1999 V70xc Turbo Oil Return restricted

hubble_xm · Post by **hubble_xm** » 11 May 2015, 21:25

Hi all,

I have been trying to get on top of all the odd jobs on my v70xc recently purchased. One of which was a leak from the turbo oil return, which had been patched up with tube sealant in a previous life. After having got the hard pipe off I saw that the return line internally was pretty much fully restricted by this sealant. Clearly increasing the pressure in there and causing the leak. I have the proper Volvo gasket and o-ring to fix this properly, but my question is would this have caused any problems with the turbo itself that I should be wary of now? This is my first turbo car, so no experience with any of this so far!

Post by **j-dawg** » 11 May 2015, 23:28

That is disgusting.

If the turbo has been starved for oil, you may have damaged the journals the turbine wheel is riding on. Feel the turbo for shaft play. If there's none, you should be good. If not, there are acceptable limits of play that I'm not very familiar with (a few thou axially and a few thou radially), and if you're beyond those you need to rebuild or replace your turbo.

I'm not sure if the leaky fitting alone would cause that, but it looks like the kinda junk that might accumulate as the result of a clogged PCV system or a failing head gasket. Not that I'm saying those are what happened, but the PCV is worth changing preemptively if you don't know its history, and compression is easy to check.

hubble_xm · Post by **hubble_xm** » 12 May 2015, 00:16

That 'gunk' is the sealant they used. There was no gasket at all when I removed the oil return pipe, so presumably they used tube gasket which then got forced into the pipe inlet as the two retaining bolts were tightened. It's not the typical sludge associated with an oil/water mix.

I've replaced this line now with the proper gasket and o-ring, and now the oil leak appears to be coming from the inlet connection on top of the turbo......Is there an o-ring/gasket in here as well?

Post by **jreed** » 12 May 2015, 04:56

Yes, if I remember correctly there is a copper crush washer at the oil inlet line near the top of the turbo.

Post by **abscate** » 12 May 2015, 06:58

That's pretty much a great commercial as to why you shouldn't use sealers.

I'm trying to imagine what this sealer looks like in the turbo journals....and the rest of the engine...ugh.

Post by **mecheng** » 13 May 2015, 11:17

Speechless....... not even Seafoam would break that down

Post by **tryingbe** » 13 May 2015, 15:28

hubble_xm wrote:my question is would this have caused any problems with the turbo itself that I should be wary of now?

How is the shaft play? If it is not bad, put everything back in and see if the turbo smokes or leak, if it doesn't, great. If it does, replace the turbo.

If the shaft play is bad, replace the turbo.

It's not the first time I've seen people use RTV in oil return. DRY GASKET INSTALL ONLY.

hubble_xm · Post by **hubble_xm** » 13 May 2015, 20:22

Glad to see it wasn't just my car that had been hacked up in the past! The gasket stuff came out in a solid plug and it all looked like a reasonably recent hack job so hopefully I got it before any major damage done. But presumably because it was restricting the oil return it would not have starved the turbo of oil - more likely adding pressure/over supply and causing leaking at the inlet?

Anyway, I put it all back together with the proper parts then the oil inlet was leaking. That banjo bolt had a combination of two synthetic washers, one copper and one aluminium crush washer. I replaced that mess with the two correct volvo copper crush washers. So far so good. No leaks and no smoke out of turbo.

I'll do a few quick oil changes over the next little while to clear out any gasket crap that may have escaped....