Disaster - advice needed

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Bikergonebald
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Disaster - advice needed

Post by Bikergonebald » Tue May 07, 2019 1:05 pm

Help needed for MX-6 auto
Hi guys, The US Mazda forum aren't as helpful as you hence why i'm posting here.

I broke down yesterday and had to get recovered. I was out for a drive and had done about 10 miles when i stopped at a junction and could smell burning rubber, I drove of another mile to my destination. When is stopped there was smoke coming from the engine bay but i couldn't see where, possibly down by the cam belt / water pump area but also from the top of the engine under the manifolds. I came back to the car after 30 mins and it started ok but there was a short puff of sooty black smoke so i started driving home carefully but i noticed that when stationary with it in drive the engine tickover slowed and it felt like it was trying to pull away more than normal when i eased of the brake, as if the clutch were dragging but of course it doesn't have a clutch. I also noticed that the temperature gauge was off the scale hot but i don't normally look at it so rather stupidly assumed it was a faulty gauge because there was no steam. It was driving fine because it was flat or down hill for 8 miles, when i got to a short incline the smoke started again along with a rattle from under the car whenever i applied throttle, then the engine died and i coasted to the side of the road.

i tried once to re-start it but it was really sluggish on the starter motor so gave up and called for recovery.

Once it was cooled down we could see there was no water in the system, top and bottom hose were both empty but it started normally and responded to throttle so we could move it close enough to get it on the truck. It was teh same for offloading, it started and ran normally but I only ran it for one minute.

My assumptions so far are.
  • The water was lost slowly perhaps on recent journeys either by a leaking hose, core plug or head gasket.
    The smoke from the engine bay was because the engine was hotter than ever and oily dirt was burning off.
    It stopped running because the engine started to seize
My questions are
Why would the autobox / torque converter start to drag? Would it be affected by extreme engine heat?
How likely is it that the engine was damaged given that it started and ran normally when cold?
I will do a compression test, if it should fail on a cylinder and i have to remove one of the heads should i do both?

Can anyone offer any other thoughts or guidance?

My wife and son found it funny but i'm gutted and fearing the worst, an engine rebuild costing as much as the car is worth.

Thanks
Kevin
Owner of a 1992 Mazda MX-6 Auto.
Sorry guys I don’t have a probe (yet ;) ) I’m asking questions here because I get better responses than on the US Mazda forum.

Micron
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Re: Disaster - advice needed

Post by Micron » Tue May 07, 2019 1:32 pm

Kevin,

I'm no expert, but as most will say, i would start with the basics.

Fill it up with water, making sure you take off both caps to fill it, run it with the caps off and check the level before replacing the caps. Run the car and see if there are any visible leaks. Leave to cool then check the levels again, it may give you an idea or clue, or us at least?
Has your oil gone like mayo? a sign of water in the oil, check under the oil cap.

You may find that the loss of water is because of the leaking water pump (common problem), or leaking rad cap, it has been known over here for them to leak. It is very unusual for a head gasket to go, or even a core plug, but a possibility?

The auto box may have been playing up because the car was not running correctly, they engines like to be full to the brim with water

the engine most probably will be fine, you just need to understand where the leak is.

I'm sure others will be along soon to give you further advice, or support my own?

Trev

Bikergonebald
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Re: Disaster - advice needed

Post by Bikergonebald » Tue May 07, 2019 3:20 pm

Hi Trev,
Thanks for replying, so far no sign of water in the oil, I will try filling it with water to see what happens.

Has anyone evert tried using an endoscope to inspect cylinder bores for damage due to seizing?
Owner of a 1992 Mazda MX-6 Auto.
Sorry guys I don’t have a probe (yet ;) ) I’m asking questions here because I get better responses than on the US Mazda forum.

mojo98
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Re: Disaster - advice needed

Post by mojo98 » Tue May 07, 2019 5:35 pm

I had a problem last year, Black smoke coming from under the car, temp gauge over the top,, engine stalled when i pulled up, plenty of black smoke but no steam, fault was the Thermostat, and a seized roller bearing, black smoke was the cam belt and the plastic on one of the roller bearing on the cam belt system, (no plastic left on the roller bearing (bearing had seized ) the other probe I had was that all the HT leads had melted and could at first remove them , I had the mess about with them after the plastic snapped leaving them in the block,
as Trevor has mentioned we have had problems with the rad caps passed light. I am with Trevor Auto box to hot ????

Bikergonebald
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Re: Disaster - advice needed

Post by Bikergonebald » Tue May 07, 2019 7:33 pm

Hi mojo.
So the HT leads melted because the engine was so hot? If so it must have got way hotter than mine did.

Any lasting damage to the engine after replacing the cam belt and stuff?
Owner of a 1992 Mazda MX-6 Auto.
Sorry guys I don’t have a probe (yet ;) ) I’m asking questions here because I get better responses than on the US Mazda forum.

mojo98
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Re: Disaster - advice needed

Post by mojo98 » Tue May 07, 2019 10:21 pm

Bikergonebald wrote:
Tue May 07, 2019 7:33 pm
Hi mojo.
So the HT leads melted because the engine was so hot? If so it must have got way hotter than mine did.

Any lasting damage to the engine after replacing the cam belt and stuff?
No lasting damage once the cam belt +kit and new thermostat fit and after manage to get all the old HT leads out (had to remove the IM off to get the back HT leads out) The car is fine and is my daily runner 8-) 8-) 8-)

fuerte
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Re: Disaster - advice needed

Post by fuerte » Wed May 08, 2019 3:29 pm

No techy but along with the advice mentioned if you smelt burning rubber then surely a rubber part is damaged somewhere so I would look for that too???
Good luck.

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Re: Disaster - advice needed

Post by Jon G 24V » Fri May 10, 2019 2:09 pm

I think i'm right in saying that the Gearbox fluid on the Autobox is cooled via the Radiator.
If the Car ran out of Water then the Autobox Fluid will also have got very hot.
Based on what i read and my own troubles with a Range Rover Gearbox, heat is the cursed enemy of Gearbox fluid.
So i would say once you have sorted the overheating engine then a Filter and Fluid change on the Gearbox would be in Order.
Never done one so not sure what's involved but based on the Range Rover Forum it's about a 50 / 50 split between those who will do it at home and those who go to a Autobox Garage to have it done.
Personally i went to a Garage only to be told my Box was well cooked and it cost me a fortune but that's the joys of owning a Range Rover :lol: :lol:

Bikergonebald
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Re: Disaster - advice needed

Post by Bikergonebald » Fri May 10, 2019 3:45 pm

Hi Jon. Thanks for replying that’s really useful to know, until now I couldn’t see the link.

I have been trying to find a garage to do a gearbox fluid change and all have declined, which has made me think I should not try it at home.

I’ve ordered a borescope so I can check the bores and valves before I try starting it up again. I will also see where I can get it in to the cooling system while it’s empty.

Thanks
Owner of a 1992 Mazda MX-6 Auto.
Sorry guys I don’t have a probe (yet ;) ) I’m asking questions here because I get better responses than on the US Mazda forum.

Bikergonebald
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Posts: 20
Joined: Sun Mar 24, 2019 7:42 pm

Re: Disaster - advice needed

Post by Bikergonebald » Mon May 13, 2019 7:25 pm

Well i got chance to look at it on the weekend starting with inspecting the pistons with an endoscope, i had hoped to check the bores but the little mirror attachment didn't work. The tops of the pistons were good, five were amazingly clean, no carbon build up to be seen anywhere, the other had no carbon build up but was a bit oily. All of the plugs looked quite old but not worn out and were generally a brown and not oily or sooty so I didn't see much to indicate any big mechanical problems.
Image

I filled it with water, it took about 5 or 6 litres then started it and it fired up and ran perfectly, revving freely. I also moved it back and forth on the drive and the torque converter wasn't dragging or dropping the engine revs. The only problem was that once it started to warm up water was pouring out of the bottom of the car, i didn't have it jacked up and didn't have any time left so that will have to wait until next weekend.

I do have a couple of questions though.

I couldn't turn the engine to where i wanted it to be for the camera inspection, it's auto so i can't just put it in gear and turn a wheel, using a spanner on the auxiliary belt pulley didn't work and you can't access the crank bolt. Is there any other way to rotate the engine to where you need it to be?

I had to turn it over on the starter with the plugs out, is there a way to kill the spark and the fuel injection while doing this?

Thanks all.

Kevin.
Owner of a 1992 Mazda MX-6 Auto.
Sorry guys I don’t have a probe (yet ;) ) I’m asking questions here because I get better responses than on the US Mazda forum.

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