Jump to content
SAU Community

Recommended Posts

Hey Guys. I just got done with an RB20DET conversion into an S14 pre-facelift silvia and im running into a few problems. Firstly, the engine overheats really quickly. I started the motor up this morning and took it for a little drive up my road. Less than 2 minutes of driving results in the temp guage reading HOT and removing the radiator cap also results in a spill of almost boiling water. The engine oil warning light is also always on even though i just did an oil change and there is plenty of oil in the motor. Could this be an electrical problem? Does this light come on when the engine oil gets really hot or is this just an indicator of low oil? The car is not running any fans at this point. But it was a cold morning and i have no bumper on the car so it is getting plenty of air. Surely it couldnt be the cause of this overheating after just two minutes?

There is also a lowd screetching noise coming from the belts. And my powersteering comes on and off for some reason (I did fill it up with power steering fluid).

There is also plenty of lag before boost kicks in. Mods are 600*300*100 front mount intercooler with 2 1/2 piping. 3inch exaust and hks pod. i suspect the blowoff valve may be causing some problems. Right now ive got the little hose that connects to the throttle chamber hooked up but the bigger hose where the air released is missing (i blocked the hole on the intake hose with a cap :( ). Could this be causing the lag and the shit drivability?

I know theres plenty of questions there but any help would be greatly appreciated. Il post some pics up of the car soon :)

Link to comment
https://www.sau.com.au/forums/topic/63687-rb20det-s14-conversion-problems/
Share on other sites

Is it actaully getting hot or is just the dash gauge saying so?reason I ask is if you have kept the RB20det water temp sensor it might read wrong with the S14 dash.I did the same with the RB20det in my silo,I put the R31 water temp sensor in the RB20det.

Hope it helps.

hmm, I have a RB20 in my S13 and I must say that the RB20 isn't as prone to overheat as quickly as the 25 or 26 so definately check your thermo and waterpump... As i have my rb20 in my car with the r32 radiator which isn't but like a 1/2 inch taller than the s13 radiator.. but the thing is that i am currently running without a fan as mine died (you know you can't fit the clutch fan) and mine hasn't overheated yet.. So make sure you check out your thermo and waterpump, one of those is most likely your problem. Good luck

fit the sr gauge temp sensor the rb one is diffrent from the sr.

the oil light is proly on if you didnt connect the oil pressure switch wire.

i ran my rb20 in my s13 on the stock radiator (tiny 1 row) for a good 2 weeks with no fans, granted the high was like 30 degrees (f) during this time.

as for the lag bit, the bpv needs to be connected to the dump tube that goes back into the turbo inlet.

Put a fan on it ASAP...

You have a masive intercooler blocking alot of flow to the radiaor as well....

My old RB20 was bad for over heating so i went and got a custom one made at "ARE" and he also supplied a craig davis thermo fan and controler... After these were installed i never had a problem again....

The front mount was the cause of my over heating problem and mine was only 77mm thick...

So put a fan on of some sort.... Check your thermostat..... Check your water pump for clicking (touch it with a flat blade screwdriver and put your ear to the other end)... If you hear clicking you need a new one.... This is common also.. The bearings wear out and the blades touch the other housing a bit... This reduces flow heaps.. Also did you bleed the air from the system when filing the radiator??? With air in the system this will cause the water to reach a super hot temp...

i would have suggested the thermostat is not opening, hence not circulating water through radiator, but if the water in the radiator is boiling, then that's not your problem.

did you remember to put the engine cooling fan on?

There should be a fan on front of engine, driven by engine (ie constantly on). Then there is an electric fan on passenger side of radiator.

i know im stating the obvious, but sometimes these things get missed.

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

    • Apologies for the long post, but needed somewhere to lay out the entire timeline of events and actions taken:   I've got an 89 GTR with a R34 RB in it. It's been running great all year, driven probably 500KM in the last month. It's not my daily driver, just a weekend fun car.    Build info: R34 RB26 - HKS 2.7 stroker kit, HKS adjustable cam gears, HKS turbo upgrades, Trust intercooler, R34 factory DENSO 440cc injectors, JUN chipped/tuned R32 ECU. All of this work was performed in Japan back in 2019.    Thursday 10/2/25 - It's a nice day and decided I'll drive it to work, I start it up in the garage and I notice it took a few extra cranks and sounded a bit funny. I figure maybe it was just because it was a pretty chilly morning. I pull it out into the driveway to warm up a bit before leaving. As I leave the driveway, it feels very off and sounds like a misfire. I pull it back in the garage to deal with after work and take the daily to work. I was able to diagnose it as a cylinder 5 misfire with the old spark plug test (unplugging each plug until a sound change with the engine running). I take off the whole ignition system, ignitor, plugs, spark. *Important note, it is still on the R32 ignition system with the separate ignitor system. I test each system with a multi-meter and nothing presents as a smoking gun. I put it all back together and it starts up no issue. I go ahead and order the PRP R35 ignition conversion kit. It should arrive today (10/13/25)   Friday 10/3/25 - Another nice day, car starts up great and drives great all day. Very pleased that everything seems to be OK   Sunday 10/5/25 - Decided I'll take it to play some golf, load up and drive to the course about 25 minutes away. Drives wonderful the whole way there, I pull in the parking lot and the engine completely comes to a stop. I do not recall if it sputtered at all, but just remember all of the sudden the engine was off. I roll it into a parking spot, try to crank it back on and nothing.  It'll crank and crank and not even try to start. End up getting it towed back to my house and push it up into the garage.    Items I have checked: Fuel in the tank Fuel Pump relay Fuel pump fuse  Spark Plugs & gap Coil packs Ignitor    I know the cylinders are getting fuel as the plugs smell like fuel after a start attempt. I tried spraying starter fluid into the manifold and cranking and not even a sputter.    I decided to do the live CAS test (removing the the CAS, ignition on and spinning the CAS stalk to see if the injectors pulse and spark is active). All of the injectors were pulsing and I have spark at the plug. The half-moon end of the CAS did seem very loose, I'm not sure how much play is supposed to be there, but it was more than I expected. There was no in/out play of the shaft, just the tip end that is pinned on had quite a bit of play.    CAS Play video   When I put the CAS back in, I stupidly did not re-time the engine. I know I need to do that tonight, however, I do not think it will start given it seemingly was not the issue. My plan is to do the PRP R35 coil kit and retime the engine at the same time.    I plan on ordering the Haltech Nexus Plug-in ECU once they are available again, but ideally would like to get this sorted before firing the parts cannon at it and potentially adding more variables.    Anything glaring that I am missing here, I'm a bit at a loss?          
    • Get it on a dyno. Get something logging Consult. Run it up and find out what is causing it.
    • Looking for a plenum for rb25 de+t neo  Not looking to push much power maybe 300kw at the wheels, is there much difference in flow for Freddy “Greddy style” compared to original Greddy or options like Proflow or Otaku garage?    I won’t be porting the de Neo head for now as I think it’ll be fine 280-300rwkw but appreciate the help and any experiences anyone has between them and any advice. Thanks  Looking at this plenum for now below 
    • engine wise almost no mods: stock ecu Greddy front mount intercooler Greddy forward facing intake w R33 TB stock fuel system, stock injectors, rail etc. Kakimoto racing hyper 3 inch exhaust system Apexi intake filter New NGK –R BCPRES (.8 gap) plugs  
    • Nice one @Pac - looks like a fair few 1600's there! 
×
×
  • Create New...