MX5Ireland

I was doing a bit of work on the car tonight, I need to do loads of work, but I need to get the leaking thermostat sorted first. I decided to replace the Thermostat housing as they're only €50 from mx5parts, but how do I remove it?

I've removed the Cam cover and the cover protecting the cogs. Do I have to remove the Cogs and belt as well, I don't want to mess up the timing. I've got a replacement Cam cover gasket to put on as well, I discovered that the first spark plug (top of pic) is swimming in oil, I presume that it'll be ok, I'll just clean that out with a rag or something. Should I remove the spark plug and let it drain out?

I'm going to replace the thermostat as well, should I just replace the thermostat cover as well? A lot of the water/coolant drained out, will that damage any of the belts below the thermostat, should I have given it a rinse with some fresh water?


graham

I've had some trouble starting it this morning, as in it won’t start, it started up for a few seconds and spluttered a bit, now it won’t start at all. I disconnected the plug covered in Oil, should it run on just three cylinders?


g

Hi Graham,

To replace the thermostat housing you'll need to remove the cambelt (no harm in changing it while you are in there, but its a bit more involved). Did you try JB weld on the leaky bit?

Don't worry about spilling coolant on stuff, thats fine.

Yeah, soak up the oil on the plug much as you can, it most likely got in there via a leaky camcover gasket (def change it).


So, did it start for a couple of seconds and then die?
Is it still turning over when you try to start?
Did you disconnect your airflow meter by any chance?

Steve

The car will run on 3 cyclinders but rough.

Did you remove the plug covered in oil? If you did clean or replace that plug it might not be sparking.

IF you removed the cambelt double check the timing.

Yeah it started for a couple of seconds and then stopped. I didn't touch the air meter. It turns over but doesnt bite. I have some jb weld, but the pipe is broken. So I thought it would be a better option to replace it. Is it just a case of slipping the belt off and then putting it back on? Or do I need to mark where the cogs, if the timing is out will it cause any damage?


g

Ah oh. The cogs have to be at the right orientation when the belt goes back on.

google changing a timing belt on a mx5/miata

you can't just really just take off the belt and slip it back on.

it also has to align with the crank.. so.. yeah as Geese says, do a bit of reading before going much further. http://www.miata.net/garage/timingbelt.html

If one wanted to check for spark (<--see what I did there?), take out the spark plug , then put the top into the spark plug wire and leave the plug on top of the cam cover so the body of the plug is touching the camcover (this will ground it). Then turn over the engine and see if the spark plug sparks. Don't do it for too long tho' or you could kill your coil (if its still alive ).

Steve

I cleaned oil out yestreday but haven't had time to check it, I'll do the spark plug test this evening, I hoping it's not the coil pack, the plug itself is very black around the tip, any recommendations on replacment plugs or will standard plugs from Halford do?

As for the timing belt / thermostat housing, I think I'll be biting off more than I can chew, I think it'll be heading into the mechanic for that job.

Graham

Dry or wet black? or brown?

If you did remove the plug the oil might have dropped down into the chamber. Don't worry a few drops won't do any harm but it can cause the car to be hard to start and stall until the engine burns it off. .

IF your car is standard then plugs from your local motor factors or halfords will do. Don't throw out your old ones keep them just incase you're given the wrong plugs.

It's kinda black, it doesn't look like its a burnt black...


g

http://www.viragotech.com/fixit/sparkplugchart.jpg

h ave a look at that.

I got the engine started today, although it need a bit of encouragement and a battery jumper pack! Eventually when it started it was very shaky, with the engine rocking from side to side, I stopped and started it again and it settled down, It looks like I need a new thermostat sensor, the origional is damaged, I think it happened when the engine was rocking from side to side.

Which one of these do I need:

http://www.mx5parts.co.uk/product_info. ... cts_id/913
or
http://www.mx5parts.co.uk/product_info. ... cts_id/706


G

One other thing is that the plugs are slightly sooty, would that indicate that its running a bit rich and I might need a new O2 sensor?

g

http://www.mx5parts.co.uk/product_info.php/products_id/706

This is the one you want. I have gone through 3 of them so far, they are really in a vunerable spot.

Cheaper on boundville.co.uk though

slightly sooty is good, it means you aren't pinging
Change your air filter and all will be well.