Former VWDieselParts.com Forum

Yesterday after putting in new glowplugs and installing oil pan heater, I drove my '83 Quantum TD 5 spd. home and blew the hose that goes from the outlet on the head down to the water pump and also it tees off in a smaller line to the oil cooler on top of he oil filter housing thing. Turns out the temp sensor in the radiator pooped out and the fan didn't come on and the resultant pressure blew the hose which was quite old. Anyway finding a factory type replacement hose here in New Mexico, even down in Albuquerque seems unlikely, short of the stealership and they are closed for the weekend.
I've replaced the hose with a non-td hose and plugged, temporarily, the oil cooler water line. Refilled with coolant and fired it up and, fortunately it didn't seem to warp the head, I hope.
I have a question and it is: Does the oil cooler serve to cool the turbo in any way and because this is a 5 speed manual trans is it needed? It may cool engine oil somewhat but I wouldn't think it absolutely essential, but then again I really don't know. What is your all experience, knowledge, etc? These tee'd off hoses are expensive, IF you can even find one. But I don't want to screw up the engine either.

Thanks Q-man, I'll plug the line to the aneroid as a safe-gaurd. I run about the same speeeds as you mention, going for mileage on the highways but I try not to get in other people's way, so 60 -70 seems to work ok on the Interstate.

My cooling fans are not coming on and it overheats idling in the driveway.
I put in a new temperature switch in the radiator that kicks the fans and refilled, whereupon after 15-20 minutes it overheats again and the fans don't come on, sitting in the driveway. The temperature gauge is practically pegged after it gets real hot. Also the bottom radiator hose doesn't really get warm at all. Is it possible and/or probable that after the first overheat that the thermostat "stuck"? Thanks for the help.
Harry

Harry wrote:My cooling fans are not coming on and it overheats idling in the driveway.
I put in a new temperature switch in the radiator that kicks the fans and refilled, whereupon after 15-20 minutes it overheats again and the fans don't come on, sitting in the driveway. The temperature gauge is practically pegged after it gets real hot. Also the bottom radiator hose doesn't really get warm at all. Is it possible and/or probable that after the first overheat that the thermostat "stuck"? Thanks for the help.
Harry

Hi Harry,
1) How do you know it is overheating?
Is there water escaping?
2) From cold have water filler cap off. Does the small pipe from the rad have a steady stream of coolant gushing out? Does it increase with revving? Is it bubble free? If there is a lot of bubbles from cold then you may well have a head gasket gone. This means water wil push out of the system if it is bad, and give the impresion of overheating.
3) Conversely, if there is no stream of coolant then water pump is knackered which may be causing real overheating...
4) Sorry, ok your gauge reads high How I mised that I don't know Gauge could be lying though. Still check 1 to 3 above.
5) bypass thermoswitch and make sure that you can power up the rad fans with a length of wire from the battery to the fan terminals.

From a cold overnight sitting, start the car up and remove the cap in the overflow jug. If you have bubbles coming up and/or steam within 30 seconds of starting the car, you likely have cumbustion gasses getting into the coolant. If not, check for the stream of coolant squirting into the overflow jug to confirm that the coolant is circulating. And, change the thermostat to verify that it's working.

Answers:

Q-man:
1) Yes water is pushing out of the reservoir tank, takes about 10 minutes at idle to do so.
2) From cold with cap off there is a pretty steady stream of water coming from little pipe in to tank and it increases with revving, no bubbles.
3)&4) Did 1 thru 3.
5) Jumpered across thermoswitch and both fans run.

82vdub:
6) From cold startup in morning no bubbles in reservoir tank and there is steady stream from little pipe into the tank. Also with cap on there is virtually no pressure building up for at least 1-2 minutes, going from cold. After about 3-4 minutes, at idle, of course there is pressure beginning to build. After 15 minutes there is coolant being forced out the cap and shutting engine off it's like boiling-bumping down in the block-head region.
At this point the bottom radiator hose is still pretty cool, barely any warmth, like it's not circulating down there. That's why I am wondering thermostat. Have to wait for tomorrow to get a new t''mostat, nobody here carries vw stuff where I'm at.

No oil in coolant at this point, hopefully still ok.

Harry, don't know if this has anything to do with your coolant problem, but it sure helped mine. Kanzan

viewtopic.php?t=9701

Jumpered across thermoswitch and both fans run

So you unplugged the thermoswitch and put a jumper wire in the plug?
Great way to test the thermoswitch.

Thermostat,
or the radiator could be plugged,....
Since the thermoswitch works but doesn't get hot enough to turn the fan on.

Answers 2:
Kanzan. Shawnee (Mission???) area? After my family left The Rosebud and Pine Ridge, SD we moved to KCMO. Finished highschool at Southwest HS, 65th St. and Wornall. Lots of my friends moved to Johnson County.

Q-man:
1) Idles same speed as usual, no tach on it but I'd guess maybe 800rpm-ish(+or-), not particularly fast at all.
2) Antifreeze and water mix, half and half. Last night on my barn thermometer it was 14F, half hour before sunrise this morning.
3) I'll check out the cap tomorrow after sun-up.

MY Q-TD has power steering with a support bracket in the way of the t'stat housing, but I see your point as it would be diagnostic as far as the t'stat goes so I'll try to test it w/o t'stat. There is some reason the bottom rad hose never gets even warm. Colder than my mother-in-laws kiss(Test pilot for a broom factory).

Fatmobile:
Yes, I just unplugged the t'moswitch wire and wired from the hot to the ground terminals in the plug and the fans run good. I hope it's the t'mostat not the radiator, but that's a very expensive possibility. What we won't do for our babies. Dam, I even talk to the thing. Old age I guess.

I'm with Fatmobile: it's got to be the thermostat, unless you recently dumped a lot of stop leak in the radiator.

Steve

New, previously mentioned, developement. This morning, early about 7AM went out and started car from dead cold, ran for a minute timed. No pressure build up. Then restarted car with cap removed and no stream of coolant into reservoir from little pipe, revved it up pretty good and still no stream from little pipe. Waited to around noon and tried again and no stream from little pipe. The water pump is gone, right? Called a friend at vw yard in town and he said sometimes the impeller of the pump lets go on the shaft or something like that. I guess that's possible just never had such happen before. Oh well. I wonder what's next? I think I'll hide under the bed, no can't, wife's cat is under there. Very surly little creature.
Yipes, where's my bailout check!
Harry

As another way to check for water circulation, do you get any heat coming from the cabin heater after you run the engine? Check for this as well before embarking on a water pump change. If you have an infrared thermometer, you can start the car, and read temps on the block, head, upper and lower hoses, and other hoses to assist in diagnosing if water is circulating or not. Hot water will migrate to a higher position even if water isn't circulating, so just keep that in the back of your mind as you further diagnose.

Harry wrote:New, previously mentioned, developement. This morning, early about 7AM went out and started car from dead cold, ran for a minute timed. No pressure build up. Then restarted car with cap removed and no stream of coolant into reservoir from little pipe, revved it up pretty good and still no stream from little pipe. Waited to around noon and tried again and no stream from little pipe. The water pump is gone, right? Called a friend at vw yard in town and he said sometimes the impeller of the pump lets go on the shaft or something like that. I guess that's possible just never had such happen before. Oh well. I wonder what's next? I think I'll hide under the bed, no can't, wife's cat is under there. Very surly little creature.
Yipes, where's my bailout check!
Harry

What is the coolant level in the tank, now that the flow isn't spurting?
As a side note, of my 7 Quantae I've had the pleasure of, none have ever had an air lock problem. They always clear out air in a short while.