Turbo/Manifold Coolant Leak

[Scott A]

Last year, had a new turbo installed on a 330 6BTA.  The guy who did it used black RTV instead of red.  Had a small leak last year that was fixed by tightening the nuts after a few hours of running.   This summer, the leak has come back.  Very small leak but it seems to be coming from the same area (turbo/manifold seal).  Coolant pools in the little depression on the engine block directly beneath the manifold/turbo connection.  Nuts are all tight.  Going to pull and redo the gasket and seal myself (one of those “if you want it done right” kind of things).  Is the black RTV the wrong stuff due to temps and the red necessary for higher temps?  Could tightening have fixed it and then it fail because they used black RTV? 

Topic

[Scott A]

To followup on the leak issue.  When inspecting all nuts again, I found three nuts tight.  I then had to disassemble the raw water pipe running under the turbo/manifold bracket to get a good purchase on the “hard to reach” nut and got about a quarter turn on it with good leverage.  Leak stopped.  I’ll wait until the winter and likely to a full disassembly and fix. 

[Scott A]

The turbo never actually failed.  For a reason that only the prior owner can answer (and he is now not available to answer), the mounting plate between the turbo assembly and the exhaust had deformed and the bolts were very rusted.  There was likely not a good way of taking it apart and replacing bolts while ensuring a good connection.  I decided to not wait for a failure and replaced both the entire turbo and the exhaust elbow with new ones. 

[donald roth]

Any time someone have to replace a turbo, I’ve got to ask why it failed?   Your problem likely goes beyond sealant choice.  Turbos are very simple, and should provide many thousands of hours service without problems, provided that they are correctly installed, particularly in relation to exhaust geometry.  

 

[Bob Neill]

Hi Scott,

Could be, it is important that the mating surfaces are well cleaned and the gasket is oriented the proper way, meaning all ports/holes are in alignment and the barely visible writing on the gasket is facing the turbo or cap. Red high temp silicone is the go to. It also doesn’t hurt to apply Rectorseal 5 to studs and bolts to achieve proper torque.  If you click on Tony Tips and go to Engines and Components>How to Repair a Leaky Turbo Gasket it will tell you all you need to know.

Best 

Bob

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