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Hi guys, I did something so stupid and I just found out. I removed the head to replace the head gasket but didn't mark the timing gear. Now i'm stuck and cannot put it back. I don't want to mess up the engine. what should I do?
I have some picture I took before taking it out. please give me some advice.






 

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So do you have the head off or not? I think you need to tell us what you've done. From the pictures, it looks like you haven't done anything yet. Have you toouched the chain or tensioners? Before you go any further, get all the concepts down on how engines are timed!

I haven't done tha slk but on most cars, you will see two timing marks, one on the crank shaft vibration damper and one on the cam. Both need to line up. If the crank lines up and the can doesn't you are one rotation off.

Rule number 1! Before anyone starts a timing job on any car, TDC the engine!

Don't worry. I'm sure you're OK as long as you didn't touch the chain.

Damon
 

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Administrator 2009 SLK 55 AMG/Founding Member 2006
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designo?

Welcome from Valrico, Florida!
And welcome to this great forum!


You might want to post an introduction in the ‘new members introduce yourself here’ section, if you haven’t already.

If you haven’t, please use the 'search this forum' feature for your questions as they have probably been asked before.
In addition, If you haven’t, please post your questions in the appropriate discussion forum for a quicker response.
And finally, if you find something useful on your visit here today, please consider donating to offset development and operating costs. Even $5 is welcome! Thanks!
 

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I just wanted to say, that I think the engine is markt from the factory out. Maybe its a good idea to get a work manual for your R170.

I can't find a good link at the moment, but some one here maybe have one.
 

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Rule number 1! Before anyone starts a timing job on any car, TDC the engine!
Hmm - not quite - some Landy engines, you time at 90deg BTDC, and if you try and figure out the timing marks on a Triumph T140V (Triumph Bonny Bike) - you couldn't do it - there are so many marks, dots & dashes that relate to different bikes/years etc.

You will need to try and find a proper timing diagram for your year of engine.
 

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If this are pictures from prior to removing the head, and you have already reinstalled it without having removed the cams; one possible problem is a bend valve.
If the engine you’re working on is a crusher (piston can interfere with the valves) you need to remove the head to make sure that there was no contact between a piston and a valve.
Further, every engine assy. will have timing marks for the gears, you just need to find the marks and know the relation to each other in the assembly.
 

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Did you actually remove or touch the chain?

As far as I know, the head doesn't interfere with the timing (correct me if I'm wrong guys). From the pics and what you said, I understood that you didn't touch the chain, and if you're changing the head gasket, you actually shouldn't. (Again, that's my understanding).
 

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Did you actually remove or touch the chain?

As far as I know, the head doesn't interfere with the timing (correct me if I'm wrong guys). From the pics and what you said, I understood that you didn't touch the chain, and if you're changing the head gasket, you actually shouldn't. (Again, that's my understanding).
Hmmm - not on any overhead cam cylinder head I've come across - the cams run ontop/through the heads, and you've got to remove the chains/belts to remove the heads. - Are you not thinking of the cam/rocker cover gasket ??
 

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Don't freak him out. All is not lost as long as he didn't try to turn over the engine mechnically or with the starter. Be gentle. The worst case is that he will need new gaskets if he has everything back together and hasn't turned the motor. My suggestion is to get a manual and read it. Ask questions for concepts that you do not understand. Disassemble everything and start over. Detail is important. Timing and tightening head bolts are very specific! You cannot just tighten the head bolts. It must usually be done in stages and in a specific pattern. If you do start over, use new gaskets and do not use the ones you just put on! Do not get this wrong, your engine could be damaged severely. This is really not rocket science. Don't worry. By the way, if you are just only using the write-up provided in your thread from Benzworld, you are missing alot! I'm not knocking the effort for the write-up, but you should know that he mentions that his write up is pictorial support for Alldata documentation. Please be more detailed on what step of the process you are at and more importantly, did you turn over the engine?

Damon
 

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Did you actually remove or touch the chain?

As far as I know, the head doesn't interfere with the timing (correct me if I'm wrong guys). From the pics and what you said, I understood that you didn't touch the chain, and if you're changing the head gasket, you actually shouldn't. (Again, that's my understanding).
This would be true for a pushrod engine; the pictures above are of a dual overhead cam engine.
 

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Discussion Starter #13
Thanks for all the reply guys. I've actually took the head out all ready. The head is being repair because there is a small crack that lets coolant into the oil. anyways everything was taken apart. now I can see the piston. I got some help from members at the slkworld. here are the diagram for the marking. Dose it make sense to you guys?




 

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Discussion Starter #16
here is how I understand it.

Cylinder number 1 is 20* off TDC means the piston is almost at it highest point in the cylinder.

Cylinder # 1 is the most forward one. Am I close, or is that way off?

I need to turn the biggest pulley counter clockwise(???) and align it at 20* TDC(the mark)
 

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Unfortunately, you cant guess - you need to know exactly which timing marks are where, and how to line them up properly to set your valve timing. At best, if you get it wrong, it won't start, at worst if you get it wrong (and in the real world) you'll end up with broken valves and holed pistons. - you must find a valve timing drawing that you can relate to and understand.
 

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Yes, you will have to time the crankshaft and the cams before assembling. I cannot verify the validity of the image that you posted but you're on the right track.

Everything must be timed before you reassemble. If 20 deg. is TDC then that is where the crank needs to be. Only turn the crank in the direction of rotation and make sure it lines up perfectly and only do this with the head off because you've already messed up the timing. There usually is a tool to lock the crank on most cars before you start but I assume you you're past that. When reassembling make sure NOTHING MOVES! Note that the timing chain usually needs to be threaded in one direction. On some cars one tooth off and it could be bad news. Take your time.

Concept: The crank rotates twice for every one revolution of the cam.

Since you have the head off, you can time the cams off the engine without damage but make sure both cams are timed. Then use the cam lock tool to hold it for installation. From your images, I cannot dicern where the cam timing marks are but I believe that was their intent. I will have to look at WIS to get you better information. Do not put the head on without getting proper headbolt torquing procedures. Make sure everything is clean on the mating surfaces. Are you using new headbolts?

People chime in if I've missed anything. Please note that I have never worked on the head of an SLK. Everything I've commented on above is based on basic engine timing principles.

Good Luck!

Damon
 

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this is not wat you want to hear but if one of the pistons is at top death point cant he figure out the time from that piston out on howe the valves need to be standing in thair time line, then again this is far from accurate.

Never mind my post, sorry
 

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In reference to desino? post. Once he gets the heads installed no covers ect.
Can he rotate engine with no plugs slowly through the fire order. Are there is a problem with timing that is variable? I've changed timing belts, the best was a mitsubishi eclipse. It had four gears and the marks would not line up no matter how many times I rotated the motor. So I made my own marks at tdc # 1 cylinder. From that point on I always make my own marks with the engines marks.
 
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