mk1 rabbit: overheating, runaway and story time.

[tSoG-84bit]

My 84 rabbit had heat and tires, and everything in between, but when I drove it home it had too much heat, and puked up some coolant.
The weather was blizzard conditions, I'd say about 10*F til it got dark, then about 0*F. After puking up coolant for a third time in the first 20 minutes of an hour long drive, I managed to get home and park it in the garage without any more problems (still running about 2/3 of the temp gauge but stable). I was unsure of why my car was overheating so I checked this site. Since nearly the entire cooling system has been replaced, I assumed it was either bad coolant gelling in the radiator, or air bubbles.  I used undiluted antifreeze rated at something like - 40*F to top it off and used the hose squeeze method to burp my rabbit. After a few startups and burpings I had my heat stable at about 3/8th of the temp gauge. I proceeded to run a 4 mile test drive, and then made a twelve mile trip into town to buy some Power service winter fuel additive. came back out about 15 minutes later, fired right up and drove the 12 miles back home, after topping off my tank and adding a bit of PS.
I drove over to the inspection station and got my car checked out, then went home to pack so I could take my 'bit back to school with me. About 10 miles from home I was chugging along up a hill, when I let off the accelerator to down shift and it continued to chug along up the hill... fortunately it was a wide open straight at the top of the hill. Strangly it didn't try running away on me... til I pushed the brake and clutch in so I could come to a complete stop and then drop clutch in 4th to stall it. I went to start it back up, and it turned over so slowly I thought the battery was dying. I turned off ALL electronics (besides 4way flashers) and tried cranking again, slowly accelerating as I continued after about the third try it fired up. I continued down the road a few miles, looked down temp was hot and climbing fast. I pulled over and the temperature settled just being at idle. I decided this was not the time to take my car to school so I turned around and headed back to my parents house.
I didnt make it a mile before it decided to overheat and puke coolant. so I used what I had left and limped closer to home. It did it again, and this time when I pulled into the parking lot, I called home and had my mom bring what coolant there was in the garage, and as much water as she could. by the time she got there it was about -5*F and my engine was nearly ice cold. I poured in coolant in the res, and it came pouring back out a blown hose in the bottom. I KNOW running an engine without coolant is generally a bad idea, but I was fed up, and it was cold (and now that I had no coolant my heater didn't work AGAIN) after limping home I parked it and there it sits.
So what I have for you nice folks, are a few questions.
If I didn't destroy anything in the overheating, what are some probable causes for overheating and running away?
Is it possible this started out as one problem, or does it look like I have more than one serious problem on my hands?
If, and this is a big "if", I didn't crack, or warp the head, what could I be looking at?
I am open to suggestions and I appriciate any and all relevant responses. If you are reading this, thanks for taking the time, and hope to hear back from you

tSoG

[burn_your_money]

1.6 NA?
Where does it puke the coolant from?
How old is your oil? sythn or dyno?
how many kms(miles) on the engine?
Did it usually start good?

[tSoG-84bit]

sorry for the lack of info initially

1.6NA
oil is fresh 10w40 amsoil that is diesel rated
engine has 120,000 miles, Starts right up down to about 40*F starts up after a few cranks down to about 20*F anything below 10*F and ether, or lots of cranking start him up.
the coolant puked out to the passenger side of the dipstick. It sprayed out and made a bit of a mess, so I cant tell which hose it came out from.
it is about 2 hours from me right now so I can't exactly check to see.

[jtanguay]

I think your lower rad hose may have been collapsed due to old age... was probably ready to go on its way out... and the extra pressure from the coolant system most likely blew the worn out hose...

If you drove it for a couple of minutes you should be fine...  my mom was driving an old golf once... had an oil change and somehow the oil pisses out (not tight enough drain plug or something) and she was wondering why the car kept overheating... so she would pull over.. stop the motor for about 5 minutes then start it back up... eventually made it home to realize that the car had no oil!!!!!!! :lol:  topped it back up and it ran just fine.  but thats on a gasser.

you did still have oil running through the head which is good... that will soak up enough heat i believe... what you should have done though is prop up your hood (pull the hood release cable and just let that little latch hold it..) the surging air should have cooled the motor sufficiently.  with low rpm's and next to no loading... you might be ok!  

if it was turbo i wouldn't drive it at at all.. the head would probably warp pretty quick

[tSoG-84bit]

thanks for input jtanguay, and burn. I am going to fiddle with it this weekend, and at the very least find out where the coolant is coming from.

tSoG

[bvolks73]

I had a similar problem with my 85 Jetta a couple weekends ago. Overheated really bad and blew the heater core because the alternator belt was slipping in the deep snow and the water pump wasn't turning fast enough to circulate well. Battery went dead too just like yours because the alternator wasn't turning fast enough to charge.  http://www.vwdiesel.net/phpBB/viewtopic.php?t=6703.
Just had it out again this morning and it worked fine. The overheating didn't seem to hurt it and it had gotten really, really hot and puked out all it's antifreeze twice.

[jtanguay]

i'm having a similar problem myself... under load my alternator slips pretty good... its probably just the pulley though.  change that and then adjust to make it tighter and that should fix it.

bvolks73, you say that because the alternator belt was slipping, that the water pump belt was slipping too? is it because there wasn't enough loading on the water pump pulley that it had slipped??? thats really weird... that could be my overheating issue (overheats at highway speeds only... at idle the needle stays bang on just half a tick over half way mark)

[Doug]

I would say that your motor overheated initially (belt slipping due to snow) which has caused a head gasket failure (compression gases in the cooling system tend to make it puke), then subsequent pressurisation of the cooling system by leakage into it from the combustion chamber. I had a similar experience once on my old 84 Rabbit NA 1.6. As far as the run away goes you probably have excessive crankcase blowby aggravated by the overheating. Vent the crankcase hose to atmosphere and plan on a new head gasket. When my motor did such it was in summer but with careful slow driving and cool down periods was able to limp home 200 Km! By the way the head was still within spec for warpage and no damaging cracks. I did a valve job at that time which helped with oil consumption. Car ran for another 3 years.

[burn_your_money]

These engines are built tough. My cousins car had a burst rad and it would only hold coolant for about 15 minutes, after that it was pretty dry. He ran it anyways and it was always 1-2 ticks away from the red line. He put over 500 kms on it like that before the HG finally crapped out, crappy thing is I was driving it when it died.  

[tSoG-84bit]

I found the latest problem, bypass hose (part# 068121053E) had about a 2cm slash at the lowest standing point, so not only does it leak when pressurized, it does until there is no coolant above the water pump. I think that it started small and held in the coolant at operating temperature, but the pressure of coolant boiling, or exhaust gas, forced the hole to be a full time problem. Right now I am looking around to see if anyone has a replacement hose, and/or is open... seems sunday isn't the day to try fixing a car in these parts.
Again, thank you for your input guys. I will see if I can get a hold of a new hose, and report back if I find anything out.
<edit>
So it turns out no one in a 40 mile radius has the hose in stock, so I guess this will have to wait another week.

tSoG

[tSoG-84bit]

So I replaced the cut bypass hose, apparently the hole was worse than I expected. After burping my rabbit, my father and I drove to the nearest VW mechanic (the car continues to run away, overrevving in neutral blowing MASSIVE clouds of smoke) the car made the trip without overheating, or switching the manual electric fan switch on (60mph at about 3/8 temp) but ran away twice in 50 miles and about a quart of oil. We explained to the mechanic what was happening and he said that without a doubt we had a bad injector pump. he was gonna check a few things but said that was the culprit. I have never read about anyone having a IP cause their car to run away, but I am pretty new to the diesel scene. I guess I am asking if anyone has had a bad IP lead to runaway issues.

thanks for the help!


tSoG.

[jtanguay]

well when your car runs away, its essentially burning its own lubricating oil... there shouldn't be any correlation between injection pump and running away... that i know of.  :?

[itzdshtz]

There was a recall out on this engine years ago, the improved crankcase ventilation hose from the valve cover to the air intake box had an Y connection in it that went down to a connection on the front of the engine block. This was to drain oil back into the crankcase and to prevent runaways like yours. Check if you have this hose.
Take your hose off the airbox and hang it down into a tin can to catch the oil, check if it still runs away. If it does, you have too much crankcase pressure and you will have to re-ring or re-bore your engine.
Don't buy another injection pump!
Make sure that your airfilter isn't oil soaked.

[BlackTieTD]

i wouldn't toss that much money (inj. pump) at the problem without a second opinion, or a lot of research on your part. IP doesn't sound right to me in this case.

[burn_your_money]

I'm also going to disagree with the mechanic.
If he reached that conclusion without even doing a simple compression test find a new shop. It sounds like he is just guessing and is hoping for some cash.