Leaking head gasket, engine rebuild

[Charles 230SL]

I don't know Charles, at this stage I'd go ahead and pull the engine, just for good measure! 

  yeah, you're right Cees - I could use a good Summer project! (just kidding)

[merrill]

this response is a little late in this post,  i had a seeping head gasket on my 66,   replaced it with a new one i bought from Metric Motors.  no more leaking.

i also recommend metric for a motor rebuild, they rebuilt mine and  many restorers send the motors to metric for rebuild.

[Charles 230SL]

..i also recommend metric for a motor rebuild, they rebuilt mine and  many restorers send the motors to metric for rebuild..

thanks Matt, when the time comes I will definitely send the long-block to Metric for a rebuild. I hope Mike Elias doesn't plan on retiring in the near future

[merrill]

hi Charles,

when replacing the head applying copper gasket spray to the gasket can also help prevent leaks

as far as the thermo time seal leak when you replace the seal maybe using some hylomar blue would help prevent leaks.

[Charles 230SL]

..as far as the thermo time seal leak when you replace the seal maybe using some hylomar blue would help prevent leaks..

thanks for the recommendation. I've never used Hylomar Blue but will try it when I remove the TTS pod. thanks again, charles   

[Charles 230SL]

Well, you guys have about talked me out of pulling the engine. Since the head was rebuilt (about 30,000 miles ago) I do wonder why the head gasket started leaking so soon. I've personally only put 29,000 pampered miles on it. Maybe I'm overreacting but those runs down the side of the block are disconcerting...but first things first, I'll retorque the head and check the compression..

Well, I finally had a chance to check the compression last week; compression on all six was much lower than I expected. Cylinders 1 thru 4 were at 115 PSI, while 5 and 6 were at 90 and 95 psi, respectively. The head gasket is probably leaking around 5 and 6.
That being said, and since Cees says I should just for good measure , I decided to go ahead and pull the engine. I'm now in the process of removing all the peripherals off the longblock (manifolds, fuel injection pump & lines, water pump, distributer, a/c compressor, etc,,etc,). I spoke with David Latham and since I'll be buying a number of parts from Bud's over the next couple of months, I decided to let Bud's Benz arrange for shipping to Metric Motors (Bud's uses Metric Motors for their engine rebuilds).

One question I have that I'm hoping someone in this Group can answer (I really don't want to bug Mike Elias or David Latham with this) regards all the studs left in the block securing the exhaust/intake manifolds, alternator, FIP, thermostat housing, etc.  For those who've had their longblock/shortblock rebuilt by Metric, is it necessary to remove all the studs? Or will Metric Motors remove and replace them? Their website doesn't provide any details about the studs and I'd hate to receive a rebuilt longblock without any studs for all the peripherals. thanks, charles

[dirkbalter]

One question I have that I'm hoping someone in this Group can answer (I really don't want to bug Mike Elias or David Latham with this) regards all the studs left in the block securing the exhaust/intake manifolds, alternator, FIP, thermostat housing, etc.  For those who've had their longblock/shortblock rebuilt by Metric, is it necessary to remove all the studs? Or will Metric Motors remove and replace them? Their website doesn't provide any details about the studs and I'd hate to receive a rebuilt longblock without any studs for all the peripherals. thanks, charles

Metric replaced all these studs when the engine was rebuild. Don’t hesitate to call them. If buds removes your motor and sends it to Metric, who is going to put it back in?

[Charles 230SL]

..If buds removes your motor and sends it to Metric, who is going to put it back in?

I'm removing and installing the engine myself. I'll deliver it to Bud's with my truck- about 1.5 hr. drive from my residence. That's good to know about the studs.  thanks Dirk.

[dirkbalter]

Ohh, got you.
Below is how I got the motor back.
I believe he buys a complete seal kit for the motor and gave me all the seals for the unused auxiliary components in a bag together with some other parts. A new oil filter housing, crankshaft damper......
I know its not cheep but I felt well taken care off.

[Kevkeller]

Did they finish the aluminum head and valve cover like that Dirk?

[Charles 230SL]

..I believe he buys a complete seal kit for the motor and gave me all the seals for the unused auxiliary components in a bag together with some other parts. A new oil filter housing, crankshaft damper...I know its not cheep but I felt well taken care off.

thanks Dirk, your post and photos answer several questions for me, one of which regarded the sleeve (see photo) pressed into the block for the fuel injection pump - I thought I was going to have to remove it (glad I don't have to). Looks like I won't need to buy a new gasket kit either.

[dirkbalter]

Did they finish the aluminum head and valve cover like that Dirk?

Kevin
Yes they did. He is within driving distance from me. Since I didn’t exactly know what he needs, I had the motor and a buch of parts in my truck. He offered to also finish some of the unrelated components for me. Motor mount brackets, fuel and oil filter housings..
at the same time. (No charge)

[Charles 230SL]

All the aluminum looks great. I wonder how they did that - bead blast?

Dirk, I assume you removed the distributer bearing plate before you dropped off the engine - have you got a photo of the front of the engine showing what it looked like when you got it back? thanks again, Charles

[Benz Dr.]

They probably have a vapor blast. We use a low pressure sand blast cabinet then I do a light polish by hand with a rotary soft wire wheel on parts going for plating.  Anything like intake manifolds and valve covers ( aluminum ) go to my machine shop where they put those parts in a big dish washer. You want all of those parts to be clean before assembly.

[dirkbalter]

Dirk, I assume you removed the distributer bearing plate before you dropped off the engine - have you got a photo of the front of the engine showing what it looked like when you got it back? thanks again, Charles

Actually, I delivered it with the plate attached and the drive in place. They of course took it of. It was returned, refinished and modified to improve oil flow or lubrication of the drive. I reassembled it with the gaskets provided, myself. I will post a pic tonight.

[dirkbalter]

Front

[Charles 230SL]

thanks!

[dirkbalter]

I suggest enhancing your timing marks when you have good access. Makes life a lot easier later on.

[Charles 230SL]

I suggest enhancing your timing marks when you have good access. Makes life a lot easier later on.

That's a great idea, I'll definitely mark the hub after I get the engine back.

[Charles 230SL]

..I believe he buys a complete seal kit for the motor and gave me all the seals for the unused auxiliary components in a bag together with some other parts.

Dirk, do you recall whether there was a water pump gasket and water pump housing gasket in the bag? reason I ask, I'm putting together a list of items I'll need when I get the engine back. Just curious, which thread sealant did you use for the studs/bolts? thanks!

[mdsalemi]

All new water pumps come with a gasket. However as our friend Joe Alexander thankfully told me when I changed my water pump back some years ago, spend the big bucks on an OEM gasket from Mercedes-Benz. At the time I believe the water pump gasket from Mercedes was about five dollars.

I don’t remember if I had a Febi or Laso pump, but when I compared the two gaskets the difference was astounding. The one that came with the pump was paper thin and looked pretty useless. The “expensive” OEM gasket from Mercedes-Benz looked like a proper gasket! Significantly thicker and more robust. I threw the other one out.

I would like to say that was five dollars well spent.

[Charles 230SL]

I don't intend to buy a new pump - it was replaced 30K miles ago. I do however intend to separate it (the pump) from the housing and clean both it and the aluminum housing. I appreciate the head's up regarding the questionable gaskets. I'll go ahead and add a water pump gasket and pump housing gasket to my list. The ones Authentic Classics carries look like Elring, so they should be ok.   

[wwheeler]

The thickness of the gasket is important because it sets the clearance between the water pump impeller and the housing. Whatever gasket you use, make sure you test spinning the pump and make sure it doesn't grind on the back of the housings. The clearance is pretty close and a paper thin gasket may allow the impeller to contact the housing.

[mdsalemi]

The thickness of the gasket is important because it sets the clearance between the water pump impeller and the housing. Whatever gasket you use, make sure you test spinning the pump and make sure it doesn't grind on the back of the housings. The clearance is pretty close and a paper thin gasket may allow the impeller to contact the housing.

A very technical explanation of high value. All I had to do was listen to Joe Alexander, see the two gaskets together, and realize that the "free" gasket that came with the pump wasn't worth the paper it was cut from. No, I didn't buy any other 3rd party gasket, got one from MB. As mentioned it was a (ha ha) bank busting $5.

[dirkbalter]

Dirk, do you recall whether there was a water pump gasket and water pump housing gasket in the bag? reason I ask, I'm putting together a list of items I'll need when I get the engine back. Just curious, which thread sealant did you use for the studs/bolts? thanks!

Yes it was. However, as mentioned here, I bought a new pump as well and it came with one. Not aware of the criticalness of the gasket thickness, I just installed it with one of them. It is spinning freely however.

I do use a “ gasket maker” in addition to the gasket itself in these application.