FORD FOCUS ST170 OVERHEATS

[ST170 Fanatic]

2003 ST170 oil/head temperature rises rapidly upon acceleration in 3rd to 6th gear but come down rapidly if I back-off on the accelerator. This car is stock standard since new with 344000km on the clock. I need a quick answer to prevent engin damage! This also happened at 285000 km which destroyed the head gasket. Also replaced the water pump. The impeller cam off the shaft and pumped the radiator full of plastic! Paid 15 000 South African Rands for the engine rebuild.
At present the motor performs well when cold but it feels like you go with the handbrake applied, when warm. I have replaced the fuel pump, fuel filter, VVT gear, cam oil solenoid valve, cam timing sensor, flywheel speed sensor - but the symptom persists. Had the timing belt replaced by a very good FORD workshop. Cam timing was out by a mile. She now pulls better but still overheats.
At speeds 120 + the oil temp indicates warmer than usual and if you go uphill it rapidly heats. If you just feed it at constant throttle - then the temp comes down fast?
Took her to a Performance shop this morning for diagnostics. Found Code P1381 Camshaft Position Timing Over Advance - looks like the cam timing sensor had enough after 343000 km's. Also Code P1518 Intake Manifold Runner Control Stuck Open. Took a video clip when driving of the actuator. Checked this unit. Look like it does not responds at all... Found this on the Web. http://www.fordstownerssa.co.za/forums/viewtopic.p...
Easy to fix it seems. – I opened my unit by gouging out the glue, no soldering! Worked fine and the contacts cleaned cleared the issue. http://myfordfocus.com/svt/

I have replaced the cam shaft timing sensor - and the flywheel speed sensor. She idles smoother, plus a lot better but still startles at every gear change and - still heats the oil - not the water circuit. This indicates the head temperature - oil flows from left to right over the head - over the sensor, which then give a very rapid indication of head temperature. So I am still stuck. Lambda sensors are ok. After so many kilo's I was told that the catalyst can block-up preventing gas flow, thus restricting gas flow and heating the engin... Sounded plausible. Had the cat removed – which made the overheating worse!

Had the Thermostat and housing replaced. This helped but only for 500km… then symptoms re-occurred. Nect to be replaced is the water pump.
All of the above during the period - November 2010 to May 2011.
Latest find is that the flywheel speed sensor housing is loose! I can’t tighten this as I need to remove the gearbox and flywheel to get to the screw that keeps this in position. Did a backyard trick fix on it – now she runs cooler to 5000 RPM. When exceeding this she still heats up. Looks like the timing is messed up under high end revs.
I will have the clutch replaced this week and while the gearbox is out – will have the flywheel timing sensor housing locked in position.
The water circuit heat sensors for oil and water temperature do not lie! The water is circulated around the block to assist warm-up from cold and reacts amasingly fast to protect the engine. Well done Ford!!!
ALL advice and tips on solving this will be immensely appreciated!

[neiljohnson]

Sounds like whoever set the varible timing up did it wrong which would cause heating up under high load & the fault code your getting from the cam sensor.

[ST170 Fanatic]

After lots of money spent on trying to identify the root cause of the problem, I found tow significant problems. 1)Flywheel speed sensor holder was loose - messing about with the ignition timing! - To fasten this the gearbox had to come out plus the flywheel removed to tighten ONE SCREW...
This FIXED the overheating problem. Previously I replace the thermostat which was sticky, causing intermittent heating.

At last this baby can again operate at 6000 rpm in 6th gear!