and the arrows on the cams are pointing straight up. 15 chain links from arrow to arrow including counting the first chain link. If these are set up right then the cams should have the flats of the REAR of the cam straight across the flats. If the rear is straight and the cam gears cannot be tightened dead center of the elliptical bolt holes then you are one tooth off. Keep trying.

If you want to check for any possible valve contact you can turn the engine over by hand and feel for any areas it is binding on and check that the timing chain and gears are in the right position.

Go through that link carefully and look at each step.

bmwpower · « **Reply #3 on:** April 25, 2008, 07:51:56 PM »

Have you confirmed that you haven't bent any valves??

If you haven't bent a valve, it will be an utter miracle.

nomad · « **Reply #4 on:** April 25, 2008, 09:18:34 PM »

yeah, you'll be pulling that head soon, don't button it up too tight.

batsbats · « **Reply #5 on:** April 26, 2008, 08:07:16 AM »

Just curious, how many miles you have? Also when was the last time the tensioner changed?

kowalski · « **Reply #6 on:** April 26, 2008, 09:52:16 AM »

i would bet that you've smashed some valves up pretty good.

elementskater_xx · « **Reply #7 on:** April 27, 2008, 04:18:19 PM »

Ok so i am dead positive that we have it in tdc. I went back and followed evryones advice to the tee. I tried to start it and it sputterd twice but did not fire up. So does anyone have a idea of why that might be doing that now? I am probably going to have a garage come tow it and hook a tester to it and get the reading. My buddy swears it's the camshaft sensor. But ia m not sure anymore advice?

kowalski · « **Reply #8 on:** April 27, 2008, 05:01:07 PM »

did you take the head off?

elementskater_xx · « **Reply #9 on:** April 27, 2008, 05:37:54 PM »

Not yet. I am so dreading taking it off. Especially if it's something small like the sensor. I am going to have a compression test done on it and see what it reads. I am so exhausted on just the timing chain i have spent 2 weeks just making sure that was correct. I am pretty sure i am just going to have a local garage try and diagnose the problem. Not fix it just figure the problem out. Like i said it just doesn't make any sense why would it sputter but not start. It's like sput sput then nothing.

bmwpower · « **Reply #10 on:** April 27, 2008, 06:42:07 PM »

Quote from: elementskater_xx;48028

Not yet. I am so dreading taking it off. Especially if it's something small like the sensor. I am going to have a compression test done on it and see what it reads. I am so exhausted on just the timing chain i have spent 2 weeks just making sure that was correct. I am pretty sure i am just going to have a local garage try and diagnose the problem. Not fix it just figure the problem out. Like i said it just doesn't make any sense why would it sputter but not start. It's like sput sput then nothing.

Are you serious? You bent the valves, that's why it doesn't start.

You're almost all the way there. You might as well take it off to inspect things.

elementskater_xx · « **Reply #11 on:** April 27, 2008, 08:03:54 PM »

Yeah yeah i know. I am just new to the rebuilding of an engine. Plus I am in the Army going to school full time. And i live in CT. So time is my concern in fixing this. Plus it's my only car thank goodness my girl is willing to drive me back and forth to work. I am sure that within my next couple months of rebuilding this car that i will be able to repeat the same quote but remember I am currently in the situation of recieving advice and not giving.Thank you though.

Artem · « **Reply #12 on:** April 27, 2008, 08:41:40 PM »

Hey element

I am sorry to inform you that you have a broken motor, if your story is exactly true.

Basically what those of us who think the motor is broken happened is:

You were driving the car
The engine's timing chain broke WHILE YOU WERE DRIVING
You pulled over, chain is broken, engine is too.
Now you have replaced the chain and the engine does not have compression.

The reason why those of us who say the motor is broken think so is because the M42 engine is an interference engine - meaning the valves, when opened, move below the top dead center position (the highest position of the piston), and in a normal operating condition this is fine and great, and the engine can have a higher compression and produce more power that way. However, if the chain is broken, the valves and the piston will move independently, and because the motor was running at a certain speed, the crankshaft was rotating by inertia and the pistons were moving up and down. Also, if you were in gear, the car's movement was adding on to the piston movement since the car's wheels were connected to the crankshaft. In essence, if your valves are bent, that is the best case scenario, as the pistons might be damaged as well.

The reason why we wanted you to take the head off while you were there, is because if your top timing cover was already off along with the intake, the only thing you would need to take off is the 12 exhaust studs and the head bolts, and that would be all you need to do in order to take the head off and look at the valves, etc.

Good news is that there is a good head for sale in Maine for $200 + shipping, and you can try to grab that. Search for a 1991 head from a 318i on http://www.car-part.com

If you were to replace the head, that would be all you need if your pistons and piston walls look good.

Headgasket set + that head would be all you need in the best case scenario, or if you relaly need a block, I have ea good one right here in MA for sale. two of them actually... pistons and all.

-Artem

nomad · « **Reply #13 on:** April 27, 2008, 09:36:35 PM »

yeah, what he said. At $200 for a head that's your best bet. Your friend and you could have that back together in a weekend. Get the headgasket set and you'll have all the seals you need to encounter but the lower timing case gasket and lower oil pan gasket, also
head bolt kit and the special extended torx socket to get the headbolts off and you'll be good to go.

elementskater_xx · « **Reply #14 on:** April 28, 2008, 06:11:54 AM »

Well I forgot to mention that my car broke down in Jersey and I live in CT. But yeah your def right. I am hopeing that i do not to get a new head hopefully i can replace these valves. I am getting my car towed today to my house. After getting my window broken on Sat night. But i did check out the website you posted. I might be interested in your block. If i do need it how much we talking? Plus you live in MA which is not far from me. So if need be i should be able to get a ride up there and pick it up from you. Everyone i have talked to has said I more than likely bent or broke some valves. I was just being stupid in thinking I was special. LOL. Does anyone know how many valves my engine is by chance i think it's 8 total not sure but I am def looking into it. Hey atleast I will get to post some cool photos up of my project. I might get my head port and polished. Thanks for everyones help. I will be statrting this amazing project sometime between now and Friday night I will keep you guys posted.