Blown Turbo's, Engine Damage?

[93gtr]

i just bought a 93 gtr with a possible blown front turbo. I never started the car, just bought it, trailered it home, the body is in good shape and some good aftermarket parts.

So i started to take the front 3 plugs out,pulled the cover and noticed splitfire coils, pulled the first plug out and sure enough its broken, tip is missing, second one third one, 4th was soaked in oil but not broken. 5 6 broken.

what do i do now? pulled the head? borescope?

[Voodoo_ChildR32]

Check to see if the timing belt snapped or skipped. Worst case, pull the head.
Either way if it were me I'd want to look inside for internal damage.

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[93gtr]

o.k. i'll check the timing belt today. also i removed all the turbo piping and there was tons of oil in there, but no metal or any signs of broken parts yet.
the seller gave me 2 extra stock turbo's with the car, one good one, and one with a broken exhaust wheel.
i think these were the turbo's that came on the car, he blew the turbo's, replaced them with the ones that are on there now, drove it and maybe the tbelt broke or the pieces from the turbo went into the engine, and he never checked.
regardless the head has to come off for inspection, and luckily the cylinder walls aren't damaged!!!
ill keep you posted

[Marke]

I would check the compression first. Could save you sometime and money.

[fwd suck]

and do a leakdown also

[93gtr]

last night i managed to get the front turbo off, and its looks o.k. even the rear turbo intake side has no damage or any play. tons of oil in them though, is this normal?
i used the borescope and looked into each cylinder, and #1 looked like there may be some scratches, but the rest looked fine.
ill do a compression test and a leak down test tonight.
also noticed that the fuel pressure regulator vacuum line was disconnected,i didn't do it, what would happen if you drove the car like this?

[93gtr]

i did the compression test today, 110 psi for the first and the rest average about 80 psi. the 4th however had no reading,just spun real fast like the timing belt is broken. this is the cylinder that had the spark plugs still good, but covered in oil.
i checked the timing belt too, it looks fairly new, and its pitworks, so it has been changed before. im pulling the head off tomorrow, could it just be a headgasket?

[Skym]

FPR vacuum hose disconnected = roughly 7.1psi higher fuelpressure. With FPR vacuum hose connected, fuelpressure should be around 35.5psi. That's with stock fuelpump, injectors, etc. If FPR vacuum hose was removed, then engine could have been running lean, which could explain the sparkplug tip damage (engine knocking).

Oil in turbo's on compressor side = excessive blowby (oil through PCV system into infront of turbo's) and rings could be the cause. If on exhaust side, then might be headgasket.

Anything below 127psi? on all cylinders usually = rebuild time.

Also clean, check deck of block for cracks when head is off. Probably would backup that there might be some ringland damage that can't be seen from the top of pistons.

[93gtr]

thank you

[Skym]

You're welcome.

Also oil on compressor side can be turbo oilseal failure due to out of balance shaft on turbo. But would get a whistle sound (compressor wheel touching compressor housing) around 0 on boost gauge, then later on a wacking sound. Sometimes the whistle sound can be a intake airleak after turbo.

What I mean with fuelpressure, is it should be 35.5psi + 7.1psi with vacuum hose disconnected to FPR while idling (same fuelpressure before turning engine on, where there is no vacuum). With vacuum hose connected to FPR it should be 35.5psi when engine is idling.

If fitting another second hand engine (cheaper than rebuild), I would check fuelpressure (when installed in car), change fuel filter, check voltage to fuelpump, etc. Also before fitting engine, change all belts, front cam seals, crank seals (front and rear) waterpump, tensioner bearing, idler bearings, mounting bolts for bearings, etc. Basically anything that's hard to access when engine is fitted.

If head is ok, could fit a refreshed Nissan RB30 bottomend with metal headgasket, metal intake gasket's, etc -

http://www.ripsltd.com/products.html

More power, torque throughout powerband than RB26 when ECU is tuned to suit and I think similar in cost to second hand replacement RB26 engine.

[93gtr]

so i finally pulled the head off, and #4 piston has a hole in it, the edge is missing. #1 cylinder has some decent marks too.

its time for a new engine, im gonna get the head looked at and decide what to do.
i would like to just get this back together as fast as possible, and save money for a nice engine down the road...

[Voodoo_ChildR32]

Kinda sounds like detonation. Burnt or broken pistons are pretty severe. I've seen it in engines where people have used regular gas instead of premium.


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