Jump to content
SAU Community

Excessive Knock And Strange Sounds ?!

Dajae

By Dajae,
in General Maintenance

 Share

Recommended Posts

Dajae Community Regular

Dajae

Posted
Posted

Howdy everyone !

Im hoping someone can help me, or atleast point me in the right direction. Saturday night I went out for a drive, went around a corner.. And then I noticed a strange sound . It would only happen (at first) under acceleration, and the knock sensor on the PFC hand controller started going crazy.

The sound which unfortunately goes along with this, is like extremely noisy lifters. That same night, I checked the oil, but I have a feeling I didnt get an accurate reading. It seemed quite low. I figure the low oil could be contributing to the "noisy lifters", but that doesnt explain why my knock sensor is reading EXTREMELY high.. And the weirdest part, is it only does it (to the bad degree) when decellerating, or when the throttle is only partially opened. Fuel is not the issue, as I had used nearly 1/2 of the tank of Boost98 without any knock issue.

Just as a comparison, even under WOT under high load, the knock sensor rarely budges over 20 - 30 . Normal driving conditions, its lucky to see over 10.

So there you have it :) any ideas? Comments? Questions? Absolutely anything would be appreciated :)

Best regards,

Ty

Link to comment
https://www.sau.com.au/forums/topic/371354-excessive-knock-and-strange-sounds/
Share on other sites
Dajae Community Regular

Dajae

Posted
  • Author
Posted

Howdy!

Sorry about the double post, I couldnt find 'edit post' button anywhere?! Lol. Anyway, so, by the looks of it my heads are screwed. Super sloppy valves and what sounds like shafted springs and lifters.

Its not all bad though, as I'm now looking at a head full of Tomei valve train gear + some nice cams.

Leads me to my next couple of questions, if anyone can help :)

Ok so first, is it possible to buy aftermarket valves for rb25det heads? Or will I simply have to get new heads? (I'm talking about the actual little trumpet shaped thing that goes up and down, lol)

Second, how much would some mild porting set me back?

Andddd while I'm asking all these questions, might as well keep going.. Engine rebuild. Parts aside, what sort of costs would I be looking at from start to finish? Including all the tid bits like chemical cleaning, etc.

Unfortunately I dont have the know-how to do any of that myself (let alone the correct tools), and nor do I have any contacts which could possibly help in the matter. So I'm looking for worst case scenario? I've tried searching for an answer in the forums, but havent come across any worthwhile answers.. Perhaps I search for the wrong thing?

Either way, thanks for reading :)

Best regards,

Ty.

DVS JEZ Grand Master

DVS JEZ

Posted
Posted

The price really depends how far u want to take the build.

What u will be using the car for, what turbo an power goals, what fuel

Just forged pistons and rods?

Then a decent oil pump,

VRS kit (new gaskets for entire motor)

Machine work

Then the head

Just a service

with new lifters (new lifters are $2400ish)

Or with tomei solid conversion new valves

Dajae Community Regular

Dajae

Posted
  • Author
Posted

The price really depends how far u want to take the build.

What u will be using the car for, what turbo an power goals, what fuel

Just forged pistons and rods?

Then a decent oil pump,

VRS kit (new gaskets for entire motor)

Machine work

Then the head

Just a service

with new lifters (new lifters are $2400ish)

Or with tomei solid conversion new valves

Hey thanks for the reply :) In the near or distant future, I want to retire the car to a weekend/occasional drag/track car. What turbo? Haha, its funny you should ask that. I was intent on going down the GTX3582 route, but after seeing Simon's Kando Dynamics Turbo thread, it changed my mind.. And now I'm also looking at BW turbo's. In terms of brand, no idea anymore :) but, as long as the turbo has the potential to flow 600 - 800hp worth of air, then I'm happy. And all on 98.

After doing a little research, it seems as though the rb26dett internals could be an cheaper alternative, as they're supposedly good for upto 400rwkw? From what I can gather, anyway. As for the head.. Ive done quite a bit of googling and come up with some good results. For a full head of Ferrea/Tomei/SuperTech goodies, I'd be looking at costs around the 2.5K - 3K mark. But, after some further reading, it appears as though labour on top of that, I'd be looking at around 5K.. That sound about right?

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GabsReDeal
      R32 GTS (RB20DE) Injectors Replacement

      By GabsReDeal · Posted

      After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
    • MBS206
      Jacks that fit under GTR lips that can reach the subframe?

      By MBS206 · Posted

      For race cars, this is one part where I find having the roll cage bar having gone through a hole in the floor better than the build it up on a ledge inside... The Merc I help on, the main hoop ends are marked on the car, and the jack is marked... Jack goes under a few inches and lifts one whole side of the car up... Removes that fight for long slim jacks for race car duties!   My biggest issue for the daily drivers I work on, is my jacks don't go high enough. The jacks start out on a few blocks, jack it up, then start a second jack under it on more blocks, and then I can get an axle stand under it. My axle stands are presently in use, and are nearly fully extended. The car is sitting with barely more than a cm of clearance to get the wheel off the studs! Sarah's Kluger is the same, as it has an ungodly amount of droop available in the suspension and a distinct lack of good jacking points!
    • MBS206
      NC MX5

      By MBS206 · Posted

      Happy? Yep, my to do list is getting shorter and shorter. Either this light approaching is the end of the tunnel, or I'm about to be hit by a train... Ha ha ha   Also, Duncan isn't that far out of town that you need to make a multi day drive out of it. 😛
    • turbo76lx
      Torana Lx Gtr Hatch, Lots Of Pictures

      By turbo76lx · Posted

      Sorry I meant that we are building the EH for a client.
    • The Bogan
      Torana Lx Gtr Hatch, Lots Of Pictures

      By The Bogan · Posted

      LOL, when one "money pit" is never enough Noice, and excellent work mate
×
×
  • Create New...