overheating
 

I have a 2006 Voyager, 2.8 SE CRD auto. It runs very well except when climbing long slow hills (to Chamonix for example) where the temperature rises above normal and the oil light comes on. As soon as the road levels out the temp drops and all's well. Oil and water levels are good, thermostat seems to be operating. My guess is that the system needs flushing. Any other thoughts?

These ally rads. won't flush. The ally usually corrodes due to the HOAT antifreeze not being replaced after 5years. Fairly certain you'll need a replacement rad., prob. also a thermostat as these are organized to jam open if there is any overheating.

Leedsman.

8 years of use with [probably] the last 5 never having the radiator & heat exchanger drained and replaced means you could be running on 10% solids. Mont-Blanc would test your engine and gearbox cooling. Leedsman is correct never flush an alloy rad, just give it new life with Hoat & Distilled water. DIY 15 minutes and £30.00.

Thanks gentlemen. Very useful.

Hmmmm.. I did not change over the coolant for about 6 years. It makes a difference to change every two years or so. I finally changed the fluids, pump a year ago. I flushed with water until the stuff coming out was clean. Checked recently as I had to drain the fluid and it was still very clean...!!!

Leedsman... are you suggesting that water flushing is also not recommended?

not so much not recommended, more futile. An aluminium radiator doesn't silt up like old radiators, the aluminium corrodes and that's what blocks it and nothing will shift those deposits. Hence using distilled water and the correct anti freeze/summer coolant/corrosion inhibitor to prevent it in the first place.

Regards
Richard

Did mine this summer, vacuum a pint into a clear jug, it looked like main course soup. It was the right colour and smell but looked cloudy. I let that sit for 2 hours, not much silt on the bottom but as cloudy after 2 hours as it was when it was fresh. My conclusion was that whatever the product was it was held in suspension and was definitely foreign [bodies] to anti-freeze.

I should have been clearer in #3 and said flush but never back-flush. I did mine old school :

- car running, heater full belt on manual not e-setting
- switch engine off
- remove cap from expansion bottle, insert garden hose
- slack off bottom hose a little
- switch engine on, heater full belt on manual not e-setting
- regulate the clean water in speed [expansion bottle] to the [bottom hose] dirty water out
- drink coffee
- when the rad & matrix is fully clear, engine off, allow 10 pints [ish] to drain from the bottom hose
- clamp the bottom hose, fill with - a gallon of hoat and a gallon of distilled
- burp and top up the expansion bottle

Thanks, I will give the hose tactic a try - nothing to lose other than grazed knuckles. I'm anticipating having to change the rad and thermostat eventually. Any possible complications with that?

Stats are a pig - workaround Leedman article here, and a~n~other workaround here. Other useful info on winterising scattered throughout the 6 pages, Leedsmans choice here.

QinteQ ... thanks for the links on Leedman mods. My dad's old Renault has the thermostat in the coolant hose. I wish I had done that with the voyager...!!!