I bought a lime green E55 about 18 months ago with 90k and a clean title. It has about 40k worth of upgrades including a stage three kit from eurocharge. I've loved every moment andand it's been all fun and games until recently. About 4k miles ago I started noticing it was down on power and did a bunch of trouble shooting but couldn't figure it out. I figured it was electrical and that it had to do with the ecu tune. I topped off the coolant once in my ownership and did the regular maintenance. But it developed a misfire one day and after that I came to that it was a head gasket. There were codes or other signs besides some white smoke. I've never opened motor prior to this but with the help of WIS and countless hours, I decided to open it up and fix it. I'm really good mechanically and figured that i would figure it out.

After a lot of work, I replaced it and put it back together. It lit up the first time. WOOHOO! After driving it for a 10 miles it was obvious there was more coolant getting back into the motor so I tore it apparent and sure enough it looked just like the first time. I can't figure out what could be causing this... My straight edge is accurate to ~.002" and my feeler gauge goes to down .0015". The block and heads are flat as can be. So they don't appear to be warped at all. I grew up buying and selling classic muscle cars that love over heating so I've always watched the temp and it's never gone above 100c. Nothing is cracked and everything looks like it's in really good shape besides a couple small marks on the cylinder walls that aren't able to be felt by touch.

WIS isn't very descriptive about where the sealant goes - it says to apply it to the "porous" areas. The picture below was found on here and it's the only other resource I've been able to find regarding the location of the sealant. My gut says it's too much and may have been why there was additional coolant getting in the cylinders. At this point I'm stumped and have no idea what the issue is or where to start. I've talked to two mechanics and they have no idea so I'm trying to get in contact with some MB techs who may have a better idea. Im thinking it's best to get the heads resurfaced given the amount of work I've got into this project already. But anyways, I would appreciate any feedback or suggestions that you guys may have.

 

What year is this. It looks like M113 pistons....early model ???
Also you may have a crack in a cylinder head because if the job was done right with the new head gaskets there should be no issues/leaks.

 

I have a 2003 - the photo was taken from another thread on mbworld when I started the job. I don't think it's a crack in the cylinder head - I replaced one of the heads when doing it the first time. Visually both both heads are crack free.

I should also add that there was coolant in all 8 cylinders the first and second time it was disassembled which is why I believe there is something else going on

 

Was the coolant seen with a bore scope through the spark plug holes or after you pulled the head ?
There is no way that all 8 cylinders leaked at the same time.

 

Intercooler leaking?

 

i tend to agree with the others. you've coolant leaking in from somewhere else

 

This

 

Good call guy's. I never saw a core leak before but makes sense for all 8 holes to have water.

 

No me neither so I offer it up with caution.
The only time I ever saw anything close to this was a mix up between breather and coolant hoses resulting in hydrolock and destruction.

OP - from your description you obviously know your stuff mechanically to strip and rebuild one of these is no mean feat, you drained
down the coolant fully before before pulling the heads? - Apologies that's not meant to be an insult in any way.

 

My thought as well on coolant pooling when heads are lifted off but I believe they are below the draining point when rad hoses disconnected.

 

No worries! I drained the heads as best I could, but there was definitely some that leaked in. I knew it was more than that when I was removing them. I installed all new spark plugs and took photos of the pistons before putting it back together the first time. All but one or two of the spark plugs had white tips and the pistons also had some white build up from the combustion of the coolant. Thats what clued me in that it was more than just a head gasket issue.

I had not thought of the intercooler leaking.. Ive had the heads resurfaced and will dig into that later.

Does anyone know the correct location for the sealant? WIS isnt very specific about it.

 

I outlined the entire head gasket when assembling my engine...all around the oil drain holes in the gasket as well. But...I have read that when the heads are removed that there is no sealant used {needed}. But to me if it was there from the factory ,than it gets it again!

 

Its funny you mention that... SK8215 (the guy who built the E55 ASL) said that he's seen sealant on all of the m113k motors hes touched and does the exact same thing.