Help Me Fix My Rb25

[SkyHi_33]

Hi guys, just got back home after the car started letting me down. Its a s1 r33 GTS-T automatic.

Up until Friday night it was going hard, not a problem. Saturday morning I changed my exhaust over for regency appointment that afternoon, it had a boost "bleed valve" so I removed that too. Well in the afternoon as I set off, the car started acting weird, the radiator fan sort of spun up a lot faster and louder than it ever used to and I started to notice that the car was barely making any boost. It was spooling but no boost.

Ok so two hours later and after a champ at regency, my car got an extra sticker but the guy was awesome and I understand why it didn't pass as, LH tie rod end is damaged and my castor rod bushes are cracked and leaking. I don't mind as they're both pretty important things.

So anyways, today I swapped my exhaust over to take it for a drive and the engine still didn't sound right as the fan spun up soooo loud after about 2,000rpm. The car was barely making any boost. Ok went home thinking maybe the factory boost solenoid is stuffed. Changed back to bleed valve and pretty much instantly my problem was fixed, or so i thought.

Driving a bit later on, the brakes went soft and I lost braking power, checked all brake lines and canister, no leaks etc... I still don't know why they went soft but to brake properly I gotta pump them up a fair bit (btw at regency the car passed the braking test with flying colours).

Then the fan noise returned, it now sounds like a truck fan getting up to revs and is again making barely any boost. On top of that it seems that there is a loudish squeak coming from the timing belt cover, i recently got this replaced by Ryan and he said that it might squeak for a bit etc, im not sure if this is related. The engine doesnt seem to missfire or anything, it still runs pretty smooth.

So after babying it home I have 4 problems.

1. The fan spins up so fast that it started to screw my bonnet matt up as its literally ripping off.

2. The car is barely making any boost under power

3. there is a squeak coming from the timing belt area

4. My brake pedal went all soft (sort of like serious brake fade or an air bubble in the lines)

I'm seriously pissed off right now as this is the last thing i need for the holidays

Any ideas?

[Madaz]

could you of gotten a pocket of air in your brake lines ?

[RubyRS4]

4. My brake pedal went all soft (sort of like serious brake fade or an air bubble in the lines)

Any ideas?

could you of gotten a pocket of air in your brake lines ?

He's already considered that. Doesn't explain the other 3 problems.

1. Is your water pump on its way out?

2. You say the car runs smooth but not making boost? Check the wastegate wasn't jammed open from exhaust swap.

3. Sure the squeak is not coming from a loose fan belt etc?

4. Check your hose that runs to the brake booster.

I can't understand how an exhaust swap would affect your fan or boost, unless the wastegate is open for whatever reason.

[4door_Sleeper]

The fan can not spin any faster than intended, my guess is that in the hot weather it the thermal coupling has come on (as intended) and is doing its job (the car was probably quite hot- but the factory gauge is useless so don't use it to claim the car wasn't hot)

Well worth getting the brakes inspected and a flush of the fluid

Timing belt noise and boost may be issues for a mechanic or Ryan.

[Ryanrb25]

as mentioned above, Perhaps the wastegate is stuck open, This could be from a stuffed actuator, or as ruby said, maybe the wastegate is stuck open from the exhaust change somehow. Does it show any boost on the guage at all?

[SkyHi_33]

im not really sure how to explain the fan speed but it pushes out a shitload more air than usual and sounds three times as loud. The cover on the bonnet has started to deteriorate from the fan blowing air on to it. Im not 100% sure if its the fan alone making the loud noise.

Water temperature im not sure, the gauge reads fine but as mentioned cant completely go by that.

Where is the wastegate actuator? I didn't change the whole exhaust, only the muffler (should have mentioned that duh..) but it seems to have happened after that was done. The muffler is quite restrictive and id imagine it would have a lot of back pressure.

With the boost gauge, it reads vacuum fine, as soon as it starts spooling it goes up to 0 then when its meant to be coming on boost it goes a tiny bit over 0 and stays there. Thats when the engine fan sound starts and its reeeallllyy loud. I can hear it over the normal cat back exhaoust. (thats 3.5" i think (haven't measured) with apexi cannon)

[SkyHi_33]

here is a video of the problems, i jsut checked over the whole engine n nothing seems out of place

http://au.youtube.com/watch?v=4tEAvQCj75k

you cant really tell the fan noise in the vid but its still noticable and you also hear the squeaking later on in the vid..

Is the wastegate actuator just under the bleed valve bit? and the actual vac hose goes in to it? It sure looks like one...

Also the car was dead cold when it was started and the fan is still going nuts etc..

Edited December 22, 2008 by tx3_90

[Jonnyboy89]

obviously the car still runs so its not cooler pipes or anything, my skyline did this at one stage, think it was the inlet manifold! as people have mentioned it cant be anything you havechanged, only querie could be if your stock boost solenoid has a crack leak in it, as it still did it with an after market boost valve??

[RubyRS4]

here is a video of the problems, i jsut checked over the whole engine n nothing seems out of place

http://au.youtube.com/watch?v=4tEAvQCj75k

you cant really tell the fan noise in the vid but its still noticable and you also hear the squeaking later on in the vid..

Is the wastegate actuator just under the bleed valve bit? and the actual vac hose goes in to it? It sure looks like one...

I can't tell with the audio on that link. However, the fan cannot spin faster than the engine. How many kms has the car done? Your water pump could be rooted by coincidence and thats where the noise is coming from? Would explain the squeak too.

The actuator is on your turbo. Remove the heat shielding and make sure all linkages are still connected. If the c-clip has come off the actuator rod to the wastegate arm, then its likely the wastegate is open fully. Make sure also that the actuator has its two bolts securing it to the turbo housing. A wastegate stuck open will also generate more engine noise, as the turbo is not helping to 'muffle' the exhaust noise.

Edited December 22, 2008 by RubyRS4

[Carbon 34]

Do you actually have a boost gauge to see if the boost is coming up? or just feels like no boost? could be a vacuum leak in a rubber hose? or intake?

or actuator stuffed? if the boost is just flowing out you wont get any power ?

or maybe a internally collapsed muffler if its on the car still?

the fan is a common problem with RB engines 3rd time on my RB30 in 485,000k, the fan clutch fails (wont lock up to cool car overheats at idle) or freezes taking all the power , my RB30 fan clutch just failed again last week, same symptoms. the squeak comes from the coupler locking up from rust etc. , replace the silver finned bit held on by the 10mm bolts in the middle of the fan, I should have taken photos of it , but the bin man just came this morning. damn. the feeling of the fan failure is a huge loss of power(cause its trying to blow hard which draws the power way down) does thepretty sure yours is stuffe fan free spin WITH THE ENGINE OFF ? it should be smooth but kinda sticky if you try to spin it. if it wont spin at all or has a squek or grind its positive a fan clutch failure?

also try to rock the fan hub from the fan base(engine off of course) does it feel a tiny bit loose ? if so the waterpump bearings are starting to go south? you might also see or smell coolant drips out of the little hole below the pump shaft or bearings? if it rocks a lot expect a waterpump to fail extremely soon and could be fatal to the engine if your driving, when they fail it tend to drop the fan sideways into the radiator and guts it like a chicken dumping coolant out of the gashed fins

after watching your video, three main things come to mind tha make that noise .

fan clutch- pretty sure yours is stuffed ?sounds exactly like my RB30 when it died and fits your symtoms to a tee

water pump - might be on its way out, check it for loosenes?

idler pulley - cant check without a lot of removing stuff? and when they go the bolt breaks off or the belt starts to sing loud with rubber burning smells

a few other items make noises like that

alternator , A/C and pulleys with bearings but doubt any of those

brakes, do the brake feel firm when parked ? engine on and off ?

hold them down do they sink to the floor with engine on? vaccum ,water,air in lines, bad fluid?

engine off ? possible leaks ?

you might have a vacuum problem, which would explain boost issues too?

check the vacuum hose from brake master cylinder to manifold ?

or throttle body hoses ?

if the brake sink with the engne on and fluid full... one suss is the vacuum booster behind the master cylinder? or water, air in the lines, but most of the time you would notice that before not just all of the sudden? boosters just fail without warning most of the time ? might be a slow feel or a sudden complete loss of real brake pressure ?

did you mix the brake fluids with other brands or types?

or old fluid sitting in the shed for a while(water in fluids )

no visiable leaks in the wheel areas on rims or the back of calipers ? no broken off or loose air bleeds on the brake calipers ?

if your not sure about brakes dont stuff with them, it could cost you a life ? ask a pro ?

[SkyHi_33]

I can't tell with the audio on that link. However, the fan cannot spin faster than the engine. How many kms has the car done? Your water pump could be rooted by coincidence and thats where the noise is coming from? Would explain the squeak too.

The actuator is on your turbo. Remove the heat shielding and make sure all linkages are still connected. If the c-clip has come off the actuator rod to the wastegate arm, then its likely the wastegate is open fully. Make sure also that the actuator has its two bolts securing it to the turbo housing. A wastegate stuck open will also generate more engine noise, as the turbo is not helping to 'muffle' the exhaust noise.

Ryan replaced the water pump with the timing belt change and service less than 500kms ago. The car has done just over 105,000kms.

I understand that the fan cannot spin faster than the engine as its very logical too but how the hell do you explain the large amounts of air coming off it making a huge WHOOOSSSHH sound and ripping my bonnet insulation up

I cant think of anything really that can make it do this. You're quite welcome to come past and take a look for yourself as I'm letf scratching my head here.

Ill take off the turbo cover and have a look.

Jonnyboy89, the boost solenoid isn't the problem as the engine does the same thing with the bleed valve on (dodge boost controller)

[Carbon 34]

Do you actually have a boost gauge to see if the boost is coming up? or just feels like no boost? could be a vacuum leak in a rubber hose? or intake?

or actuator stuffed? if the boost is just flowing out you wont get any power ?

or maybe a internally collapsed muffler if its on the car still?

the fan is a common problem with RB engines 3rd time on my RB30 in 485,000k, the fan clutch fails (wont lock up to cool car overheats at idle) or freezes taking all the power , my RB30 fan clutch just failed again last week, same symptoms. the squeak comes from the coupler locking up from rust etc. , replace the silver finned bit held on by the 10mm bolts in the middle of the fan, I should have taken photos of it , but the bin man just came this morning. damn. the feeling of the fan failure is a huge loss of power(cause its trying to blow hard which draws the power way down) pretty sure yours is stuffed does the fan free spin WITH THE ENGINE OFF ? it should be smooth but kinda sticky if you try to spin it. if it wont spin at all or has a squeak or grind its positive a fan clutch failure? if it spins free without sticky its stuffed, it should stop spinning in about half to 1 turn if hot ?

also try to rock the fan hub from the fan base(engine off of course and not too hard if you do it from the blades they break easy in old age) does it feel a tiny bit loose ? if so the waterpump bearings are starting to go south? you might also see or smell coolant drips out of the little hole below the pump shaft or bearings? if it rocks a lot expect a waterpump to fail extremely soon and could be fatal to the engine if your driving, when they fail it tend to drop the fan sideways into the radiator and guts it like a chicken ,dumping coolant out of the gashed fins

after watching your video, three main things come to mind tha make that noise .

fan clutch- pretty sure yours is stuffed ?sounds exactly like my RB30 when it died and fits your symtoms to a tee

water pump - might be on its way out, check it for loosenes?

idler pulley - cant check without a lot of removing stuff? and when they go the bolt breaks off or the belt starts to sing loud with rubber burning smells

a few other items make noises like that

alternator , A/C and pulleys with bearings but doubt any of those

brakes, do the brake feel firm when parked ? engine on and off ?

hold them down do they sink to the floor with engine on? vaccum ,water,air in lines, bad fluid?

engine off ? possible leaks ?

you might have a vacuum problem, which would explain boost issues too?

check the vacuum hose from brake master cylinder to manifold ?

or throttle body hoses ?

if the brake sink with the engne on and fluid full... one suss is the vacuum booster behind the master cylinder? or water, air in the lines, but most of the time you would notice that before not just all of the sudden? boosters just fail without warning most of the time ? might be a slow feel or a sudden complete loss of real brake pressure ?

did you mix the brake fluids with other brands or types?

or old fluid sitting in the shed for a while(water in fluids )

no visiable leaks in the wheel areas on rims or the back of calipers ? no broken off or loose air bleeds on the brake calipers ?

if your not sure about brakes dont stuff with them, it could cost you a life ? ask a pro ?

[Carbon 34]

in case your wondering, the fan does speed up when the coupler engages, it locks the blades to the engine speed, when it unlocks it nearly free spins to save you power, fuel and keep the engine at the optimum temp. upon start engine cold they tend to blow hard and loud then taper off to free spin nearly in about 30-45 seconds.

you can't check with the engine running without timing light to stop the action in motion, but engine off you can see the failure of the coupler. as I described above

[SkyHi_33]

Do you actually have a boost gauge to see if the boost is coming up? or just feels like no boost? could be a vacuum leak in a rubber hose? or intake?

or actuator stuffed? if the boost is just flowing out you wont get any power ?

or maybe a internally collapsed muffler if its on the car still?

the car is not making boost, the factory turbo gauge is reading 0 at highest and there is no push in the seat or anything, i do have a gauge sitting next to me but its pointless hooking it up as im certain its getting no boost

the fan is a common problem with RB engines 3rd time on my RB30 in 485,000k, the fan clutch fails (wont lock up to cool car overheats at idle) or freezes taking all the power , my RB30 fan clutch just failed again last week, same symptoms. the squeak comes from the coupler locking up from rust etc. , replace the silver finned bit held on by the 10mm bolts in the middle of the fan, I should have taken photos of it , but the bin man just came this morning. damn. the feeling of the fan failure is a huge loss of power(cause its trying to blow hard which draws the power way down) pretty sure yours is stuffed does the fan free spin WITH THE ENGINE OFF ? it should be smooth but kinda sticky if you try to spin it. if it wont spin at all or has a squeak or grind its positive a fan clutch failure? if it spins free without sticky its stuffed, it should stop spinning in about half to 1 turn if hot ?

yep its rooted. with engine off its completely stuck, wont spin. so im up for a new fan clutch. it makes sence now, the clutch retards the fan speed to keep it constant. with that not working the fan speeds up with the engine speed therefore blowing shitloads more air than it would normaly

also try to rock the fan hub from the fan base(engine off of course and not too hard if you do it from the blades they break easy in old age) does it feel a tiny bit loose ? if so the waterpump bearings are starting to go south? you might also see or smell coolant drips out of the little hole below the pump shaft or bearings? if it rocks a lot expect a waterpump to fail extremely soon and could be fatal to the engine if your driving, when they fail it tend to drop the fan sideways into the radiator and guts it like a chicken ,dumping coolant out of the gashed fins

water pump is 500kms old, done with timing belt as well as ideler and tensioner pulleys

after watching your video, three main things come to mind tha make that noise .

fan clutch- pretty sure yours is stuffed ?sounds exactly like my RB30 when it died and fits your symtoms to a tee

water pump - might be on its way out, check it for loosenes?

idler pulley - cant check without a lot of removing stuff? and when they go the bolt breaks off or the belt starts to sing loud with rubber burning smells

oh its more stuffed than a christmas the sphincter of the universe, ideler pulley new as above

a few other items make noises like that

alternator , A/C and pulleys with bearings but doubt any of those

brakes, do the brake feel firm when parked ? engine on and off ?

hold them down do they sink to the floor with engine on? vaccum ,water,air in lines, bad fluid?

engine off ? possible leaks ?

no leaks anywhere, checked all lines and master. i have a feeling secondary seal in the master is gone as you need to pump the brakes up to get normal pressure. believe im up for a new master cylinder

you might have a vacuum problem, which would explain boost issues too?

check the vacuum hose from brake master cylinder to manifold ?

or throttle body hoses ?

nothing found so far but will keep at it

if the brake sink with the engne on and fluid full... one suss is the vacuum booster behind the master cylinder? or water, air in the lines, but most of the time you would notice that before not just all of the sudden? boosters just fail without warning most of the time ? might be a slow feel or a sudden complete loss of real brake pressure ?

brakes still work but there is no pressure, the pedal is soft however when pumped up theres plenty of pressure as above

did you mix the brake fluids with other brands or types?

or old fluid sitting in the shed for a while(water in fluids )

no visiable leaks in the wheel areas on rims or the back of calipers ? no broken off or loose air bleeds on the brake calipers ?

no mixing, never done that. haven't put new fluid in since i had the car. Will bleed the brakes and see how i go

if your not sure about brakes dont stuff with them, it could cost you a life ? ask a pro ?

Im not gonna drive the car or mess around wit hit untill the brakes are fixed. I had another opinion given to me that the clutch fan could have blown off a vac line somewhere which is affecting the boost and brakes. Although it seems very unlikely weirder things have happened. And considering it all happened at once I wouldn't be surprised at all. Atm really pissed off about the bonnet insulation, its ripped to shreds, was mint before now the car looks like its been thrashed since it was built

Edited December 22, 2008 by tx3_90

[Carbon 34]

Im not gonna drive the car or mess around wit hit untill the brakes are fixed. I had another opinion given to me that the clutch fan could have blown off a vac line somewhere which is affecting the boost and brakes. Although it seems very unlikely weirder things have happened. And considering it all happened at once I wouldn't be surprised at all. Atm really pissed off about the bonnet insulation, its ripped to shreds, was mint before now the car looks like its been thrashed since it was built

well at least you found the fan clutch problem, junkyard item for me...lol only takes about 20 min to change tops

and I really doubt it could ever blow off any lines, just not that much pressure from the air.

hint on the shroud- clutch,removal, take off the 4 10mm bolts on pump nose while the fan is rooted it turns the pulleys to remove the bolts, take out the screws holding the shroud , slide it up over the fan onto the pulleys then the fan fits between the radiator and comes out easier.?

Idea for you,,,,if you take off the bonnet insulation and use it for a template for some sound deadener from Dynomat ? cheaper then a new one and looks nicer too.

check the brake booster vacuum lines ? the leak will cause minimal manifold boost and no brakes ?

good luck pm me if you need help

[SkyHi_33]

check the brake booster vacuum lines ? the leak will cause minimal manifold boost and no brakes ?

good luck pm me if you need help

ive had a detailed hunt around the engine and found nothing that was disconnected, unplugged etc... im not exactly sure where to find the booster vacuum lines but nothing seems out of place. where exactly are they?

atm im thinking that the booster itself is the problem.

Bought a fan clutch and fan itself (mines is all cracked etc), haven't installed it yet though. Still unsure about boost issues, haven't driven the car since the night it all happened as i really don't want to be testing boost with no brakes.

Is there any chance the clutch fan could be restricting the boost at all? As when the car went back to normal for a bit, the boost was kicking in fine. as soon as the clutch fan completely went, so did my boost.

[BensDR30]

Glad that you've resolved the fan issue - simply seeing that the fan stopped with the engine was enough to tell that the hub was stuffed. FWIW the fan doesn't spin at full engine speed - it's designed to turn at (from memory) 2000-3000rpm for maximum cfm efficiency (when hot).

Regarding the boost issue, take the heat shield off the turbine (5x10mm bolts) & see what's happening with the actuator, it's worth assessing if it's seized or not.

Curious that you've experienced the boost issue along with the brakes - the inconsistency is that if you've split a line, or the master-vac is buggered, you should have a hard pedal not soft...

[Carbon 34]

Lack of vacuum power assist may be due to low engine vacuum, a leaky vacuum hose or a defective booster. Sometimes a faulty check valve will allow vacuum to bleed out of the booster causing a hard pedal when the brakes are applied. This condition can be diagnosed by starting the engine (to build vacuum), shutting it off, waiting four or five minutes, then trying the brakes to see if there is power assist. No assist means a new check valve is needed

________________________________________________________________________________

A quick way to check the vacuum booster is to pump the brake pedal several times with the engine off to bleed off any vacuum that may still be in the unit.

Then hold your foot on the pedal and start the engine. If the booster is working, the amount of effort required to hold the pedal should drop and the pedal itself may depress slightly. If nothing happens and the vacuum connections to the booster unit are okay, a new booster is needed (the vacuum hose should be replaced, too)

I would suspect a vacuum line is leaking, it would explain the boost issue as well ?. the brake vacuum line is about as big as your little finger in diameter and goes from the intake to the big black cylinder behind the master cylinder on the brakes. I'll take a photo soon and post it up if you need one ?

Ben is right to a point with hard brakes? but if the rear seal fails in the master cylinder ,it doesnt have the hard pedal feel at the start , or might be intermitten if the check valve fails ?

has the system lost any brake fluid at all ? when it leaks sometimes you dont see the fluid leak because its leaking internally into booster or into intake line and burned off in engine?

______________________________________________________________________

you asked about the fan dropping boost, its not possible but feels like it robbed a lot of power from the engine , RB25 dont have heaps of off boost torque so when the fan fails it will feel shithouse !!! the main fan is mechanical not electrical feedback (but the A/C fan is) . unless the water temp was hot, which would put the ECM into a failsafe(limp home mode) situation but highly unlikley.

when the fan fails it goes two ways, one freezes up or close to it and it doesnt always stop instantly when you shut off the engine, mine still spun but not well, and if you move it my by hand you could feel it was stuffed without a doubt and upon removal you could see the failure of the bearing coupler, second way to fail, it refuses to engage and spins free with no resistance at all, which overheats the car a bit. because it wont lock up to cool off the car. in which case when you shut off the engine it spins for a fair bit before stopping. cold or hot it free spins without the gooey feel of the fluid in the coupler

___________________________________________________________________________

the turbo , it wont produce much boost if you have a blockage in the tailpipes ,cat or muffler ? get a vacuum gauge tester and see if your getting vacuum before tearing your car apart on a witch hunt. if the engine at idle has low vacuum it has a blocked tailpipe or a intake leak which would also be a part of the brake booster issue?

if you have a vacuum leak it can also make the car hard to start or idle like crap, or surge on idle ? check all the hose clamps on the intercooler lines as well... all intake lines ? some look fine but are brittle and leaking.

does the car blow black smoke ?

if the ECM has gone into limp mode it wont produce any power to speak of , only enough to get you home without stuffing up the engine? have you checked the engine ECM codes yet ? only takes a few min to get them ?

have you checked the boost control solenoid valve to see if its sticking

sorry if its overload of info..lol good luck

Edited December 27, 2008 by sapphiregraphics

[Murry33]

maybe theres no turbo in there? hehe jokes

ask ryan on here to check it out if he can

[Carbon 34]

this is the vacuum line and booster location

hope this helps