Mazda MX-6 Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #1 ·
for all those who have had an exhaust manifold leak...is the ticking noise always there? or is it there only under acceleration? can u hear the noise when u rev the engine in neutral?
 

·
Registered
Joined
·
1,153 Posts
i had quite a bad one.. it started out quiet and barely audiable at idle..

the sound got louder and louder over time.. the car loses boost and starts to sound more like a tractor..

the sound will be louder underload, and will increase in speed with revs.
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #3 ·
well in that case, i can rule that out. my car doesnt sound loud, and i havent felt and significant power loss.

did u hear the noise when revving it in neutral?
 

·
Registered
Joined
·
182 Posts
Hey Duck :D When I replace the head on my car, I managed to break two of the bolts from the turbo flange to the exhaust - so I have a marvelous tractor noise happening - seems to have dropped performance slightly. The noise is quiet at ldle, but gets louder under load (not necessarily revs).
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #5 ·
its not a tractor noise at all. it quite literally sounds like a belt flicking something. im gonna open the timing belt cover and see if the belt is touching the cover.(but that wouldnt explain why i dont hear it when revving in neutral?)
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #6 ·
p.s. no one has still answered this: did u hear the noise caused by the exhaust manifold leak when u revved the engine in neutral? cause i hear nothing in neutral.
 

·
Registered
Joined
·
1,153 Posts
i didnt answer previously because it depends on the severity of the leak.. initially i couldnt hear anything, but as it got worse i could hear it at idle, in neutral, basically whenever..
 

·
Registered
Joined
·
4,695 Posts
I broke a stud just b4 chrissy and it started as a flutter under load ( I knew it was a stud, I've lost at least 4 in 8 years) it gets worse though....much worse. Mine is definately at tractor status now. I haven't had chance to fix it because i've been tanny my arse on the beach for 2 [email protected] But back to the other stud, you might find some other nuts have worked loose at well, that's always been the case with me anyway. Be gentle though man, don't make your situation worse.
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #9 · (Edited)
ok im leaning towards exhaust manifold leak now.
ive taken some serious time to see where the sound is from. it seems to be coming from or around cylinder#4. but it is certainly in the vertical line of cylinder 4.

in neutral, there is no sound, but while idling in Drive or reverse, it sounds more like a gargling noise. when i accelerate, it sounds like a flickering/ticking which is loud. weird thing is, it is loudest in 1st gear(i.e. higher the gear = less noise) and the sound does NOT get louder after about 3500rpm(infact, u almost cant hear it above that)

now the quesitons are:
1. how do i check the studs or whatever? do i need to remove anything(heat shields/turbo)??? anyone who can post some pics to show me where to look would be very good.

2. when i look at the studs, how will i know if they are leaking?

3. if they are leaking, can i just tighten them? or do i need to get new studs?

4. how much does it cost to fix an exhaust manifold leak?

5. from all this info i have given...could it be a bad injector clicking?
i really ned some quick help guys.
cheers :)
 

·
Registered
Joined
·
4,334 Posts
Hey...

On some exhaust leaks... on smaller ones anyway, the noise can sometimes go away as the car warms up. Probably due to the slight expansion of hot metal closing the gap. So that may be why you only hear it now and then. But, I'm pretty sure you should be able to hear it in neutral with head under the bonnet.

What you could do is remove the top heat shield, I think there is two bolts on top, and one on the front. Then start the car and feel around the exhaust manifold where it joins the head (don't burn yourself) for any leaks. When mine leaked it was pretty bad and you could see where the fuel etc was all over the head. But the leak could be underneath so you might not see it anyway.

If it is leaking, you may / probably have snapped a stud, which is very common and annoying.

You could try doing up all the nuts, but more than likely you'll just snap the stud and definately need to pull the stuff apart. So, maybe just see if any are loose and if they are see if you can pull it out, and if you do you may pull the entire stud out with it... and you will have found your problem.

To fix it, it is quite annoying... assuming you have broken 1 stud, then you will need to remove the radiator (not compulsary but makes it easier) then remove the turbo and manifold in one go. Which includes disconnecting the intake, oil lines, and some are annoying as hell to get at. Then you'll need someone to take out the broken stud and replace it (I just paid for a mobile mechanic to do it $20). New manifold was about $20... then you put it all back together.

After this novel, it probably isn't the manifold :)

Tripharn
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #11 ·
But, I'm pretty sure you should be able to hear it in neutral with head under the bonnet.
when in neutral, u cant hear anything major when ur sitting inside the cabin. but when i stick my head and listen in the engine, the is a defined GARGLING sound. and also a ticking sound from around cylinder 4. ill remove the heat shield tomorrow and see if i can just torque up the studs.
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #12 ·
ok guys i took off the heat shield. i see 4 bolts(2 top, 2 bottom). they all seem fine to me. but under the area that the noise is coming from(cylinder 4 side of the head), it is all black and looks like carbon buildup. but it isnt on the other side of the head(cylinder 1 side)

???
 

·
Registered
Joined
·
4,334 Posts
Hey,

I went on the cruise last night and now my manifold is leaking... it is pretty bad... Actually have two leaks. I'll take some photo's and maybe record the sound and show you what it's like. I'm working today and tomorrow, so I'll probably do it tomorrow night. New gasket cost me $5.50

Tripharn
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #14 ·
ok i torqued down all the bolts. but the one on the top right hand side seems to be broken.
i.e. the screw came out when i turned the nut. what do i do about this?

p.s tripharn, if u could take photo's of how u actually do it..that would be great.
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #15 ·
ok my boost seems to have dropped to almost nothing(my mates VY S manual beat me tonight). however, the noise of the exhaust manifold leak certainly gets much softer in the hot weather. hopefully she will hold up until i can buy a manual mx6 and sell this one.
 

·
Registered
Joined
·
182 Posts
G'day Duck,
changing the stud is relatively easy - the only problem is you need to remove the manifold completely to do it. after its off, just grab the remaining stud with a pair of pliers, and un screw it. It may be a good idea to blast it with wd-40 or RP7 first, they get jammed pretty good :rolleyes: then its just a matter of screwing in a new stud (around 2-3 bucks from repco, bursons etc)
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #17 ·
i dont wanna attempt this on my own. basically cause i couldnt be bothered right now with my mx6. it seems when i try to do something in the engine bay, i either hurt myself or lose something(i lost 2 of the bolts from the heat shield somewhere in the engine bay AGAIN and cut my hand pretty bad when i checked the studs)

but after i torgued down the other 3 studs, the sound has DEFINATELY gotten much softer. u cant even hear it when the windows are down now.

1. how many hours would a mechanic take to do this job?
2. should i just get all 4 new studs while am at it?
 

·
Registered
Joined
·
1,364 Posts
Ducktape, i just did mine about a month ago. It's easy, more so time consuming. The only posing challenge is putting the coolant hose back on. It took me just over 3hrs and i took my sweet time.
Replace all your studs! That is a must! Due to the extremety of the heat temps, it's caused the strength of the studs to deteriorate.

My car is back to her glory! No sh:tty tractor sounds, nor a loud screech at high boost levels. Just a loud motor roar when the boost kicks in saying "GEDDAFCUKOUTTAMYWAY!" :D
 

·
Registered
Joined
·
2,440 Posts
Discussion Starter · #19 ·
anyone that can take pics of how to take off the oil/coolant lines off the turbo would breat cause i have no idea how or even which ones are the oil/coolant lines.

cheers guys

p.s. are the studs available from any auto store like repco/autobarn?(are all 6 the same cause i have 2 different types on the manifold now...i.e. one type is with a nut, the other is just a bolt)
 

·
Registered
Joined
·
4,334 Posts
Hey ducktape,

They are all the same, and I'm 99% sure you can get them from Repco, ring first just to be sure I suppose.

When you take the manifold off (read the 1st Gen FAQ under Important Info for a step through) you will need to disconnected everything from the turbo / manifold, so it is pretty straight forward.

Tripharn
 
1 - 20 of 21 Posts
Top