any turbo experts please have a look and tell me what you think :)

[kewp]

Ok, its not a toyota, but the people on nissansilvia.com in general are useless

I'm doing a sr20det conversion to an E30 BMW, when I bought the engine from the importer the turbo was seized, I had to put a socket onto the compressor wheel to even turn it!. So I sent it back under warantee and they sent me a replacement turbo which span freely like normal. Now I've installed the new turbo onto the car and run the motor for about 15min - but havn't actually driven anywhere. The new turbo has seized again - after only 15min of idleing!
What could possibly be causing these turbos to seize up? I've checked all the oil and water lines and they are not blocked... The only thing I can think of is that the wrecker has done a dodgy and just sprayed the faulty turbo with wd40 to loosen it up a bit and sent it back to me.
Turbo is stock sr20det (t25G), the rest of the motor is running perfectly, except for the obvious lack of boost!

[Joshstix]

It may be that the oil feed is also feeding metal bits into the bearings.

[BeRad]

its usualy advised to fill the core with oil before putting the oil feed on and turning the engine on.... even still it shoudlnt have caused it to seize, maybe he has done the dodgy or you have some bad luck

[EVOSTi]

send it back to them again. whether it be a turbo or engine problem they sold it to you and you are entitled to some degree of warranty. have you tried disconnecting the turbo feed and seeing if oil comes out when you crank it?

[kewp]

why do you need to fill the core with oil before starting it? won't it get filled with oil as soon as the pressure comes up? As I said, i checked the oil lines and they aren't blocked. The only thing could be if there is a blockage inside the block itself - which would be a big problem....

[BeRad]

yes but the turbo is spinning pretty fast and it takes a second or 2 to get to the turbo, it just eliminates any chance of damage to bearings etc.

[kewp]

evosti - unfortunately its taken me more than 3 months to get to this stage of the conversion, warantee has expired. I am going to disconnect the oil return hose this weekend and make sure oil comes out when I crank it - can anyone tell me how much oil I should expect, like a little trickle, or a big gushing flow?

[BeRad]

in between, it wont gush out but it should be more than a trickle

id still be getting on the blower, that shit aint fair to have 2 dud turbos. but thats the fun of 2nd hand stuff. still worth a shot

[EVOSTi]

yeah thats always the way with conversions, noone has them in within warranty. but give them a call and maybe they will be reasonable.

i wouldnt have thought starting a turbo without oil in it would be a problem, its only a split second and the turbo probably isnt moving at idle.

[BeRad]

yer thats right it wont damage it 99.99999% of the time but its still pays to do it and is recomended by garrett and im sure others.

[kewp]

I'm gonna try and pul the turbo apart this weekend - do you need any special tools? I've played with a couple of turbo cars before, but never actually pulled apart a turbo. I figure is stuffed already so I can't damage it worse than it already is

[BeRad]

housings might be tight dont flog them with a hammer or you will break something. other than that no special tools should be needed..

[EVOSTi]

if you separate the shaft from the core it will need to be rebalanced.

and when removing the housings, inox is your friend

[kewp]

thanks mate! - as long as I put the wheels back on the shaft at the same alignment, it shouldn't put th balance out? right?

[thechuckster]

as soon as you remove the wheels, you need to balance it. there's no way you'll get things back in the exact same spot ...

before destroying any chance of getting a replacement turbo, i'd suggest you:
remove the spark plugs
remove power to the fuel pump
remove the turbo oil feed line - not the drain (and put the open end in a small container)
crank the engine for a few secs - you should be getting oil at the end of the hose
if not, then oil feed is the problem
if there is oil feed, point finger at turbo.