Whoops ... 1JZ turbo blown?

[BabyZ]

Well, the 1JZGTE MX83 I built with the help of Toymods (and Sideshow) hasn't missed a beat ... until today

For a while (since I got a boost gauge to check, maybe longer), it has only been boosting to 10PSI. It's stock but for twin dumps to the cat and a 3" exhaust, but I would have expected more boost than that. I'm not sure if it was a forewarning of today's disaster or just coincidence.

Cruising along the highway, 75% throttle to overtake, backed off, then ... nothing. Didn't want to accelerate, felt a little rough, so I pulled over. White smoke. Hmmm. Did a U-turn hoping I'd make it home. 40km/h max, rough as, more white smoke. Decided I'd better not push the poor thing any further (only went ~300m).

So, I reached under and wiped off a little bit of black oil dripping off the front turbo . I pulled an intercooler pipe off (the one right after the turbos), but there was negligible amounts of oil in there. The dipstick oil looked clean, and no smoke or odd smells when I opened the oil filler cap while it was running. I haven't had a chance to pull any spark plugs to check for fouling or do any other checking yet (it's in the NRMA yard tonight - I'll get a trailer on the weekend).

My question for the Toymods gurus is ... is this a 'common' mode of failure? I can understand oil in the exhaust side = much white smoke, but why the instant rough running? I would think if there was enough oil getting to the intake side to foul plugs that I would see residue in the cooler pipework. And that it would take a little longer to manifest. Has something else coincidentally gone kaput? The engine has (supposedly) done under 100K km, so this is a little distressing.

Oh, and does anyone have some decent spare CT12a's lying around?

[The Real Roadrunner]

could be running rough due to three cyl having a turbine wheel stopping airflow through the cyl but still throwing the amount of fuel it thinks it needs if its map sensor and tps.
or only really breathing through the one turbo and same situation as above but you should hear a funny wooshing noise aswell if the turbo has gone.

i had one snap one blade when a (champion) plug tip went through it but it still drove fine. just no boost

[Ribfeast]

If you can find out which one went bang, and block it off with a home made flange (chop up some aluminium sheet), you'll at least have *some* boost while you hunt for another turbo.
Might want to check for boost leaks in your intercooler piping, as this might cause overspeeding and premature failure of the turbo(s).

[EldarO]

one of your coilpacks may have bitten the dust.

id say around 10psi is normal for your mods, retaining the cat, maybe just a slight bit more.

1J coilpacks tend to crack along their stems (at the end, where they clip onto the plugs.) and cause all sorts of rough running.

if the cracks arent visible, pull the plugs and see which ones very fouled up.

Elmo.

[Mr DOHC]

O/T, if u run it down the 1/4 mile, let me know, i have a thread of the quickest cressidas in oz

[Mundoolun]

Sounds like a broken turbo. Hard to find a replacement due to lots of failures. If you are unable to find a replacement and still want to keep the standard turbos but want more boost and relaibilty there is a option. Go done to local import wrecking yard and buy two Starlet turbos Ct10 used on the 4FTE engine. The have very similuar compressor but are steel wheeled and welded to shaft as apposed to your ceramic glue which easily becomes brittle with age. Go to local turbo guru and have the hi flow your stock item with starlet internals and hello 15psi and no relaibilty problems. Was done in HPI on editiors Soarer and with a GTR core and large exhaust and custom dump pipe between turbos and Apexi he reached 270rwks with original turbos hiflowed and ran them for over two years with out trouble before uprgrading to large frame t04s.

[The Real Roadrunner]

donnons soarer did not use CT9 turbos just stockers wih dumps.
its the heat that builds up between the two that causes probs as well as shaft overspeeding (high boost)

if you read this guy has dumps so its not heat and is only runnig ten psi so its not overspeeding.

yes ct9 centres can be retrofitted and they are a good ugrade but a single will be better

[love ke70]

umm...rough running and white smoke out exhaust = blown headgasket in my book.
blue smoke = oil being burnt, so its not the turbo seals leaking oil into the exhaust or inlet.
white smoke = water being burnt...well turning to steam anyway, pretty hard to burn water these days
a bit of oil on the outside of your turbo could be anything, but i dont think it has anything to do with rough running and white smoke.
rough running could be caused if u have a turbo scraping the housing...but thats not gonna cause white smoke.

any other takers on bhg?

[BabyZ]

Thanks for the input, guys

We'll all have to wait a couple of weeks to find the result though - uni exams next week take precedent

Maybe love ke70 is right, but I had sort of ruled out BHG as the oil and coolant were both still clear (and I was being optomistic ...). The smoke was predominantly whitish, but there were periods of bluey-white and once it was distinctively blue-black (when idling, and I revved it slightly to stop it stalling). Do stock 1JZs ever blow head gaskets?

I looked at the oil again today - it is now 'black'. Well, pretty black compared to the usual reddy-brown almost translucent colour it usually is. The oil leaking from the front turbo is definitely a new feature - the engine bay was spotless before this incident.

There is a definite possibility that there was a boost leak somewhere. This is my first turbo car, and there was always a whooshing-slurping kinda noise that I never knew whether it was normal or not. Maybe Ribfeast was right - leak = slightly lower boost, and maybe turbos overspeeding???

EldarO - I was getting the same boost levels on half to 3/4 throttle as I was getting flat out. I thought this a little odd, but maybe not ...

If needed, I'll probably just replace the turbos with stockers (or China copies at worst). This is meant to be a daily driver after all. Although ... Mr DOHC's list sounds interesting

[rob_o]

babyZ - I have 4 spare turbos laying around. If you wanted to come up and inspect them before purchasing then give us a holler.

[EldarO]

dude, from all your symptoms, id say you blew the MAP line off the sensor.

because that would accoount for every single one of your symptoms, bar one, the white smoke.

very few people have blown a 1J headgasket, but they are out there, i beleive its more common to crack the head.

check your vac line to the MAP sensor, it should run directly from the intake plenum to the sensor, with nothing tee'd off it.

Elmo.

[The Real Roadrunner]

just had that prob yesterday.

[BabyZ]

OK, I've only just got onto this again (finally!!). All I've had time to do is pull the plugs and take the heat shield off the turbos.

The oil leak is into the dump pipe from the front turbo - it's weeping out around the gasket. This explains the smoke and loss of power, but not the rough running. Next step here is obviously to rip off the dumps (fun ...)

The plugs all look pretty clean. Some looked a little wet and smelt a little oily/fuely, but certainly not sufficiently fouled to stop sparking by any means. A couple of coil packs showed classic signs of cracking, but no evidence of arcing (no grey traces). I'll deal with these, but I'd be surprised if the cracking could be responsible for such a sudden onset of symptoms (although I've been surprised before ...)

The MAP sensor line is connected and clear (assuming the MAP is that little thing by the ignitor labelled 'Turbo Pressure Sensor'). Pity - that would have been a nice, easy fix

The search continues ...

[fixeruperer]

ive had brand new coils not work or read a high resistance so never count anything out, measure them.

[BabyZ]

OK, so what is normal resistance for these coil packs? I've searched but not found anything definitive. And is it measured output --> ground, or across the input terminals?

Looking at the inlet manifold, there is zero oil in there (ruling out simple plug fouling) but it smells like it's full of raw fuel even after sitting for weeks. I think I'm looking for a fuelling and/or failed spark issue that arose independantly of the turbo problem. The two may not be related at all. (Hell of a coincidence though ...)

I'm going to measure the injector pulses and check the caps in the ECU (plus test the coil packs when I work out how). Any other ideas where to look?