Potential Valve Spring Problems

[aps]

This may be of interest to the forum, with reference to the car in Sydney which has damaged no 2 piston.

This has been caused by the valve making contact with the piston. We know of a number of XR6 turbo Falcons that have experienced both cam lifter and soft valve spring issues. A soft valve spring causes the lifter to pump up and consequently holds the valve open.

In a worst case scenario the valve spring will become softer, losing spring tension. The valve can make contact with the piston, therefore damaging it. – Obviously the same can occur if the valve spring breaks. In early cases, from what we know of, the engine will miss and run on five cylinders after high RPM operation. The engine miss will usually disappear after the engine is shutdown or idled for a few minutes, as this allows time for the hydraulic valve lifter to bleed off and operate normally.

After some research we have been informed that there has been a number of revisions to the valve spring specification by the manufacturer. Once this valve spring issue is resolved by the manufacturer, this entire issue will cease to be a problem.- Our car is currently running over 325 kW at the rear wheels, without any sign of a problem, so obviously it is a random incidence issue. For those who are considering high power levels and frequently using high rpm, superior valve springs would be a good investment.

Guys, this problem may not occur in every engine. - If you have experienced a miss after high rpm operation, let the engine idle, allowing the lifter to bleed off. I would then recommend you have your dealer inspect and check the valve springs. Catching this before it becomes a major problem is much less of a hassle than replacing valves and/or pistons.

Best Regards,

Peter Luxon

[Turbo6man]

Where does a hydraulic cam/valve (as you mentioned both) lifter fit in the scheme of things regarding the overhead cam turbo motor?

[DallasQLD]

This was the problem with my car in Canberra. They replaced the engine once it dropped the valve. New motor seems Ok so far

[xa-coupe]

there will most likelt be a small lifter (of sorts) between the rocker arm head and the valve tip. There is usually some form of device that makes allowances for wear and tear. Otherise you would have to get the clearances checked and adjusted every service and that will cost big bucks if they need doing as it's not a hard job, but it's not a short one either.

Some manufacturers use shims, I guess ford are using 'lifters' in this case

[Guest ante]

ok

[NT TURBO]

Where does a hydraulic cam/valve (as you mentioned both) lifter fit in the scheme of things regarding the overhead cam turbo motor?

Yes there is a lifter type device between the overhead cam and each valve.

[ASNU]

I saw this car yesterday with the number 2 piston completly gone and Ford not doing any warranty claims as work had been done on the ECU.This car was a October build date so when and how many spring revisions have been done?.

This is going to be critical for the motor to last so maybe the Ford guy who comments on this forum can enlighten everybody.If there is going to be a question regarding these failing I will ask ford to update my motor as soon as possible.This is all we need to hear.

[Cobra]

in this forum there have been posts about experiencing acute power loss while overtaking (described as maybe fuel starving at the time if I recall rightly) .... I suspect that they maywell have the valve/lifter problem ..

dropping a gear, planting the foot to overtake and coming out into cold air gives the motor/turbo something to think about .... and bingo :nugget:

have experienced it and it is totally unforgetable ... and yes new valve springs and lifters ... thanks Ford :spacecraft:

agree with Peter that this area should be monitored and possibly upgraded ... a suspected problem can be re-produced regularly on a dyno so diagnosis is possible without breaking land speed records ...

Peter and APS are providing a great product with an immense amount of research and developement (past and ongoing) ....

cheers

[Guest ante]

I wonder if any of the non turbo cars experiance valve bounce at high rpm? (or valve piston contact problems) normally engines that are turbo charged by the after- market gear usually recommend higher poundage valve springs for keen driving.

[Venom XR6]

I looked at a head at work today and there are no lifters on this motor. The cam works directly onto the rocker arm which works directly onto the valve, and I mean directly strait onto the valve, nothing in between. Correct me if im wrong.