Rover V8 Knocking Liner
Discussion
HELP !
Before I end up divorced or bankrupt (or both) can anybody provide advice on the implications of a liner that's shifted and causing slight knocking when warm ?
Probably due to excessive heat caused by an incorrect air/fuel mixture but is it possible to fix without removing the block and replacing all liners ?
What will happen if nothing is done ?
Please note previously posted on TVR wedge forum and some more info there - www.pistonheads.com/gassing/topic.asp?t=135597&f=12&h=0
>>> Edited by chunder on Thursday 18th November 14:11
Before I end up divorced or bankrupt (or both) can anybody provide advice on the implications of a liner that's shifted and causing slight knocking when warm ?
Probably due to excessive heat caused by an incorrect air/fuel mixture but is it possible to fix without removing the block and replacing all liners ?
What will happen if nothing is done ?
Please note previously posted on TVR wedge forum and some more info there - www.pistonheads.com/gassing/topic.asp?t=135597&f=12&h=0
>>> Edited by chunder on Thursday 18th November 14:11
If you go to www.rpiv8.com they seem to have a fair bit of info on loose liners.
steve_D said:
Who says the liner is loose/shifted and how do they know?
Steve
A supposed expert on RV8's (well probably as close as you would get to someone who knows what he is talking about here anyway). I have seen some of the engines he has built and no just enough to tell when someone knows their stuff and I think he is genuine.
Immediately he heard the car he asked how long had it been knocking. Hadn't really noticed it myself much but to me it is more of a ticking sound - only when warmed up and not all the time. However the engine had suffered 500 miles of being set up very weak after a full rebuild.
The rebuild (by previous owner) included a V8 Dev 414 cam and solid lifters - I put this ticking down to the lifters ?
With no loss of coolant at all, aside from heads off is there any way of telling whether piston slap, lifters or just the way it is (tis a bit loud full stop). Is a stethoscope a good investment and even so what am I trying to determine ?
Any opinions greatfully received.
Edited to improve spelling - only had two tins as well !
>> Edited by chunder on Tuesday 14th December 14:19
Ok - no pressure in the cooling system and a slight loss of coolant.
Strange as it doesn't overheat and this is with ambient temps of 35degC + but with water temp at 90 taking the pressue cap off reveals no pressure.
No visible leaks from the cooling system and only a very slight loss of coolant.
What's next - pressure test (and how do you do this - do I simply pressurise the cooling system to say 12 psi ? and then see whether it holds this pressure - do I do it when hot / cold / running ?)
or heads off and inspect ?
Strange as it doesn't overheat and this is with ambient temps of 35degC + but with water temp at 90 taking the pressue cap off reveals no pressure.
No visible leaks from the cooling system and only a very slight loss of coolant.
What's next - pressure test (and how do you do this - do I simply pressurise the cooling system to say 12 psi ? and then see whether it holds this pressure - do I do it when hot / cold / running ?)
or heads off and inspect ?
I'd guess the water may be entering a cylinder so pull the plugs and see if they look the same. Also as suggested before, pressure test the system and see how quickly pressure drops. With a leak it should drop fairly fast. Then remove the plugs and crank the engine over. You may get water coming out of a plug hole.
Boosted.
Boosted.
There was a modification a while back for engine knock and i remembre doing a disco 3.9 with the problem,it was caused by the cam thrusting,the mod was a moded retianing bolt(cam sprocket)knock went all ok,liner's do move on these seen it,head gaskets can only put water into the outter four cylinders cus theres only water flow there,
Dale.
Dale.
Pressure tested the cooling system today - made up a T piece with a gauge and put 10 psi in - slowly leaked away and I heard it coming from the expansion tank cap.
Took it apart (it's one of the plastic things from a Range Rover) and the pressure relief part seemed to have come unclipped (even though it was only 3 mths old). Put it back together and tried again - this time pressure held steady for an hour.
Ran the car up till 90degC and the fans cutting in - pressure rose to 12 psi but cap relief valve stayed closed - coolant now seen to expand in the tank so maybe cured the no pressure in coolant problem.
Anyway - no apparent signs of pressure loss from the coolant side. Next thing is as suggested and check the plugs and do a compression test.
Took it apart (it's one of the plastic things from a Range Rover) and the pressure relief part seemed to have come unclipped (even though it was only 3 mths old). Put it back together and tried again - this time pressure held steady for an hour.
Ran the car up till 90degC and the fans cutting in - pressure rose to 12 psi but cap relief valve stayed closed - coolant now seen to expand in the tank so maybe cured the no pressure in coolant problem.
Anyway - no apparent signs of pressure loss from the coolant side. Next thing is as suggested and check the plugs and do a compression test.
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