PLEASE GIVE ME A BREAK! (overheating) - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• PLEASE GIVE ME A BREAK! (overheating) by SMOKEYDUB on 10 Jan, 2007 07:05
• I just cant do it anymore.....the cooling system wont bleed out all it does is steam like a mofo. Overheats,pressurizes the coolant so much it pops the cap and pisses its coolant out. I can never get the coolant to flow well and i have all new coolant stuff accept rad it it flows well so....I havnt checked my timing but when i have the cap off when im trying to bleed it out i the cooland will sometimes jump out of the coolant bottle.The only other thing i can think of is the headgasket AGAIN (4) I have arp headstuds torqued to there spec. Please help wtf am i missing?
  
  Thanks
  
  Jeff
• #1 by smutts on 10 Jan, 2007 09:44
• I don't envy you.
   
  If it does all this when cold, then it sounds like head doom of some sort. If when hot, a circulation hassle of some sort.
  A few things to look at,
  1) The head was straight? Smooth? No deep gouges across the fire rings?
  2) The block was straight?
  3) No big cracks in the head or block? Apart for 0.5mm between valves.
  4) Bolts torqued in the right order?
  5) Thermostat? If missing, the bypass hose will bypass the radiator!
  6) Internal collapse of bottom radiator hose? Might only happen when revving.
  7) Impeller of water pump slipping on the shaft? Had this on another car, it certainly had me scratching my head, I don't know if it's one that veedubs suffer from.
  
  A quick test, put the coolant in (or most of it), start engine & run for 30 seconds, turn off, squeeze radiator hoses, if rock hard, bad news, gasses are escaping into the coolant.
  
  Good Luck
• #2 by 745 turbogreasel on 10 Jan, 2007 11:55
• Could be the old rag in a hose factor?
• #3 by andy2 on 10 Jan, 2007 14:56
• This engine (1.6) still has the 1.6 head on it or the 1.9 head?
  Could be a porus or cracked head I just went through this my cyl head It was so screwed that I got another head due to poor welding repair and or high stress and high boost/EGT's doesn't help either.Have you tried using another head?I actually had boost pressure entering my cooling system not combustion pressure/gases.
  
  Also does your rad fan work?Have you tried manually powering up the fan to see if it changes anything.It does however sound like you are getting some serious pressure entering your cooling system from either the head or headgasket.
  
  Are you torquing those studs down to 120 ft lbs with motor oil?
  
  Just some thoughts,Hopefully we'll get this fugured out!
• #4 by wyldman on 10 Jan, 2007 16:11
• Did it puke the coolant out first ? Or did you change it and now can't bleed it ?
  
  My Golf is a PITA to bleed.You fill it,and if you leave the cap off,it starts puking it back out.If you leave the cap on,it slowly heats up and then will overheat if you let it.
  
  I've found that the rad itself is the biggest place for trapped air.Mine will get all the hoses hot,but the drivers side of the rad will stay cold.
  
  Now what I do,is remove the upper hose,and hold it way up in the air.Fill it right up until it won't take anymore.Now reach down and "pump" the lower hose to help push the air through.you will hear it gurgle,and the level will drop.Keep doing this until it's full.now reconnect the upper,and fill the tank.That should get most of it.I then put the cap on,and run the engine about 2500 RPM until the stat opens.The reservoir should drop again,and you can top it off.
• #5 by wolfsburgnut on 10 Jan, 2007 16:24
• What I do to bleed the coolant system, and this seems to work really well, is I cup my hands to the top of the resevoir to make a loose seal and blow into the resevoir.  Pretty soon you will here the coolant burping out the air.  I managed to 5 litres of coolant into the system this way before startup.
  
  Peter
• #6 by SMOKEYDUB on 10 Jan, 2007 16:41
• its been doing it for a while i think its head or headgasket.anyways today i put my winter beater on the road (95 passat AAZ).So i will have time to put another engine in it (stock td) and stick my "GOOD" one in my rabbit which is currently equipped with the 1.6 head and am later goin to the 1.9 one.
• #7 by burn_your_money on 10 Jan, 2007 16:52
• I've found that the easiest and fastest way to bleed to coolant system on mk1s and early mk2s (before the round tank upgrade) is to squeeze and hold the upper rad hose. Then cover the overflow line from the rad to the res with your finger, and let go of the upper rad hose. Repeat this until a steady stream of coolant comes out of the small hose. I also always drill a 1/8 hole in my thermostat if it didn't already come with one from the store.
  This would be easy enough to do with the later style tanks as well
  
  As for your problem SMOKEYDUB I think your head is cracked, seeing as you have gone through 4 HGs already
• #8 by jtanguay on 10 Jan, 2007 17:34
• i kinda messed up changing my thermostat too... i didn't fill the rad first and the driver side was cold and the engine was getting pretty hot.  took the cap of the reservoir off, and as soon as the thermostat opened, bubbles came out and the coolant level rose up quite a bit.  turned the car off and it sucked some coolant back through.  topped it off and done.  there may still be some air in the system though...
  
  you don't have the stock cooler do you???
  
  i really do wish there was a mod to install a merc diesel head on our engines...  never ever have to worry about heads warping...
• #9 by RabbitJockey on 10 Jan, 2007 18:29
• fill the motor through the upper radiator hose if you haven't that seems to help.
• #10 by LeeG on 10 Jan, 2007 19:42
• I always try to keep track of how much coolant I have put back in vs how much came out or the capacity so I have some idea about trapped air.
  Squeezing the lower rad hose repeatedly before and after starting seems to help shift the air around.  With the '91 TD it seems to take 5 minutes or so of squeezing and topping up tank until 80-90% of coolant is in place, any air remaining seems to bubble out quickly once t-stat opens.
  
  I second the hole in t-stat.  I usually try to get ones with a hole that has the little rattle thing in the hole to keep it from plugging up.  Most seem to have it these days.  Failing that I drill a 1/8" hole at top edge of tstat.
• #11 by fatmobile on 10 Jan, 2007 23:41
• Is the restrictor in the overflow hose clogged up?
   Do you have coolant/air flowing through this hose and into the resevoir.
   My resevoir overflows when the thermostat opens too.
• #12 by SMOKEYDUB on 11 Jan, 2007 12:51
• i do fill up the engine throught the upper rad hose and non of the tubes have any blockage.and yes i still have the factory heat exchanger. One thing came to mind the other day... I have my cylinder head really ported out i wonder since the walls are probably so thin it transfers alot more heat to the cooling system.hmmmmm.
• #13 by jtanguay on 11 Jan, 2007 20:31
• Quote from: SMOKEYDUB

  i do fill up the engine throught the upper rad hose and non of the tubes have any blockage.and yes i still have the factory heat exchanger. One thing came to mind the other day... I have my cylinder head really ported out i wonder since the walls are probably so thin it transfers alot more heat to the cooling system.hmmmmm.

  
  
  well i guess it may/may not be the factory heat exchanger... because mine only gave me problems when it was hot.  it was pressurizing hoses, etc.
  
  i think it would really be worth a shot at taking a look at your cooler... will save a lot of time/aggravation if thats the culprit!
• #14 by SMOKEYDUB on 14 Jan, 2007 20:00
• thanks for the input guys im currently drivin my diesel passat for the winter so i have tim to pull it out and fix it and dump it in my rabbit. Im going to build a nice little stock 1.6 for the jetta and use a k03 on it so i can drive it without thrashing it to get light to light power.