GazaGt6 Posted July 31, 2008 Share Posted July 31, 2008 Hi Guys, My car seems to be burning a lbit of oil, but only under acceleration in lower gears it seems, i have checked the oil and its not milky so doesnt sounds like the head gasket, it could be the valve seals, this would make sense if the oil pressure was low, but the pressure seems very healthy at around 65. i may be wrong though! (most probably :)), any other ideas or ways in which i can find the culprult? :-/regardsGarry Link to comment Share on other sites More sharing options...
toomanyprojects Posted July 31, 2008 Share Posted July 31, 2008 Worn bores/loose piston rings? I think that makes sense from what you descride, High crank case pressure combined with high manifold vacuum blowing/sucking oil up past the breather...Worn valve seals tends to chuck out loads of smoke on start up (residual oil aroun the valves leaking past and sitting on top of the pistons when you stop the engine).A blown head gasket does not neccesarily let water into the oil. If it's only blown between an oilway and a cylinder then this could also be the problem.You've probably little option other than "whipping" the head off and having a look. You could do a compression test, but I always feel that that only tells you that somethings wrong (which you already know) and most likely not what's wrong. Link to comment Share on other sites More sharing options...
GazaGt6 Posted July 31, 2008 Author Share Posted July 31, 2008 Yep, that sounds like the problem, the rev range seems to be a bit "fluttery" in lower gears and slakens at about 3800 rpm, so it can be frustrating, although alot more economical ;D i had this problem before and checked the whole electrical system, the coil was the problem, and was causing the car to misfire, although i do have a dodgy rotor arm :B. but i do seem to be having the problem again, you reckon this could be contributing to it or is it more likely to be the electrical side of things?regardsGarry Link to comment Share on other sites More sharing options...
Desperate Damson Posted July 31, 2008 Share Posted July 31, 2008 When using the seperate oil feed pipe can cause this as well, i have to keep an eye on it myself, but becasue i don't drive the car every day just keep i topped up, i beleive there is a solution (might be on rimmers site)Paul 8) Link to comment Share on other sites More sharing options...
toomanyprojects Posted July 31, 2008 Share Posted July 31, 2008 Look at you're plugs, are they wet with oil?Oily plugs don't always spark!Maybe one is worse than the others, if so it's most likely head gasket. If they're all oily then it's rebuild time most likely! Link to comment Share on other sites More sharing options...
GazaGt6 Posted July 31, 2008 Author Share Posted July 31, 2008 The Plugs arent oily, slighty carbonated though, a bit sooty. so basically i havent set carbs up properly, which is another job, its been hard to get the right set up since the new manifold. :-/ there has also been problems with the 6th cylinder, wen i got the car rebuilt the guy said i didnt have it, however ther was compression, so as you do, i checked the plugs and they were fine, and to be honest i cant see any problems with it. but im going to take off the head to have a look, i havent taken the head of a GT6 before, i have on other cars so is disconnecting the camshaft/big ends the usual operation :PregardsGarry Link to comment Share on other sites More sharing options...
Clive Posted July 31, 2008 Share Posted July 31, 2008 Don't need to touch cam, crank etc, if you are lucky you can just drop the exhaust off the manifold, drain the water and disconnect cables etc, whip the head studs out and lift it off. IF you are lucky. Often easier to take manifolds off the head, and makes it loads lighter.Clive Link to comment Share on other sites More sharing options...
toomanyprojects Posted July 31, 2008 Share Posted July 31, 2008 As Clive suggests, I'dd go the remove manifolds from head route.... A few more bolts, but of the type that tend to come out easily!Head off is an easy job, I would take the rocker off before you unbolt the head and remember that you need to put the push rods back in the same places.Here's how I do it!Although that's exactly half as many push rods as you'll have! Link to comment Share on other sites More sharing options...
rotoflex Posted July 31, 2008 Share Posted July 31, 2008 If the head won't come off after the manifolds & nuts are removed, the best technique I've read is to remove the rocker gear assembly and turn the motor over with the starter. I'd still go with some penetrating oil down the studs as part of the process. Link to comment Share on other sites More sharing options...
neilnaz Posted July 31, 2008 Share Posted July 31, 2008 I wouldn't bother taking the head off until you are sure that it isn't just running rich. What colour is the smoke? If dark then it is simply running rich. If blue then there is something wrong but it might be that a does of redex will sort it out.I doubt you have any issues other than poorly setup carbs. Drive along at 3000RPM plus and cut ignition and park up (where it is safe to do so) and check the colour of the spark plugs. Look for biscuit colour. If dark/sooty (which I reckon they will be) then lean off 2 flats. Repeat until they are biscuit coloured (think digestives - yummy (not the chocolate ones (yummy *2))) then balance the carbs and set idle. Repeat drive and check spark plugs once again to ensure mixture is good.I bet you are running rich and that is all.Cheers, Neil Link to comment Share on other sites More sharing options...
rotoflex Posted July 31, 2008 Share Posted July 31, 2008 Good advice from neilnaz.Plugs in a car running rich have dry black deposits, also called 'carbon fouling'.The internet's filthiest spark plug chart is athttp://www.viragotech.com/fixit/sparkplugchart.jpg Link to comment Share on other sites More sharing options...
GazaGt6 Posted July 31, 2008 Author Share Posted July 31, 2008 ok, thanks for the advice, i will do that, will the sparks colour change that quickly?? i thought it took a while for the change of set up to effect the sparks colour.regardsGarry Link to comment Share on other sites More sharing options...
neilnaz2 Posted August 1, 2008 Share Posted August 1, 2008 Gaza the spark plug colour will change fairly quickly (within 2-3 miles). Drive along at 3000RPM plus and, as I said, cut the ignition and coast to a halt. Don't let the engine idle. What you should see is the colour of spark plug relating to mixture at the rev range you were travelling at. If you have twin carbs check no.1 and no.6 so you see the balance between front and rear carb.If you want you can see what is going on at 2000RPM and 4000RPM so you effectively see the tuning across more of the rev range. I would just concentrate on 3000RPM which, to me, is indicative of what is going on. You only get the picture at that rev range and you are relying on the needle profile being the right one. The only real way of getting this absolutely spot on is a rolling road session.I hope this helps.Neil :) Link to comment Share on other sites More sharing options...
GazaGt6 Posted August 1, 2008 Author Share Posted August 1, 2008 Cheers Neil, I will do that this morning...luckily i have sorted the running on problem or else cutting the engine would have been interesting ;) regardsGarry Link to comment Share on other sites More sharing options...
rotoflex Posted August 1, 2008 Share Posted August 1, 2008 When dealing with a plug-checking situation like this, especially if it's plugs fouling, it's useful to have 2 sets of plugs.When you find the set in the car has fouled, swap in the other set, clean the previous set, repeat.You can clean a good spark plug that has carbon fouled by giving it a squirt of brake parts cleaner, then brushing the electrode areas with one of those small brass brushes that look like toothbrushes, then giving another short squirt of brake parts cleaner. Then re-gqp the plug. Link to comment Share on other sites More sharing options...
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