Jump to content
SAU Community

Rb25Det Neo Cold Start Knock. Piston Slap?

NeoMaggots

By NeoMaggots,
in Engines & Forced Induction

 Share

Recommended Posts

NeoMaggots Apprentice

NeoMaggots

Posted
Posted

Here is a video of the knock from underneath the oil pan. https://www.facebook.com/photo.php?v=10202158035533359&l=7946916124426248770 I shut the car down once the knock was over. After those first few it stops. Going to start tearing into it tomorrow. plans are to go over the timing belt/ tensioners. cut open oil filter see how that looks, and drop the oil pan have a look in there.

NeoMaggots Apprentice

NeoMaggots

Posted
  • Author
Posted

=x Full tear down is necessary you would assume from that mild knock? It only does it on full cold starts. Im going to drop the pan and check the crank for out of round, but only being able to get 2 points checked isnt proper ><

scotty nm35 Grand Master

scotty nm35

Posted
Posted

What oil filter are you using? If the anti drainback valve is leaking overnight it can take a few seconds to pump the oil up. Mine was doing a similar thing with a certain brand filter. I changed to K+N and never looked back.

Is it fine at all other times and just does this at startup? No other noises?

Ben C34 Grand Master

Ben C34

Posted
Posted

=x Full tear down is necessary you would assume from that mild knock? It only does it on full cold starts. Im going to drop the pan and check the crank for out of round, but only being able to get 2 points checked isnt proper ><

That seems pointless.

NeoMaggots Apprentice

NeoMaggots

Posted
  • Author
Posted

^ yeah I don't know what I was saying :domokun: well the motor is out of the car now, should be on a stand tomorrow. It was not the oil filter drain back valve, i tested it did not leak a drop :( Guilt-Toy seems to be correct. I'll know in a day or two. Pictures to come. And picking up a s2 long block tomorrow. Any chances I will be able to get it to work with my NEO ECU/Harness?

scotty nm35 Grand Master

scotty nm35

Posted
Posted

You pulled the engine already? I would have cut open the oil filter and dropped the sump to see if there was bearing particles first.

Keep us posted, I think the cas is different between the two engines, and a few other small differences.

NeoMaggots Apprentice

NeoMaggots

Posted
  • Author
Posted

Yeah the motor was in a 240sx super easy to pull. I was in need of a new timing belt and water pump a few seals and pulleys. No signs of bearing in the oil filter, my last oil sample came back pretty regular but there's no telling until I tear it down. Any tips for When I pull the head to keep any stray coolant from getting down the cyl. Don't want a bunch of glycol getting down there if everything ends up looking healthy and it was just a bad tensioner pulley or oil pump

GTSBoy Grand Master

GTSBoy

Posted
Posted

I asked because #6 can be leaned out by a bad plenum. Even without that possibility, #6 often suffers before the other cylinders because it runs hottest. I suppose you could/should go looking for things like bad injectors/plugs and possibly even oil squirters for other reasons why it might have pinged itself to death.

NeoMaggots Apprentice

NeoMaggots

Posted
  • Author
Posted

I'm assuming I should go ahead and port out this oil drain? if I do this and put in the restrictors should I still pop out that rear welch plug and install a drain right to the sump. (drift car) I would like to not need to install a drain.

post-113457-0-21893400-1381029707_thumb.jpg

GTSBoy Grand Master

GTSBoy

Posted
Posted (edited)

External vents are almost essential. If you don't provide them then ALL the air flow from the bottom of the engine up to the top has to pass up through the drains, against the flow of oil. The extra up velocity makes it hard to get the oil to go down. Add in some extra flow area, velocity goes down, drainage works better.

Edited by GTSBoy

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

    • Piggaz
      R32 gtr transmission strength, billet plate

      By Piggaz · Posted

      You’ll be very upset when you bust that too not to mention the gearing totally sucks. Don’t do it.
    • MBS206
      R32 GTS (RB20DE) Injectors Replacement

      By MBS206 · Posted

      Is the panel filter one that is oiled? Have you ever cleaned or touched the AFM?
    • The Bogan
      NC MX5

      By The Bogan · Posted

      So.... the K&N air box thingo was too big, ended up gifting it to a mate, well, by gifting it he actually supplied food and beer at the pub,  which was nice, as it will not sit on a shelf in the garage for the next 10 years I did trim up some of the existing stuff to neaten it all up and gave it some wrinkle paint, unfortunately it currently has a used and abused mish mash of different types of hose clamps, 4 big fat T bolt type (shit), and a few normal clamps of vairing sizes and brands, but..... only until the 6 constant tension black worm clamps that I ordered from EFI solutions turn up next week Currently the current hose clamps are triggering me hard, LOL Is this the final version, probably not, I really want just 2 silicone pieces, a straight bit of silicone from the filter to the MAF is easy and will happen as soon as I head into Just Jap tomorrow, the problematic part is a 30° silicone bend from the MAF to the TB that I can connect the engine breather from the head, I found that there are bulk head fittings for boat bilge pumps that should work, but until I can get a 30° silicone bend the alloy pipe, and the 11ty thousand hose clamps, are there for the foreseeable future 4 hose clamps are golden, 6 are grudgingly acceptable, the 8 currently holding it all together is just taking the piss    I've also ordered 60 more retaining wall blocks for the front yard, I mis-gonculated the height that was required to get above the base of the Photinia's (red robin's) that are the hedge behind the front fence, currently it is 2 blocks high, and about 1/2 a block short, so going 3 blocks high will be above the base of the red robin's, and allow some room for mulch
    • GabsReDeal
      R32 GTS (RB20DE) Injectors Replacement

      By GabsReDeal · Posted

      It is the stock air box with the panel filter. Everything else is stock except the exhaust at this point, as I also went back to the cleaned 270cc injectors. I will check the RPM when the IACV is unplugged and report back.
    • joshuaho96
      R32 GTS (RB20DE) Injectors Replacement

      By joshuaho96 · Posted

      As MBS suggested if this is happening when the engine is cold you're going to want to remove the intake air regulator and verify resistance + that the shutter is physically opening and closing. At -20C should be fully open, 20C half open, over 60C fully closed. At 20C should be 70-80 ohms. For AAC valve testing using a Consult cable see if you can raise and lower the idle by commanding more or less AAC duty cycle. Hopefully it's pretty linear as well, shouldn't be like 30% AAC valve is barely idling and 40% is 1500 rpm.
×
×
  • Create New...