22-04-2019, 02:35 PM
The water level should normally be about 3/4" - 1" above the top of the radiator core (anything higher than that will find its own way out anyway).
Sports cars often have slightly reduced water capacity, especially if the rad has been re-cored. That said, mine runs alright with 5 1/2 pints capacity (certainly doesn't boil at tickover).
No there shouldn't be a water pump (not on a conventional A7 anyway). It's a thermosiphon system.
Use water (or water + corrosion inhibitor), not anti-freeze.
Is this a newly re-built engine? They can get pretty hot when first running in.
I would check to be sure the ignition timing is approximately correct.
Quite likely you may have some scale/ rust/ obstruction in you water passages. The 'easy' way to deal with this is a de-scale kit from Halfords. The downside is that a lot of the debris it creates will remain in your engine, and may make matters worse. The hard way is of course to strip down and clean out part by part. Or perhaps both in combination.
You can check for a radiator blockage by spraying a mist of water over it when hot, patches which stay wet indicate possible obstruction. Or simply feel for temperature differences with your hand.
In my experience the worst spot for blockages is the side water manifold, why not try removing that? It might be clear or it might be blocked solid.
Sports cars often have slightly reduced water capacity, especially if the rad has been re-cored. That said, mine runs alright with 5 1/2 pints capacity (certainly doesn't boil at tickover).
No there shouldn't be a water pump (not on a conventional A7 anyway). It's a thermosiphon system.
Use water (or water + corrosion inhibitor), not anti-freeze.
Is this a newly re-built engine? They can get pretty hot when first running in.
I would check to be sure the ignition timing is approximately correct.
Quite likely you may have some scale/ rust/ obstruction in you water passages. The 'easy' way to deal with this is a de-scale kit from Halfords. The downside is that a lot of the debris it creates will remain in your engine, and may make matters worse. The hard way is of course to strip down and clean out part by part. Or perhaps both in combination.
You can check for a radiator blockage by spraying a mist of water over it when hot, patches which stay wet indicate possible obstruction. Or simply feel for temperature differences with your hand.
In my experience the worst spot for blockages is the side water manifold, why not try removing that? It might be clear or it might be blocked solid.