Explosive engine?

[Tokyo-Joe]

Hey all,

Apologies for the dramatic title but I wanted to attract some views, I'm sat at the roadside pondering what went wrong with my car and what its likely to cost to put it right..

I just had the car mot and serviced by Honda, very happy and running great, I just did 50 easy miles up the a1 in fifth gear, no problems. I get a couple of miles from my destination and the engine bogs down, its losing power, I drop cogs to keep revs up as its a busy road, no avail it just keep dropping. Warning lights go crazy across the dash and the engine is incredibly sluggish. I come to a halt, turn it over it will catch chug cough black smoke then die. I turn over again a high pitch high rpm scream and no engine response.

It's soon to be on its way back to Honda and I was looking for some advice (reassurance?) It's not as bad as I think it is. Any thoughts on what happened would be appreciated.

Thanks,
Joe

[NSXGB]

Which warning lights?
Try to turn crank gently by hand to make sure the engine can turn over.
Assuming no water \ oil leaks externally?
Temp ok just before it died?
Hopefully you will be able to extract some fault codes which will help you greatly...

'High pitched scream'...did this sound like the starter not engaging properly?

Plenty of things to check before you get too worried. You've got a warranty, right?

What work was recently carried out?

[Nick Graves]

Oh s hit.

Hopefully, just a main relay or injection fault (flooding hence black smoke).

I take it no nasty noises beforehand?

[Kaz-kzukNA1]

I think you are flat bedding your NSX at the moment so should not be a problem but please do not even crank the engine unless you are 100% sure that it’s not a mechanical failure.

For the engine to run smoothly, you need good compression, good spark and good fuelling.

From the compression point of view, you were running the NSX up until it stopped and from what you wrote, sounded like no major mechanical noise, big smoke, etc just before it stopped so seemed to be very unlikely to have compression issue unless your crank pulley weight chewed in to the timing belt (TB).
You can check this from the top or bottom of the engine without cranking the engine.

Also, quite often, you will see something on the coolant and engine oil if you have mechanical failure and these can be checked without cranking the engine.


Probably, you wrote this post while waiting for the road rescue so not much info about the spec of your NSX but from what you wrote, sounded like spark/fuel related.

....... Warning lights go crazy across the dash and the engine is incredibly sluggish. I come to a halt, turn it over it will catch chug cough black smoke then die. I turn over again a high pitch high rpm scream and no engine response.
.........

If you saw lots and lots of lights flashing randomly all over the dash, then that will happen if you lost the power supply to the multiple system or the main relay and/or the IG sw got intermittent connection. Or, it could be a short circuit somewhere on the car but this can be checked by the fuse.

Check both battery terminals to make sure they are secure. If they were loose and causing intermittent connection, then it will trigger many warning lights that anything registered during that point were false errors.

If main relay fails, it will cause intermittent power to the ECU and INJ as well as to the Fuel Pump. The power supply to the starter is through the different circuit so you can crank the engine but the engine won’t catch a single spark or it may start up but dies immediately or sometimes within a few miles depending on how bad the intermittent connection is inside the main relay.

If the IG sw got intermittent connection, it is like switching On and Off the system using your key while driving.

If these parts were not replaced, first replace the main relay and start from there.
The main relay on even the later spec NSX such as 2001 models started to fail few years ago so even the last 2005 models are no longer safe from this failure.

Without starting the engine, if you put the key into IG ON position (lights on the dash), you should hear the fuel pump running for 2sec. It will be like humming/hissing/high pitch sound for 2sec from somewhere behind the centre speaker between the two seats. If you don’t hear it or if you hear random fast clicking noise, you have a main relay issue.

There are lots of other things to be checked but above can be done without cranking the engine so good starting point.

Kaz

[Tokyo-Joe]

Hey guys, thanks for the responses

The car is dropped off at Honda now but I did gleam a little more info:

- Car was serviced last week, oil, filters, fluids, plugs, clutch master cyclinder adjustment, misc body work/electrical issues (popups)
- Driving the car since has been fine, probably put 80 miles on it
- Drove around 50 miles today, sat around 70-80 in fifth with no rapid acceleration (saving fuel, boring huh?), no bad noises, absolutely no indication of any issues
- Main relay replaced from a newer model at christmas, no issues since then (car actually turned over okay, when my main relay broke before it would not start at all)
- As described the engine just kept bogging down, from memory the warning lights were the battery warning and the other red one next to the battery warning, sorry I was trying to find a place to crash land on a dodgy road so didn't get a proper look at them but it was only lights on the left hand side of the dash.
- I checked the oil and it is full, battery terminals properly connected
- Visually inspected the belts, no problems that I can see (but hey i'm no pro!)
- I had it flatbedded and Honda has instructions not to try and start it so fingers crossed the damage has been minimsed

I'll be keeping this updated incase it comes in handy for other owners

[Tokyo-Joe]

Temp ok just before it died?

'High pitched scream'...did this sound like the starter not engaging properly?

Plenty of things to check before you get too worried. You've got a warranty, right?

Temp, oil pressure and voltage were fine, no issues at all before.

Hmm yes it could be put down to sounding like a starter motor going crazy, or a pulley spinning with no resistance.

I'm sure Honda will warranty their work.

[Hagasan]

Sorry to hear about your troubles so soon after seeing your car up at NW the other week...

The other red warning light on the left is the low oil pressure light.

Not to sound alarmist and I sincerely hope I'm wrong but.... I hope you haven't spun a main bearing?? The screech you heard. Was it instantaneous as you tried to crank the motor over again? I doubt you had a stuck starter for 50 miles and I'm not even sure if that could happen, to wreck it, then when you tried to crank it it was finished?

Good luck....

[NSXGB]

Fingers crossed for an inexpensive electrical fault...Are you sure you tightened those battery terminals up before?!

[Tokyo-Joe]

I'm hoping for a reasonable result but realistically those were very bad noises..

Haha yes bloody terminals tightened up with spacers

[AR]

Oil pump perhaps?