Fitting a new sump to an Impreza Turbo, am I doing it right?!

[The_Bronze]

Hi all,

 

So, my Impreza's always weeped a little oil since I bought it, and it's constantly annoyed me, too.

 

After inspecting the sump some time back I noted that the front was looking like rusty orange puff pastry, lots of oil weeping out of the 'puff pastry too, but none above.

 

Fairly atypical Japanese car problem, porous sump due to severe corrosion, balls!

 

I cleaned it up and as a temporary stop gap I slathered the offending area with Chemical Metal (don't look at me like that), it worked an absolute treat, no more oil loss! well asides the small amount that hits and burns off the headers, rocker gaskets to do at some point, then.

 

Then after accidentally going through a particularly jarring pothole the car started weeping, then virtually wetting its self, deep joy.

 

Soooo, the car is off the road, I'm in my comfy armchair of a Focus estate (great cars, actually!), brand new sump is ordered and on route for Friday.

 

Now, here comes the bit which pertains to the thread title, I've read so much conflicting advice within the confines of internet land that it's not funny any more.

 

So far as I know, they left the factory with just RTV liquid gasket and no actual solid gasket in place.

 

I purchased some ultra high temp clear RTV, some say RTV is fine, some say threebond, some say various other Loctite products, and some advocate the use of an actual gasket in conjunction with RTV, some say use RTV/threebond on its own yada-yada, you get the idea.

 

I have found that there are a few suppliers on eBay who can supply a sump gasket.

 

In the past when refitting/replacing things like sump gaskets I've just used RTV in conjunction with a separate gasket and this has never provided anything but oil-tight sumps and various other water and oil bearing engine parts.

 

Is there any specific reason why RTV and a sump gasket would be a bad idea?

 

Cheers all!

 

 

[Scooby Pete]

Personally I would have thought there would be a gasket.

If it were me I'd go for the gasket and sealant, overkill never hurts.

[Tlag]

All the engines I've stripped and rebuilt, I have never seen a gasket yet, other than a very old 2.2 n/a.

[savage bulldogs]

I think subaru just use three bond as I've never seen one on any of the turbo impreza engines I've stripped .

saying that ,on my engine build I used a group n cork gasket with a light smear of three bond .

2 main reasons were I was advised to by a rally engine builder and I didn't fancy doing it again if it didn't seal properly

I did build mine intending on tuning it so it might be over kill for your needs but ,if you do need either gasket or sealant I bought both from "import car parts"

[Gambit]

I'd always feel safer with the over kill option :) 

[Jay762]

RTV and a sump gasket will be fine

[Pommy]

Overkill for piece of mind alone is worth it for me.

[The_Bronze]

Sorry for the slow reply!

 

Thanks for the replies chaps, all very appreciated!

 

I ended up plumping for using clear high temp RTV with a cork gasket, so far so oil tight! :)

 

Getting the sump back in was a total pain though, you foul the left hand manifold shrouding with the dipstick tube stub and the other side fouls the oil filter pipework, took lots of jiggering and swearing!

 

I also whipped the oil pick up strainer assembly to clean some bits of what looked like sealant out of the mesh.  I used new 'O' rings on the pick up strainer pipe fastening and also on the dipstick tube, cost around £4 inc VAT from Subaru and Holdcrofts Subaru local to me got the bits next day for me, awesome stuff!

 

I observed no swarfy looking debris in the strainer or in the sump which I took to be a good sign!  It was also quite clean inside which means it's had regular oil changes.

 

As a final note, I'm impressed by the standard sump baffling system and also the plate which keeps excess oil away from the crank, these cars are a lot more specialised under the skin than most people realise.

[savage bulldogs]

Glad you've got it sorted without any issues :-)

And yes I agree about the subaru boxer lump being ahead of it's time design wise .

The engine I rebuilt was a cdb out of a 93 sti which has a few other things that other manufactures have only just started to use a decade later .

like sodium filled valves and under piston oil squirters

[The_Bronze]

Very cool tech indeed!

 

Thanks by the way man, really happy it's all sorted now, along with the power folding mirrors now fitted along with the found lost boost I'm really happy with it! :)