MID RANGE POWER LOSS

Daz

vocky said:

Daz said:
Why the disection neil?

do you honestly think I would go that far :shock:

I wudnt have been suprised if u had done it neil.... 😃

vocky

:lol:

george

Thanks vocky amazing pics of top of cylinder head. Trying to understand all pics of top of block, underside of head, gasket and top of head to appreciate which ports circulate oil and which water and possible tracking routes for oil and water if head gasket either does not seal or wrong head gasket used. Assume ports nearest bores carry water and furthest away carry oil. notsure.gif notsure.gif

When my engine was reassembled after the head work, Courtenays found that there were 2 types of head gasket. The first one wasn't correct and leaked water into the cylinders.

JohnnyN

Can you explain the there are 2 possible head gaskets so wrong one may have been used. Have you come across this mix up before ? :? :?

Water ways are so close to bores so not difficult to imagine loss of water through tracking by gasket failure. :roll: :roll:

vocky

I only use genuine gaskets, but the gasket above is a pattern and might be different dunno..

this pic shows roughly which are which notsure.gif

blue = water

red = oil [single pressure feed and the cam chain as the drain back to the sump]

yellow = not 100% but water

george

Thanks, I would have got it wrong - far fewer oilways than I thought!! Not much chance of an oilway tracking.

vocky

if the head is warped next to the oil feed it will leak dunno..

JohnnyN

george said:
Thanks vocky amazing pics of top of cylinder head. Trying to understand all pics of top of block, underside of head, gasket and top of head to appreciate which ports circulate oil and which water and possible tracking routes for oil and water if head gasket either does not seal or wrong head gasket used. Assume ports nearest bores carry water and furthest away carry oil. notsure.gif notsure.gif

When my engine was reassembled after the head work, Courtenays found that there were 2 types of head gasket. The first one wasn't correct and leaked water into the cylinders.

JohnnyN

Can you explain the there are 2 possible head gaskets so wrong one may have been used. Have you come across this mix up before ? :? :?

Water ways are so close to bores so not difficult to imagine loss of water through tracking by gasket failure. :roll: :roll:

TBH George, I haven't heard of this anywhere else before but Courtenays said that when they'd put the car back together, they noticed water in the bores when they were putting the spark plugs back in. It was quite a lot because the bore was full of water. They told me that there were 2 types and that they had bought in the wrong one??

notsure.gif

vocky

reading throught your posts again I think it could be the cam timing is out dunno..

george

Very interesting could account for engine 'hunting up and down' particularly noticeable when motorway cruising plus rattle on start up, perhaps chain stretch dunno.. dunno..

**What specifically makes you think? **

reading throught your posts again I think it could be the cam timing is out dunno..

vocky

Could timing being out cause smoking or chocking of engine?? notsure.gif

Engine runs smoothly when cold but not when hot, with performance drop off.

vocky

lumpy tickover - cam timing causes this [also a side effect of performance cams]

intermittant misfiring - sometimes engine works with the incorrect valve timing

the head has been off - it's very easy for the crank to jump a tooth when setting up the z22se timing [happened to me and I even double checked it - I noticed on the third check :lol: ]

george

Thanks vocky, is the only way to check if cam timing ok is by visual check of crankshaft, inlet and exhaust cam markings or will a fault code pick this up? notsure.gif notsure.gif

Could a faulty tensioner cause timing problems because the car seems to vary running worse sometims than others, a bit diesel sounding at times? dunno.. dunno..

vocky

yes a dodgy tensioner could cause the problem, but I would get a new timing chain kit fitted as the timing marks need to be checked anyway 🙁

george

Sorry to labour the point vocky but could timing being out cause smoking choking of engine, stalled again last night at road junction due to smoke build up? notsure.gif notsure.gif

Need to decide if new timing chain alone would cure problem or if its a new gasket, head off, new valve stem oil seals job especially since this is a second potential head off job and not an endless source of cash to spend on top of £1K already spent!! :evil: :evil:

vocky

difficult decision notsure.gif

I would get the timing checked, if it's fine then the head will probably need to come off dunno..

if the timing is out then it's worth resetting it and seeing if the smoke goes dunno..

too hard to call dunno..

george

Thanks vocky, is the only way to check if cam timing ok is by visual check of crankshaft, inlet and exhaust cam markings or is there an easier way? notsure.gif notsure.gif

vocky

you might be able to check by removing the cam cover notsure.gif

it's not 100% that way, but if the timing is out between the cams you will see it.

I would remove the lower timing chain cover and check all three positions, trouble is it only takes another 20 minutes to replace the chain with it that stripped :roll:

george

It's the original 2001 chain without the coloured links. Do you know if it will still have markings? notsure.gif notsure.gif

vocky

if it's the old chain, buy a new one and fit that :shock:

the old chain is going to break at some point anyway 🙁

george

Hi vocky noticed project thread on 2.2 sri which you suggest damaged pistons and piston rings unable to move causes smoking. Doesn't this sound just like my problems?? :shock: :shock:

vocky

I didn't think your chain had any problems, just head gasket replaced notsure.gif

the valves would bend as they hit the pistons, did they replace any valves dunno..

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