Broken - but on with fixing it...
Discussion
My G plate Eunos has been misbehaving for some months - it would randomnly engage James Bond white smoke screen on starting (sometimes) and often start on less than the complement of all 4 cylinders. COuldn't suss it out, and wasn't losing a lot of coolant, or overheating...
...but, it'd sat for a few weeks while I was away working, and decided that it would lose a couple of litres of coolant. Invisibly.
I'd suspected some sort of internal leak problem, and some mayonaise under the oil filler seems to confirm it, so today it's been a head off day!
Interesting looking inside a 100k engine. No ridges on the bores, carbon on all the pistons, bit of cleaning to do on the combustion chambers. It's off to be skimmed right now - 18 years of life has seen the old gasket fret away at the head (never seriously overheated btw), and wanted it pressure checked for any cracks.
My stuck No2 spark plug has now been unstuck by the engine people - it'll need a steel insert as it took the threads with it... copperslip will now be obligatory at all plug removal ceremonies...
Lucky I did this now, looks like a foreign bolt (probably from inside the cambelt cover) has taken a walk, belt was a bit chewed and shredded.
Anyway, biggest surprise was everything coming apart, without a single sheered bolt.
I'll post some pictures for anyone interested in MX5/Eunos open heart surgery!
...but, it'd sat for a few weeks while I was away working, and decided that it would lose a couple of litres of coolant. Invisibly.
I'd suspected some sort of internal leak problem, and some mayonaise under the oil filler seems to confirm it, so today it's been a head off day!
Interesting looking inside a 100k engine. No ridges on the bores, carbon on all the pistons, bit of cleaning to do on the combustion chambers. It's off to be skimmed right now - 18 years of life has seen the old gasket fret away at the head (never seriously overheated btw), and wanted it pressure checked for any cracks.
My stuck No2 spark plug has now been unstuck by the engine people - it'll need a steel insert as it took the threads with it... copperslip will now be obligatory at all plug removal ceremonies...
Lucky I did this now, looks like a foreign bolt (probably from inside the cambelt cover) has taken a walk, belt was a bit chewed and shredded.
Anyway, biggest surprise was everything coming apart, without a single sheered bolt.
I'll post some pictures for anyone interested in MX5/Eunos open heart surgery!
Munter - what's the trouble with yours?
Airbox out...
Manifold heatshield off - I cannot believe the bolts came out of this!
Other side...
Inlet manifold off (bolts awkward but not impossible to get too - but have plenty of socket extension combinations to try - ideally 3/8" drive!)
Manifold balanced on inner wing, saves undoing the fuel pipes mainly
Damage to the timing belt - I think a bolt had fallen out of the plate that goes behind the top timing cover - hole is right through the belt! Not good for 6500-7000rpm use...
Open rocker box from above. No 2 plug waving and chanting "I ain't coming out!"
Airbox out...
Manifold heatshield off - I cannot believe the bolts came out of this!
Other side...
Inlet manifold off (bolts awkward but not impossible to get too - but have plenty of socket extension combinations to try - ideally 3/8" drive!)
Manifold balanced on inner wing, saves undoing the fuel pipes mainly
Damage to the timing belt - I think a bolt had fallen out of the plate that goes behind the top timing cover - hole is right through the belt! Not good for 6500-7000rpm use...
Open rocker box from above. No 2 plug waving and chanting "I ain't coming out!"
And it's off! No pics of the head disassembled - I was in a hurry to get it down to the machining people. I'll probably take some as I reassemble if anyone's interested.
Munter - since I seem to have become more aquainted than I ever wanted to today with the Eunos/MX5 head - I notice yours is a) cleaner! and b) has the crank angle sensor on the opposite side (exhaust cam) to the 1.6. I've got a few little tips if you are taking your head off, let me know if that's the case, I'll drop them through if so, may be of use, may not be!
Munter - since I seem to have become more aquainted than I ever wanted to today with the Eunos/MX5 head - I notice yours is a) cleaner! and b) has the crank angle sensor on the opposite side (exhaust cam) to the 1.6. I've got a few little tips if you are taking your head off, let me know if that's the case, I'll drop them through if so, may be of use, may not be!
DennisTheMenace said:
If all goes to plan mines having an engine transplant at the weekend , and then when ive got time the old one will be rebuilt .... thats if the replacement engines ok 
If you've not done it before - be aware a full on freshen up of a motor can quite easily run to over a grand - and that's if you're doing it yourself. That's assuming rebore, new pistons, bearings, crank rebalance, blah blah. I was agonising over a three angle valve job today - but that would have run to £96 + VAT - must remember it's the daily driver! Were you getting any symptoms of old age with yours?If it's an imported Jap one then odds on it'll be good. I've had two (one MX6 and a Yank engine) and both seem to live up to the 'less than 50k km claims.
In fact, thinking about it, the MX5 engines are pretty resilient, leaving out early crankshaft pulley woes. I'm not so convinced by the durability of the fuel/air systems though (mine seems to have an appetite for O2 sensors, and idle speed control is just plain wonky. And it'll stay that way given price of a new idle air valve!!!), and of course ignition leads that last 10 minutes...
In fact, thinking about it, the MX5 engines are pretty resilient, leaving out early crankshaft pulley woes. I'm not so convinced by the durability of the fuel/air systems though (mine seems to have an appetite for O2 sensors, and idle speed control is just plain wonky. And it'll stay that way given price of a new idle air valve!!!), and of course ignition leads that last 10 minutes...
franv8 said:
If it's an imported Jap one then odds on it'll be good. I've had two (one MX6 and a Yank engine) and both seem to live up to the 'less than 50k km claims.
In fact, thinking about it, the MX5 engines are pretty resilient, leaving out early crankshaft pulley woes. I'm not so convinced by the durability of the fuel/air systems though (mine seems to have an appetite for O2 sensors, and idle speed control is just plain wonky. And it'll stay that way given price of a new idle air valve!!!), and of course ignition leads that last 10 minutes...
Its come out of a rolled car , so im hoping it hasnt suffered from oil starvation , also its the later 3 pin coil engine , and im scratching my head , Are the CAS different on the 4 pin coiled cars to the 3 pin coiled cars ? In fact, thinking about it, the MX5 engines are pretty resilient, leaving out early crankshaft pulley woes. I'm not so convinced by the durability of the fuel/air systems though (mine seems to have an appetite for O2 sensors, and idle speed control is just plain wonky. And it'll stay that way given price of a new idle air valve!!!), and of course ignition leads that last 10 minutes...
Hopefully have it back together and running sat evening
FranV8 all that was wrong with mine as an oil leak on the cam cover gasket. So I didn't need to go any further.
I noticed my head was much cleaner as well I think this is the last 60,000 miles of running with Mobil 1 0W-40. I dont know what was used before I had it. But I'm happy with the result.
I noticed my head was much cleaner as well
I think this is the last 60,000 miles of running with Mobil 1 0W-40. I dont know what was used before I had it. But I'm happy with the result.redgriff500 said:
Nieither of those has had frequent oil changes.
I've just done a headgasket and mine was a still a lovely silver colour under the cam cover.
(Conversely I've seen them black before too)
It's not so much the frequency of oil-change, more the quality of the oil used. Cheap oils, especially cheap mineral oils will leave gunk and deposits whereas a high quality oil, particularly a good synthetic such as Mobil 1 have detergents in them which keep the engine clean.I've just done a headgasket and mine was a still a lovely silver colour under the cam cover.
(Conversely I've seen them black before too)
Hmm, well mine's on fully synthetic (although does get topped up sometimes with a part synth or occasionally mineral) - and I change it at 6000 miles, oil and filter. I think it also depends on how hard the oil is worked too, and if there is blowby passing the rings.
Before everyone says of course we all thrash our cars, I would suspect the harder use is actually periods of time at speed, e.g. motorways/dual carriageways - short gearing on these cars means it will be spending a lot of time at 3k + rpm.
Redgriff - what mileage have you on yours?
My problem has got a bit worse. I have been told the head 'failed spectacularly' on the pressure test, no. 3 combustion chamber had a crack all the way from (and through) a valve seat to outside of the combusion chamber - so it's a scrapper.
Anyone have a spare 1600 (116 hp) head, engine or contacts to get one?
Grr. Cars. Cost. Grief. Hassle. Long walk to work.
Before everyone says of course we all thrash our cars, I would suspect the harder use is actually periods of time at speed, e.g. motorways/dual carriageways - short gearing on these cars means it will be spending a lot of time at 3k + rpm.
Redgriff - what mileage have you on yours?
My problem has got a bit worse. I have been told the head 'failed spectacularly' on the pressure test, no. 3 combustion chamber had a crack all the way from (and through) a valve seat to outside of the combusion chamber - so it's a scrapper.
Anyone have a spare 1600 (116 hp) head, engine or contacts to get one?
Grr. Cars. Cost. Grief. Hassle. Long walk to work.
TBH I think its down to what the previous owners did (or rather didn't, do)
I have a head...
But its got bits of ring stuck in it from a spectacular piston failure due to a lose CAS advancing the timing (not my doing I hasten to add)
So I'm looking for a complete engine.
Heads do come up on the forums - Nutz / OC etc so try a wanted ad.
I have a head...
But its got bits of ring stuck in it from a spectacular piston failure due to a lose CAS advancing the timing (not my doing I hasten to add)
So I'm looking for a complete engine.
Heads do come up on the forums - Nutz / OC etc so try a wanted ad.
It's an interesting conundrum - and one I had been thinking about. I tried one of the popular general 'give us our parts enquiry' people, and quite frankly, well, Dick Turpin had the decency to wear a mask...
I'm on with the MX5 specific breakers, they are a lot more helpful (and knowledgeable too - must make sure I get the right head code!) - I'm looking into both options of the whole engine vs just the head, at the moment it's looking more like just the head as I've found these prices to be a bit more reasonable!
Thanks for the tips, will try out a couple of other sourcs as suggested.
I'm on with the MX5 specific breakers, they are a lot more helpful (and knowledgeable too - must make sure I get the right head code!) - I'm looking into both options of the whole engine vs just the head, at the moment it's looking more like just the head as I've found these prices to be a bit more reasonable!
Thanks for the tips, will try out a couple of other sourcs as suggested.
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