The BP engine is a free-wheeling one that doesn't hit valves when the belt goes.
If your belt has gone, the engine should sound completely different when it cranks - no distict compressions at all.
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I suspect it's flooded. Check the cambelt first though just to make sure. Do so either by pulling the timing cover back just far enough to see it, or by removing the oil filler cap, and then turn the engine by hand.
If the belt is not broken locate the fuel pump fuse and pull it. Crank the engine with the fuse out and the engine may try to start. Juggle around with the fuse until the engine runs normally. MAKE SURE YOU HAVE CHECKED THE CAMBELT FIRST BEFORE YOU DO THIS, AND IF IT IS BROKEN DO NOT CRANK THE ENGINE !!
Flooding is a very common occurance on petrol engines in cold weather, and especially after the engine has been run for a very short period of time and then switched off. The excess fuel for cold starting washes the oil off the cylinder bores resulting in a loss of compression. It's therefore very easy to suspect that the cambelt has broken. If the above method does not work (it will if you persevere and know a bit about what you are doing) remove the spark plugs, clean them, and squirt a small amount of engine oil down the plug holes. Be sure not to squirt too much, one squirt with an oil can is quite sufficient for each cylinder. Replace the plugs and start the engine......
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I think you can see one of the cams by looking through the oil filler orifice.
Get a torch and have a looksee while someone cranks it. I'm fairly sure the later 1.8's are the same as the 1.6's and non-interference.
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Many thanks for all the helpful replies.
I've now taken the car to the local Mazda dealer (who have always serviced it) and (anxiously) await their verdict.
Surprisingly they are saying if it is the cambelt, there's only a 20% chance of no damage to valves. Either they have 'the knowledge' or else they're flannelling me - we'll see.
The reason I thought it was probably cambelt is that after coughing once, and failing to start, further cranking sounded very odd, sounded and felt like no compression - didn't fire, just occasional quiet backfires.
Obviously if the valves do contact the pistons, I've already done the damage by cranking it, but hopefully you guys are right and it's 'just' the cambelt. Or maybe something else, hooray!
We'll see. Thanks again.
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there is a "magic book" where cambelts are concerned, it gives standard replacement time guides and % chance of damage when a belt breaks
i.e. - 2ltr montego petrol engine - 85% valve damage
1600cc petrol - 0% damage
moral? - buy a 1600.............lol
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mondeo1306
You mentioned a "magic book" about how long it takes for a cam belt change. Tried searching for info on it, but no luck. Any furhter info, please, or a link to it?
Wife's V40 just lost cam belt & dealer claiming massive costs! All this when belt changed only 11K ago!
Many thanks
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If the cambelt has broken it's possibly due to a frozen engine due to the lack of anti-freeze, and the water pump is unable to turn. Somehow I doubt that though on a properly serviced and maintained car, and also not if the outside temperature is above zero. I've got a sneaky feeling that the cambelt hasn't broken at all.
You are describing the symptoms of a flooded engine down to a tee, which I still suspect it is. (See my post above). This is extremely common, and I have attended hundreds of petrol engine vehicles with this problem, and the fault and cure is always the same. If it is that I doubt the garage will tell you, instead they'll more likely make it out to be something far more serious than it actually is and charge you accordingly, and give you the technical jargon to go with it. You will get this problem if you start the engine from cold and switch it off again after a very short time, such as moving the car off the drive onto the road. You won't be aware of anything being wrong until you come to start it again several hours later, or the next morning. This applies to just about any make and model car with a fuel injected petrol engine. In this situation the more you crank the engine the worse the problem becomes, so you must cut off the fuel supply. The best and easiest way to do this is to pull the fuel pump fuse and crank it again. The engine will quickly use up what fuel is in the system, and you usually find it will begin to fire. Juggle with the fuse until it runs normally. sometimes this can be quite fiddley, but 95% of cars will eventually start this way.
Also if the car has been left for a long period of time the ECU can lose it's memory settings, and literally forget how to run the engine. Therefore it over-fuels when cranking from cold, and starting will be very difficult. It will re-learn as you drive, so take it for a good run afterwards once you do get it started.
The rule of thumb is if you must start your engine from cold, you must at least give it time to warm up before you switch it off again.
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The MX5 water pump is not driven by the cambelt. It has its own drive from a V belt.
I have moved son's Mx5 from the drive to get my car out frequently (3-4 times a week)in all weathers with no re-start problems. This involves the engine running for about 4 minutes maximum.
If the engine is taking little effort to turn over it suggests little compression. Cam belt breakage will give this symptom. If it is reluctant to start and the cam belt is intact then I would be looking at HT leads and coil pack first.
For a garage with the right equipment the cam belt is an easy job.
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I have moved son's Mx5 from the drive to get my car out frequently (3-4times a week)in all weathers with no re-start problems. This involves the engine running for about 4 minutes maximum. If the engine is taking little effort to turn over it suggests little compression. Cam belt breakage will give this symptom.
And so will fuel washing the oil off the cylinder bores. You'd be easily forgiven for thinking the cambelt had broken, where as in fact it hasn't. I've seen this more times than I can remember.....
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Railroad. I like your reply.
I was baby sitting a Yaris and driving once a week or once a fortnight.
I had to call out the AA as it would not start. It had a new fully charged battery.
The AA guy was straight onto the problem.
He too said it is a very common problem.( except for SAAB).
Typically, back the car out of the garage onto the drive, wash it and then it will not restart so blame water in the electrics.
Yes I had just moved it a few yards.
My only concern re your approach and his to the problem is what damage is done to the cat with unburnt fuel being passed through it, which might be found until the next MoT ?
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Almost certainly none whatsoever. There's a lot of rubbish spoken about catalysts, and they're a lost more robust than people are led to believe. It certainly is not true that one shot of unburned fuel and the catalyst is ruined. Their ability to recover is quite considerable. Speaking of Yaris's, I've been to a few of those flooded too. They're no more common than most other makes, but the reason why it tends not to happen on Saab's is because the plugs all fire rapidly for about 1.5 seconds after the engine has been switched off. This will disperse any unburned fuel, and prevent flooding......
Edited by Pugugly {P} on 04/01/2008 at 10:00
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Railroad. Thanks for info on Saabs. Their design seems to work well.
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Vauxhall cars with Multec single point injection are the only other manufacturer that I know of that have given any thought to this problem. On this system if the throttle opening is greater than 75%, and the engine speed is less than 400rpm (ie. engine cranking with the drivers foot on the pedal) the ECU switches off the fuel injector to prevent the engine becoming flooded. This is called 'Clear Flood Mode'.
So if anyone has an Astra or Nova C12NZ or C14NZ model with single point injection and thinks it's difficult to start then this may be the reason why. Don't try to start it with your foot on the throttle because it won't, and it isn't supposed to.........
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Did you check or charge the battery as I suggested??
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Again, thanks for all the info.
J1mbo, I towed the car to the dealer yesterday am before reading your reply. I'm hoping you're right about the battery - I do recall a somewhat similar problem a few years ago when the first battery died - and this batt has been a bit flaky of late. I hadn't realized that the ECU can do that if the voltage drops too far...
The flooded engine seems possible as well - thanks Railroad. OAT was about 1 deg. and the car has anti-freeze, so not likely to be a frozen water pump. However, the sound of the engine turning over really was VERY different to usual - it didn't sound like an engine that would be capable of starting.
Trouble is, the car sits on my driveway and is often not used for a week at a time or more. I do always run the engine long enough to re-charge the batt etc when I do run it though.
Should find out today what the deal is. Will post it here, it might be useful to someone else.
David
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J1mbo - you get the cigar.
The problem is not the cambelt, it's just a low battery. Phewww...
It really did sound VERY like no compression. Lesson learned.
thanks
David
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Thanks for the update - Optimiser now ?
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I'm glad you've got it sorted, although I am a bit baffled as to how you managed to confuse a flat battery with a loss of compression.......lol.
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J1mbo - you get the cigar.
snipquote
Only to pleased to have helped! The problem you had was exactly the same problem I had with my Mondeo a few years ago. The car sounded like it had an electric motor when I started it!! I quickly checked the min voltage for the ECU and the battery was dropping below it. Popped to local factors and chucked a new battery on and sorted. Hope you did'nt get too hammered by the dealer for the tow and repair.
Most people don't release what can happen when a battery is just starting to go, the clue was the fact you had'nt used the car for a while and I had just been watching a program on the TV about recorded numbers of AA callouts for flat batteries!!!
Job done.
Edited by Dynamic Dave on 04/01/2008 at 23:11
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hi,
just a quick one, dont know if youll be able to help!
i have a mazda mx5 1.6 1991, and driving in 5th today at about 25, pulling upto a junction, the cam belt went! great! just wondering if you know what i need to replace it? and whther the valves are knackered! will the kit on mx5 parts plus thermo housing be enough or is there going to be more?
thanks in advance
mark
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