I have recently become involved with sorting an overheating problem on a 1.8VVC MG TF, and I'm hoping some of the forum gurus could point me in the right direction
(as my knowledge of this problem is minimal).
The car will drive for approx 10 mins or idle for about 20 mins without any real problem, then the coolant in the header tank slowly starts to rise (over maybe 5 mins, pulsating up & down slightly in the process), but eventually filling the bottle right to the top. Finally, the system starts to emit quite violent blasts of air/coolant into the header tank (which can be clearly seen next to the cap, every few seconds), much like a small volcano. At this point, a temp reading on the head outlet shows around 110-115'C.
Now, not wishing to automatically assume it's a 'K-series...it'll be the head gasket'
, I have:
Fitted a new coolant cap.
Fitted a new 88'C thermostat.
Removed and flushed the radiator (in both directions), flow seems decent.
Blown through the radiator fins with an airline to clear out any muck.
Flushed the cooling system from front to rear, all seems good.
Bled the radiator, heater matrix and engine bleed points.
Taken temp readings around the system from cold, to check for correct flow as the engine warms up.
Checked that the heater is working - all ok.
Checked both the rad fan and engine bay fan - both working.
Plugged diagnostics in to ensure the ECU is seeing sensible figures from the new temp sender - all ok , fan on at 105'C, off around 96'C, all tested and working.
Now after doing all this, there wasn't much else in the system to suspect than the head gasket, so took it off yesterday. The previous owner had said he'd recently done the gasket - he'd had it skimmed and fitted an MLS along with a head saver shim.
However, on disassembly, the shim just fell away from the head - shouldn't it have been bonded on with a product such as Wellseal or similar ?
Secondly, a quick check today appears to show the liners are sitting about 1-1.5 thou proud of the block. Is this acceptable for an MLS gasket ? I was under the impression they should be 3 thou proud or more - would this make a difference ?
Everything else appears to look pretty good (although closer inspection tomorrow), but based on all the above, which gasket do you think I should use ? And is the N-series kit (with revised oil rail & stronger bolts) worth the extra ?
Car has done approx 60K.
Please let me know your experiences and anything else I may have missed - many thanks in advance !
