How bad did I screw up - PeachParts Mercedes-Benz Forum

81 Olga · #1 04-09-2011, 02:46 AM

Hello folks, Today I adjusted my valves for the first time on my 81 300d turning the engine clockwise (to the right) while facing the engine. I believe this is the right direction? I got into a little bit of a rush to try and beat the rain and accidently turned the engine counter clockwise (to the left) a slight ammount maybe 5mm.

So how bad is it, should I try to start the engine or have I jumped time or somthing. Also my glow plug light will not come on. I pulled the insrument cluster replaced the bulb and cleaned the contacts. The glow plug light started to work intermittently before the valves were adjusted. It seemed like a bad contact because I could jiggle the glow plug bulb socket on the cluster and it would work but now no glow light at all. Could backwards rotation and glow light failure be related? Any help would be appreciated

aaa · #2 04-09-2011, 05:32 AM

They're not related, check your strip fuse. Rotate your engine the right way one revolution, if it doesn't bind up you're good.

81 Olga · #3 04-09-2011, 06:35 AM

Yeah I did not think they were related. I checked the fuse box and no blown fuses. I guess the next thing to check will be the glow plugs. When I first got the car in 05' the glow plug light stoped coming on so I replaced the plugs and then it worked. I will have to try and rotate the engine 1 full revolution. thanks

aaa · #4 04-09-2011, 08:25 AM

The strip fuse is not in the fuse box, it's in the gp relay.

Yak · #5 04-09-2011, 09:57 AM

Since the GP light was acting up before you did the valves, they're probably unrelated.

However, it'd still be prudent to recheck the GP wires and look for any dropped/missed tools near the wires and make sure you didn't crack or break a wire.

leathermang · #6 04-09-2011, 10:16 AM

Quote:

Originally Posted by aaa

They're not related, check your strip fuse. Rotate your engine the right way one revolution, if it doesn't bind up you're good.

A four stroke engine requires TWO revolutions to check that.
This should be accomplished by using a socket and ratchet by hand.. on the CRANK END...
if any resistance is felt stop immediately...

barry123400 · #7 04-09-2011, 10:16 AM

The slight backward movement of the engine you quote is inconsequental. It would have not been enough even to pick up any slack mind jump teeth.

leathermang · #8 04-09-2011, 10:24 AM

Quote:

Originally Posted by barry123400

The slight backward movement of the engine you quote is inconsequental. It would have not been enough even to pick up any slack mind jump teeth.

There is a procedure in the FSM which allows a slight movement backwards...but one sure wants to minimize this in order not to reach the place where serious consequence occur......

dieseldan44 · #9 04-09-2011, 11:21 AM

Quote:

Originally Posted by leathermang

A four stroke engine requires TWO revolutions to check that.
This should be accomplished by using a socket and ratchet by hand.. on the CRANK END...
if any resistance is felt stop immediately...

just to clarify - if you rotate via the crank if you dont feel any variation resistance as you go around (assuming GP's and injectors are installed) then you have a problem

(no compression!)

you will feel a lot more resistance at each compression stroke, but not 'metal on metal' resistance.

i mention this because it worried me the first time I felt it on a diesel engine.

leathermang · #10 04-09-2011, 11:30 AM

LOL, and to clarify even more... in the old days engine manufacturers posted how much torque they expected it to take to turn an engine over by hand... I seem to remember one engine I was dealing with being about 70 foot pounds ... and that may have been with the head off... just the friction ( all friction parts with breakin lube on them ) to turn it... this was a check to see if something was too tight before going further.
But if you ever feel a ' clunk' stop right there and find out what it is before going further..

Codifex Maximus · #11 04-09-2011, 02:05 PM

Make sure the balancer is not loose. I've never had the problem but folks here have mentioned that if you turn the crank backwards, there is a chance that you might have loosened the crank bolt. Not likely but maybe possible and worth checking.

81 Olga · #12 04-09-2011, 06:00 PM

I checked the strip fuse in glow plug relay on drivers side fender, checked out ok. I pulled the glow plugs and they looked ok. Is there any way to check the glow plugs? Since I could jiggle the glow plug light socket on the back of the cluster could there be some problem there? Also I did not have a socket to turn the engine at the crank. I had to use 22mm on the power steering pump pulley. Turned the engine over that way and did not hear any strang noises or excessive binding. I have a test light is there any way I can check the relay or plugs with it?

leathermang · #13 04-09-2011, 06:08 PM

Quote:

Originally Posted by 81 Olga

I had to use 22mm on the power steering pump pulley. Turned the engine over that way and did not hear any strang noises or excessive binding. I have a test light is there any way I can check the relay or plugs with it?

The power steering pump pulley is a tapered shaft..... The Factory Shop Manual specifically forbids using it to turn the engine. There are stories in the archives about this.. putting excess pressure on it makes it an interference fit...

I Told You this is supposed to be done by using the crank nut...
If you do not listen people will not be motivated to explain things to you.

81 Olga · #14 04-09-2011, 06:32 PM

I had already turned it by the power steering pump pulley before you told me not to do that. I did not know it was bad to do this as I followed the advise in the pictoral on diesel giants website where he suggest to use the power steering pulley.

vstech · #15 04-09-2011, 06:33 PM

Yeah, that guy has some shortcuts that are annoying sometimes... Great help for the forum members, but checking here first is a good idea!