Author Topic: crank is stuck. (Read 15828 times)

jan lauwers · « **on:** June 27, 2015, 21:54:40 »

Gentlemen,

I am busy replacing the back and front crank ace seals. I have cut the lower half circle of the back seal as described on this forum, leaving some 0,6 mm on each side etc. Obviously I have my engine out, but not the crank since I am only replacing the bottom half of the rear seal. While I had the oil pan off, I noticed at the front of the engine, that the chain was hanging somewhat loose… it troubled me, because I was not sure if this is normal or not (see attached pic). After I had put in the 2 new seals, I decided to rebolt the oil-pan without any sealant, only to give myself a rehearsal for the real work later (WITH the sealant). A second reason for doing this was to check if the crank can rotate freely… to check if I had not cut the rear seal too tight. So, I bolted the pan at the right torque settings, tried to rotate the crank… and found that it is stuck!. I then removed the oilpan again. Then I guess I probably did something stupid… I tried again to rotate the crank without the oilpan on… I am not sure now, but I think the chain may have jumped one tooth. Questions:

Is it a problem that the chain was half loose over the wheel of the crank?

Why is it stuck now?

What should I do?

Help please!

Many thanks!

jan lauwers · « **Reply #1 on:** July 03, 2015, 10:22:07 »

is there nobody here who can help me? I 'd really like to understand why the crank ace suddenly is stuck... and how I can resolve it. I am a bit desperate folks...help needed please!

Many thanks.

Jan

mbzse · « **Reply #2 on:** July 03, 2015, 13:46:01 »

Quote from: jan lauwers

.../... I 'd really like to understand why the crank ace suddenly is stuck... and how I can resolve it

Probably the chain is stuck at the screw you see in my diagram here... unscrew it, should release your chain
/Hans in Sweden
.

jan lauwers · « **Reply #3 on:** July 03, 2015, 13:53:26 »

Thanks a lot Hans. I will try that tonight... even though I have not touched that screw... so I'd be very surprised... BUT I am very grateful for your reply!

Jan
Greetings from a sunny Belgium!

ja17 · « **Reply #4 on:** July 04, 2015, 13:58:07 »

Hello Jan,

Your thread is lost in "General Discussion" you will have more response if you post it in the other category "drive train etc." I just accidentally came across it myself.

Yes, your chain is stuck. You may have to gently back up the crankshaft. Try using the Flywheel to move the crankshaft. After it is free again, turn the engine only in the normal rotation.

Peter van Es · « **Reply #5 on:** July 04, 2015, 16:42:08 »

Moderators just moved it.... but Joe, you are right!

jan lauwers · « **Reply #6 on:** July 04, 2015, 17:49:12 »

Thank you Joe. I will try yr suggestion. I will report back. I will also keep the advice in mind about the forum categories. Continuous learning!

Jan

Benz Dr. · « **Reply #7 on:** July 04, 2015, 20:56:49 »

If your timimg chain is loose and it did slip a tooth or more then you could have a valve hitting a piston. If this is the case, your engine is definately out of time.

ctaylor738 · « **Reply #8 on:** July 04, 2015, 22:20:56 »

Something is wrong here. How did the chain get the slack in the first place? Did you take the tensioner out?

jan lauwers · « **Reply #9 on:** July 05, 2015, 12:30:53 »

Just a recap to make sure I am giving you guys the correct information.

My engine is out for replacing the crank seals. Since it has been out, I have always been able to turn the crank ace, using a 27mm wrench. A while ago I noticed that the chain was not taut at the righthand side of the front sprocket (while standing in front of the engine, see pic at the beginning of this thread). Not sure if that is normal or not. Then later I suddely could not turn it anymore. It is stuck, I can move it about 1 cm back and forth, and yes it feels as if it is touching someting, so I also think that a piston is hitting an open vale.
I do not understand how this could have happened. I think I have not done anything that could put it out of time… at least not conciously!.

To answer Chuck’s question: No I did not take the tensioner out.

What is the best procedure now?

Thanks guys!

Jan

ja17 · « **Reply #10 on:** July 05, 2015, 13:12:11 »

Hello Jan,

You might also try taking up the slack on the IP side of the chain by backing up the camshaft. If the chain becomes taunt then you can continue turning the engine via the crankshaft in the normal direction of rotation.

jan lauwers · « **Reply #11 on:** July 06, 2015, 07:31:50 »

Hmm that didn't work Joe.

Jan

ctaylor738 · « **Reply #12 on:** July 06, 2015, 20:27:34 »

Before I went that far, I would try loosening the bolt discussed earlier, and turning the cam backwards to pull the chain back, then see if you can go forward on the crank. Then bring the engine to TDC on #1 and see where the marks on the cam are.

Benz Dr. · « **Reply #13 on:** July 06, 2015, 21:55:09 »

I think I would had the head off a long time ago.

jan lauwers · « **Reply #14 on:** July 07, 2015, 06:31:21 »

Chuck,

I suppose you mean the bolt that Hans was referring to, right? what is the function of that bolt except for holding the Power Steering reservoir?

Thanks,

Jan

ctaylor738 · « **Reply #15 on:** July 07, 2015, 13:44:41 »

Yes. It makes sure that the chain stays on the auxiliary sprocket. It's also the most likely place for the chain to bunch up and jam.

jan lauwers · « **Reply #16 on:** July 07, 2015, 14:04:27 »

Thanks Chuck. How far can I loosen it? is there no risk that I loosen something inside that I have no access to?

Jan

ctaylor738 · « **Reply #17 on:** July 07, 2015, 14:48:41 »

Try two turns. It just sticks out on the inside, it doesn't hold anything.

jan lauwers · « **Reply #18 on:** July 11, 2015, 20:33:24 »

Today I found that my engine is definitely out of time. I removed the circular cover that holds the front of the axle of the injection pump. There I could see another big part of the chain. The chain was not jammed there. The bolt that Hans talked about did not hinder the chain. Then I removed the rocker arm of the valve that was standing lower than any other valve. Now I could turn the CA a lot further, which proves that a piston was hitting that lowest valve.

Here is my plan, I will:

Remove all the rocker arms so that no more valves are open
Turn the CA untill 0 on the damper is up against the triangular mark.
Hopefully I can then see the master link of the chain on the camshaft sprocket.
Undo the master link and make sure that the chain stays streched at both ends
Turn the camshaft on its marks.
I must make sure that the chain stays taut between CA sprocket and injection pump sprocket so that injection pump stays in time.
Close the masterlink.

Is the the right procedure gentlemen?

Key to my problems is to understqnd why the chain went loose in the first place. As long as I dont understand that, I run the risk of it getting loose again. I think it has to do with the chain tensioner not doding it’s job, but I dont understand why. Is it because I have drained the oil of my engine? Can anybody explain that part for me as well please?

Thanks a lot!

Jan

ja17 · « **Reply #19 on:** July 12, 2015, 03:43:32 »

Jan, the chain most likely went loose by turning the cam or crankshaft the wrong direction. Turn the engine by the crankshaft bolt only in the correct direction. Check the timing marks after turning the engine in the correct rotation. You may not be out of time.

jan lauwers · « **Reply #20 on:** July 12, 2015, 12:03:05 »

OK I was not aware that it should only be turned clockwise. So, this must have caused my problem. Not that I have ever had the need to turn it anti clockwise, but perhaps this has happened accidentally while I was trying to move it... going up and down a bit with the wrench.

But then still Joe, the fact that I hit an open valve can only mean that it is out of time, or am I misreading something here? In any case, in order to set it at the marks again, I must be able to turn it. So, the only option that I see is to remove all the rockers and work out the plan that I described.

Thanks for all your help guys.

Jan.

jan lauwers · « **Reply #21 on:** July 12, 2015, 12:43:10 »

Joe,

I was doing some more searching here and then I found this topic:

http://www.sl113.org/forums/index.php?topic=1811.0

From reading that topic, I am thinking:
My engine is out of the car, the oil is drained, so, no oil in the tensioner, thus the tensioner does not work, which caused my chain to jump. Is that correct?

By the way, by turning the CA clockwise I see the tensioned arm move up.

Sorry for all my questions, but I am trying to learn here.

Thanks again,
Jan

ctaylor738 · « **Reply #22 on:** July 13, 2015, 15:05:22 »

The tensioner shouldn't move when you turn the engine. I would say you need a new tensioner. It has it's own little pool of oil in the cylinder head, so it would have oil unless you turned the engine upside-down or on its side to work on the seal. But even then, it should have stayed pressurized, IMO.

Your plan sounds good, but I suggest removing the sprocket from the camshaft instead of un-doing the chain. Bring the engine to TDC on #1, remove the sprocket, turn the cam to align its marks, and reposition and reinstall the sprocket. You may want to take the tensioner out to get more slack in the chain.

Good luck,

jan lauwers · « **Reply #23 on:** July 16, 2015, 09:22:50 »

Chuck,

Many thanks for your reply, I find this very helpful.

I have now removed the rocker arms and I can turn the CA round now. My engine is definitely out of time, I measure it to be about 100 degrees on the CA damper. The good news is that I don’t see the tensioner arm move anymore, so I presume it is still working OK.

Chuck, why are you suggesting to remove the camshaft sprocket rather than undo the chain? For me I think it is easier to open the chain, I am not so confident to remove the tensioner. I will make sure that I keep the chain taut while it is undone.

Then my last concern now is the timing of the injection pump. I don’t think that one is off, but I would sleep better if I knew 100% sure. Is there a simple way to check and set this?
Thanks!
Jan

ctaylor738 · « **Reply #24 on:** July 16, 2015, 22:26:21 »

First of all, to break the chain, the master link will need to be in a place where you can work with it. Second, the tensioner will push against the chain, and may make it difficult to position it on the cam sprocket. Third, it is very easy for one of the clips or part of the master link to fall into the chain galley.

Again, I think you should replace the tensioner in any case.

Cheers,

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Author Topic: crank is stuck. (Read 15828 times)