Jump to content
SAU Community

Recommended Posts

hey guys well cut a long story short just wondering if anyone has had the same problem as me or could lead me in the right direction as to wot im looking 4.

cooler

exhaust/dump

slide stage3 hiflow

stock ecu

walbro pump

2 days ago i was heading home brought the car on boost in 2nd think it spiked to 16ish psi

once i had pulled up at home the car suonded like it was miss firing on idle(which it was after gettin out of the car) now the motor has a fair bit of blow by..if i pull catch can hoses off the rocker cover the after a bit of a floggin the car is fairly smoking/breathing,catch can is vented to atmosphere! ive done a compression test and results are

cyc1 145

cyc2 148

cyc3 100

cyc4 150

cyc5 145

cyc6 147

but yeh ive changed the plugs and no change in the miss fire(car doesnt miss fire,still comes on boost hard thru the rev range) but does NOT sound healthy down low/idle... i was thinkin maybe head gasket? but there is no oil in water or water in oil so yeah. also usually every 2-3weeks im emptying my catch can with a good 100ml+ of oil in it...basically this coming friday(2morrow) we were going 2 pull motor out,rip the head off and check everything out. if anyone has had similar experiences could they shed some light or maybe someone who has an idea what i could be lookin 4 in the bottom end that could be shagged.

thanx

Justin

Edited by l0WRB
Link to comment
https://www.sau.com.au/forums/topic/157493-need-help-rb25det-problem/
Share on other sites

thanx guys well out come the pistons then and check them all over! oh joy this weekend is gona be fun (NOT) haha :P the link ecu and fuel reg just arrived today, now my motor is f*ked :P there goes my tune money:|

Edited by l0WRB

get a set of forged pistons, and there is a user "roguepi" on ebay that sells good rods for RB25, RB26, and RB30.

Get a set, some big end bearings (ACL) and a new head gasket. There will be a few other things you need and I am sure the rest of SAU will help.

im kinda on a budget at the moment,not really interested in forged pistons and rods and all that other kind of stuff, it is my daily driver and im trying to find the cheapest way out of this..has anyone got contacts for supplier of rings/bearings/pistons etc if i need any of these parts, genuine nissan will charge arm and a leg. do i really need forged pistons and shot peen rods for 300rwhp? as a daily driver on 14psi?

im kinda on a budget at the moment,not really interested in forged pistons and rods and all that other kind of stuff, it is my daily driver and im trying to find the cheapest way out of this..has anyone got contacts for supplier of rings/bearings/pistons etc if i need any of these parts, genuine nissan will charge arm and a leg. do i really need forged pistons and shot peen rods for 300rwhp? as a daily driver on 14psi?

If u jsut got forged pistons they shouldnt be much more expensive than stock? foged pistons can be had for under 1k i think.

Hope you sort it out easy enough mate

You wont get out of this cheaply... its going to be 4 figures even if you do it yourself by the time you buy new bearings, machine it all up etc etc.

And if your doing it yourself your gonna be without a car for quite a while.

Guess thats lesson learnt the hard way.

Should never be running with a stock ECU/Hi-flow and increased boost. Its always going to end sadly

You wont get out of this cheaply... its going to be 4 figures even if you do it yourself by the time you buy new bearings, machine it all up etc etc.

And if your doing it yourself your gonna be without a car for quite a while.

Guess thats lesson learnt the hard way.

Should never be running with a stock ECU/Hi-flow and increased boost. Its always going to end sadly

yeah if i can get out of it for 1k im a happy man and yes im assuming it is going to take my car off the road for atleast 2-4weeks :teehee: but luckily work at a car yard and i can borrow a drive around car hehe im actually lookin forward 2 pullin motor out atleast now i can clean my engine bay and paint stuff that i couldnt cause i didnt want to take it off the road for more then 24hrs haha this time car comes back on the road with link ecu and a tune :thumbsup:

Just a quick update

started on it yesterday afternoon,by around 9 last nite we had the motor out and the manifolds off and the head off, this is where the fun begins lol..from what we could see it all looked fine 2 me(i dont know shit really bout cars haha) all cyclinders still have hooning marks still in them,but anyway piston 3 looked to have a few burn marks at the top of the cyclinder so cant wait to check out the piston once we pull them out..1 quick question if anyone has done this before..when the piston is at its full stroke sitting at the top of the block is it normal for about 1mm clearance movement side 2 side?

just a few pics below guys, sorry bout quality was on my phone

post-29137-1172269918.jpg

post-29137-1172269928.jpg

post-29137-1172269938.jpg

post-29137-1172269948.jpg

post-29137-1172269957.jpg

post-29137-1172269971.jpg

post-29137-1172269980.jpg

post-29137-1172270024.jpg

post-29137-1172270032.jpg

Just a quick update

started on it yesterday afternoon,by around 9 last nite we had the motor out and the manifolds off and the head off, this is where the fun begins lol..from what we could see it all looked fine 2 me(i dont know shit really bout cars haha) all cyclinders still have hooning marks still in them,but anyway piston 3 looked to have a few burn marks at the top of the cyclinder so cant wait to check out the piston once we pull them out..1 quick question if anyone has done this before..when the piston is at its full stroke sitting at the top of the block is it normal for about 1mm clearance movement side 2 side?

just a few pics below guys, sorry bout quality was on my phone

yes you wil have movement from side to side.

remember metal expands when hot so clearances are setup to be right at running temp.

thats why flogging your engine when its cold wears it out fast cause the pistons are slapping around in the bore and results in cylinder wear and piston skirt wear

i am surprised you are seeing this much damage

the stock ecu would have dropped to low octane map the moment it saw detontion, so that could have been well before it went bang

it also would have been activating its rich and retard cut proteciton

long before you flew past 16psi pressure.

i expect there is something missing from the picture

check the usual suspects

fuel rail / reg

fuel pump

something has made it fail in a big way, so make sure you double check all of these before rebuilding and trashing it agian. make sure its tuned properly and the afrs are checked to be safe. get an ecu with knock support so you can see detonation.

i am surprised you are seeing this much damage

the stock ecu would have dropped to low octane map the moment it saw detontion, so that could have been well before it went bang

it also would have been activating its rich and retard cut proteciton

long before you flew past 16psi pressure.

i expect there is something missing from the picture

check the usual suspects

fuel rail / reg

fuel pump

something has made it fail in a big way, so make sure you double check all of these before rebuilding and trashing it agian. make sure its tuned properly and the afrs are checked to be safe. get an ecu with knock support so you can see detonation.

well i have bought a LINK ecu through aaron and im pretty sure thats got a knock support on it, but ur right once car is back together only place it goes from there is pushed onto the dyno 4 its tune!

just lucky it didnt mark bore! still looks new, but still going to give it a hone..does anyone know any good online suppliers for pistons/rings etc?

ouch. 4 of them!

Didn't see that coming.

regarding the rebuild; spend the money on rods and pistons now and maybe valve springs and head studs if you intend to run upwards of 20psi in the future.

For supply, talk to CRD or Just Jap who are forum sonsors, http://www.hioctaneracing.com.au/ do online sales.

Proengines on the forums has done rebuilds for a few members

ouch. 4 of them!

Didn't see that coming.

regarding the rebuild; spend the money on rods and pistons now and maybe valve springs and head studs if you intend to run upwards of 20psi in the future.

For supply, talk to CRD or Just Jap who are forum sonsors, http://www.hioctaneracing.com.au/ do online sales.

Proengines on the forums has done rebuilds for a few members

well ive decided once motor is back together im only going to run around 15psi tuned, head studs cross my mind but yeh i dont really have the money to be UPGRADING as i should say..will standard rods be fine for 300rwhp and 15psi?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Yes to both! Yes to standard ECU and tune, but exhaust is aftermarket. Unsure on brand. Actually have it sitting in at my desk haha! I have to set it up on my laptop but this is a great next step, will do. So I generally try to shift before 4.5K RPM most times. I largely don't do a lot of high-rev driving, but I will take it up to red 1-2x a week max, as I know the occasional "Italian tune-up" is good for these cars.  Oh wow, is this way better than what I'm getting. Does this mean there's a good chance I have an issue?   Thanks for all the info so far guys.
    • Old Son, did you re-use the Holden ABS in the new shell or try a different module?
    • Yeah, nah. I had the actuator rod off it today. The arm will not move at all. Neither out, nor in. Yeah, you'd think so, but I've been thinking about that. Even when the actuator rod fell all the way off at the beginning of this saga, it would build more boost and faster in lower gears than it would in higher gears, and you'd think that that was the opposite of what should happen. But I strongly suspect that there is a thing with the gearing getting the revs to rise faster, that there must be some transient effect with the gas flow rate rising quickly, that you don't get with the more steady state case of the higher gears. Keep in mind - the gate is not shut in either of my weirdnesses. So things are not "normal". We normally think about a turbo spooling up (below the wastegate target) with the gate shut. I have all sorts of mental models running now where the gate is a little bit open, and having it stuck open allowing gas out while it should be going through the turbine has all sorts of weird effects (in these mental models). I'm thinking in the higher gears, the ex mani pressure builds to the point where enough gases spill out the wastegate to just prevent the pressure rising much more at all, or just creeping up, all the whole the revs are increasing and getting closer to the point where a gear shift becomes necessary.
    • Is it possibly wastegate actuator itself is sticking, or even the rod to flapper? Otherwise I reckon things are getting a bit rusty/worn   Also odd it won't boost in 3rd to 5th, but will in 1st, I'd expect the other way around with it slightly open as there's more time on your way to redline for it to spin up
    • Does anyone know ow what these two plugs are for and if they should be unplugged? Just put the dash back together and can't remember if these were plugged in before or unplugged! (Blue and white plugs) 🤦🏽‍♂️
×
×
  • Create New...