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So to add to my boost woes, over about a 50 mile journey I lose about a litre of coolant. We filled the system by pulling about 20"hg out of the coolant system with a vacuum pump, then pressure filling it and vacing it down again to make sure there is no air in there. Just to note the VW coolant is horrible greasy stuff! The coolant system would hold a good vacuum so I doubt there is a leak. I get no strange running issues, no misfires or anything, the car runs fine (with the exception of the boost issue mentioned in my other thread). The header tank is venting over past the cap and dumping the coolant into the scuttle area.

any thoughts

Thermostat.

Head gasket possibly.

If you open the expansion tank when cold, then close again, drive for 2 mins then open it again, is there a release of pressure?

Log group 001 to see what the engine temp is doing.

Any white smoke? Hard to tell in this weather but with that much being lost I'd assume big clouds if the turbo was drinking it. Blanked that you were losing it through the expansion tank.

Maybe a blocked air/locked radiator. You could try the old school method of purging from the heater matrix bulkhead connections.

No smoke, no mayo under the oil cap, oil level is staying spot on. Engine temp is staying 90-92 on the gauge, I'll try checking on VCDS this evening, but it seemed pretty consistent when driving on the dash. Will do the 2 minute driving test and release before leaving work today.

I've since found their is a bleed screw on the back of the head, did not try this, will look at that also.

You can also display the water temp on the AC controls (see FAQ). Don't trust the dash, it's pinned to 90 unless there is a serious temp diff.

I have no refrigerant in the AC yet but I may be able to run that. Will check and set that up for the journey home.


thanks

Might be worth doing an output test on the fans, too.

Definitely need to do a test on the fans. My temps vary from 86-105degC, normal driving I'm sitting between 88-94. Slow (traffic) or uphill driving raises it over 100.

Need to check fan output, I could just be boiling it past the rad cap.

Ive ordered a CO coolant sniff tester for checking the headgasket at the weekend.



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Bufkin pipe?

Did that when I had the engine out. And I've taken the gearbox oil out of the main rad too.

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105 seems a bit high. I did some tests for Classik on mine to compare our temps but I can’t remember what they were. Can you remember Classik?

/and it was summer

Yes, standard temp is 98°C, so if you're pushing the engine a bit, 105°C is not surprising I'd say..

EDIT: all temps measured with the Vagcom, not the Dashboard needle...

So. Both fans fire up OK from Vagcom. The 3 minute drive I did round the block was enough to pressurise the header tank.

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