Help 318ti wont start

[MCS02]

Hi
I have a 96 ti it’s my daughters car. I got in it to go get gas and when I tried to crank it up it would not start. When I spin it over it does not sound normal so I did a compression test on it. 1-3 80psi 4 is 70 psi. is this normal? It has over heated once about a year ago. There is no water in the oil. She told me it was running fine when she parked it.
Thanks

[MCS02]

One more question. I used to work on fiats, my 318 sounds just like they did when a timing belt broke. I have checked the timing chain, it seems fine but at TDC the intake valves are not fully closed (I'm just pitting the number one piston on TDC, I cant find any timing marks). Could the chain have jumped a tooth?
Thanks

[cooljess76]

A common problem on these cars is the cam position sensor and crank position sensors. I didn't even read your whole post before the idea of a valve being open came to mind. This could be caused by a bad sensor not allowing the crank to return to TDC. I highly doubt the chain jumped a tooth. Our timing chains are pretty beefy. Many of us have over 200k miles on the original chains. What you can do, try to push the car forward or back a couple feet and try to start it. You could also clean the crank and cam position sensors(it's just a magnetic pulse generator), but beware that they often become brittle and break when you loosen them.

[dave45056]

There are no timing marks on the chain or sprockets. BMW uses special tools to lock the flywheel when the #1 cyl is at TDC. Then another tool is installed on the square ends of the cams. If this were part of replacing the HG, this is when you'd install the cam sprockets and timing chain.

You can verify the cam timing by setting the #1 cyl at tdc and using a straight edge across the flats on the camshafts. They should be parallel to the top deck of the head. If the chain jumped a tooth this would be way off.
And if it is the case, you have to start worrying if the valves crashed into pistons, etc.

The compression readings you mentioned were less than half of what a properly running ti should have.

[MCS02]

Thanks For the help. I found that my compression gage was bad. I checked the cams and all was fine.
I put new spark plugs in it and puled the fuel pump fuse to check it.
The old plugs were not that bad I just had some new ones so I changed them. The Car is running fine now I'm just not sure why.
Thanks agin for the help

[xxxJohnBoyxxx]

Originally Posted by MCS02

One more question. I used to work on fiats, my 318 sounds just like they did when a timing belt broke. I have checked the timing chain, it seems fine but at TDC the intake valves are not fully closed (I'm just pitting the number one piston on TDC, I cant find any timing marks). Could the chain have jumped a tooth?
Thanks

I think it has jumped cam timing. Take a small rod or dowel and find TDC on #1 piston travel then with valve cover off see if your camshaft squares on the back are dead top with a straight edge (you will be able to see it off without the edge if it jumped). Also both valves should be shut on #1 if in the rare case one cam has jumped. Sounds like you skipped a 1 tooth on the the cam timing since all cylinders are off on compression just about right for this when it happens.

Lucky you have not skipped anymore teeth or it's valve to piston contact time and major damage.

Best of luck, John S

[cooljess76]

I'm not a believer of the "straight edge across the squares" method. Reason being, mine are nowhere near square. I ran into this problem when I did my timing and found that the sides of the blocks are machined by BMW to accept the cam locking tool. The tops and bottoms are just cast and never make contact with the tool. It's the sides of the "squares" or rhombus' in my case that need to be squared to the profile of the head. Take a look at this post and you'll see exactly what I'm talking about:
http://www.318ti.org/forum/showpost....2&postcount=13
FWIW, I have an S52, but the M42 and M44's should look the same.

[dave45056]

Jess, I was not suggesting doing the timing that way... but is a good way to see if the chain has jumped a tooth. If it has jumped a tooth the top of the flat will be way off. If it's a little off, you may need to use teh cam locking tool to verify.

I know exactly what you are talking about with the square end of the camshaft. Only the sides are intended to be straight by BMW. Mine was no where near as out of wack as your photos show.

[xxxJohnBoyxxx]

Originally Posted by MCS02

Thanks For the help. I found that my compression gage was bad. I checked the cams and all was fine.
I put new spark plugs in it and puled the fuel pump fuse to check it.
The old plugs were not that bad I just had some new ones so I changed them. The Car is running fine now I'm just not sure why.
Thanks agin for the help

Sorry I missed this post. I'm wrong and please ignore my post...

[cooljess76]

Originally Posted by dave45056

Jess, I was not suggesting doing the timing that way... but is a good way to see if the chain has jumped a tooth. If it has jumped a tooth the top of the flat will be way off. If it's a little off, you may need to use teh cam locking tool to verify.

I know exactly what you are talking about with the square end of the camshaft. Only the sides are intended to be straight by BMW. Mine was no where near as out of wack as your photos show.

No you're absolutely right, my bad. A straight edge would quickly identify if the timing was off. Just not a precise way of actually setting the timing