Discussion
I`ve used the S while the daily hack is buggered, so today on the short journey to work the engine made a sound like a huge loss of pressure from an air hose, then a total loss of power. I stopped the car and the car will not start, I am suspecting a camshaft or cam chain problem. I`ll have a closer inspection over the next few days, anyone had similar problems with the V6 engine? or any idea what it could be. Now on start the engine seems to turn over to quickly without firing, this is why I thought cam related problems??. Is the V6 a safe engine, i,e, the pistons are clear of the valves if the chain breaks? Your thoughts are most welcome and I`ll keep you posted 
i am no machanic but i seem to recall valve timings should be checked regularly, (i havent done mine, has anyone else?) there is no cam chain on the v6 however the gear that drives the cam has fibre teeth so prehaps they have stripped? if that is the case i doubt the engine would turn over as i am afraid the timing would be all over the place. keep us informed and please, anyone else feel free to correct me if I am misinformed.
The 2.8 engine uses fibre gears to drive the cam from the crankshaft - the 2.9 has a duplex chain which is normally tough as old boots.
In either case, if the gears or chain broke, the engine would still turn over (since the starter turns the crankshaft) but wouldn't start (if the camshaft isn't turning).
Easy check - take the dizzy cap off and turn the engine - if the rotor arm turns, the camshaft is still turning. If not, it's not!
If it's not that, could be a number of things - the camshaft might have jumped a couple of teeth on the chain, but the chain would have to be very loose (and rattling like buggery) before that could happen. Unless the sprockets were VERY badly worn.
If the engine is turning over freely it suggests there's no compression though - like you, it's difficult to see what else could cause total compression loss...
In either case, if the gears or chain broke, the engine would still turn over (since the starter turns the crankshaft) but wouldn't start (if the camshaft isn't turning).
Easy check - take the dizzy cap off and turn the engine - if the rotor arm turns, the camshaft is still turning. If not, it's not!
If it's not that, could be a number of things - the camshaft might have jumped a couple of teeth on the chain, but the chain would have to be very loose (and rattling like buggery) before that could happen. Unless the sprockets were VERY badly worn.
If the engine is turning over freely it suggests there's no compression though - like you, it's difficult to see what else could cause total compression loss...
Edited by tvrgit on Sunday 3rd October 22:10
The only other thing I could think of Steve is head gasket with the air noise - but Andrews rotor arm test is a top tip so try that first.
If head gasket has gone - particularly between 2 cylinders - you'll struggle to start it and as you've lost compression on 2 cylinders it will turn over erratically as its only making good compression on 4.
If rotor arm is turning try a compression test.
I bet you a beer its head gasket
Chris
If head gasket has gone - particularly between 2 cylinders - you'll struggle to start it and as you've lost compression on 2 cylinders it will turn over erratically as its only making good compression on 4.
If rotor arm is turning try a compression test.
I bet you a beer its head gasket
Chris
gotta keep my chin up.Just to add - I did think of head gasket but couldn't see how that would make it stop, and then not start - it should run on the other 4 cylinders (it would be as rough as a badger's but it should go). The chances of head gasket failure losing compression on all cylinders (or enough to prevent the engine running) on a VEE engine seemed unlikely - you'd need simultaneous failure of BOTH head gaskets...
Might be that, it's worth a test - but I think you'd have evidence of water / oil pishing out plus overheating if it was that bad...
Might be that, it's worth a test - but I think you'd have evidence of water / oil pishing out plus overheating if it was that bad...
If its blown between cylinders it tends to really screw things up I think - when one cylinder is on compression it blows through to the other cylinder and can blow out via the inlet manifold if the inlet is open etc. Its a different ball game to just a couple of ignition leads hanging off.
Chris, I agree with you - it's not the same as a cylinder or two just not firing. I was only thinking that because it's a Vee, one gasket is likely to be unaffected, and the engine should at least TRY to fire on the 3 cylinders (at least) on that side, that are unaffected.
You might be right though, I don't deny that - I was just thinking of probabilities, based on Steve saying it was turning over "too quickly". It's hard to diagnose unless you can hear it for yourself - is it "too quick" all the time, or is it erratic, as you posted earlier?
You might be right though, I don't deny that - I was just thinking of probabilities, based on Steve saying it was turning over "too quickly". It's hard to diagnose unless you can hear it for yourself - is it "too quick" all the time, or is it erratic, as you posted earlier?
Edited by tvrgit on Monday 4th October 10:03
tozerman said:
My guess (from bitter experience)is a bent pushrod or similar, it sounds as though a valve may be slightly open upon compression thereby giving then symptoms you describe, remove both rockere covers to confirm eitherway a valvetrain issue, good luck
Cheers.....Tony..
Did that prevent it starting on the other 5 cylinders?Cheers.....Tony..
tvrgit said:
tozerman said:
My guess (from bitter experience)is a bent pushrod or similar, it sounds as though a valve may be slightly open upon compression thereby giving then symptoms you describe, remove both rocker covers to confirm eitherway a valvetrain issue, good luck
Cheers.....Tony..
Did that prevent it starting on the other 5 cylinders?Cheers.....Tony..
Cheers.....Tony..
Here`s the latest fellas, distributor not turning, valves and pushrods not moving. At the moment I can`t get the crank pulley off but I`ve got the bolts out of the timing cover and can see the chain is still in place, however it doesn`t move when I turn the crank. I think the chain has indeed given up the ghost and is hanging on the cam sprocket, to be sure, I`ve got to get the crank pulley off and it`s bloody tight.
Could be the woodruff key has given up in the crank.
http://en.wikipedia.org/wiki/Key_(engineering)
I don't know if the pistons hit the valves on the V6 if the cam isn't turning - but a woodruff key or even a timing chain set won't cost much so got to be worth a try before you start
http://en.wikipedia.org/wiki/Key_(engineering)
I don't know if the pistons hit the valves on the V6 if the cam isn't turning - but a woodruff key or even a timing chain set won't cost much so got to be worth a try before you start
steve j said:
Here`s the latest fellas, distributor not turning, valves and pushrods not moving. At the moment I can`t get the crank pulley off but I`ve got the bolts out of the timing cover and can see the chain is still in place, however it doesn`t move when I turn the crank. I think the chain has indeed given up the ghost and is hanging on the cam sprocket, to be sure, I`ve got to get the crank pulley off and it`s bloody tight.
If you are trying to take the front pulley off, I needed to make a small tool, can post it to you tomorrow if you have time to wait?Gassing Station | S Series | Top of Page | What's New | My Stuff