Exhaust leak

wiztek · Postby **wiztek** » Sun Apr 29, 2012 3:00 pm

Im really spamming this forum :oops:

with an array of issues.
So i changed radiator - flushed with tap water (eveyrthing seemed normal), reconnected, filled with premix coolant and started up.
With car still jacked up, loud pop/explosion from engine passenger side, possible exhaust manifold area. Let the car run for a bit, and started again, still a loud pop.
Started the third time a couple of hours later and was normal - no loud sound (car was on the ground now). its started several times since then and no issues.

With the car idling, everything seems normal except for water spitting from exhaust (could just be condensation, i dont know). On revving it around 4-5k rpm, there is a plume of white mist. Not a lot, just mist that quickly evaporates/dissapears, it doesnt plume and linger like you would see from smoke. Water continues to spit from exhaust. I let the car warm up around 5-10minutes and it was still happening, but i have not dríven the car and taken to full operating temp yet.

had a look under the car and noticed a brown liquid leaking from a canister on the exhaust (not idea what it is, towards the centre middle of my NB8A). Small canister. Smells exactly like and strongly of unburnt petrol you would smell at a petrol station.

With the car off, there is no leaking. Only was leaking when car was running.

There is no milky substance on oil cap.
There is no oil in radiator (as far as i can tell from taking rad cap off).

Anyone know what it is?

Apu · Postby **Apu** » Sun Apr 29, 2012 3:36 pm

Might be an idea to just take it to a mechanic. Helpful as the guys are here, it is sometimes safer to have a professional see what the issue is than try and diagnose it online...and you can have them check your radiator too.

wiztek · Postby **wiztek** » Sun Apr 29, 2012 3:45 pm

I agree
But i would like to cross out all the obvious issues before getting charged for something i could check/fix myself.
Its part of the appeal for me...learning bits and pieces and DIYing, of which this community has done a lot to contribute to.
To be quite honest im tight on time (I should be studying) so i havent even jacked up the car properly and located the specific oil leak area. I just had a quick look and assumed it to be the exhaust. I dont know where the fuel lines run on the mx5 or how that whole system works so i might have to do some more research.

I am definitely an alarmist. The smallest anomalies on a car get me worried.

Mr Morlock · Postby **Mr Morlock** » Sun Apr 29, 2012 11:45 pm

Grab a workshop manual and do some reading. Most libraries have them.

hks_kansei · Postby **hks_kansei** » Mon Apr 30, 2012 10:34 am

I think a little more info is needed.

Is it idling and running smoothly?

The canister with the petrol smelling leak, is it a part of the exhaust? or near it?
(if it's a canister just near one of the rear wheels, it may be the fuel filter...... if that's leaking, get it fixed, it's a fire risk.

deviant · Postby **deviant** » Mon Apr 30, 2012 11:13 am

Are you able to take some pictures? We can often help on the forum and pictures make it so much easier.

wiztek · Postby **wiztek** » Mon Apr 30, 2012 1:22 pm

I believe its the presilencer (from some diagrams i saw online). Definitely not the cat.
I havent been under the car yet, so i cant confirm the leak is actually from the presilencer, but thats definitely where this liquid was pooling itself.
I will jack up the car when i get the chance and try to locate the exact location of the leak and take some pics...What sits above the presilencer in terms of the fuel system?
Thanks for your help all. :beer:

Postby **NitroDann** » Mon Apr 30, 2012 1:32 pm

Mate no idea.

Jack it up, and get under it, I reckon it will be pretty clear by the time you get under there.

Dann

deviant · Postby **deviant** » Mon Apr 30, 2012 1:58 pm

Sounds like the leak is the AC drain which is above the exhaust and is normal.

This would be unrelated to the misty exhaust but without the car being run up to temperature you wont know if that is an issue or not. Note: running up to temperature means going for a decent drive to get heat through everything, the steamy exhaust can just be condensation forming in there from hot exhaust meeting cold pipe. The exhaust pipe wont heat up quickly without driving.

No idea what the loud pop could have been.

Fuelly smell could just be cold start fuelling, mine smells like it sometimes especially if I only run it long enough to move it.

I would just check the liquid dripping under the car to be sure it is not important and then probably not worry to much especially as the car seems to be running okay.

Mr Morlock · Postby **Mr Morlock** » Mon Apr 30, 2012 8:19 pm

Dann got it right - mate no idea- where do we start? An exhaust leak -one way of detecting an exhaust leak or other odd noises is with a nurses stethoscope- not expensive- better than a screwdriver and plastic tube.

93_Clubman · Postby **93_Clubman** » Tue May 01, 2012 3:04 pm

More info here: viewtopic.php?f=29&t=52439&start=15

wiztek · Postby **wiztek** » Thu May 10, 2012 4:28 pm

Hey guys
Thought i'd follow up on this.
The leak is gone. I think deviant was right...must of been the AC line mixing with something along the way to give it a petrol smell as i had just changed the radiator.
As i said, i get worried over small things...very pedantic in that way. No smoke too. Was just condensation creating mist.
Also, installed my intake...sounds like a mini v8...in my mind anyways.