mx5JAR

Hi everyone, i'm new to the site, so apologies in advance if this is in the wrong section!
I'm currently driving a 92 Eunos 1.6 Td04 on 'bandaids

I was driving the car the other day, everything was running sweet, no weird noises, car was boosting fine etc. But one night, I was on my way home and the engine started misfiring! When I got home, I switched it off and I heard a squelch noise, almost as if a pipe had split and you could hear the oil dripping out, I checked and there was oil on the floor, although not a lot! I checked the oil pressure feed, it was fine, I checked the return line and it had a very small split. I temporarily taped up the return line until a new one would come.
After buying new plugs, a couple of days later, I noticed that boost wasn't fully spooling up until 4.5k, when it usually fully spools at 3.5k
I took the car for a spin to see if I could sus out anything, went through the gears and around 5-6k in 3rd, I had lost all oil pressure but as soon as I took my foot off the throttle, oil pressure returned. I took it home, I checked the turbo and the actuator pipe had melted on the manifold causing it to overboost and essentially, damaged the fins my compression wheel... Today, I removed the turbo to check and the exhaust side looks fine, no cracks, chips, broken fins etc on the turbine, but there was a small bit of dirt in the wastegate.(I honestly couldn't tell if it was metal shavings, or just soot buildup, but I'm leaning more towards metal shavings, I was so scared that I didnt pay attention)

Thats the back story!

My questions are,
Why was the turbo taking longer to spool?
What could cause a loss of oil pressure at high rpm?
Do I get a lighter and some petrol and just blown the c**t up?

I understand that the metal shavings off the turbo could damage the engine, so I'm on my way to buy a compression tester, to find out what sort of numbers are in each cylinder

Sorry for the huge backstory, I've got nowhere else to turn and I don't know too much about these engines, especially if I've blown it up!
For any Mx5 genius's that could recommend my next protocol, the advice would go a heck of a way, i'd gladly appreciate it!

Thanks in advance to anyone who helps, I honestly appreciate it

jstck

It might be it spools just fine, but bent fins on the compressor wheel is going to give you not very much boost.

Didn't know it was possible to damage the compressor wheel through overboost though (unless you're massively overspeeding it or something). Overboost usually kills engines by detonation or throwing a rod.

Not sure what would be a common Miata cause (never had that happen on any MX-5/323 of mine), but there are a lot of things that could potentially cause that. A blocked screen in the oil pickup, bad o-ring in the pickup/oil pump, clogged oil filter, being low on oil, wrong viscosity, screwed up PCV (blowing/sucking oil out somewhere under boost), and probably lots more.

Also for ***** sake don't drive around with an oil line patched up with tape.

mx5JAR

Hi mate, thanks for the prompt reply!

When driving it didn't seem like it overboosted, I got to around 11psi (boost controller). My intake is still using an AFM plus a panel filter which was sealed well! So I can't understand any foreign objects getting sucked in
It's my daily, I had no other choice but to use it, so I haggard'd it for a 5 mile commute :(