Why NOT to use RTV!

[Tom '74 911]

I split the case on my 3.6L engine yesterday and found some interesting things. I had been second guessing myself over tearing it down because the leak down I did mid-disassembly was 26%, 10%, 4%, 4%, 4%, 4%. I was thinking that maybe the 26% was an anomaly or something and I was wasting time & $$ on something that was just fine to begin with (I have a history of doing that). After splitting the case, I'm feeling much better about my decision.

The photos show big chunks of RTV gathered on the oil pump screen and inside the case below the oil pump pick up. Imagine how many smaller pieces of RTV have gone through the oil circulation system and likely clogged passages... A bit of a mess I think.

On this engine, RTV was used on just about every sealing surface - case halves, chain housing gaskets, cam housing to head surface, chain tensioner covers - everywhere. On the positive side, the engine was pretty dry on the outside!

I've only had the engine for a few years (purchased as a rebuilt engine) and I have cut open oil filters to look for debris etc... There were always some smaller black specs that I bet were some of the little bits that circulated through...

Also, as is quite typical I am sure, the engine did not have many of the upgrades on the build sheet that was part of the selling point when I bought it.... Broken record, I know.

[Steve@Rennsport]

Nice pics, Tom.

For those who are looking at this mess,...just remember, there is more of that nasty stuff in places you cannot see and therein, lies the real danger. It migrates everywhere,.......

[e3photo]

I think these are my favorite Halloween pictures. Scary.


Emerald

[KTL]

Oh man....... Yep do yourself a favor and pull the plugs and disassemble your external t-stat too. Definitely get your oil coolers ultrasonically cleaned. Take a look inside your tank and see what amount of RTV you find on the screen inside the top region of tank

Wouldn't surprise me to also find a few piston squirters that don't jet very well.

"Nice" thing about the RTV is it's soft so at least it won't mangle the oil pump. At least remove the venturi pipe and backflush that.

[Tom '74 911]

Originally Posted by KTL

Oh man....... Yep do yourself a favor and pull the plugs and disassemble your external t-stat too. Definitely get your oil coolers ultrasonically cleaned. Take a look inside your tank and see what amount of RTV you find on the screen inside the top region of tank

Wouldn't surprise me to also find a few piston squirters that don't jet very well.

"Nice" thing about the RTV is it's soft so at least it won't mangle the oil pump. At least remove the venturi pipe and backflush that.

Oh yes, every nook & cranny will be flushed and inspected. I'm just about finished with superficial cleaning round #1. The plan is to drop everything at Steve W's doorstep next for a through inspection and measuring. I bet he's excited! : ) : )

[KTL]

He'll be truly excited if you pull the case plugs and recon a lot of the pesky areas ahead of time?

I'm surprised that thick layer of silicone didn't open up the bearing clearances such that they didn't get ample crush/push at the parting lines to keep the bearings from moving! Just kidding......... But that is a thick coat of sealant that definitely would increase bearing clearances on the mains and intermediate shaft.

[Schmierung]

It may be good information to disclose the rebuilder. I cannot think of anyone who would find that acceptable. sheesh.