Well, for months now ive thought i had a blown head gasket and so did about 20 other people who looked ta my car... heres the story... Bout 6 months ago sitting in traffic in brissy temp gauge soared to red, couldnt do nothing as i was sitting in the right lane, nursed it along till i got out of the traffic realised thermo fan wasnt turning on, (turned on air con to manually keep it going) temps seemed fine... couple days later happened again. Spoke to a mechanic mate suggested i have an air lock, bleed system, thermo kicked in when it suppose to all was good, 2 weeks later happened again, this time im also losing water. this went on for a few weeks happening more and more, losing more and more water, no milky water or oil, no water leaks etc etc, car running hot. Did a compression test, all cylindars were 180-185 psi except #3 which was 110, suspected blown head gasket, got some chemiweld into it and changed thermostat, 2 days later compression back up to 160 and water stopped leaking. 3 months later losing water again, decided time to do the head, so i just did the head, got it crack tested valves check, new lifters pushrods acid cleaned to clear blockages and all that general maintenance...... now, car is back up and running, left bank is noisier than it used to be, have a strange knocking sound AND cylindar #3 is still at 160 PSI, head gasket didnt fix it, so far no major water loss, car still runs hotter than it should. now the fun part, seen 4 mechanics all of which replied with "i dunno" to my question of what the hell is wrong with my car.. best guess to me is somehow i have damaged my rings or valves in #3, valves were checked by engine rebuilding and surface ground and they said its fine, so im guessing my rings are shot... im also guessing this is where my knocking noise is comming from which i couldnt hear befotre i done the head. anyway, end of the story is fixing head gasket seems to have done nothing except stop my water loss, i still have low compression and my car still seems seriously under powered and im still getting hotter than i think it should be. anyone got any bright ideas for me before i rebuild the bottom end????
Hey ragrim, wow sounds like you've been busy lol. just from what ive read. One thing ive noticed that you havent done is a pressure test of the cooling system. Regardless of whether u think there is or isnt any water leaks u should do a pressure test and let it sit between 15-20 psi for a good 10 mins. see the thing is you can bleed the cooling system but if theres a leak somewhere and it could very well be ur heater core coz u wont see it only smell it (if its bad enough) and there u have it you've got urself an air lock which will send ur temp sky high. This is wot id be doing. 1) Pressure test cooling system ensure no leaks, (heater core, water pump etc) You'll know by the pressure dropping on the gauge whether its leaking or not. 2) If no visible leaks do a head check, you can by kits and determine whether its dumping water in one of the cylinders or not. 3) If those 2 things check ok u could very well have insufficent coolant flow, this can be caused by corrosion to ur water pump fins/impellers or a siezed thermostat which you've already replaced, also a blocked radiator. or Blocked up water jackets in the block itself. Any of these can cause ur temp to spike.. Last but not least. Having a VS myself and working for Holden i know that VS's underwent 2 revised temp switches this is the temp sender ok not the temp sensor 2 different things here. Either of which may be faulty. It'd be interesting to see actually how hot its getting because although the gauge may be showing hot the temp might only be at 95-100 which is quite norm. Gauge could be reading inaccurately, so those checks should keep u busy let me know how u go... GL
pressure testing the cooling system is my next step.. i have replaced both the temp sender and temp sensor but i replaced them with 2nd hand ones so for all i know they are shot aswell, ill replace them next week with new ones, even if thats not a problem itll give me piece of mind. id like to replace my water pump and probably will, again for piece of mind. i did a flush of the cooling system today and the radiator seems to flow good, but im a bit sus on the flow of water through the engine, it was comming out at half the speed it was going in, then again im a novice a t this so i could have been doing it wrong. as for your step 2, water should not be leaking into the head anywhere, as ive just done my head gaskets and had a crack test. hmmm, its frustrating, after just forking out about $800 on my engine and box im still having problems... blood cars. they are an expensive hobby
You can also try checking if yer rings are shot by putting a few squirts of oil into cylinder which will temperarily seal the piston. The procedure is, do a compression check and get a base reading, add a few squirts of oil, compression test again. If the reading increases then yer rings are dodgey, if it doesn't then its more than likely the valves (i know they've been redone but you never know)
was just reading my gregories tonight and it mentioned the oil in the cylindar, ill give that a crack tomorrow see what the results are.. atm i have bigger issues now lol, seems like my oil pickup is blocked or my oil pump is failing, im getting oil lights after i rev the car hard, let it rest for 5 minutes and its all good... might be time to rebuild my bottom end
