MX5 won't start after overheating

MX5 won't start after overheating

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Synchromesh

Original Poster:

2,428 posts

166 months

Tuesday 12th September 2017
quotequote all
On a recent track day a cloud of white smoke came out the back of my MX5 (mk1, 1.8, standard), followed by a complete loss of engine power.

Someone else was driving, but as soon as they rolled into the pits I checked the temperature gauge and it was at maximum. eek

The car now won't start. Starter motor turns it over but it shows no sign of wanting to fire.

I've opened the oil cap and the cams are moving so not a cam belt issue.

Any ideas of what to do next in terms of diagnosis? I'm (evidently) no mechanic but happy to get the spanners out and give fixing it a go. Dangerous combination I know hehe

Thanks in advance!

200Plus Club

10,752 posts

278 months

Tuesday 12th September 2017
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compression test and all the obvious stuff ie fuel and sparks. prob done headgasket, plugs out and look at every one, then compression test each cylinder.

justinio

1,152 posts

88 months

Tuesday 12th September 2017
quotequote all
If you're handy with the spanners, it's going to be a case of pulling the head off and having a look to see whats going on.

If the cambelt did snap it's not a big deal on these as they are a non interference engine (just stick a new belt on). It's possible the belt may have jumped a tooth or two, but I wouldnt have thought so.

Synchromesh

Original Poster:

2,428 posts

166 months

Tuesday 12th September 2017
quotequote all
200Plus Club said:
compression test and all the obvious stuff ie fuel and sparks. prob done headgasket, plugs out and look at every one, then compression test each cylinder.
Thanks, I'll get a compression tester bought. Am I right in thinking I should be looking for readings of about 200, and within 30 between the cylinders?

Will find out how to check sparks and fuel too.

justinio said:
If you're handy with the spanners, it's going to be a case of pulling the head off and having a look to see whats going on.

If the cambelt did snap it's not a big deal on these as they are a non interference engine (just stick a new belt on). It's possible the belt may have jumped a tooth or two, but I wouldnt have thought so.
I wouldn't call myself handy with the spanners but I should be able to get the head off. Whether I'll be able to spot what's wrong once I've done this is another question. Are there marks on the crank and cams to make sure they're lined up?

Cheers

justinio

1,152 posts

88 months

Tuesday 12th September 2017
quotequote all
Synchromesh said:
I wouldn't call myself handy with the spanners but I should be able to get the head off. Whether I'll be able to spot what's wrong once I've done this is another question. Are there marks on the crank and cams to make sure they're lined up?

Cheers
Yeah the crank and cams are all marked. They're a really nice engine to work on.