Rb25 Usin Oil After Rebuild And Waste Gate Sticking Open

[gtst4d]

Hi all, i have 2 questions, the first one is that after i did the rebuild on the rb25 it seems to be using oil, about 1 litre per 3000kms and i am starting to think that i have not bedded the rings properly and have glazed the bore. If this is the case is it possable to deglazed the bore by going back to mineral oil for 5000km or so.

The second problem is that the waste gate on my r33 rb25 turbo gets stuck open. Every time I stand on it, it comes on boost and goes great but once i have boosted it a couple of time quickly the wastegate stays open and it wont build boost, then if i give it a couple of minutes of cruising it it will close and then will build boost again. Is my wastegate actuator stuffed and if so will the standard r33 computer handle the one of a r32.

Any help would be great, thanks

Andrew.

[RB30-POWER]

all the clearances were ok for the pistons when assembled?

was it run in for a substantial time on mineral run in oil after the build?

[kimbod]

Hi all, i have 2 questions, the first one is that after i did the rebuild on the rb25 it seems to be using oil, about 1 litre per 3000kms and i am starting to think that i have not bedded the rings properly and have glazed the bore. If this is the case is it possable to deglazed the bore by going back to mineral oil for 5000km or so.

The second problem is that the waste gate on my r33 rb25 turbo gets stuck open. Every time I stand on it, it comes on boost and goes great but once i have boosted it a couple of time quickly the wastegate stays open and it wont build boost, then if i give it a couple of minutes of cruising it it will close and then will build boost again. Is my wastegate actuator stuffed and if so will the standard r33 computer handle the one of a r32.

Any help would be great, thanks

Andrew.

How many klm's did you do with mineral oil in the sump.

[Mumbo#5]

im pretty sure that u actually have to pull down the motor again and re-hone the bores if in fact they are glazed. maybe you could have blown the turbo oil seals?

[gtst4d]

All the clearances where good the machine work was done in a good machine shop and i did most of the asembly in a mate mahcanic workshop, I made sure the the ring gaps where in the right position and that every thing was checked befor it went in.

As far as run in went this is what i did: started engin up and run it for 10 minutes with mineral oil then dumped the oil and filter then put mineral oil back in and did 500 kms with that then changed to motul 4100 turbolight. I then did 5000 kms with that then changed the oil and filter i did notice a little oil useage in that first 5000 kms and i am about 3000kms into the next one.

My concern is that mabey i babyed it to much in that first 500 kms.

Is there any whey to check if the turbo seal is going?

thanks for the in put.

Edited February 22, 2006 by gtst4d

[R31Nismoid]

Once the rings are bed in (on a dyno, takes not too long either) then you dont have to worry about all this 500km's, 5000km's, mineral etc etc.

see that many RB's done this way now and not one has had anything adverse to this day

[gtst4d]

Any other ideas or ways to find out where my oil is going, is there some checks i could be doing.

And does anyone have any ideas on the waste gate problem and i forgot to say that i have a turbo smart 2 stage bleed valve. thanks for the input.

[slydin_s13]

if its glazed bore i know a trick with cream clenser you wack some of that white gritty shit in to your cylinders (not 4 the faint hearted) ok but i would do a few checks first, do you have any oil around your front cover sump gearbox housing ect, do a compression test, if you dont know how to do this ill write it up for you, is your turbo leaking oil in to exaust/intake,

when i ran my car in i gave it alot of stick after about 500k its beautiful it was leaking oil but it was from the front seals they burnt out because i did not smother them in rubber greese,

now be a champ and look in your work shop manual and give me the torque settings for the 25det exaust manafold

i also have a spare auxuator i can drop it off on my way to swan lake

[Mumbo#5]

when i ran my engine in (forged arias and crower rods) i used valvoline running in oil. its a nice monograde lightweight mineral oil that is designed for bedding new engines in. I did 2 oil changes with it in the first 1000km of the engines life. I also went on a long drive up the ranges around here (to bed in the new seats and valves because the head was full re-worked and loaded it up nicely in every gear) and also did a rev-out of each gear without coming onto boost at all. It seems as though its done very well and i havnt used any oil at all since changing to synthetic. blown turbo seal would indicate blowing bluish smoke out the exhaust as a simple check I'd say?