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Excessive Knock And Strange Sounds ?!

Dajae

By Dajae,
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Dajae Community Regular

Dajae

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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

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Dajae Community Regular

Dajae

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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?

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