Weird Engine Knock And Whining Sound

[aaron1259]

I first noticed the knock (which isnt very loud) when I was in gear and clutch out, just slowing down. The whining was been there for a while and suspect a belt tensioner needs replacing, but I have no idea what this knock is. It can only be heard when I back off the accelerator.

Here is a video:

[aaron1259]

Could it be the bottom end bearing starting to wear out, I did have quite a bit of metal shavings in the pan during the last oil change.

[jiffo]

Do you care about this engine at all or is she a junker?

If you keep running it, it will die.

Metal in the oil was an SOS.

Think how difficult it will be to ensure all metal particles are removed, if you intend to repair this engine.

[XGTRX]

Yep its a death rattle.

[Scott Black]

yep, big ends, the more you drive the more damage your doing, if you strip it now you might be able to get away with linishing the crank (or maybee machine to undersized )and new bearings, if you keep driving, (maybee already to late) you will destroy the crank, rods, even have the motor let go and leave you stranded, pretty much if you want to rebuild, the more the motor runs the higher your bill gets

[aaron1259]

That's f**ked, just got the car, the funny thing is it only started making the sounds after I dropped the oil (Which was SO filthy and full of metal) and put fresh golden stuff in it.

Would the be damage to the head as well?

Also I was planning to drop this in: http://www.ebay.com.au/itm/RB25DET-New-Forged-Short-Engine-RB25-Block-Bottomend-Race-Drag-Drift-/371239977607?pt=AU_Car_Parts_Accessories&hash=item566fa08287

Would the be fine with the neo head?

[Scott Black]

If the motor let's go it will damage the head, if metal shavings go up to the cams it will damage the cams and the head, the previous owner probley put a really thick oil in the car to mask the noise so he could sell it to rip someone off into thinking the motors fine.

[aaron1259]

Anybody know if a shortblock rb25det block will bolt up to the r34 neo's head with no clearance issues or anything? I don't really want to be using the existing crank so I might just get a pre forged block

[aaron1259]

Bump

[XGTRX]

You can always try slick50 with a 50 or 60 weight oil and see how you go. But if you want to half save it then get it done and don't drive it. Good luck.

[Stixbnr32]

Yup after 25,000 in my GTR I had the same death rattle. Be careful I didn't notice and was boosting around (music going) for an afternoon and that was enough to bend the crank (ruin the journal) and crack the block - I was running 340kw at the time

I also had to recon my turbos (new -5's with 4000km on them). Head was fine though was pretty happy about that. Also had to replace oil cooler core as it could not be cleaned.

good luck.

[Ben C34]

If you put a non neo bottom end under your neo head you will have crazy high compression.

????

Edited February 4, 2015 by Ben C34