head gasket changed. hot start probs and warming up far too
Discussion
i had a suspected h/g failure on my mk2 abf digi. (mk2 golf running a golf mk3 16v 2.0 anf code engine. full ecu and harness etc)
head rebuilt by a reputable engineer with new vw parts etc.
all went well until the first journey. car was warming up far too quickly. whereas usually it would take say 3.5 miles on my normal work route to gety to 50'c oil on the mfa, now it takes 1 mile. this is repeating itself on every drive.
also im having terrible hot start probs. when warm it just wouldnt turn over. sounded like the battery was flat, but my vdo was reading 12 volts with ignition on, 10.5 cranking and 14.5 charging with motor running.
leave it to cool to around 50'c, and it will just turn over. iv never had any start probs before the gasket change. the bottom end/gearbox/starter were not touched. perfect from cold.
im using an 020 box, a starter reconditioned sometime in the late 90's and a cheapo battery, although above reccommended specs. also golf 3 power/earth cables from battery to chassis to g/box. looped back round to battery. i may earth one directly to starter
the old man reckons timing, as we were having trouble timing it up. put it seems to run smoothly with no backfiring and a smooth delivery.
its also been said that retarded timing causes quick warm up, yet advanced causes hot start problems. the dizzy on these are fixed
any thoughts?
head rebuilt by a reputable engineer with new vw parts etc.
all went well until the first journey. car was warming up far too quickly. whereas usually it would take say 3.5 miles on my normal work route to gety to 50'c oil on the mfa, now it takes 1 mile. this is repeating itself on every drive.
also im having terrible hot start probs. when warm it just wouldnt turn over. sounded like the battery was flat, but my vdo was reading 12 volts with ignition on, 10.5 cranking and 14.5 charging with motor running.
leave it to cool to around 50'c, and it will just turn over. iv never had any start probs before the gasket change. the bottom end/gearbox/starter were not touched. perfect from cold.
im using an 020 box, a starter reconditioned sometime in the late 90's and a cheapo battery, although above reccommended specs. also golf 3 power/earth cables from battery to chassis to g/box. looped back round to battery. i may earth one directly to starter
the old man reckons timing, as we were having trouble timing it up. put it seems to run smoothly with no backfiring and a smooth delivery.
its also been said that retarded timing causes quick warm up, yet advanced causes hot start problems. the dizzy on these are fixed
any thoughts?
50*C for the oil temp is cold, you want it to be in the mid 80s before you start giving the engine a work out so if anything if previously it was only getting to 50*c after 3.5miles that isnt normal.
Mine gets to over 60 within half a mile an in heavy traffic/hard driving conditions reaches 92-96ish. 84-88 being the norm.
When you rebuilt the motor you said you didnt touch the starter/bottom end so its unlikely you have disturbed any earths in that area, what about the earth strap from the COIL to the RIGHT hand side of the cam cover next to the dizzy, is this fitted/clean/secure?
You said you are having problems timing it? what kind? are you setting the timing to 6* BTTC ie factory settings based on the marker on the flywheel? you can run up to 8-9ish if you have the ignition advance available (IIRC ECU recalculates this on a Digi3) Do you have the OBD port installed on your car? that might help to identify if there is a sensor related problem.
Hot start problems that im aware of are
earths.
the fuel pressure dropping - can be due to leaking O rings on injectors flooding the engine after a run or fuel pressure accumilator not holding pressure? BUT are you having problems starting from cold- does the engine turn over several times before catching and does it fire onto 4 cylinders straight away?
Another possability is a temperature sender not working, if it thinks the car is constanly cold it will be overfueling. There are 3 temp sensors on the side of a 16v head - ECU , dash guage an ISV , you can swap them around and see if this changes anything
dave
Mine gets to over 60 within half a mile an in heavy traffic/hard driving conditions reaches 92-96ish. 84-88 being the norm.
When you rebuilt the motor you said you didnt touch the starter/bottom end so its unlikely you have disturbed any earths in that area, what about the earth strap from the COIL to the RIGHT hand side of the cam cover next to the dizzy, is this fitted/clean/secure?
You said you are having problems timing it? what kind? are you setting the timing to 6* BTTC ie factory settings based on the marker on the flywheel? you can run up to 8-9ish if you have the ignition advance available (IIRC ECU recalculates this on a Digi3) Do you have the OBD port installed on your car? that might help to identify if there is a sensor related problem.
Hot start problems that im aware of are
earths.
the fuel pressure dropping - can be due to leaking O rings on injectors flooding the engine after a run or fuel pressure accumilator not holding pressure? BUT are you having problems starting from cold- does the engine turn over several times before catching and does it fire onto 4 cylinders straight away?
Another possability is a temperature sender not working, if it thinks the car is constanly cold it will be overfueling. There are 3 temp sensors on the side of a 16v head - ECU , dash guage an ISV , you can swap them around and see if this changes anything
dave
you just beat me to it dave. everything you mentioned is present and in working order!
the cams were 1 tooth retarded. ! im retarded!
pulls like a bloody train now. the starter seems to be the issue with the hot start. i use a garage called midland vw. top top chaps! the head was re-built, 3 angle valve seats etc, seals, guides. they reckson things are little tighter now. comprression maybe better with the new seats. it'll take a little while to loosen up a bit. i assume rings expand when warm too?
the starter is as old as the car, and seeems to never of been rebuilt now.
iv got my hands on a td starter which can crank more. il also replace the brass bush.
in ref to the initial start up temp. its reassuring to hear you reach 50' so quickly. im letting it cool now and il see how long it takes to warm up. but on the way home, and it was getting some, it never went over 100'.
the only post issue i have now is that im getting oil film in the expansion tank.
i fitted a massive td rad, and new mk4 expansion tank. whch is now dirty! its only a light film around the edges. but noticeably oil.iv drained the tank a few times and its coming back. im assuming as the tank is the highest part of the cooling system, the oil will collect here?
im hoping its just cross contamination from when the head came off. oil and coolant went everywhere. so im ASSUMING oil may of got in the block coolant channels. iv seen pics of when coolers go, and its nothing like that.
all new vw/tps gasketts/bolts were used
the cams were 1 tooth retarded. ! im retarded!
pulls like a bloody train now. the starter seems to be the issue with the hot start. i use a garage called midland vw. top top chaps! the head was re-built, 3 angle valve seats etc, seals, guides. they reckson things are little tighter now. comprression maybe better with the new seats. it'll take a little while to loosen up a bit. i assume rings expand when warm too?
the starter is as old as the car, and seeems to never of been rebuilt now.
iv got my hands on a td starter which can crank more. il also replace the brass bush.
in ref to the initial start up temp. its reassuring to hear you reach 50' so quickly. im letting it cool now and il see how long it takes to warm up. but on the way home, and it was getting some, it never went over 100'.
the only post issue i have now is that im getting oil film in the expansion tank.
i fitted a massive td rad, and new mk4 expansion tank. whch is now dirty! its only a light film around the edges. but noticeably oil.iv drained the tank a few times and its coming back. im assuming as the tank is the highest part of the cooling system, the oil will collect here?
im hoping its just cross contamination from when the head came off. oil and coolant went everywhere. so im ASSUMING oil may of got in the block coolant channels. iv seen pics of when coolers go, and its nothing like that.
all new vw/tps gasketts/bolts were used
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