engine is dead!!

[chrissyboy]

Originally Posted by Fingers21

Ok, got the mg in my garage and started to strip it back to pull the head off, 1) the head bolts weren't very tight.

This is what i found!!!

christ ...... show the garage the the pic so they will know they did somethig wrong and they are liable to pay the full cost of repair .... make a list too as the head bolts wasnt tightened to the correct torque.....imho that is the cause of this terrible job.they should be shot ..your need new stretch bolts just to rule out the possiblity of them having stretch so couldnt hold together at the right torque

[Mike Noc]

Originally Posted by Fingers21

Ok, got the mg in my garage and started to strip it back to pull the head off, 1) the head bolts weren't very tight.

This is what i found!!!

That is shocking. Do you think the head bolts weren't tightened correctly or have they stretched due to the hydraulicking?

Mike

[marinabrian]

Originally Posted by mikeseignot

Brian are you saying the engine won't run if timed 180 degrees out?

As the flywheel turns twice for every one revolution of the camshaft the only way for the ECU to check cam position is by the cam sensor. From there it can work out as number one piston comes down whether it is on its induction stroke - first crankshaft revolution, or power stroke - second crankshaft revolution.

How can the ECU determine from the reluctor ring which revolution the crankshaft is on without reference to the cam sensor - or am I missing something?

Moving the cams 180 degrees just times them to exactly the same position in the next crankshaft revolution, and the fuel injection and sparks move with them as they are triggered from the cam sensor, although timed from the crank sensor. What's not to work?


Mike

P.S. Thinking about it could Phil T4 have had a failed cam sensor? That is a completely differant scenario, as then the engine can run 180 degrees out of phase from where the ECU thinks the cams are and although the engine will run you will get problems.

H Mike, right, here we go, the crank sensor signal is used by MEMS for the timing, along with inputs from coolant temperature sensor, inlet air temp sensor, and throttle position sensor, etc.
The cam sensor however, is used in conjunction with the battery voltage inputs to the MEMS, simply to calculate the dwell angle of the wasted spark ignition.
There is an extra cutout on the reluctor ring of the flywheel to allow the signal from the crank sensor to be interpreted by the MEMS for "static" timing purposes, for this reason there is a locating dowel on the port side of the crankshaft which allows the flywheel to be fitted in one position only.

Clear as mud?
Brian

[Mike Noc]

Originally Posted by marinabrian

H Mike, right, here we go, the crank sensor signal is used by MEMS for the timing, along with inputs from coolant temperature sensor, inlet air temp sensor, and throttle position sensor, etc.
The cam sensor however, is used in conjunction with the battery voltage inputs to the MEMS, simply to calculate the dwell angle of the wasted spark ignition.
There is an extra cutout on the reluctor ring of the flywheel to allow the signal from the crank sensor to be interpreted by the MEMS for "static" timing purposes, for this reason there is a locating dowel on the port side of the crankshaft which allows the flywheel to be fitted in one position only.

Clear as mud?
Brian

Brian my turn for an Oh no it isn't! The cam sensor's input also allows the ECU to determine the camshaft position relative to the crankshaft as I mentioned earlier, so that it knows which part of the four stroke cycle it is on, so as to synchronise fuel injection.

Thinking about it surely the dwell angle would be better calculated from the crank sensor input along with the battery voltage?

All the rest is perfectly clear apart form one thing - you didn't answer the question: Are you saying these engines can't run with the cams timed 180 degrees out 'cos I can't see any reason why they shouldn't?

Mike

[eurorover]

The pic looks like the haed has been taken off without the coolent being drained via vacum. If that is the case you will get fluid loss into the bores when you take the head off.

The 1.8T has the auto tensioner (I Think) If that is not set correct it will start to send the timming out untill it hits the valves. hence why it will turn with the key and not with a socket on the crank.

So check your valves

[Phil63]

Any chance someone can have a look at this for me?? http://www.the75andztclub.co.uk/foru...ad.php?t=84330

[eurorover]

If i was closer yes