Jump to content
SAU Community

Loud Crunch On Cold Start!

R33Turbo

By R33Turbo,
in Engines & Forced Induction

 Share

Recommended Posts

R33Turbo Proficient

R33Turbo

Posted
Posted (edited)

Hi guys,

I get a loud crunch for about 1-2 sec everytime i start the engine and also loud tapping sound (sounds like pistons) when i first start my car in the cold morning. Now if i was to warm the car up, take it for a drive then turn the engine off to start it back up again to look for the sound, the sounds gone away due to it being warmed up. Hence, why is the reason i can't take it to any mechanic to show the issue. :domokun:

Ive only noticed this loud crunch for 1-2 on cold start after ive changed my oil to 'Elf Synthetic Oil 10W50'. This is pretty much all the relevant information i can provide from my knowledge, and also that the sound is coming from under the hood on the passengers side, kinda sounds like its coming from the head area on the passengers side where the turbo is and all.

Could it be that im using a real thick oil, hence is why its making weird noises on cold start till its warmed up?

Note: The crunch sound is only for about 1-2 sec on cold start and not constant whilst idling in cold or driving.

Much appreciated for any helpful response.

Edited by R33Turbo
Link to comment
https://www.sau.com.au/forums/topic/223890-loud-crunch-on-cold-start/
Share on other sites
nizmonut Community Regular

nizmonut

Posted
Posted (edited)

need a better decription of a "crunch" dude...

example

is it similar to some one standing on a aluminium coke can or like some one scrunching up a chippie packet,or someone crunching first gear??????? could be the starter motor drive not retracting quickly enough on start up cause the lithium grease on the shaft is cold and thick?? who knows.

Edited by nizmonut
R33Turbo Proficient

R33Turbo

Posted
  • Author
Posted (edited)

actually it could more sound like short 'gear crunches' as well.

Basically, if the sound dies down after warm-up, it wouldn't be engine head related or anything severe right? So it wouldn't do any harm driving it around?

Edited by R33Turbo
nizmonut Community Regular

nizmonut

Posted
Posted

i think you will find the rattle and the crunch will dissapear if you have rices for breakfast instead of cornflakes, a snap crackle n pop from the exhaust is usually a good sign of a nice flowing exhaust, however in this case drop the gluten from the crankcase and run some thinner oil as obviously what is in there isnt protecting the mechanically moving bits on startup.

nizmonut Community Regular

nizmonut

Posted
Posted (edited)

yeah well im running 25w50 mobil 1 in my gtr and starts on the first cylinder to reach TDC, no knocks rattles, purrs beautifuly so yeah i guess so.

and dont be fooled by the advertising of "synthetic" a federal court ruling allowed the oil companys to label highly refined mineral oil as synthetic.... so you dont always get what you pay for. make sure its says 100% fully synthetic as apposed to

just synthetic

Edited by nizmonut
R33Turbo Proficient

R33Turbo

Posted
  • Author
Posted
its not your starter motor sticking? is there actually a sound that continues on while the car is warming up?

Nope, as i mentioned above the the 'crunch' sound which sounds like 'gear crunch' is only to be heard for 1-2 sec after engine start then goes away. However, if i turn the engine back off and on to hear the sound again, it will still be there (when the car has not yet warmed up properly). If its been warmed up properly, you would not hear the sound regardless of how many times you turn the engine on and off repetitively, hence is why i cannot show the mechanic as i got to drive there with my car.

-_-StRyDeR-_- Experienced

-_-StRyDeR-_-

Posted
Posted

yeh id take a wild guess at starter motor also...

you could always leave the car with ur mechanic over night?? drop it off real late and get there early in the morn to watch them start it, so u know they aint taking it for a thrash...?

blind_elk Grand Master

blind_elk

Posted
Posted
hence is why i cannot show the mechanic as i got to drive there with my car.
Leave the car overnight with the mechanic. That's the only way you will demo it to him.

nizmonut, you really using 25W50 oil? 25 is waaayyy too heavy, and 50 ain't much better.

PS - how about just having ONE thread on the problem.

R33Turbo Proficient

R33Turbo

Posted
  • Author
Posted
Leave the car overnight with the mechanic. That's the only way you will demo it to him.

nizmonut, you really using 25W50 oil? 25 is waaayyy too heavy, and 50 ain't much better.

PS - how about just having ONE thread on the problem.

Im planning on doing that if i have time for it, however can't do it at the moment. Does that mean 10W50 is real heavy compared to average oils as well?

blind_elk Grand Master

blind_elk

Posted
Posted
what do you mean by turn my a/c off? like disconnect the whole thing? cuz my a/c will obviously be off when im starting the engine in the 'cold morning'.
If you had your A/C on when you last turned off the engine, it will still be on when you go to re-start. Make sure you turn it off before actually cranking the engine.

10 is a bit heavy for starting (which is the only time it's important), but not too bad. Nissan's spec is 7.5W30 - you'd probably be slightly better using a 5W40.

R33Turbo Proficient

R33Turbo

Posted
  • Author
Posted (edited)

oh alright, thanks for ur help there blind_elk... so ppl are suggesting it could be the 'start motor' dying out, maybe it could be... then again it could be cuz my oil is to thick for the weather these days if thats wat ur saying blind_elk...

i think i'd try thinner oil to see if it goes away....

If it was the 'starter motor', where is it? how much to repair or replace?

Edited by R33Turbo
Tomei_33 Rising Star

Tomei_33

Posted
Posted
If you had your A/C on when you last turned off the engine, it will still be on when you go to re-start. Make sure you turn it off before actually cranking the engine.

10 is a bit heavy for starting (which is the only time it's important), but not too bad. Nissan's spec is 7.5W30 - you'd probably be slightly better using a 5W40.

isnt nissans spec 7.5W40? maybe im wrong :)

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

    • wizlb
      Who has a Infiniti Q60, Q50 (V37)?

      By wizlb · Posted

      I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Kinkstaah
      Starting again

      By Kinkstaah · Posted

      Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
    • GTSBoy
      What brakes on R34 GTT(Europe)

      By GTSBoy · Posted

      I'm not going to recommend an EBC pad. I don't like them. Just about anything else would suit me better. I've been using Intima pads for a while now.
    • Duncan
      R32 GT-R: 4WD Light Turns On After Bumps – Code 19 (ETS Motor) But No Issues Found

      By Duncan · Posted

      Agreed, and in particular the earth strap that should go from the subframe to the chassis but it often broken or left off. There is a section in the R32 workshop manual you can follow for troubleshooting if you don't see anything suspicious, and depending where you are (there is no location on your user profile) you should be able to get your hands on a second hand replacement unit still if needed
    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      Yeah they mention as a R34 for 2.5 Turbo...but then again thos "small" were also for R34 by that different site. But i look into it and that 310mm EBC is for R34 GTT. And by those you linked the specs are the same 🙂    EDIT: I found these on one site here: DBA 4000 series T3 DBA42304S They are 310mm...and it says are for R34GTT...are there good? EDIT2: ok they have pads too.  What "color" should i get for street use? I dont want/need some noisy ones...(and if they are not that dusty that is good too)
×
×
  • Create New...