Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: lurtch on August 12, 2010, 04:07:01

Title: Engine Disaster averted, I hope
Post by: lurtch on August 12, 2010, 04:07:01
Hello All,

I have been methodically building up my replacement engine, moving all the components over from the old run-out one.  I fabricated a rolling engine stand that is ideal for this purpose when the engines are sitting side by side. I placed the engine back into the car last week.

The work was progressing well today until the hex bit driver that I am using to torque down the small head bolts in the cam chain cavity . . . .  binds up  in the socket head screw and disengages itself from my ratchet. The clink-tink sound I heard as it reached its destination was not a happy event.

Needless to say this is high on the list of  "OH SH_ T" things that can happen.

So,  after my stream of profanity  dissipated, I drop the oil pan to retrieve my tool. Then I get a  second nasty surprise. My engine builder has neglected to tighten down a part on the oil pump! Could someone post a reply and tell me what this is?

My intuition tells it is the pump pressure reief poppet valve. Am I correct? What should the torque on this be?


Larry in CA


Title: Re: Engine Disaster averted, I hope
Post by: ja17 on August 12, 2010, 04:49:48
A stroke of luck !   This is an oil pressure relief valve. If it had come out your oil pressure would have gone to Zero.

There is probably no torque spec on it. It does screw into the aluminum oil pump so don't get carried away and strip something.
Title: Re: Engine Disaster averted, I hope
Post by: tel76 on August 12, 2010, 07:26:01
I would also question the four bolts that hold the the pump together,they are much longer than the ones i have recently fitted.
Title: Re: Engine Disaster averted, I hope
Post by: jeffc280sl on August 12, 2010, 15:32:12
Here is the torque setting you require.
Title: Re: Engine Disaster averted, I hope
Post by: Benz Dr. on August 12, 2010, 16:21:48
The one nice thing about our engines is that you can remove the sub pan on the oil pan. Try that on a 107 car. You have to pull the engine or drop the sub frame - neither is a lot of fun. :'(

I had the same thing happen to me once and it wasn't pretty. I think some of these pumps went down the line and that step was missed. Earlier pumps don't have this oil pressure relief valve so it's only the late ones. I check that valve to make sure it's tight as a matter of course now. :)

This wouldn't really be your engine builders fault. Normally, when you get a new part right out of the box it's ready to install, and particularly on something as important as an oil pump. Unless you were familiar with this vague possibility you wouldn't even consider it as a rule.
Your guy really didn't do anything wrong but it would be pretty easy to draw that conclusion. Only a very careful inspection would have revealed why the engine failed although I suppose the loose valve laying in the oil pan might have been a clue. :(